Filters with picometer sensitivity of coaxially stacked macrocycles incorporated into embedded solid filler materials and methods of manufacture thereof

Abstract

A filter configured to allow communication of a substance from one side to another and configured to separate a substance passing therethrough, the filter comprising a mechanically stable porous substrate; and a solid material in contact with the porous substrate. The solid material defines a surface layer having at least one channel, each channel having at least one inlet at a surface of the surface layer and at least one outlet at a pore of the porous substrate. The inlet of each channel has a diameter of 3 nm or less and optionally between 2.5 angstroms and 4.5 angstroms. Each channel can comprise a tubular structure comprising a macrocycle at least partially embedded within the solid material. Optionally, a top portion of each channel comprises an asymmetric tubular structure. The asymmetric tubular structure comprises at least one molecule having a second inner diameter that is narrower than a first inner diameter.

Description

[0001] Related applications This application claims priority to U.S. Provisional Patent Application No. 63 / 592,646, filed October 24, 2023, entitled “Methods for Modifying Surface Properties and for Constructing Membranous Materials,” the contents of which are incorporated herein by reference as fully set forth herein. Technical Field

[0002] This disclosure relates to the fields of supramolecular chemistry, composite materials, and filtration, and more specifically, but not exclusively, to constructing highly sensitive filters by forming a generally vertical array of channels formed by tubular structures comprising coaxial stacks of macrorings embedded within a solid material deposited between such tubular structures on a porous substrate. Background of the Invention The energy, transportation, food, agriculture, semiconductor, plastics, and other industrial sectors rely heavily on small molecules. The generation of some small molecules, such as O2 from the air, is simply a matter of separation. In most cases, the generation of other small molecules requires a chemical reaction combined with a separation process. Small molecules can generally be separated using only three methods: distillation, adsorption, and membrane-based filtration.

[0004] Distillation uses temperature changes to separate mixtures into their components, in which some components of the mixture change their physical state. It is energy-intensive. Some important mixtures, such as air, are still distilled to obtain high-purity air components (by first liquefying the air to -200°C).

[0005] Using chemisorption to separate high-purity mixtures requires the formation of chemical bonds between the adsorbent and the components, followed by the breaking of these bonds to regenerate the adsorbent. Therefore, this process is also energy-intensive.

[0006] Filtration is a technique that separates two or more substances in a mixture by passing it through a medium that allows some substances to pass through while blocking others. Theoretically, filtration has the ability to perform separation with low energy consumption and simple equipment to obtain high-purity components. Filtration is a common and well-understood process for relatively large molecules. However, filtration of extremely small molecules, such as those with a diameter of 3 nanometers or smaller, presents unique challenges.

[0007] A common technique for filtering very small molecules is reverse osmosis. Reverse osmosis utilizes industrial membranes comprising a continuous polymer layer on top of an intermediate layer of polymer, which in turn rests on top of a fabric serving as mechanical support. See [1]. Familiar examples include layers of polyamide and polyacetic acid cellulose on top of an intermediate polysulfone layer, which rests on top of a polyester fabric. The selectivity of these membranes is due to the different miscibility of the materials. To illustrate, even if one material is 20 times more permeable through a membrane than another, such a difference is used to pass a mixture of these materials through a series of such membranes to obtain a purer material.

[0008] Porous materials can be used as another type of filter. Generally, material requires less energy to pass through a layer with precisely defined pores than through a polymer layer because this passage occurs not through miscibility and dissolution, but through the voids. To filter extremely small molecules, membranes can theoretically be designed with pore sizes small enough to distinguish between different picometer-sized and angstrom-sized molecules. For example, methane has a kinetic diameter of 3.8 angstroms, and carbon dioxide has a kinetic diameter of 3.3 angstroms. If these two gases are exposed to a membrane with precisely tailored pore sizes within a 0.5 angstrom size difference between them, filtration of the two gases will occur.

[0009] Various attempts have been made to fabricate such filtration membranes, but all have been hampered by technological limitations. Typically, periodic three-dimensional materials such as zeolites, metal-organic frameworks (MOFs), and covalent organic frameworks (COFs) have been considered for porous membranes. However, fabricating continuous, thin, uniform membranes from these 3D materials on an industrial scale is challenging.

[0010] Current research focuses on incorporating nanocrystals of such 3D materials into thin polymer films as hybrid matrix films (MMMs), also known as thin film nanocomposites (TFNs). An example is disclosed in [2] where researchers used a MOF film of ZIF-8, which has excellent permeability but low selectivity due to pores of 3.4 Å, which fall just between the diameters of methane and carbon dioxide. However, even such films have a major drawback due to the presence of two types of pores in ZIF-8—the aforementioned 3.4 Å and another type exceeding 1 nm. Most 3D periodic porous materials contain pores that are too large to be excluded based on size, as the typical pore size is 5 Å. Even if 3D materials contain pores of diameter that can be excluded by size, mixtures of 3D materials can have larger pores in other orientations of their crystal structure, and controlling the orientation of nanocrystals within the polymer layer is difficult.

[0011] As an alternative to 3D periodic materials for membranes, 2D periodic materials are proposed. [3] DFT simulations have been published showing that periodic 2D 'graphene-like' membranes of 2D polyphenylene self-supporting sheets can exhibit unprecedented selectivity. The simulations show that the 2D sheets exhibit 10% higher selectivity for H2 relative to CO2, CO, and CH4 compared to conventional silica and carbon membranes. 23 However, this is merely a simulation; there is still no known method to manufacture such a membrane or any other 2D self-supporting sheet with precise pores and no defects.

[0012] Due to the extreme difficulty in fabricating self-supporting periodic 2D sheets, some current research has focused on self-supporting porous graphene / graphene oxide, which is a 2D material but not periodic and, moreover, lacks precisely uniform pores. One of the best publications in this field is [4], which claims to be the first to fabricate defect-free porous graphene as a mechanical support on top of porous tungsten. However, a population of pores with diameters ranging from 0.6 nm to 1.2 nm was obtained. Their membranes were 25 times more permeable to H2 than to CH4, which is far less selective than the 2D polyphenylene materials discussed above.

[0013] Recently, [5] disclosed a system and method for molecular sieving using aligned macrocyclic pores. The macrocycles are selectively functionalized and aligned at the liquid-liquid interface to generate well-defined ordered pores on ultrathin nanofilms. The pore size is tuned to an accuracy of about 1 angstrom by modifying the properties of the macrocycles, and the narrowest pore diameter obtained is 4 angstroms, which is still larger than many important small molecules. The macrocycles were used to filter between cannabidiol oil (0.65 nm wide) and chlorophyll (1.17 nm wide). However, these films are generated at the liquid-liquid interface – they are crosslinked and yield covalent organic framework (COF)-like materials. The liquid-liquid interface may limit the ability to generate high surface area versions. [6] disclosed the formation of pore channels in host-guest inclusion complexes consisting of α-cyclodextrins housed within nanochannels of covalent organic frameworks (COFs). The pore channels are able to separate hydrogen with only low selectivity from carbon dioxide and methane, as both gases can pass through the center of the cyclodextrin. Unlike [5], [6] cannot provide a passage that is only via the large loop.

[0014] Rotaxanes are supramolecular structures containing a template molecule threaded into the lumen of a macrocycle. Polyrotaxanes are rotaxanes in which more than one macrocycle is threaded around the template molecule. The formation of rotaxanes and polyrotaxanes of cyclodextrins has been extensively studied. Examples can be found in [7] and [8].

[0015] References [1] Duke, Mikel et al., F unctional nanostructured materials and membranes for water treatment . John Wiley & Sons, 2013。

[0016] [2] Venna, Surendar R. and Moises A. Carreon. "Highly permeable zeoliteimidazolate framework-8 membranes for CO2 / CH4 separation." Journal of the American Chemical Society 132.1 (2010): 76-78。

[0017] [3] Li, Yafei et al., "Two-dimensional polyphenylene: experimentallyavailable porous graphene as a hydrogen purification membrane." Chemical Communications 46.21 (2010): 3672-3674.3。

[0018] [4] Huang, Shiqi et al., "Single-layer graphene membranes by crack-freetransfer for gas mixture separation." Nature communications 9.1 (2018): 2632。

[0019] [5] Jiang, Zhiwei et al., "Aligned macrocycle pores in ultrathin filmsfor accurate molecular sieving." Nature 609.7925 (2022): 58-64。

[0020] [6] Fan, Hongwei et al., Pore-in-Pore Engineering in a Covalent OrganicFramework Membrane for Gas Separation, ACS Nano 2023, 17 (8), 7584-7594。

[0021] [7] Harada, Akira, Yoshinori Takashima and Hiroyasu Yamaguchi. "Cyclodextrin-based supramolecular polymers." Chemical Society Reviews 38.4(2009): 875-882.

[0022] [8] Gao, Yaohua et al., "Hollow spheres with α-cyclodextrin nanotubeassembled shells." Carbohydrate polymers 83.4 (2011): 1611-1616. Invention Overview This disclosure describes a solid-state 3D device for filtering molecules with diameters ranging from a few angstroms to a few nanometers, wherein the increments between the diameters of the separated molecules can be sub-angstrom or even picometer-level in resolution. The device comprises: a porous substrate; aligned tubular structures formed within the substrate, each tubular structure comprising a coaxial stack of large, cylindrically arranged rings and having openings sized according to the desired pore size and composition; and a filler material deposited between the tubular structures and configured to be embedded in at least a portion of the sides of the tubular structures.

[0024] In a preferred embodiment, the tubular structure is asymmetrical in its height. The structure can be relatively wide at the base and relatively narrow at the tip, allowing only selected molecules to enter the structure.

[0025] The device described in this paper has several advantages over known filters. First, the size of each pore opening can be customized as needed to be larger than the size of the molecules to be filtered, while being narrower than the molecules to be excluded. The opening can contain tip molecules bonded to the top of the stack of macrocycles.

[0026] Secondly, because the large rings are embedded in the surface layer of the porous substrate, and because the large rings are arranged in a three-dimensional stack, the device is solid. The device is stable in response to motion, heat, and chemical stimuli.

[0027] The manufacture of the device described in this article requires overcoming many technical challenges. These include: - Prepare a substrate for attaching tubular structures.In a preferred embodiment, the tubular structure is constructed directly on a solid substrate. This solid substrate typically cannot support direct attachment of organic materials. Therefore, it is necessary to prepare the substrate by filling the pores of the substrate with a sacrificial material such as gold and associating the tubular structure with the sacrificial material. Optionally, template molecules can be attached to the sacrificial material, around which the tubular structure is arranged. The gaps between the tubular structures are then filled. The sacrificial material is then removed to complete the device, thereby creating pores.

[0028] - Construct a tubular structure. Tubular structures can form at least partially in solution and then subsequently associate with the substrate. Macrocyclic stacks can be constructed in different ways depending on their location within the tubular structures. Macrocyclic stacks can also be formed entirely on the substrate.

[0029] - The gaps between the tubular structures in the filling array are thus formed to create a tight seal. Using techniques such as atomic layer deposition (ALD) and molecular layer deposition (MLD), the gaps between the macrocyclic stacks are adequately filled to ensure that no sufficiently large space is left for larger molecules to enter via the sides of the macrocyclic stack and / or via the ALD layer itself. This process must be performed while ensuring, on the one hand, that no gaps are left between the tubular structure and the filler material, and on the other hand, that the filler material does not bury the tubular structure.

[0030] - Fill the space between adjacent large rings within the stack. Inevitably, the large ring stack includes vertical gaps that may exceed the filter's desired sensitivity. In the lower portion of the stack, these gaps are covered by packing material and therefore do not impede filter performance. The large rings at the top of the stack are optionally bonded together at multiple locations before being placed on the stack, thereby reducing the gap size to below the required tolerance.

[0031] - An opening is formed at the top of the large ring stack. Typically, macrocycles themselves have lumens that are too wide for effective filtration. Therefore, it is necessary to narrow the gap between the openings. This can be achieved by bonding a tip molecule, or "endcap" molecule, to the top of the macrocycle stack. This article will describe methods for bonding such endcap molecules. Alternatively, a bulky stopper can be associated with an opening that allows only narrow molecules to enter the gap between the bulky stopper and the macrocycle tubular structure.

[0032] In summary, this disclosure incorporates a number of novel techniques that, when combined, achieve the desired results of a robust and stable filter array with picometer-level sensitivity.

[0033] According to a first aspect, a filter is disclosed, configured to allow material to pass from one side to the other and configured to separate material passing through therein. The filter comprises a mechanically stable porous substrate; and a solid material in contact with the porous substrate, the solid material defining a surface layer having at least one channel, each channel having at least one inlet at the surface of the surface layer and at least one outlet at a pore in the porous substrate. The inlet of each channel has a diameter of 3 nm or less. The terms "inlet" and "outlet" should be understood as referring to... Optionally, at least one channel contains a solid material without any other material encapsulating it. In such an embodiment, the large ring used to construct the channel is removed from the final product.

[0034] Optionally, at least one channel comprises a solid material, to which one or more tubular structures of large rings are covered. In these embodiments, the tubular structures are attached to the top of the solid material, but this is not mandatory.

[0035] Optionally, at least one channel comprises one or more tubular structures containing macrocycles at least partially embedded within a solid material. In this embodiment, the tubular structures used in the construction of the channel are retained in the final product. Each tubular structure may comprise a stack of coaxially associated macrocycles having a first inner diameter. The macrocycles may comprise cyclodextrins, calixarenes, columnar aromatics, porphyrins, crown ethers, helical molecules, Cubril[n], cucurbituril, aspherands, Kekulenes, cage molecules, metal macrocycles, carbon nanotubes, or any combination thereof. In a particularly advantageous embodiment, the macrocycle may be an α-cyclodextrin, β-cyclodextrin, or γ-cyclodextrin.

[0036] Macrocycles can have a generally truncated shape, as is typical for cyclodextrins and other macrocycles described above. The molecular orientation of adjacent macrocycles can include one or more of the following: wide-to-wide association, narrow-to-narrow association, and wide-to-narrow association.

[0037] Each large ring in the stack can be bonded to one or more adjacent large rings in the stack using filler material.

[0038] Each macrocycle in the stack can be connected to an adjacent macrocycle in the stack by one or more molecular bridges.

[0039] Optionally, the top portion of each channel includes an asymmetric tubular structure. The asymmetric tubular structure includes at least one molecule having a second inner diameter narrower than the first inner diameter. The molecule with the second inner diameter is located at the tip of the asymmetric tubular structure, such that the tip constitutes the entrance to the channel. In some such embodiments, the outer layer extends above the height of the tip molecule but does not enclose the entrance to the channel. Alternatively, at least one molecule with the second inner diameter is within the asymmetric tubular structure but not at its tip, such that the asymmetric tubular structure has an hourglass-like structure. An example of a molecule with a second molecular diameter is a crown ether.

[0040] Optionally, the filter includes at least one stopper molecule and an elongated molecule attached to at least one stopper body and inserted into the top of the uppermost tubular structure in the channel. The gap between the stopper molecule, the elongated molecule, and the top of the uppermost tubular structure is a second inner diameter, wherein the second inner diameter is narrower than the first inner diameter and constitutes the entrance to the channel.

[0041] In another embodiment, the filter includes end-capping molecules and elongated molecules attached to at least one end-capping body and inserted into the top of the uppermost tubular structure in the channel. A passage between adjacent large rings at the outer shell of at least one tubular structure defines a second inner diameter. The second inner diameter is narrower than the first inner diameter and forms the entrance to the channel.

[0042] In another embodiment, the entrance to at least one channel is blocked by at least one of the following: end-capping molecules and elongated molecules, the elongated molecules being attached to at least one end-capping body and inserted into the top of the uppermost tubular structure in the channel; elongated molecules being attached to solid material and inserted into the top of the uppermost tubular structure in the channel; and solid material being deposited in a manner that buries the top of the uppermost tubular structure in the channel. A passage between adjacent large rings at the outer shell of at least one tubular structure defines a second inner diameter, wherein the second inner diameter is narrower than the first inner diameter and constitutes the entrance to the channel. In this embodiment, the entrance to the channel originates from the side of the channel, rather than from the top of the channel.

[0043] Optionally, the filter includes at least one elongated molecule inserted into the top of the uppermost tubular structure in the channel and chemically associated with the uppermost tubular structure in the channel or with a solid material, such that the uppermost tubular structure and the at least one elongated molecule define a second inner diameter, wherein the second inner diameter is narrower than the first inner diameter and constitutes the entrance to the channel.

[0044] Optionally, the surface layer encapsulates at least one lower portion of the tubular structure, but not at least one upper portion of the tubular structure. The lower portion of at least one tubular structure comprises large rings associated with each other in a manner that maintains a gap larger than the size of the channel inlet. The upper portion of each tubular structure comprises large rings associated with each other in a manner that reduces the gap between adjacent large rings to below the size of the channel inlet. Advantageously, only for those portions of the channel that are not embedded in the solid material and are thus exposed, association with more chemical bonds is required, and the formation of such associations is more challenging.

[0045] Optionally, the solid material is embedded in at least one tubular structure without being attached to at least one tubular structure by a chemical link. Optionally, the solid material is attached to at least one tubular structure by at least one chemical link. This choice is determined in particular by the material from which the tubular structure is formed and the manner in which the solid material is deposited (e.g., ALD or MLD).

[0046] At least one tubular structure may also include one or more anti-stick functional groups on its outer surface. The anti-stick functional groups help prevent the tubular structure from adhering to the surface of the substrate during the patterning process.

[0047] In some embodiments, at least one channel extends from the inlet of the at least one channel to the outlet of the at least one channel with a generally uniform width at a pore in the porous substrate. In some embodiments, at least one channel includes a narrower portion adjacent to a pore in the porous substrate. For example, the channel may be constructed on a narrow “pit” previously formed with a solid material on the porous substrate.

[0048] The substrate can be anodized aluminum oxide (AAO).

[0049] At least a portion of the solid material can be deposited via atomic layer deposition. In such embodiments, the material deposited via atomic layer deposition is one or more of titanium dioxide, silicon dioxide, aluminum oxide, or silicon nitride. At least a portion of the solid material can also, or optionally, be deposited via molecular layer deposition.

[0050] The inlet diameter can be between 2.5 Å and 4.5 Å. Advantageously, 4.5 Å is the inner diameter of the α-cyclodextrin. As discussed, the inner diameter can be calibrated to be even narrower than that based on the use of tip molecules, template molecules, and / or bulky endcaps at the inlet. The minimum diameter of 2.5 Å to 4.5 Å is sufficient to filter gases and other small molecules with diameters within this range.

[0051] According to a second aspect, a method for manufacturing a filter is disclosed. The method includes: constructing at least one tubular structure on at least one pore of a porous substrate filled with a sacrificial pore filling material, each tubular structure comprising a coaxial stack of associated macrorings; filling the gaps between the tubular structures with a solid gap-filling material; and removing the sacrificial pore filling material from the pores of the porous substrate; thereby creating at least one channel, wherein the solid material defines a surface layer, the inlet of each channel is at the surface of the surface layer, and the outlet of each channel is at a pore of the porous substrate. The inlet of each channel has a diameter of 3 nanometers or less.

[0052] Optionally, the method may include filling the pores of the porous substrate with a sacrificial pore-filling material prior to the construction step. Prior to the pore-filling step, the method may include laminating a sacrificial layered material on the porous substrate, wherein the sacrificial layered material is configured to associate with both the sacrificial pore-filling material and the porous substrate. In such an embodiment, the pore-filling step includes adhering the pore-filling material to the sacrificial layered material. The method may also include, after the pore-filling step, selectively etching the sacrificial layered material to leave a porous substrate with pores filled with the pore-filling material. These steps are intended to enable the porous substrate to chemically associate with tubular organic materials.

[0053] Optionally, the porous substrate is a high surface area ceramic material. Optionally, the porous substrate is anodic aluminum oxide, the sacrificial pore filling material is gold, and the sacrificial delamination material is silver.

[0054] In an alternative implementation, the method includes selecting a substrate for the sacrificial material prior to the construction step; depositing a porous layer on the sacrificial substrate; filling the pores of the porous layer with a sacrificial pore-filling material to adhere the pore-filling material to the sacrificial layer, and selectively etching the sacrificial substrate. The porous substrate may be a high surface area material or ceramic.

[0055] Optionally, each tubular structure comprises a stack of coaxially associated macrocycles having a first inner diameter. Without limitation, the macrocycles may comprise cyclodextrins, calixarenes, columnar aromatics, porphyrins, crown ethers, helical molecules, kubryanides, cucurbita, nonspherical aromatics, Kekulenes, cage-like molecules, metal macrocycles, carbon nanotubes, or any combination thereof.

[0056] Macrocycles can have a generally truncated shape. The molecular orientation of adjacent macrocycles includes one or more of the following: wide-wide association, narrow-narrow association, and wide-narrow association.

[0057] The construction steps may include: patterning template molecules on a sacrificial pore-filling material; and threading at least a portion of at least one tubular structure around the template molecules. The step of patterning the template molecules may include: attaching a precursor molecule to the sacrificial pore-filling material, the precursor molecule being formed of an XYZ structure, wherein the Z functional group is configured to bond with the pore-filling material, and the XY bond is cleavable; and cleaving the XY bond. The template molecule itself may be the remaining ZY structure. Alternatively, after cleaving the XY bond, the template molecule may be bonded to the Y group. Optionally, X is any type of branched polymer. In this early stage of the patterning process, a branched polymer may be useful to help ensure that the template molecules are patterned at sufficient intervals, such that there is an appropriate spacing between adjacent tubular structures.

[0058] The method may further include forming at least one molecular bridge between the coaxial tubular structure and the adjacent tubular structure when the tubular structure is threaded onto the template molecule. Optionally, this molecular bridge is formed by: attaching a bulk end cap to the template molecule to form a rotaxane or polyrotaxane; forming at least one molecular bridge when the bulk end cap is attached to the template molecule; and removing the bulk end cap and the template molecule. The threading step can be performed while immersing the tubular structure and the porous substrate in a solution, and optionally by sonicating or heating the solution. In an advantageous embodiment, the solution is a dilute solution, as this results in a higher yield, although a saturated solution can also be used.

[0059] When using template molecules, the template molecules can be removed after the gap-filling step.

[0060] Optionally, after the gap-filling step, the template molecule can be elongated. The method then involves threading at least one additional macrocyclic or tubular structure onto the elongated template molecule, thereby extending the channel. The step of elongating the template molecule can be performed using click chemistry.

[0061] Optionally, the template molecules attached to the bulk endcap can be threaded into the entrance of each channel, thereby defining the pathway into each channel based on the size of the entrance, the size of the bulk endcap, and the size of a portion of the template molecule near the entrance of each channel.

[0062] Optionally, the method may include forming a tubular structure by creating molecular bridges between macrocycles in solution prior to the construction step. Advantageously, the available chemical methods for constructing molecular bridges in solution can be more diverse and versatile than those applicable to construction on porous substrates. In such embodiments, the step of constructing the tubular structure includes introducing macrocycles into a solution containing template molecules, thereby allowing the macrocycles to thread around the template molecules. The method may also include sonicating the solution. The solution is advantageously a saturated solution that yields high yields, but can also be a dilute solution.

[0063] In embodiments where association is formed in solution, the step of forming a molecular bridge may include: modifying at least one functional group of each macrocycle; and forming a molecular bridge between adjacent macrocycles by associating the macrocycles at the modified functional groups, thereby generating a train of macrocycles. This train is a multifunctional structure that forms the basis for further chemical reactions. For example, the method may further include: threading the macrocycle to a template molecule having a bulky end cap removably attached at one end; attaching the bulky end cap to a second end of the template molecule; forming at least a second molecular bridge between adjacent macrocycles, thereby generating a ladder of macrocycles; cleaving the removable bulky end cap from the template molecule; and removing the template molecule from the ladder of macrocycles.

[0064] Bridges can be formed in sequential reactions, where each sequential reaction increases the proximity of different parts of the macrocycle to each other, thus enabling subsequent reactions. This can be analogous to the closure of a zipper, where initiating the closure process makes the remaining closure easier.

[0065] The method may also include using a connector molecule to form a bridge with at least one branched bridge, the connector molecule forming a connection between adjacent macrocycles at two or more locations. After attaching the connector molecule to the adjacent macrocycle, additional functional groups can be added to the connector molecule, and additional functional groups can be used to add additional bridges between adjacent macrocycles. In this way, the branched bridges can potentially grow indefinitely to form more bridges between adjacent macrocycles.

[0066] Optionally, the tubular structure formed in solution is an asymmetric tubular structure comprising a coaxial stack of associated macrorings having substantially the same inner diameter and a molecule having a second inner diameter narrower than the first inner diameter of the macrorings in the coaxial stack. In such an embodiment, bridges between macrorings adjacent to the tip molecule reduce the gap between the macrorings to less than the second inner diameter. The second inner diameter can be between 2.5 angstroms and 4.5 angstroms.

[0067] The method may further include elongating the asymmetric tubular structure in solution by associating the asymmetric tubular structure with the symmetric tubular structure. Optionally, the elongation step includes forming a hemirotaxane comprising a template molecule inserted into both the symmetric and asymmetric tubular structures, associating the asymmetric and symmetric tubular structures, and removing the template molecule.

[0068] The method may also include modifying the tubular structure with anti-adhesion functional groups on the outer shell of the tubular structure before the construction step.

[0069] The method may also include modifying the tubular structure with a branched polymer before the construction step to promote the spacing and perpendicularity of the tubular structure relative to the substrate, and removing the branched polymer before the filling step if the branched polymer does not form a chemical bond with the filler material.

[0070] The construction step may include directly patterning at least one tubular structure onto at least one pore, without first patterning the template molecule onto the pore and without patterning the tubular structure on the template molecule. In such a case, the patterning step may include patterning the tubular structure containing at least one template molecule associated with at least one bulk end cap. Thus, the template molecule may be included without being bound to the pore and may be used, for example, to lengthen or narrow the channel. Optionally, at least one bulk end cap is chemically attached to at least one tubular structure.

[0071] In some embodiments, the filling step includes performing atomic layer deposition (ALD). In some such embodiments, the solid interstitial filling material is one or more of titanium dioxide, silicon dioxide, alumina, or silicon nitride. The method may also include attaching precursor molecules to the tubular structure prior to ALD, such that the interstitial filling material is directly attached to the tubular structure. The method may also include attaching protecting groups to the tubular structure prior to ALD, such that the interstitial filling material does not adhere to at least some portions of the tubular structure. Optionally, the method may include using a cleaner or etchant during the ALD process to regenerate functional groups present at the shell of the tubular structure in a supercycle process. In addition to or as an alternative to ALD, the filling step may include performing molecular layer deposition.

[0072] The method may also include sequentially elongating the tubular structure after the filling step, and repeating the filling step with respect to the elongated tubular structure. Advantageously, this repetitive process can be used to elongate the tubular structure to a sufficient height in the nanometer range without requiring all the deposition of solid material to be performed at once.

[0073] Optionally, after the step of filling the gaps, the method includes decomposing the tubular structure to obtain a channel with a surface layer formed only of solid material after the step of removing the sacrificial hole filling material.

[0074] According to a third aspect, a method for manufacturing a filter is disclosed. The method includes: selecting a sacrificial substrate capable of attaching to an organic compound; attaching template molecules to the sacrificial substrate; constructing at least one channel on the sacrificial substrate, each channel comprising one or more tubular structures comprising coaxial stacks of associated macrocycles; filling the gaps between the tubular structures by adhering a solid gap-filling material to the sacrificial substrate; attaching a porous substrate to either the open end of the tubular structure or one of the filler materials; and removing the sacrificial substrate and the template molecules. Optionally, the method further includes extending the channels by attaching additional tubular structures to the ends of channels previously associated with the sacrificial substrate.

[0075] According to a fourth aspect, a method for forming a tubular structure comprising macrocycles linked by molecular bridges in solution is disclosed. The method includes modifying at least one functional group of two or more macrocycles; and forming a molecular bridge between the macrocycles by associating the macrocycles at the modified functional groups, thereby generating a macrocyclic chain. Optionally, the method further includes threading the macrocyclic chain onto a template molecule having a bulky end cap removably attached at one end; attaching the bulky end cap to a second end of the template molecule; forming at least a second molecular bridge between adjacent macrocycles, thereby generating a macrocyclic ladder; cleaving the removable bulky end cap from the template molecule; and removing the template molecule from the macrocyclic ladder. Bridges can be formed in sequential reactions, wherein each sequential reaction increases the proximity of different portions of the macrocycles to each other, thereby enabling subsequent reactions. Bridges with at least one branched bridge are formed using a linker molecule, which forms a connection between adjacent macrocycles at two or more locations. Optionally, the tubular structure formed in solution is an asymmetric tubular structure comprising a coaxial stack of associated macrocycles having substantially the same inner diameter and a molecule having a second inner diameter narrower than the first inner diameter of the macrocycles in the coaxial stack. In such an embodiment, the asymmetric tubular structure can be extended in solution by associating the asymmetric tubular structure with a symmetric tubular structure. The extension step may include forming a hemiroroline comprising a template molecule inserted into both the symmetric and asymmetric tubular structures, associating the asymmetric and symmetric tubular structures, and removing the template molecule.

[0076] According to a sixth aspect, a method for filtering a mixture of two or more substances is disclosed. The method includes: exposing the mixture of substances to any filter described above, wherein at least one of the substances is of a smaller size such that it is configured to pass through a channel, and at least a second of the substances is of a larger size such that it cannot pass through the channel; and passing at least one molecule of the at least one smaller-sized substance through the filter. The substances may be, for example, two liquids or two gases, or a liquid undergoing desalination.

[0077] Optionally, the mixture is in chemical equilibrium. Filtering one of the substances thereby shifts the equilibrium, causing a reaction to proceed.

[0078] Optionally, the mixture is brought into contact with a catalyst. Filtering one of the substances into the catalyst causes a chemical reaction to proceed. Brief description of the attached diagram To better understand the subject matter disclosed herein and to illustrate how it can be implemented in practice, implementation methods will now be described by way of non-limiting example only, with reference to the accompanying drawings, in which: Figures 1A-1H The figure illustrates a process for constructing a tubular structure on a substrate according to an embodiment of the present disclosure; Figures 2A-2D The figure illustrates the process of constructing a tubular structure and attaching the tubular structure to a substrate according to an embodiment of the present disclosure; Figure 3A and Figure 3B The schematic maps show Figures 1A-1H and Figures 2A-2D The process; Figure 4A The figure illustrates a cross-section of a channel comprising a tubular structure according to an embodiment of the present disclosure, the tubular structure having tip molecules chemically bonded to the opening of the tubular structure; Figure 4B The figure shows Figure 4A A variation of the channel, wherein the channel comprises a pattern of repeating tubular structures; Figure 4C The figure shows a cross-section of a tubular structure having a large-volume end cap that fills the opening of the tubular structure; Figure 4D The figure shows a cross-section of a tubular structure in which solid material rises above the tip molecules; Figures 4E-4J The figure illustrates small macrocyclic molecules, demonstrating picometer-level sensitivity between derivatives of the same macrocycle; Figures 5A-5S The figure illustrates the process of constructing tubular structures in solution; Figures 6A-6EThe figure illustrates the process of constructing tubular structures on a substrate and forming crosslinks between adjacent tubular structures; Figures 7A-7B The schematic diagram illustrates the process of attaching a tubular structure directly to the surface of a substrate; Figures 8A-8I The figure illustrates the process of extending a tubular structure while attaching it to a porous substrate. Figures 9A-9L The figure illustrates experimental results of a gap-filling process according to an embodiment of this disclosure.

[0080] Figures 10A-10E The figures illustrate the steps for manufacturing, sealing, and filling pits according to an embodiment of this disclosure; Figures 10F-10I The figures illustrate the steps of constructing a structure on a pitted substrate according to an embodiment of the present disclosure; and Figure 11 The partial gap filling according to the embodiments of this disclosure is depicted.

[0081] Detailed description of the implementation plan This disclosure relates to the fields of supramolecular chemistry, composite materials, and filtration, and more specifically, but not exclusively, to constructing highly sensitive filters by forming a generally vertical array of tubular structures comprising macrorings embedded in a solid material deposited between such tubular structures on a porous substrate.

[0082] Before explaining at least one embodiment of the invention in detail, it should be understood that the invention is not necessarily limited in its application to the details of the construction and arrangement of the components and / or methods set forth in the following description and / or shown in the drawings and / or examples. The invention is capable of other embodiments, or can be practiced or carried out in various ways.

[0083] As described in this disclosure, the term "rotaxane" refers to a supramolecular structure in which cyclic molecules are threaded onto an "axis" molecule and end-capped at the ends of the "axis" molecule by bulky groups. The term "end-capped," in its broadest sense, should be understood to encompass any type of material, such as molecular materials or surfaces, that holds the threaded molecules in place. The term "polyrotaxane" refers to a structure in which multiple cyclic molecules are threaded onto an axis molecule in a chain. The terms "pseudo-rotaxane" and "pseudo-poly-rotaxane" refer to cases in which the axis is not end-capped, but the cyclic molecules are retained in thermodynamically preferred positions on the axis. A hemirotaxane is a supramolecular structure similar to a rotaxane, but in which only one end is capped. Similarly, a hemi-polyrotaxane is a tubular structure similar to a polyrotaxane, but in which only one end is capped. An "inclusion complex" is a supramolecular complex in which at least one compound ("host") has one or more cavities in which one or more guest compounds are contained, and wherein the interaction between the host and the guest involves a purely weak interaction.

[0084] As used in this disclosure, the term "massive end cap" refers to a molecule bonded to or otherwise located within a rotaxane or inclusion complex in a manner that prevents unthreading. A massive end cap prevents the macrocycle and its polymers forming tubular structures from separating from the template molecule of the inclusion complex. A massive end cap also prevents any material from entering the inclusion complex, depending on the size of the macrocycle at the tip of the inclusion complex and the size of the massive end cap. An exemplary massive end cap used in embodiments of this disclosure is a DNBS. The massive end cap may also include a branched polymer, such as a dendron or dendritic polymer, attached thereto.

[0085] Generally, this disclosure uses three terms to refer to cylindrical structures—macrocycles, tubular structures, and channels. A “macrocycle” is a molecule comprising three or more atoms arranged in a ring structure. Examples of macrocycles include cyclodextrins, calixarenes, columnar aromatics, porphyrins, crown ethers, helical molecules, kubryanides[n]aromatics, cucurbiturates, nonspherical aromatics, Kekulenes, cage-like molecules, metal macrocycles, and carbon nanotubes. A “tubular structure” is a molecule comprising a single macrocycle arranged in a coaxial stack, wherein adjacent macrocycles are bonded together by at least one molecular bridge. In some instances herein, the term “tubular structure” may also be used to describe a single macrocycle or its dimer or polymer that associates in place in a fixed manner (e.g., by embedding within a solid interstitial filling material). A tubular structure can be “symmetric,” meaning it has the same cross-section throughout its entire length; or “asymmetric,” meaning it has at least one macrocycle that is narrower than the other macrocycles in the tubular structure. This narrower macroring can be the "tip" molecule of a tubular structure, or it can be inside the tubular structure. The term "channel" refers to a complete passageway with an inlet and an outlet. A channel can be formed from a coaxial stack of macrorings or a tubular structure that leads from the inlet to a pore in a porous substrate, which serves as the outlet. Channels can also be formed partially or entirely from a solid material, where the macroring or tubular structure around which the channel is constructed has been removed. A "channel" can comprise multiple tubular structures coaxially stacked one on top of another, wherein in some embodiments, at least one tubular structure is an asymmetric tubular structure.

[0086] Other relevant terms will be defined subsequently in the specification.

[0087] I. Overview This disclosure describes novel membranes for filtration, with the ability to design membranes with picometer-level sensitivity. In some embodiments, the membrane consists of channels made of tubular structures, wherein the tips of the uppermost tubular structures are modified to obtain openings of a specific diameter that undergoes normal variation due to atomic vibrations. The gaps between the tubular structures are filled with a solid material.

[0088] Furthermore, this disclosure discloses a method for surface modification to construct such channels on a substrate. This method allows for bottom-up construction of nanostructures or sub-nanostructures with ordered pores and sub-angstrom level precision.

[0089] The filter described herein is configured to allow substances to pass from one side to the other and is configured to separate substances passing through it.

[0090] The filter is formed by channels, which are generally vertically oriented structures arranged on the inner surface of a solid material. Typically, the surface is a porous substrate. The channels define an inlet at the surface of the surface and an outlet at the pores of the porous substrate. The inlet has a diameter of 3 nm or less, and in a particularly advantageous embodiment, between 2.5 angstroms and 4.5 angstroms.

[0091] Typically, channels are formed by coaxially stacking macrorings or tubular structures, and optionally by adding end caps or a series of end caps to the top or uppermost tubular structure of the macroring stack. Each end cap, also described herein as a “tip” molecule, has an inner cavity whose diameter defines the diameter of the pore or feature and the ability of material to be contained within or permeate through it. Other ways of controlling the diameter of the tip will be described further herein.

[0092] Because different macrocycles and different end-cap molecules have different internal lumen "textures," effective size-dependent or function-dependent separation can be achieved. Multiple molecules that would otherwise be inseparable due to great similarity in size, chemical properties, or physical properties may now be separable.

[0093] Stacks of macrocycles, such as nanotubes, rotaxanes, polyrotaxanes, helical molecules, and others, and / or tubular structures formed from such macrocycles, provide elongated channels or features that are generally parallel to each other and generally perpendicularly oriented within the surface layer on the substrate surface region. These channels serve as a means of patterning the surface of the substrate. Such channels can also serve as templates or structural precursors for constructing organic or inorganic or hybrid (organic / inorganic) membranes. The substrate can be further modified by a variety of means, such as atomic layer deposition (“ALD”), molecular layer deposition (“MLD”), and other techniques and combinations thereof, to fill the gaps between the channels, thereby incorporating / embedding the channels into the bulk material (“filler” material).

[0094] In subsequent steps, the membrane can be further modified to allow gas and / or liquid communication between its two ends. In one case, the initial substrate can be a composite material, such as a porous substrate, where its pores are filled with another sacrificial material to induce association with the tubular structure. The sacrificial material can be removed at a later stage. Alternatively, deposition can occur on the sacrificial substrate. After membrane formation, a porous layer can be deposited on top of the active layer to increase its mechanical stability; the initial substrate can be removed after deposition.

[0095] A. Direct manufacturing on a mechanically stable substrate Figures 1A-1H The figure illustrates a high-level overview of the first manufacturing method of the filter.

[0096] exist Figure 1AIn this context, a substrate 10 is provided. The substrate 10 is typically a porous, mechanically stable solid material, such as nanoporous anodic aluminum oxide (AAO) or a porous ceramic material. The substrate 10 has a plurality of pores 12.

[0097] exist Figure 1B Layer 13, such as silver, is deposited onto the surface of the porous substrate 10. Layer 13 is also referred to herein as a "sacrificial layered material." Figure 1C A second pore-filling material 14, such as gold, is adhered to the sacrificial layering material 13, thereby filling the pores 12 of the porous substrate. Material 14 is also referred to herein as the "sacrificial pore-filling material." The second material 14 is capable of associating with both the capping layer 13 and the organic compound. The organic compound particularly includes those incorporated into the tubular structures and channels. Figure 1D Remove the delamination material 13 and leave the gold layer 14 in the appropriate position within the hole 12.

[0098] exist Figure 1E Optionally, template molecules are attached to the gold layer within the pore 12. In an alternative embodiment, template molecules are not used.

[0099] exist Figure 1F By covering the template molecule, a coaxial stack 16 of a single macrocycle or a tubular structure containing such a coaxial stack is constructed on the substrate 10. The uppermost tubular structure may have a tip molecule 18 attached thereto.

[0100] exist Figure 1G The gaps between the coaxial stacks 16 are filled with a solid material 19. The solid material 19 may also be referred to herein as "gap filler material," "gap filler layer," or simply "filler." The solid material 19 may be added, for example, by atomic layer deposition (ALD) or molecular layer deposition (MLD), or a combination thereof.

[0101] exist Figure 1H The sacrificial pore filling material 14 and template molecules 15 are removed, leaving pores 12. The coaxial stack is held in place. Thus, a through channel 20 is formed, which has a narrow opening at the tip 18 forming an inlet and a wide outlet at the pore 12 forming an outlet.

[0102] Figure 3A yes Figures 1A-1H Another schematic diagram of the process is shown. Tubular structures 31 are constructed on a substrate, and gap-filling layers 32 fill the spaces between the tubular structures. The initial substrate includes a porous layer 33 and a secondary pore-filling material 30, which is selectively removed at the end of the process.

[0103] B. Fabricating tubular structures on a temporary substrate Figures 2A-2DA high-level overview of a second manufacturing method for filter arrays is provided. In this method, instead of constructing channels on a composite substrate, the channels are first constructed separately, and only thereafter is a surface layer including the channels attached to the substrate. Figure 2A A sacrificial substrate 24 is provided. The substrate is made of a material capable of attaching to organic materials, such as gold. The substrate is sacrificial so that it is used only during manufacturing. Channels 22 made of tubular structures are constructed on the substrate. Channels 22 may be polyrotaxanes having internally threaded molecules 21 around which tubular structures are threaded, and large-volume end caps 26 for holding the tubular structures in place. Figure 2B The gaps between channels 22 are filled with a solid layer 25, such as ALD or MLD. In Figure 2C, the gold substrate layer 24 is removed. The device is then flipped over. Figure 2D This involves attaching a porous permanent substrate (such as AAO or porous ceramic) to a filler material, thereby creating channels. The order of these steps can be varied, such as removing the gold layer as the final step.

[0104] Figure 3B yes Figures 2A-2D Another schematic diagram of the process. In Figure 3B In this process, tubular structures 31 are added to the sacrificial substrate 30. The gaps between the tubular structures are filled with a gap-filling layer 32. Then, a porous layer 33 is deposited, followed by selective removal of the sacrificial substrate 30 (by flipping the device over).

[0105] In this embodiment, the gap-filling layer, arranged as a surface layer, is attached to the porous support after formation. In some embodiments, the porous support is added by depositing or placing the porous layer on top of the device. The porous support layer may be chemically attached to the gap-filling layer and / or the tubular structure. The porous support layer may be retained by the accumulation of weak interactions (e.g., hydrogen bonds) with the gap-filling layer. The gap-filling layer may be trapped between two porous layers (with or without chemical bonds, with or without accumulated weak interactions).

[0106] CVD and sol-gel techniques can be implemented in the deposition of porous supports. Another technique involves taking nanoparticle powder or nanoparticles immersed in an oxide solution and generating a porous layer from them on top of the interstitial filling layer (under a moisture-free condition). The conversion of nanoparticle powder or solution into a porous support can be accomplished by applying the following and / or combinations thereof: 1) heating (which can condense two M-OHs into MOM); 2) pressure; 3) water vapor; 4) ALD (ALD should be performed carefully to avoid burying tubular structures).

[0107] In alternative methods, to produce a porous support under destructive conditions (e.g., high temperature) on the tubular structure, the following can be performed: After depositing an interstitial filling layer (e.g., TiO2), immediately following or subsequently, another additional sacrificial material (e.g., ZnO) can be deposited to cover the tubular structure. Thereafter, a porous support (e.g., porous TiO2 or SiO2) can be deposited. An etchant (acid or alkali) can be used to selectively remove the additional sacrificial material (ZnO), and if a very diluted (acid or alkali) or small amount of acidic gas is used to remove the additional sacrificial material (ZnO), some of it can remain as a binder between the interstitial filling layer and the porous support.

[0108] C. Cross-sectional view of the filter implementation scheme Figure 4A The figure illustrates a cross-section of a filter 40 manufactured according to the methods described herein. The filter 40 comprises a mechanically stable solid porous substrate 41. For example, the substrate 41 may be an AAO (Alternating Atomic Oxide). For illustrative purposes, only the top portion of the substrate 41 is shown, making the substrate appear relatively thinner than the tubular structure and surface layer; in reality, the substrate is substantially thicker than the tubular structure and surface layer. The substrate has one or more pores 42. Channels 43 are located above the pores 42. The channels 43 have a height of approximately several nanometers to tens of nanometers. Each channel 43 has an inlet at the top of the channel and an outlet at the pore. The channels 43 comprise a series of large rings 44. Functionally, the “large rings” described herein may also be tubular structures. In the lower layers, the large rings are connected by a minimum number of bonds or bridges 45 sufficient to maintain the structural integrity of the structure, such as one or two bonds. In these lower layers, the channels are surrounded by a filler material 48, such as metal oxides (ceramics) deposited by ALD or organic materials deposited by MLD, or combinations thereof. In the upper portions of the channels 43, portions of the tubular structure are not embedded in the filler material 48. At these locations, a denser ligature 46, consisting of multiple molecular bridges (e.g., more than two), is formed between adjacent macrocycles, thereby blocking pathways between the macrocycles. At the top of the filter 40, a tip molecule 47 is attached to a tubular structure 43. The tip molecule 47 has a diameter ("second inner diameter") narrower than the inner diameter ("first inner diameter") of the remaining macrocycles containing the structure. The tip molecule can be selected to have a specific diameter configured to allow selected molecules to pass through while excluding other molecules. The second inner diameter can be 3 nm or smaller, or even as low as 2.5 angstroms to 4.5 angstroms.

[0109] Once the tubular structure has been constructed on the channel, the tip molecules can be attached to the uppermost tubular structure. Alternatively, the uppermost tubular structure can be pre-formed in solution using the tip molecules.

[0110] In the illustrated embodiment, the tip molecule is located at the entrance of the channel. In an alternative embodiment, a molecule with a second inner diameter can be located within the channel, such that the channel (and particularly the tubular structure with molecules having a second inner diameter) is shaped like an hourglass.

[0111] Figure 4B The figure shows a cross-section of a second embodiment of filter 40. Filter 40 is constructed as similar to... Figure 4A The filter differs in that, in this case, the channels are constructed from a pattern of tubular structures with different types of bridges between them. Specifically, some large rings 44 embedded within the packing material have denser connectors 46 connecting them. This construction may be preferred if the tubular structures are formed in solution in this manner before constructing the channels on the substrate, as will be discussed further herein.

[0112] Figure 4C The figure illustrates a cross-section of a third embodiment of a structure that can be manufactured according to the teachings of this disclosure. In this embodiment, a large-volume end cap 49 having long template molecules 50 fills the opening, allowing molecules of certain sizes to penetrate the opening only. In this embodiment, instead of a pathway via an opening formed at the top of the tubular structure, the pathway passes through the outer shell of the tubular structure.

[0113] To create such a configuration, a polymer template molecule bonded at one end to a bulky end cap can associate with the open end of the channel. The bulky group can then be bonded to the top of the channel at certain locations, leaving an opening of the desired size at the entrance. Optionally, the bulky end cap 49 is anchored to the tubular structure with one or more bridges 51; these are not required in all embodiments.

[0114] The formation of such a complex between a bulk terminator and a channel can be controlled through a variety of mechanisms. In one example, the channel can be constructed at its tip with a reactive functional group (such as an alcohol). The channel can then be exposed to a surfactant molecule containing a bulk terminator with a functional group (such as a primary alkyl bromide) that associates with a template molecule. The surfactant assembles into the opening of the channel. With or without drying, the alcohol or other functional group can be activated (e.g., with a base) to chemically bond the bulk terminator to the opening of the channel. This process can be repeated to increase the yield of the reaction. The bulk terminator-template molecule combination can be selected to fill only a small portion of the channel volume.

[0115] In theory, a similar effect can be achieved by using surfactant molecules containing bulky endcaps that block the channel opening without bonding to it. In yet another embodiment, the template molecule can chemically associate with the channel in a way that narrows the channel entrance, even without a bulky endcap.

[0116] Typically, blockages can be placed at the entrance of each channel in one of three ways: as discussed, large-volume endcaps and elongated molecules; elongated molecules that are attached to the surface solid material and inserted into the top of the uppermost tubular structure in the channel, or solid material can be deposited in such a way that the top of the uppermost tubular structure is buried in the channel, followed by etching the solid material to expose the outer shell of the tubular structure.

[0117] In another embodiment (not shown), regardless of whether an end cap or a bulk end cap is used, the bottom of the channel can be filled with a valve. The valve is oriented between the porous support and the lower portion of the surface layer. The valve can block the flow from the higher-pressure side of the membrane, so the flow can be formed only through the outer shell of the tubular structure.

[0118] Figure 4D The figure illustrates another embodiment in which an ALD or MLD can be used to block the opening of the channel. An ALD or MLD can be used instead of a surfactant. In such an embodiment, the ALD or MLD can even be intentionally laid down to “bury” or embed the opening of the channel, and then selectively etched to expose the opening of the channel of the desired size.

[0119] In each of the depicted embodiments, the channel includes a tubular structure at least partially embedded therein. In other embodiments, this construction is merely an intermediate step, and the tubular structure is removed before the channel is completed, leaving a channel of solid material without any additional material encapsulating or embedding therein.

[0120] The filler material surrounding the tubular structure can be laid in different layers, each made of a different material. For example, one of the layers could be titanium dioxide (TiO2), and the second layer could be silicon nitride (Si3N4). One of these layers can be selectively etched with an etching solution to expose tiny pores on the exterior of the tubular structure's shell.

[0121] Figures 4E-4J The figure illustrates an example of a crown ether, demonstrating how similar macrocycles can exhibit very slight, even picometer-level, variations in their inner diameter. These will be discussed further in this paper.

[0122] II. Substrate selection and preparation A. Base According to Figures 1A-1H And especially Figures 1A-1D In some embodiments of the method, the substrate 83 is defined by an array of pores, which can be presented at any density, can be random or ordered, and can be uniform or non-uniform in its pore size. The substrate may or may not have asymmetric pores. Despite any particular material or processing conditions, the diameter of the pores can be as low as 1 nanometer to 5 nanometers or smaller, and as high as 200 micrometers or larger.

[0123] The selection of a porous substrate depends in particular on its ability to react with precursors used in the process of filling the gaps between the tubular structures, its mechanical stability, chemical stability, thermal stability, and other considerations. Typically, the substrate must possess suitable physical properties to support both the filter's construction (channels and the surface layer formed by the gap-filling layer) and to provide mechanical support for the finished filter.

[0124] A specific example of a porous substrate is anodic aluminum oxide (AAO), whose pores are filled with a material such as gold or a gold alloy. A porous substrate with its pores filled may be referred to herein as a "composite substrate," and a gold alloy may be referred to herein as a "sacrificial pore-filling material." Other examples include oxides and other ceramics having pores pierced within them using electron beams, ion beams, or other types of beams or techniques. Other such porous materials can be manufactured using sol-gel, plasma processing, CVD, PVD, plastic extrusion, and any other methods known in the art.

[0125] This article will further describe innovative techniques for adjusting the parameters and properties of composite layers. In some implementations, depending on how the composite layer is generated, polishing and / or other means are used to expose the composite layer.

[0126] In some embodiments, the porous substrate is a plastic or polymer filled with gold or a gold alloy. In some embodiments, gold nanoparticles or gold alloy nanoparticles are integrally embedded on the topmost surface of the porous material, while the gaps between them are filled.

[0127] In some embodiments, the porous substrate is a layered material consisting of two or more porous layers on top of each other, with no chemical bonds between them. In some embodiments, the substrate has a high surface area, such as hollow fibers, stacked sheets, and others.

[0128] In some embodiments, one or more "connector" molecules may associate with the surface of the porous substrate. The molecule uses a portion of itself to associate with the substrate, while another portion of such a molecule reacts with a precursor used in the process of filling the gaps between the tubular structures, as will be discussed further herein. An example of a connector molecule is triethoxysilane (CH3CH2O)3Si-(CH2)3-NH2. The silicon-triethoxy group can bind to the ceramic surface, while the amine can react with silver nanoparticles. In some embodiments, the porous layer ultimately chemically associates with the gap-filling layer and / or the tubular structure and / or associates around the gap-filling layer and / or the tubular structure and / or through the accumulation of weak interactions. In another alternative, the diameter of the pores can be filled with gold, and in the case of defects where the voids are not properly filled with gold, the filling gaps can also cover / block such pores if the pores are narrow enough.

[0129] The choice between the two main methods of membrane production depends in particular on the desired porous layer for mechanical support (which can be industrially available) and the ability to deposit such a porous layer in the presence of tubular structures that may contain organic materials.

[0130] In the device constructed according to the present disclosure, a silicon wafer coated with a 100 nm gold film (with a few nanometers of chromium as an adhesion layer between the gold and an oxide layer present on the surface of the silicon wafer) is used as a substrate.

[0131] B. Attaching sacrificial materials to form a composite substrate In this section, the terms "primary sacrificial material" and "secondary sacrificial material" are used. The "secondary sacrificial material," also referred to herein as "sacrificial layering material," is a material deposited directly onto the substrate and can be used as a precursor for depositing another sacrificial material ("primary sacrificial material"). The "primary sacrificial material," also referred herein as "sacrificial pore-filling material," is a material deposited onto the secondary sacrificial material while simultaneously filling at least partially the pores of the porous substrate and serving to form a base for attaching other materials such as template polymers and / or tubular structures.

[0132] In some embodiments, a dense layer of secondary sacrificial material is deposited on the surface of a porous substrate. Then, primary sacrificial material is deposited de novo inside the pores of the substrate to fill them. The dense layer of secondary sacrificial material is then etched, leaving the pores filled with primary sacrificial material. Tubular structures are then deposited on this material.

[0133] In one example, the substrate is an AAO (anodic aluminum oxide) film. The secondary sacrificial material is silver. Silver is deposited on the outer surface of the AAO substrate (e.g., using CVD and PVD methods such as thermal deposition, sputtering, and electron beam deposition) via CVD and PVD methods. Figure 1B (As shown in the image). Then, gold (Au) is electroplated (electrodeposited) as a primary sacrificial layer to fill the holes, as shown in the image. Figure 1C As shown in the diagram. Selective etching, such as selective etching with nitric acid, can then be performed to remove the silver layer.

[0134] Other materials can be used as substrates, with different materials requiring different types of deposition techniques, including materials with high surface area structures, such as hollow fibers. The substrate can be formed from titanium dioxide (TiO2), silicon dioxide (SiO2), or silicon nitride (Si3N4). When the porous substrate is titanium dioxide, silver can be deposited directly using electroless deposition (ELD). ELD can then be used to deposit gold within the pores. Note that the ELD process does not deposit gold directly onto the titanium dioxide. This is advantageous because it is desirable to insert gold into the pores rather than covering the surface of the substrate with gold.

[0135] A similar two-step process can be used to deposit gold in the pores of porous Al2O3.

[0136] When the porous substrate is silicon dioxide (SiO2), additional preparation steps are required. For example, a self-assembled monolayer (SAM) can be formed on the surface of the silicon dioxide. Silver is then deposited on the outside, and the remainder of the SAM is removed from the interior of the pores. The SAM can be of the structure H2N-(CH2). n The amine form of SAM, -Si-(X)3 (where X is a leaving group), can associate with SiO2 and subsequently with Ag. + Ion association occurs, followed by ELD of Ag. After ELD, the remaining Ag can be removed by adding a ligand and / or an acid. + The ions can then be removed by immersion in H2O, and the remaining SAM-amine can be removed from the metal Ag membrane. Finally, if present, the ligands can be removed from the membrane by an electric current.

[0137] In some embodiments, a sacrificial amine (SAM) is first formed on the surface of a porous substrate, and then all or some of the external SAM is temporarily protected, while the remainder of the SAM is removed from the interior of the pores. The protection of the external SAM is then removed. The remaining external SAM is then used to deposit a secondary sacrificial film, with or without further modification. For example, if the porous substrate is SiO2, amine SAM can be specifically protected externally by depositing nanoparticles that are too large to pass through the pores of SiO2. Such nanoparticles protect the SAM from external removal. The nanoparticles can then be removed by selectively etching them (Au and Ag nanoparticles can be selectively etched using cyanide and / or iodine solutions) or by separating them using a weak acid. In some embodiments, the unprotected SAM is not removed but reacted to become inert / non-reactive (e.g., amine SAM can react to form amides, oxidize to nitro groups, etc.). The remaining external SAM can be used to initiate the deposition of a secondary sacrificial material by CVD, PVD, ELD, or any other means such as nanoparticle deposition and combinations thereof.

[0138] In some embodiments, nanoparticles that are too large to pass through the pores of a porous substrate are deposited on the exterior of the porous substrate to induce the deposition of secondary sacrificial materials. Such nanoparticles may contain one or more secondary sacrificial materials in their composition. In some embodiments, the nanoparticles are ligandized, and the ligands may be used for surface association on the exterior of the porous substrate.

[0139] The deposition of functional groups can occur on the exterior of the porous substrate. For example, molecules of the type (X)3-Si-YZ can be used, where X is a leaving group, Z is any type of branched polymer that is too large to pass through the pores of the porous substrate, and Y is a selectively cleavable linker that generates functional groups upon cleavage, including -NH2, -SH, and -S. - -COO - And -COOH are of particular interest.

[0140] Another approach involves creating a porous layer, such as SiO2 and / or Al2O3, around a non-porous, dense fiber (which may be hollow) of, for example, a Cu / Ag / Cu-Ag alloy. The pores are then filled with Au, and finally the Cu / Ag / Cu-Ag is selectively etched using nitric acid.

[0141] In some implementations, the porous substrate has relatively uniform pores. After its pores are filled with a primary sacrificial material, it can be drilled / polished / ground / patterned to obtain high surface area structures, such as linear arrays, stacked sheets, arrays of pores, or even separated fibers or other shapes. The secondary sacrificial material can or can be etched non-selectively before or after the drilling / polishing / grounding step.

[0142] In some embodiments, the surface of the hollow or non-hollow, polymeric (e.g., PEI) or non-polymeric dense wire may be sparsely deposited with nanoparticles made of or containing a primary sacrificial material. This surface is further deposited by a porous layer for mechanical support, which has pores at least in the layer adjacent to the dense wire and the nanoparticles of the primary sacrificial material, the pores being narrow enough to be covered and closed during the manufacturing advancement steps. Finally, the dense wire is removed.

[0143] In some implementations, thin composite membranes can be used, for example, on top of a porous substrate, using known methods for producing such thin composite membranes having metal nanoparticles embedded within a cross-linked polymer for reverse osmosis. The nanoparticles can be made of a primary sacrificial material.

[0144] Figures 2A-2D The fabrication steps for a layered, non-composite substrate are illustrated. This method can also be used for high surface area fabrications, for example, by associating tubular structures on the outer upper surface of a dense fibrous substrate, depositing a gap-filling layer between the tubular structures, subsequently depositing a porous layer, and finally selectively etching the initial substrate. The initial substrate can be hollow fibers of a gold alloy with a small amount of silver, and these hollow fibers can be mechanically stable.

[0145] Variations of the mechanism described above are disclosed in the literature. These variations include alternative methods using SAM during the deposition process, alternative methods for selectively etching secondary sacrificial materials, using ligands to initiate the deposition of secondary sacrificial materials, using water-oil interfaces to stack films containing secondary sacrificial materials, activating porous substrates before depositing secondary sacrificial materials, and others.

[0146] C. Etching of the gold layer In some embodiments, regardless of whether a first or second primary method for producing the film is used, selective removal of gold or gold alloys, such as gold-silver alloys, is required at the end of the process. Specifically, gold can be used as a material that can fill pores in the substrate, and tubular structures can be constructed on top of it. After the gaps between the tubular structures are filled, the gold can then be selectively removed in an etching process to clear the pores. In the presence of oxides such as silicon dioxide, gold can be selectively etched using sodium cyanide or potassium cyanide. The process can also selectively etch silver. Another process for selectively etching gold is by using iodine. In other embodiments, silicon oxide is selectively removed, which can be selectively carried out under humid conditions by hydrofluoric acid and its buffer, or selectively by dry etching in the presence of titanium dioxide or aluminum oxide.

[0147] In some embodiments, a protective coating layer is first used as a molecular binder between the sacrificial surface and the gap-filling layer. Such a coating layer also protects the porous substrate. Such a protective coating layer can also be used if the materials are not identical. In some embodiments, the tubular structure can allow etchants to reach the other side of the membrane, which is undesirable; therefore, they can be temporarily blocked by adding a cap or by forming an inclusion complex with template molecules associated with bulky groups at one end. In some embodiments, a second porous layer is coated / deposited / placed from the other side of the membrane.

[0148] In some implementations, a temporary layer, such as wax, is applied prior to etching to increase mechanical stability and allow for more vigorous agitation during etching. Another reason is when the entire layer of a continuous substrate is etched and the porous support is desired to be located on the side where the continuous substrate layer is situated. Yet another reason is to maintain the integrity of the tubular structure with a gap-filling layer and to thicken the outer layer of the tubular structure on the side where etching has already occurred after etching.

[0149] III. Template molecules and methods for attaching them to substrates In many embodiments of this disclosure, and as Figure 1E As seen in the diagram, channels are formed on the template molecule. The template molecule is then attached to the substrate, for example, to a primary sacrificial material covering the substrate. Following the attachment of the template molecule, macrocyclic monomers or tubular structures are coated onto the template molecule.

[0150] refer to Figure 6A Template molecules 61, such as polymers, are attached to the surface region of substrate 60. Functional groups, depicted as asterisks, are positioned at the ends of template molecules 61. Although only one polymer is attached to the substrate in the illustrated figure, it should be understood that a polymer network is attached to the substrate.

[0151] The template molecule is patterned at surface sites within the surface region, enabling the direct placement of tubular structures at these sites. The template molecule can be any elongated molecule having a linear backbone and at least one terminal functional group that can associate with the surface region of the substrate. Similarly, the template molecule can be selected from linear molecules that are monofunctional or optionally bifunctional, meaning they have two or more terminal groups, at least two of which are functionalized, substituted, or located at different ends of the linear molecule (one or more terminal groups at one end and one or more identical or different groups at the other end). In the case where both ends are substituted with functional groups, one end can be selected for surface bonding, while the other end is used for association with a functional group that acts as, for example, a capping group or a stopper group after the macrocycle and / or tubular structure is threaded onto the template molecule.

[0152] The choice of functional groups depends in particular on the template molecule used, the surface material to which the template molecule will associate, and other processing parameters. Functional groups can be selected as atoms containing at least one heteroatom or having an affinity for the surface material or the ability to associate with the capping material. Such functional groups can include sulfur atoms, selenium atoms, carboxylic acid groups, esters, activated esters, amine groups (or nitrogen-containing groups, including cyclic amines and aromatic amines), hydroxyl groups (including phenols and other molecules containing -OH), azides, aryl halides, alkyl halides, aryl pseudohalides, alkyl pseudohalides, and pseudo-stabilizing functional groups such as acyl halides, among others.

[0153] The template molecule can be selected from aliphatic molecules having a number of carbon atoms that define the molecular length. The template molecule can be further selected from polymers or mixtures of polymers and oligomers. Elongated molecules are selected from compounds having a measurable length or an effective length that allows for the efficient construction of tubular structures between multiple atoms in their linear backbone.

[0154] Template molecules associate with surface regions of a substrate material to achieve a patterned surface. Therefore, in some embodiments, the template molecules are more than one such molecule, either identical or different, each of which associates with a surface region to provide a pattern with a preselected or random surface density and profile. The more than one template molecule can be a group of materials, such as polymers, wherein the group is homogeneous, i.e., each template polymer is the same as another, or heterogeneous, i.e., the group contains different template molecules, wherein the differences lie in material composition, length, molecular weight, presence of functional groups, and at least one of the following; or the chemical, physical, or mechanical properties of the material.

[0155] Generally, a surface region can be any area on the surface of a substrate material that needs to be patterned or whose surface properties will be modified. A surface region can be made of a single material, or it can comprise two or more surface regions, each with a different surface material. In such cases, patterning with template molecules can be targeted at one or two of the different surface materials.

[0156] As discussed above, the substrate and its surface can be made of the same material, or the substrate can be coated with a film of a different material. The materials of the substrate and / or surface can be selected from metallic materials, polymeric materials, glass, paper, ceramic materials, oxide materials, nitride materials, phosphates, sulfides, carbides, and others. In some embodiments, the surface is a metallic substrate, such as gold. In some embodiments, the substrate is a substrate surface coated with a metallic material such as gold (e.g., silicon).

[0157] Patterning of template molecules on a substrate surface can be achieved to provide ordered, random, or hybrid patterns, where a region of the surface is ordered while a second region is not. Layered patterning is also possible, where surface regions can be patterned in an ordered manner, and template molecules will randomly associate within each ordered region. Ordered patterns can be formed by any means known in the art. These include photolithography, optical photolithography, soft photolithography, dip-pen nanolithography, mask methods, photoresist-based methods, focused ion beams, electron beams, reactive ion etching, plasma reactive etching, and others. Random patterning can be achieved, for example, by contacting the surface region with a solution containing template molecules and allowing molecules to associate onto the surface region. Patterning of the template material can be performed in one or more steps, such as associating molecules with a surface, which can be homogeneous or self-patterned; selectively breaking at least one of its chemical bonds with the obtained residues on the surface, with or without further association of another molecule or sequentially multiple molecules, to obtain a surface associated with the template molecules.

[0158] In some embodiments, contacting the surface with a solution will produce an ordered patterning. Specific examples of interest are polymers having dendritic motifs / dendritic polymers / branched polymers and combinations thereof, whose surface spacing has been investigated. For illustration, dendritic motifs with selectively cleavable chemical bonds near their stems (where the stem tips have functional groups for surface association) can be used for the ordered patterning of residues on a surface (there are even commercial examples of such dendritic motifs). The entire spectrum between dendritic motifs and dendritic polymers can be used to determine such surface spacing of the patterned template molecules / residues associated with the template molecule. In some embodiments, such polymers are also degradable under certain conditions, and not only one linker between their atoms is selectively cleavable. Molecules used to pattern residues on a surface can have more than one functional group, such that after molecule removal, each such molecule will have more than one residue. The spacing between residues originating from the same molecule can be controlled due to the shape, flexibility, and other properties of such molecules. Residues originating from the same molecule can have the same or different functional groups. The means of surface association depend in particular on the surface used, the functional groups present on the template molecules that are intended to achieve surface association, the required structured pattern, the desired association density, and others.

[0159] Attaching molecules to a surface is a process with several possible deposition kinetics, such as island formation, especially for small and linear molecules. Important parameters and conditions that determine the kinetics include: the phase / state of the deposited molecules, the solvent (solvent mixture, buffer), the concentration of the template polymer in the solution, temperature, immersion time, stirring, shaking, sonication (during immersion), suction (to evaporate the solvent), and atmosphere.

[0160] Adding additional materials that cannot chemically react with the surface but can only physically adsorb onto it before or during immersion can provide some control over the process. Regardless of whether the previous method or another method is used, the physically adsorbed materials can be removed later by stirring and / or ultrasonic treatment.

[0161] The following methods describe the conditions and processes for attaching template molecules to a surface while controlling the surface density of the template molecules, their spacing, and other parameters.

[0162] As discussed above, in a preferred embodiment, the substrate is a metallic substrate, such as gold, or a gold layer overlaid on another substrate. Advantageously, the gold reacts with groups that can be functionalized onto the polymer, such as thiols, selenols, and disulfides. The template molecule has such a group, such as a thiol group, at one end. The template molecule can be functionalized with an amine or a protected amine at its other end. An example of a suitable polymer is polyethylene glycol (PEG), and more specifically, a polymer functionalized with a thiol group at one end and an amine group at the other end.

[0163] If the template molecules do not tend to form islands on the surface, attachment can be performed by immersing the substrate in a diluted solution containing the polymer.

[0164] If the template molecules tend to form islands on the surface (and in such islands the distance between each molecular chain is too close and interferes with the threading of macrocycles or tubular structures), the attachment of the template polymer can be accomplished by immersing the substrate in an extremely diluted thiol solution while simultaneously heating, sonicating, and / or vacuum pumping. This produces a polymer-grafted surface where the individual polymer chains are attached separately from each other without forming islands. Oxidation of the thiol can be avoided by working under an inert gas atmosphere. The template polymer can then be functionalized at its other end with an amine or a protected amine.

[0165] In the aforementioned example, the template molecule is attached to the surface in a single step. In an alternative embodiment, the process can be further divided into two or more steps. First, a molecule having the structure XYZ-SH is attached, where: X represents a sacrificial polymer or other functional group, optionally having a bulky group (e.g., a dendritic motif or dendritic polymer) at one end. Y represents a cleavable linker between X and Z, such that Z will be terminally functionalized after cleavage. Z represents a short molecule. SH represents a thiol group. After immersing the substrate in such a dilute solution containing such a thiol, thereby attaching the thiol to the substrate, the Y linker is cleaved. Subsequently, the template polymer is added by reacting with the terminal functional group of Z. Instead of the thiol group, a disulfide group can also be used.

[0166] For example, molecular HS-CH2-COO-PEG can be prepared. 10k A solution containing -OCH3. In this case, the "X" group is PEG with OCH3 as a long group, and the "Z" group is CH2-COO. The gold surface is immersed in a vial containing the solution. After cleaning (washing, rinsing, and sonication with various solvents), the surface is immersed in an alkaline solution (NaOH) to produce the following surface: Au-S-CH2-COO - Na + This group can be templated with polymers such as H2N-PEG.2k -NH-triphenylmethyl is functionalized via EDC-NHS coupling of a carboxylic acid and an amine (or through other ester activation procedures). The amine (triphenylmethylamine) protection can be removed under mild acidic conditions or reduction after washing (washing, rinsing, and sonication with various solvents). After forming an inclusion complex with the tubular structure, a bulky endcap can be attached to the amine.

[0167] Without departing from the scope of this disclosure, various other examples of the “X” group, “Y” group, and “Z” group may be used. For example, a disulfide group may be used instead of a thiol group.

[0168] In some embodiments, after the cleavage step, the remaining molecules on the surface are not short, but sometimes even template molecules that do not require further modification / activation, so they can be threaded through and react with the bulk end-capsule to produce rotaxane / polyrotaxane. In such embodiments, the "Z" component becomes the template molecule.

[0169] The method described in this article can be used to attach to surfaces other than gold.

[0170] Furthermore, the preceding discussion involves the use of template molecules attached to the surface of the substrate. In an alternative embodiment, the template molecules can be used in solution during the process of forming the tubular structure. These embodiments will be discussed in the next section.

[0171] IV. Macrocyclic and tubular structures and their preparation methods A. Large ring The large ring is the skeleton of the channel described in this disclosure.

[0172] A "macrocycle" is a cyclic macromolecule containing multiple ring structures (e.g., three or more) or atoms linked together to form a cyclic molecule. As defined, a cyclic molecule does not have ends and is defined by a cavity formed by the atoms, bonds, or rings that form the macrocycle. A cyclic macromolecule can be any such structure known in the art. Macrocycles can be produced synthetically, can be derived from nature, or can be chemically modified to provide derivatives, substituted or modified forms, or analogs thereof.

[0173] Macrocycles can be used as is, i.e., as cyclic molecules as defined herein, or manufactured during any of the process steps disclosed herein. For example, macrocycles can be constructed from linear segments and form cyclic molecules or tubular structures as defined herein around a central template molecule. Whether macrocycles are prepared in advance and used as is, or formed during the construction of tubular structures, macrocycles should be understood in their broadest known definition.

[0174] Non-limiting examples of such macrocycles, as defined, used as is or constructed around a template molecule or during the preparation of a tubular structure, are known in the art, and therefore any such cyclic molecule, after being threaded onto the template molecule, can be depicted as rotaxane or polyrotaxane. Such cyclic molecules can be, for example, calixarenes, porphyrins, cyclodextrins, columnar aromatics, crown ethers, helical molecules (which may, for example, be constructed around a template molecule), kubryanides, cucurbiturils, nonspherical aromatics, cyclophanes, carcerands, cavitands, cyclohexyl-m-phenylene macrocycles, azacyclic macrocycles, thiocyclic macrocycles, glycophanes, oxacalixarenes, pyrogallol[n]arene, resorcinol[n]arene, kekulenes, cage molecules, inorganic macrocycles, metal macrocycles, organic-inorganic hybrid macrocycles, organosilicon macrocycles, organoboron macrocycles, carbon nanotubes, and others. In the process of this invention, macrocycles are typically stacked coaxially to provide elongated channels that can contain any number of macrocycles. Therefore, a channel can be formed as an elongated assembly of more than one large ring, which are coaxially stacked and associated with each other, i.e., every two adjacent large rings are chemically or physically associated with each other. Each large ring in the channel can be identical or different, and can be selected based on the large ring size, the presence of functional groups, stability, the structure of the large ring cavity, the size of the cavity, the functional groups present in the cavity, and other factors. Thus, channels can be identical or different, and can differ from each other in the large rings used, the order of the large rings used, the length of the channel, the average core diameter, and other aspects.

[0175] The channel can be selected from homogeneous structures with the same macrocyclic structure and heterogeneous structures with more than one macrocyclic structure, wherein the more than one macrocyclic structure can differ in at least one of chemical and physical properties. Such properties can be selected from, but are not limited to, macrocyclic size, presence of functional groups, stability, structure of the macrocyclic cavity, size of the cavity, functional groups present in the cavity, and others.

[0176] A suitable, exemplary macrocycle is α-cyclodextrin. Nanotubes containing α-cyclodextrin cross-linked together using supramolecular chemistry have been fabricated. Furthermore, the inner diameter of the α-cyclodextrin is only 4.5 Å. As a result, it is feasible to attach end caps to α-cyclodextrin to produce membranes with sub-4.4 Å domains, particularly between 2.5 Å and 4.5 Å, as discussed. α-cyclodextrin has many known and possible modifications. Such modifications can alter the selectivity and permeability of membranes composed of the tubular structure of α-cyclodextrin.

[0177] Another exemplary material is γ-cyclodextrin. γ-cyclodextrin has an inner diameter of 8.5 Å and also presents a platform for producing sub-8.5 Å size films, polyrotaxanes, and modified quasi-polyrotaxanes.

[0178] B. Macrocycles associate in solution to form tubular structures. According to this disclosure, the tubular structure is formed by large rings that are linearly associated to form a tube.

[0179] Various techniques for associating adjacent macrocycles are known in the art. Macrocycles can be associated with or without supramolecular chemistry using any methods known in the art and combinations thereof.

[0180] Macrocycles, their openings and / or other portions, can be modified and / or transformed and / or decorate and / or patterned and / or inactivated and / or protected, with or without supramolecular chemistry, using any methods and combinations thereof known in the art, with the aim of associating macrocycles into elongated tubular structures.

[0181] Figures 5A-5F The figure illustrates an exemplary schematic model for associating adjacent macrocycles in solution. Figures 5A-5C The schematic diagram shows two cyclodextrins 51 aligned opposite each other. Cyclodextrins are asymmetric compounds with a cross-section similar to a truncated cone, exhibiting a "wide" side 52 and a "narrow" side 53. Prior art has demonstrated that narrow-narrow junctions can be formed... Figure 5A ), wide-narrow connection part ( Figure 5B ) and wide-to-wide connection ( Figure 5C To form dimers of cyclodextrins. Each of these types of association can exist in the tubular structure according to this disclosure. In each case, the linking portion is one or more bridges 54 between possible opposite sides or positions of the two cyclodextrins via a reaction such as a condensation reaction. Each carbon of the macrocycle has a terminal group (such as an alcohol) at both the "wide" end and the "narrow" end of the macrocycle. These terminal groups can be functionalized to enable the formation of bonds between the cyclodextrins. Functionalization can enable the association of two opposing groups at the wide side or the narrow side of the cyclodextrin. Prior to association, it may be necessary to deactivate other groups, such as by methylation.

[0182] Figures 5D-5F A schematic map illustrates how bridges can be used to form α-cyclodextrin chains. Figure 5DIn this process, multiple α-cyclodextrins 51 are threaded together along a template molecule 56 and sealed in place by a large-volume end-capping body 55, thereby forming a polyrotaxane. The α-cyclodextrins 51 are arranged such that the wide end of one cyclodextrin is opposite the narrow end of a second cyclodextrin. Figure 5E In the middle, bridge 54 is formed to connect adjacent cyclodextrins. Figure 5F In the process, the bulk end cap 55 and template molecule 56 are removed, leaving the cyclodextrin polymer 57, which can be used as a structural unit of the tubular structure.

[0183] Threading Macrocycles can be threaded together to form inclusion complexes. The term "threading" refers to inserting a template molecule into the lumen of each macrocycle, or into the lumen of a macrocyclic dimer, trimer, etc., to obtain an inclusion complex. Threading of more than one (or more) macromolecules can be achieved by mixing the macrocycle and template polymer in a solvent. Solutions can be selected for specific properties and can be saturated or diluted with the macrocycle. Optionally, sonication and / or temperature control can also be utilized.

[0184] Threading macrocyclic or elongated tubular structures, such as nanotubes containing two or more macrocycles already bonded together, onto template molecules to form inclusion complexes between them is a process dependent on a variety of factors, sometimes referred to as polyquasi-rotaxanes or quasi-rotaxanes. These factors include the functionality and other properties of the template molecules, including their polarity or α-polarity and the cavities of the macrocycles, tubular cavities, tubular shells, solvent / solvent mixtures, temperature, the flexibility / rigidity of the template molecules, their length, macrocycle / tubular structure, and others. Sonication is typically used to initiate the threading process. In some cases, threading is achieved in a saturated solution of the macrocycle or tubular structure, and in others in a diluted solution. Some inclusion complexes form in water also due to hydrophobic interactions between the tubular cavity and the template molecules. After their formation, some inclusion complexes can persist for a period of time without disintegrating in solvents that do not promote the initial formation of the inclusion complex. For example, some inclusion complexes formed in water can persist for a period of time in polar aprotic solvents. Some nanotubes containing macrocycles can be threaded by template molecules in polar aprotic solvents. In some cases, even when hydrophobic interactions play a role in inclusion complex formation, the hydrophobic cavities of tubular structures can be threaded by template molecules with polar groups.

[0185] In some cases, more than one macrocycle can associate with each other prior to surface association. In some embodiments, the shell of the tubular structure, or a portion thereof, is to some extent sacrificed, i.e., it can be selectively removed, for example, to increase the solubility in the solution that promotes inclusion complex formation, and also generally to increase the solubility of the tubular structure itself. In some embodiments, surfactants can be used to increase such solubility of the tubular structure, or a portion thereof. Surfactants that do not compete with template molecules to form inclusion complexes with the tubular structure are of particular interest. Such surfactants can be, for example, surfactants whose ends are associated with bulky groups that prevent threading.

[0186] The addition of bulk end-capsulants 55 can be achieved through various mechanisms. Typically, the bulk end-capsulants can be added to a solution containing quasi-polyrotaxanes in one or more of the following ways: as a powder; or dissolved in a separate solution. A base can be added to promote the attachment of the bulk end-capsulants to the template polymer.

[0187] Exemplary mechanisms for adding bulk end-caps to template molecules in liquids are described in the art. In one example, the polymer template molecule ends in a primary amine, and the bulk end-cap is sodium 2,4,6-trinitrobenzenesulfonate or sodium 2,4-dinitrobenzenesulfonate. In this case, polyrotaxane is generated on the surface. Other mechanisms for attaching bulk end-caps to template molecules in liquids are also described in the art.

[0188] In another mechanism, the surface with the threaded template polymer and macrocyclic / tubular structure is dried, and a volatile bulk end-capping agent is evaporated onto the surface. Another gas can be used as a base. In yet another mechanism, the bulk end-capping agent is added as a solid powder. Various bulk end-capping agents can be used, and various methods for applying the bulk end-capping agent can be employed in manners known to those skilled in the art.

[0189] Formation of molecular bridges The formation of molecular bridges between adjacent (ortho) macrocycles produces a tubular framework. Association can occur via any chemical association or bonding, such as ionic bonding, covalent bonding, hydrogen bonding, and others. In some embodiments, association can be achieved via covalent bonding, for example, by forming a covalent bond between a functional group on one macrocycle and a functional group on another or an adjacent macrocycle. Typically, the functional groups that allow association are located on the periphery of the macrocycle and not within its lumen. However, association can also occur via any functional group present on the macrocycle, either on its periphery or within its lumen.

[0190] Association can be achieved by chemically reacting functional groups present on a macrocycle, for example, by reacting a carboxylic acid on one macrocycle with an amine on another macrocycle, or by associating macrocycles through a linker motif (linker molecule) containing two or more functional groups, which can associate with functional groups present on each macrocycle.

[0191] In some embodiments, association can be achieved via crosslinking. In this context, crosslinking refers to the addition of an external molecule that connects two different macrocycles or tubular structures. In some embodiments, association is achieved via a condensation reaction between adjacent macrocycles. In some embodiments, association is achieved through a combination of methods, i.e., for example, via a condensation reaction followed by crosslinking. The condensation reaction may require some group transformation.

[0192] For effective crosslinking, macrocyclic / tubular structures can be densely threaded onto the template molecule, or at least a portion thereof. Crosslinking can occur in solution after surface drying, or in the gas or solid phase. The exposure rate of the crosslinking agent, its shape, and other parameters can control the association rate.

[0193] Various methods for connecting adjacent macrocycles at adjacent sites have been disclosed in this art. Generally, there are two basic approaches: directly using chemical bonds, and using supramolecular chemistry to achieve chemical bonds.

[0194] Regarding the direct formation of chemical bonds, one approach involves using a macrocyclic calix[4]arene and adding two externally opposing bridges to each side of the macrocycle. Using the two bridges, another such macrocycle is bifunctionally chemically associated. This process can be repeated to produce nanotubes of calix[4]arene. In some embodiments, the groups at the desired positions react with a single molecule (sometimes referred to as a “looper”) more than once. After different interconnections are formed, the looper can be removed as needed to produce specific modified sides of the macrocycle.

[0195] In some embodiments, after modifying one or both sides of the macrocycle (by conversion and / or protection and / or inactivation of groups), one or more sides may associate with molecules serving as “arms,” which will later form bridges with other macrocycles or the tubular structures containing them. One side of a cyclodextrin may associate with two or more “whole” arms or “half” arms, or any partition such as a single “whole” arm. As used herein, a “whole” arm is an arm that extends from one cyclodextrin to another within a tubular structure, while a “half” arm meets another “half” arm in the middle. The tips of any arm may be protected.

[0196] Associating cyclodextrins with the tubular structures containing them can also be accomplished using supramolecular chemistry. In these embodiments, the cyclodextrin is threaded around the template molecule to form a quasi-polyrotaxane, a bulk end-cap is attached to the template molecule to hold the cyclodextrin in place (optionally, the bulk end-cap is attached to both ends of the template molecule), and thus a polyrotaxane / rotaxane is formed, bridging adjacent cyclodextrins, and then the template molecule is removed. Optionally, after removing the bulk end-cap, the template molecule can be elongated so that more macrocycles can be attached to the chain.

[0197] Supramolecular chemistry has been employed to generate α-cyclodextrin nanotubes using polymers that penetrate more than one such macrocycle in a single pass. The tip of the penetrating polymer reacts with a bulk group to prevent the macrocycle from detaching from the polymer, resulting in a dense polyrotaxane. An external bridge is then added to chemically associate the ortho-macrocycle. Finally, the linker between the tip of the penetrating polymer and the bulk group is selectively cleaved, and the penetrating polymer is released, yielding α-cyclodextrin nanotubes.

[0198] In some implementations, the bridging molecule can be added slowly. The reaction can be carried out in the solid, gas, or solution state.

[0199] When polymers form in solution, the type of linkers between adjacent macrocycles can vary. For macrocycles located in the lower portion of the tubular structure and which will in any case be buried by the interstitial filling layer (see...),... Figure 4A One or two bridges are sufficient to connect the large ring. This type of connection is used in... Figures 5A-5F As shown in the middle diagram. Conversely, for the large rings located in the upper part of the tubular structure (which are not buried by the interstitial filling layer), the large rings are connected in more than two locations. Additional connectors ensure that no molecules can enter the tubular structure in the areas not buried by the interstitial filling layer.

[0200] Specific strategies for forming bridges include the initial formation of "trains" and "ladders". Figure 5G The diagram illustrates a general strategy for forming tubular structures. Figure 5GIn this process, a macrocycle 501 having functional groups X and Y (such as a cyclodextrin) can be bonded to a second macrocycle 502 having functional groups X, Y, and additional functional groups Z and W (e.g., which may be alcohols). Functional group "X" includes an arm that will subsequently be used to form a bridge between adjacent macrocycles and may also include a protecting group to make the arm non-reactive. Functional group "Z" also includes an "arm" that may include a protecting group. The functional group "Z" from macrocycle 502 reacts with the group "Y" from macrocycle 501 to form a dimer 503. This process is repeated to form a polymer 504. Although only a single pair of "X" and "W" is shown for each pair of adjacent macrocycles in the illustrated embodiment, more than one such pair may be included.

[0201] The tubular structure 504 is referred to herein as a “chain” construction because it resembles a train with multiple carriages connected by only a single connector. Typically, for a tubular structure with a “chain” design, the tubular structure comprises at least two large loops, where adjacent large loops are associated with each other by at least one association, and where at least two adjacent large loops are associated with each other by exactly one association. Thus, some chains comprise “units”, where within each unit, a large loop is associated with its adjacent large loop by at least two associations, and units are associated with each other by exactly one association. This design is also of particular interest due to its relatively simpler production. The lengths of units in a tubular structure with a chain design can be inconsistent.

[0202] exist Figure 5H A template molecule 506, having a large-volume end cap 507 at one end, is mixed with a polymer 504 in solution to form a complex. The length of the template molecule 506 is chosen such that the end 508 of the template molecule extends just beyond the terminal macrocycle in the polymer 504.

[0203] The presence of the bulky end cap 507 is valuable in ensuring that the end 508 of the template molecule 506 remains exposed. In the absence of the bulky end cap, molecules such as... Figure 5I The described chain will bury the ends 508 of the template molecule, preventing further reaction at those ends. The junction between the bulky end cap 507 and the template molecule 506 is selectively cleavable, as will be discussed further herein.

[0204] Next, in Figure 5J A second, larger-volume terminator 509 is introduced and reacts with the terminator 508 of the template molecule. This reaction does not necessarily form a selectively cleavable linker.

[0205] exist Figure 5KThe “X” protecting group is removed and / or activated. Specific examples are further discussed in this paper. The “X” functional group at the end of the tubular structure can also be replaced and / or selectively protected after bridging. This reactive group reacts with the opposing W group, thereby forming a second bridge between adjacent macrocycles in the tubular structure.

[0206] exist Figure 5L The first large-volume end-cap molecule, 507, cleaves from the template molecule 506. Figure 5M This allows for the removal of the second largest volume end cap and template molecule, leaving a tubular structure with two linkers between each macrocycle.

[0207] The resulting tubular structure can be analogized to a "ladder," as long as each large loop is connected to two connecting parts, much like the rungs of a ladder. Typically, for a tubular structure with a "ladder" design, the structure contains at least two large loops, where adjacent loops are associated with each other by at least two associations and may be substantially opposite each other. Therefore, some ladders contain "units," where within each unit, a large loop is associated with its adjacent large loop by at least three associations, and the units are associated with each other by exactly two associations and may be substantially opposite each other. The lengths of the units in a tubular structure with a ladder design can be inconsistent.

[0208] Optionally, in this construction method, the first macrocycle (the macrocycle closest to the first large-volume end cap) may have specific functional groups. These functional groups can be used to bond to either the tip molecule or the cap molecule.

[0209] In cases where not all reactions have proceeded to completion, any known separation technique can be used to separate the completed tubular structure from the partially formed tubular structure.

[0210] Optionally, the bridges between adjacent macrocycles can be selectively cleaved. For example, when two bulky endcaps are attached to a template molecule, one or more bridges can be cleaved.

[0211] The advantage of arranging large rings in a "chain" or "ladder" orientation and then removing the bridges between the corresponding large rings is that, after removing the bridges, the large rings remain in a specific orientation. For example, the orientation can be a pattern where paired wide ends face each other, or paired narrow ends face each other, or a repeating wide-narrow pattern exists. As a result, certain types of association can be achieved after removing the bridges, which would not be possible without the previous orientation of the large rings. Some of these associations are described in the following examples.

[0212] Figure 5N The diagram illustrates two functional groups, S and T, located at the openings of two adjacent macrocycles within the same supramolecular structure, where a bridge will form between them. Although Figure 5NOnly one S and one T are shown in the diagram, but in some embodiments, more such groups may be present to form more than one bridge between two adjacent macrocycles. Furthermore, one or more bridges may have already formed before the bridge between S and T is formed. In some embodiments, both S and T are primary alcohols. The primary alcohols are converted to primary alkyl bromides, for example, by reacting them with NBS / PPh3. After the addition of a catalyst, carbon-carbon bonds are formed. This process can be carried out to create one or more bridges between adjacent macrocycles.

[0213] In some embodiments, a second type of bridge, an ether bridge, is formed between adjacent macrocycles. The process begins with each macrocycle containing a primary alcohol (S=T=primary alcohol). Next, only one primary alcohol is converted to an alkyl bromide, while the other remains a primary alcohol. A strong base, which is not a nucleophile, is added. The base removes hydrogen from the unreacted alcohol, thereby activating the primary alcohol for nucleophilic reaction. As a result, an ether linker is formed. The bromide salt formed as a byproduct can be removed and discarded. Similarly, the process can be carried out to create more than one bridge between adjacent macrocycles.

[0214] If, initially, both primary alcohols are converted to primary alkyl bromides during this process, the two alkyl bromides cannot react to form an ether bridge. Therefore, bromination must be reversed. NaOH base is added to convert one or both bromides back to the alcohol. At this point, the process can be repeated to form a molecular ether bridge, as discussed.

[0215] In alternative configurations, one of the alcohols can be converted into different leaving groups. One example is through reaction with a molecule of the Cl-S-O2-R type.

[0216] The conversion of two ortho-primary alcohols to an ether bridge can be carried out via acid catalysis. Catalysis can be performed with any acid. Lewis acids can also be used for catalysis.

[0217] If, for example, the narrow-sided natural primary alcohol is reacted, the process can be carried out to produce a large number of linkers, such as up to 6 narrow-narrow linkers for α-cyclodextrin or up to 8 narrow-narrow linkers for γ-cyclodextrin.

[0218] In some implementations, the formation of distinct bridges between different adjacent macrocycles can be carried out in sequential reactions rather than all at once, which may require reversing certain transformations before repeating one or more processes used to form the bridges. Each sequential reaction increases the proximity of the different parts of the macrocycle to each other, thus enabling subsequent reactions. This can be advantageous because the formation of one bridge may cause other opposing functional groups to come closer together, making reactions impossible when the macrocycles are simply complexed together on the template molecule. In this way, the macrocycles can be gradually “ratcheted” shut until a sealed structure is obtained.

[0219] In some embodiments, one of the macrocycles includes an arm in the form R-CH2-OH (=S), ending with a primary alcohol, or alternatively, S is a natural primary alcohol with an open macrocycle. The other macrocycle has only non-primary alcohols (=T, secondary alcohols, and / or phenols). Primary alcohols can be selectively converted to primary alkyl bromides using NBS / PPh3 or Br2 / PPh3 or other leaving groups. In cases where more than one bridge is formed, all primary alcohols may not be brominated at once. A non-nucleophilic base is added to remove the hydrogen from the non-primary alcohol. The activated alcohol attacks the bromide, and the result is the formation of two ether bonds. Two bridges can be formed in generally opposite positions in this process. The process can be carried out, for example, by reacting the narrow-sided natural primary alcohol with the wider-sided natural secondary alcohol to produce a large number of linkers, such as up to 6 narrow-to-wide linkers for α-cyclodextrins or up to 8 narrow-to-wide linkers for γ-cyclodextrins.

[0220] In some similar embodiments, in two adjacent macrocycles, each macrocycle is equipped with one or more arms (in the form of R-CH2-OH) and a non-primary alcohol at two generally opposite positions. The reaction is carried out as previously described to prepare the two bridges.

[0221] refer to Figure 5O In another embodiment, a branched bridge is formed. In this embodiment, two macrocycles (and / or tubular openings) are arranged adjacent to each other within the same supramolecular structure, each macrocycle may have the same functional groups (S=T). The macrocycles react with groups having the form X1-R1-X2-R2, which is also referred to herein as a "connector" type. X1 is a group capable of reacting with S or T but not with both. R1 is the bridge or a portion thereof. R2 is a long molecule, a dendritic moiety, or a dendritic polymer. The size of R2 allows the molecule to react with only one molecule of S or T. The bond between X2 and R1 can be selectively cleaved, allowing X2 to react with another branched molecule having at least three functional groups, some of which may be protected. After linking with X2, the other functional groups of the branched molecule can be used to form a linker with unreacted functional groups (S or T). This intermediate state is... Figure 5O The diagram in the middle illustrates this. Having more than one functional group increases the chances of reaction with that functional group (S or T). Alternatively, after attempting to link between the branched molecule and S or T, the remaining functional group of the branched molecule can iteratively react with other branched molecules, with occasional attempts to react with the remaining functional group S or T. As a result, the bridge can be constructed with any degree of branching as needed. Furthermore, as a result, the branched bridge can connect more than two groups, i.e., groups at the same opening can be connected in addition to two adjacent groups. This method can also be used to add more associations to the chain structure.

[0222] The process for producing the gap-filling layer, which will be described below, can also be used to form a branched bridge, which is also chemically associated with the shell of the tubular structure.

[0223] Figure 5P The schematic map illustrates the process of adding associations to an asymmetric tubular structure, such as a chain structure. A chain structure with only one linker is formed between adjacent macrocycles or units. A template molecule with only one tip associated with a bulky end-cap is then inserted into the asymmetric chain structure (forming a hemiroroline), thereby bringing the two openings of the two macrocycles connected by exactly one bridge closer together. Further association occurs using any of the reactions described above, and the template molecule is removed.

[0224] Figure 5Q The diagram illustrates another process for forming chain or ladder structures. Initially, a tubular structure is mixed in solution with template molecules attached to a bulky end cap. Another template molecule is added and bonded to the first template molecule, and a second tubular structure (here illustrated as a tip molecule) is threaded onto the elongated template molecule. The two tubular structures are then bonded to each other at two (or more) junctions, and the elongated template molecule is removed.

[0225] Figure 5R The figure illustrates another embodiment. In this embodiment, after the template molecule associates within the tubular structure, the bulk end caps of the template molecule are bonded to the tubular structure. The template molecule can then be extended (in... Figure 5R (not shown in the image), and can associate with another tubular structure (possibly asymmetrical), similar to... Figure 5Q As described in [the text]. Finally, the bulk endcap is removed from the tubular structure, and the template molecule is removed. The advantages of using a bulk endcap that associates with the tip of the template molecule and also with the opening of the tubular structure to add / form further associations within the tubular structure include that the solution used may not promote threading and / or make sonication possible.

[0226] Combination Figure 5P , Figure 5Q and Figure 5R One advantage of the described processes is that they can be used to elongate asymmetric tubular structures in solution. Such elongated asymmetric tubular structures can then be incorporated during channel construction.

[0227] Figure 5SThe diagram illustrates an alternative process for forming the "ladder". This process begins with two cyclodextrins, functionalizing two opposing groups on their wide sides and deactivating and / or protecting the remaining groups on the wide sides (e.g., via methylation). As part of this process, all functional groups on the narrow sides except for one can be temporarily protected. A bond is then formed between the two narrow ends of the cyclodextrin. This bond is selectively cleavable. Next, a rotaxane comprising a cyclodextrin dimer is formed, wherein at least one bond between the template molecule and the bulk end cap is cleavable. Finally, the bond between the two cyclodextrins is broken. The resulting structure is a polyrotaxane with the narrow end pointing centrally and the wide end pointing towards the bulk end cap.

[0228] Next, one of the processes described above is performed to form at least two ether linkages between the primary alcohols. The primary alcohols are spaced far enough apart from each other around the periphery of the cyclodextrin that they will react with alcohols or other functional groups on adjacent macrocycles, but will not react with each other within the same macrocycle.

[0229] Next, at least one large-volume end cap is selectively removed to generate a dimer.

[0230] The resulting dimer has open ends on both sides. These open ends can be further functionalized, for example, with two arms, each associated with a different open end, by reacting one such functionalized dimer with two unfunctionalized dimers, thereby enabling the formation of a chain. Using the method described above, this chain can be used as a precursor to supramolecular structures to increase association and form ladders.

[0231] C. Preparation on the substrate Figure 6A Figure 6H illustrates different processes in which tubular structures are formed on a substrate. In the illustrated example, the tubular structure is formed from monomers of macrocyclic rings bonded together. In an alternative embodiment, the tubular structure is formed from polymers previously prepared in solution.

[0232] exist Figure 6A In this process, template molecule 61 is attached to substrate 60. Figure 6B In this process, a saturated or diluted solution is used to thread the macrocycle 62 onto the template molecule 61. As a result, a polyquasi-rotaxane is formed, in which the macrocycle 52 is stacked around the template molecule 61 on the substrate 60.

[0233] refer to Figure 6C In the third step, a bulky end cap 63 is attached to the template molecule 61. This results in the formation of polyrotaxane.

[0234] exist Figure 6DIn this process, an outer bridge 64 is added to the space between adjacent large rings 62. As a result, a rigid structure is formed on the surface, which consists of large rings 62 connected via the bridge 64. The outer bridge 64 is also referred to herein as a crosslink.

[0235] Optionally, in Figure 6D In this process, a connector 66 is added to directly adhere the macrocycle to the surface 60. The connector 66 can be the same molecule as the bridge 64 or a different molecule, and they can adhere during the same or different reactions as the bridge 64.

[0236] In some implementations, as discussed, bridges between macrocycles are formed before threading the macrocycles onto the template molecule (i.e., Figure 6D The steps are in Figure 6C (This step is performed before the previous one). Therefore, the macrocycle is threaded in the form of a tube. For example, the tubular structure can be a dimer or trimer before it is threaded onto the template molecule. Then, the dimer or trimer is connected by bridging after threading.

[0237] In other embodiments, crosslinking can even be performed without the addition of a bulk end-cap. That is, an array of tubular structures containing polyrotaxane can be crosslinked without first forming the polyrotaxane, i.e., without the tips of the template polymer reacting with the bulk end-cap after the tubular structures are threaded. Such a process in the liquid phase has been described. This can also be carried out in the gas phase. Another approach is to thread the tubular structures around the polymer using a template polymer or a surface grafted with a template polymer, and chemically attach the tips of the tubular structures to the surface, with or without special activation after threading.

[0238] D. Asymmetric tubular structure As discussed above, this disclosure teaches the formation of a macrocyclic tube with a narrow opening at its tip, which enables filtration between small molecules. The macrocyclic α-cyclodextrin has an inner edge diameter of 4.5 Å. This diameter is still larger than the diameter of many molecules that are expected to be filtered, such as carbon dioxide and methane. Therefore, in order to use the macrocyclic tube as a filter, an even narrower opening must be attached to one of the inlets of the tubular structure.

[0239] In one exemplary embodiment, a narrower large loop (“tip” or “end cap”) is associated with the tip of a tubular structure consisting of a wider large loop (i.e., a large loop with a larger inner lumen). The tip is attached to the tubular structure, wherein at least two external bridges are positioned substantially opposite / relatively opposite each other at their openings or vents. The shell between the associated narrower large loop and the tubular structure is less permeable than the opening in the end cap, thereby ensuring that the material to be filtered enters the tube through the end cap. One or more medium-sized large loops can be used as bridges between smaller end caps and larger large loops. More than one end cap may also be applied, with its inner diameter gradually decreasing. A given end cap can be associated with the same tip of the tubular structure by different types of connections, wherein different bridges, their number, and different bridging positions can each produce tips with different parameters.

[0240] The modified tip exhibits a unique cavity, the shape and atomic composition of which, along with the diameter of its inner cavity, influences its selectivity and permeability to different materials. The flexibility of the tubular structure also plays a role in restricting or forcing the conformation of the macrocycles. An additional layer at the surface of the membrane can further contribute to this effect.

[0241] The tip of the tubular structure can be modified while it is already embedded in the membrane, or during / between different steps in its fabrication. The tubular structure and even a single macroring can be optionally modified before incorporation into the membrane, where the relative tips of the tubular structure / macroring may potentially be elongated, as previously described. Such a single-tip modified tubular structure can itself be incorporated into the membrane device or used as a surface for a membrane precursor at different fabrication stages.

[0242] Figures 4E-4J The figure shows macrocyclic molecules with similar structures but different inner diameters.

[0243] Figure 4E 15-crown-5, a crown ether with an inner diameter of 1.7 Å–2.2 Å, is depicted. This diameter is too small to be penetrated by gases expected to be filtered in embodiments of the invention. Figure 4F and Figure 4G Variations of the 15-crown-5 ether were depicted, in which the furan ring ( Figure 4F ) and pyran ring ( Figure 4G (Drawn around the oxygen atom.) Figures 4H-4J Variations of 15-crown ethers are described, which have additional groups attached to carbon-carbon bonds, such as alkyl carbons ( Figure 4H ), Aromatic rings ( Figure 4I ) or functionalized aromatic rings ( Figure 4J ).

[0244] Modification of crown ethers introduces subtle changes in flexibility and length. For example, the bond between the two aryl carbons ( Figure 4I , Figure 4J) than the bond between two alkyl carbons ( Figure 4H The diameter difference is approximately 14 picometers or 0.014 nm. This 14-picometer difference at the periphery translates into an inner diameter difference of less than 5 picometers. Further functionalization of benzene itself, such as the addition of nitro groups, can lead to even more subtle diameter differences.

[0245] Another crown ether, 18-crown-6 (a crown ether with six oxygen atoms), has an inner diameter between 2.6 Å and 3.2 Å. The pores of a membrane containing an 18-crown-6 derivative at the tip of its tubular structure are capable of separating gases with a kinetic diameter of 2.89 Å, such as hydrogen, from gases with diameters greater than 3.2 Å, such as methane and carbon dioxide. Due to different selectivity, such pores can also separate gases with diameters in the range of 2.6 Å to 3.2 Å.

[0246] To generate spacing in the range of 3.3 Å to 3.8 Å, another end-capped molecule can be employed, including but not limited to larger crown ethers. The macrocycle can have specific functional groups or compositions similar to those of the crown ethers described herein in order to produce a “second inner diameter” with picometer-level sensitivity.

[0247] In addition, optionally, and returning to the reference Figure 4A and Figures 5P-5R Various types of tubular structures can be prepared in solution. These include: a “lower” portion of the tubular structure composed of identical macrocycles with only minimal connecting portions; an “upper” portion of the tubular structure composed of identical macrocycles with substantial connecting portions; and a “tip” tubular structure comprising at least one tip molecule having a diameter narrower than that of the lower portion of the tubular structure. More generally, any combination of macrocycles of different widths can be included in the tubular structure.

[0248] In the illustrated embodiment, the pointed molecule is located at the end of the tubular structure. As discussed, the narrower molecule can also be located at the point in the middle of the tubular structure.

[0249] In the illustrated embodiment, a single “tip” molecule is present. In an alternative embodiment, a sequence of multiple “tip” molecules may be present, each “tip” molecule having a gradually narrowing diameter.

[0250] E. Removal of large-volume endcaps and template molecules exist Figure 6E In this process, large-volume endcaps and template molecules are removed. The stacked tubes of macrocycles remain on the matrix, possessing internal pores. Typically, this process is only performed after the interstitial filling layer is completed, and therefore, following a discussion of the interstitial filling, this paper further discusses the specific methods used for removing template molecules.

[0251] F. Direct attachment of the largest ring closest to the surface refer to Figure 7A The largest ring 72 closest to the surface (“first large ring”) can associate with the surface region 70 via the connector 71. This can... Figure 6D It occurs during the cross-linking process or in a separate process.

[0252] To achieve this attachment, the first macrocycle may have one or more protected functional groups, which can be activated to form such surface associations after one or more such associations with such residues using unprotected functional groups. Furthermore, the patterning of the surface of such tubular structures or even single macrocycles can be spatially controlled by bulky protecting groups present at different locations on the shell of the tubular structure. These protecting groups function similarly to the dendritic motifs of the template polymer, as discussed above. The protecting groups can be removed after surface association. The bulky protecting groups at the shell, or a portion thereof, should be understood in their broadest context as oligomers, polymers, dendritic motifs, dendritic polymers, branched polymers, oligomers / polymers that are too thick to be threaded through the tubular structure, or alternatively, their other tips associated with the bulky groups to prevent threading, and so on; that is, their association with the shell of the tubular structure is selectively cleaved without damaging the tubular structure, the surface, and the surface association. In some embodiments, such polymers at the shell are degradable under certain conditions, and not only is their association with the shell selectively cleavable. In some embodiments, after removing such protecting groups, the resulting functional groups can be used for extension of the tubular structure, reaction, and / or for use with precursors of one or more gap-filling processes and / or other different uses.

[0253] Figure 7B The schematic map illustrates a prototype tubular structure that can be directly used for surface patterning without prior patterning via template molecules. In such a case, it is desirable to form a shell with a tubular structure having functional group 73 that can be bonded to the surface.

[0254] Not Figure 7B All options presented must be implemented in a single embodiment. For example, groups 74, 75, and 76 all represent sites for containing bulky protecting groups as described above, and in embodiments, typically only one type will be used in a portion of the tubular structure—near its group (74) for surface association, at its opening (75) away from the surface substrate, or at its cap (76). The number of such groups may differ from that illustrated in the figure.

[0255] In some embodiments, there is no threading template molecule. In some embodiments, there is no selectively removable connector 78 between the opening and the cap 77 of the tubular structure.

[0256] If a threading template molecule is present, then Cap 77 must also be present. In this case, Cap 77 also serves as a large-volume end cap.

[0257] In some implementations, cap 77 is not present at all.

[0258] G. Extended Channel As discussed above, channels can be formed from tubular structures with different, small macrocyclic structural units. Channels can be further extended by associating them with more tubular structures to form extended tubular structures that are associated with the surface. The extension process can utilize supramolecular chemistry, such as threading template molecules. In some embodiments, the surface-associated tubular structure is extended beyond its surface-associated template molecules and may potentially thread another tubular structure, thus making the two tubular structures adjoint. This adjointness can be used to associate the two tubular structures.

[0259] The elongation process can occur once, for example, if one of the openings / tips of the added tubular structure is permanently blocked or narrowed, preventing the threaded template molecule from penetrating such an opening / tip. In such cases, the length of the portion of the template molecule extending out of the surface-associated tubular structure should be less than the length of the added tubular structure. Alternatively, the elongation process can be iterative, by adding and associating tubular structures one after another on the same template molecule (extending from the surface-associated tubular structure), optionally by repeatedly elongating the template molecule by associating it with another template molecule before associating one or more tubular structures.

[0260] Instead of directly chemically anchoring the tip of the tubular structure to the surface, a gap-filling layer or another layer deposited on the surface surrounding the tubular structure can be used to provide further association between the tubular structure and the surface (methods for producing such layers will be described later). Furthermore, the gap-filling layer can be iteratively thickened to associate the added tubular structure.

[0261] In some cases, the ortho-tubular structure can be chemically associated without forming a polyrotaxane, for example, if the resulting inclusion complex can be maintained for a sufficient time in a solvent suitable for a chemical reaction between the tip of the surface-associated tubular structure and the tip of the added tubular structure (the inclusion complex can be formed in one solvent, the surface dried, and the reaction formed in another solvent). Another option is to form the inclusion complex on the surface, dry the surface by evaporating the solvent (by heating and / or using suction and / or purging an inert gas from the surface), and expose the surface to a vapor of a gas that will promote the reaction (e.g., a non-nucleophilic nitrogen-base gas), or a powder of the added material. If this is not possible, then a polyrotaxane should be formed, and more group compatibility should be considered.

[0262] Another advantage of forming surface-associated polyrotaxanes is the ability to use sonication to remove physi-adsorbed tubular structures (if such tubular structures are present). However, by pre-selecting parameters—for example, by selecting the length and flexibility of the tubular structure associated with the surface via its tip (and not just by threading the template molecule to the surface)—so that the distance from its other tip to any potentially shorter added tubular structure that can also be physi-adsorbed to the surface is far enough, it is possible to avoid any tubular structure threaded by the template molecule to associate with the physi-adsorbed tubular structure. This consideration is also relevant if it is desired that the added tubular structures be 'long'—but adsorption to the surface means they are horizontally positioned—and therefore shorter than their 'full range'. After elongation due to association between the tubular structures, sonication can remove the physi-adsorbed tubular structures.

[0263] In some cases, even if an inclusion complex is formed, or if the polyrotaxane can be maintained in a solvent for a sufficient time to achieve the desired chemical reaction, it should still be formed. Therefore, heating and / or stirring and / or sonication can be performed so that the groups present at the adjacent tubular structures can come closer and react in order to associate the adjacent tubular structures.

[0264] The methods described in this section are also compatible with tubular structures containing cyclodextrins associated with each other via ethers and other bonds.

[0265] refer to Figure 8A The surface-associated template molecule 81a is threaded to provide a tubular structure 88a associated with the surface 80 via means 89. First, if the bulky group 83a has already associated with the tip of the template molecule 81a, it is removed to produce the functional group FG1.

[0266] Secondly, FG1 reacts with the functional group FG2 present in the introduced template molecule 81b, yielding an elongated, surface-associated template molecule 81c. The elongation of the template molecule can occur through any known mechanism, including click chemistry. The elongated template molecule can now thread one or more tubular structures. This is in… Figure 8B As shown in the middle figure, the tubular structure 88b is threaded onto the template molecule 81c, and the bulk end cap 83b is associated with the end of the template molecule 81c.

[0267] For example, if rotaxane / polyrotaxane is formed by generating a bulky amide (bulky group 83a) at the tip of the template molecule, the amide can be selectively cleaved under extremely basic conditions or by addition to LiAlH4 or amines (via carbonyl addition-elimination) or other processes. It should be noted that some bulky amides, such as FMOC, can be cleaved under milder conditions, such as tertiary amines. 2,4-Dinitroaniline can be selectively cleaved under extremely basic conditions. After cleavage, the amine can be further reacted to form a non-bulky amide, for example, to extend the template molecule. The additional tip of the template molecule can be functional (potentially protected) or non-functional (potentially unprotected).

[0268] Figure 8C Another way of connecting two tubular structures is depicted. The template molecule is depicted as associating with a bulky group, which facilitates further association between two tubular structures that are already partially connected (not specifically shown) and coaxial. Figure 8D and Figure 8E Another alternative solution was introduced. Figure 8D In this process, the thread-threading template molecule associates with a bulky group, which itself associates with the opening of the tubular structure. The thread-threading template molecule is threaded into the surface-associated tubular structure. Figure 8E In this process, the associated tubular structure is achieved by forming a reaction between two functional groups, FG1 and FG2, through association with the ends of template molecules that penetrate them.

[0269] An exemplary two-step method can be used to extend chemically anchored tubular structures to a surface (or through a gap-filling layer / another layer), and the surface-associated template molecules that are threaded through them also extend them. The added tubular structures have at least two functional groups at each of their tips, and are identical in both tips, such as primary alkyl halides / quasi-halides, while the surface-associated tubular structures have groups that can attack alkyl halides, with or without additional materials that promote the reaction, such as alcohols with added non-nucleophilic bases.

[0270] This method assumes that the reaction can be formed after the inclusion complex is formed, with or without drying and changing the solvent, or otherwise drying and exposing to the vapor of another material, such as the vapor of a nonnucleophilic base such as DIPEA or DBU to activate the alcohol, or with the addition of a nonnucleophilic base such as sodium hydride (NaH) powder.

[0271] If several added tubular structures are stacked on top of each other in the formed polyquadrorotaxane, they cannot react with each other, and the reaction can only occur between the surface-associated tubular structures and the first added tubular structure threaded by the template molecule, because the ortho-alkyl halides do not react with each other in the presence of a non-nucleophilic base.

[0272] After extension, sonication removes the remainder of the tubular structure. In the next iteration, tubular structures with only functional groups capable of attacking alkyl halides (e.g., alcohols) are added. This "AB cycle" can be repeated as needed.

[0273] Sufficiently long template molecules can be used in advance to form several iterations. However, since some inclusion complexes form within template molecules of a certain molecular weight range, it may be necessary to extend the template molecule itself from time to time. For example, aryl bromides do not react under conditions suitable for reaction between alcohols / phenols and alkyl halides. When such an aryl bromide-terminated template molecule has a tubular structure containing an alcohol / phenol rather than an alkyl halide, the Suzuki reaction (some schemes of which can occur in the presence of an alcohol) can be used to extend such an aryl bromide-terminated template molecule with a template molecule whose tip includes a derivative of arylboronic acid and whose other tip is an aryl bromide. It should be noted that, due to the process of this reaction, it is possible that the aryl bromide in the same molecule as the boronic acid derivative will not react during coupling with the surface-associated aryl bromide, and thus the proposed process can be repeated. Alternatively, an “AB cycle” can also be performed here, in which the template molecule is terminated by two arylboronic acids and the other template molecule is terminated by two aryl bromides.

[0274] If the template polymer is first elongated after the bulk groups of the protecting amine are cleaved, and the amine reacts to elongate the template molecule by forming amide functional groups, then the conditions should be chosen such that the amide does not attack the alkyl halide. First, the amide may be hindered and unable to react within its tubular structure. Second, only very strong bases can activate amides, while some alcohols can be activated by much weaker bases, especially some carbohydrate alcohols.

[0275] The surface may contain Si-OH groups or M-OH groups (where M is a metal). Such groups, especially in the presence of a base, can attack primary alkyl halides. However, the bonds formed are unstable and can be readily broken with water or small amounts of acidic / alkaline water, without breaking ethers formed, for example, during association between tubular structures. Pre-forming a protective monolayer on top of the oxide layer can also help avoid this. The protective monolayer may contain protected functional groups that can be activated in future processes.

[0276] In cases where polyrotaxane formation is necessary, another method can be used to extend the tubular structure. For example, in... Figure 7A In this process, the tubular structure is not only surface-associated via a template molecule. The functional groups on both the surface-associated tubular structure and the added tubular structure are primary alcohols. The tip of the template molecule in the surface association is an amine, and after forming the inclusion complex, polyrotaxanes are formed by reacting the amine with an activated ester associated with a bulky group to form an amide. Now, acid catalysis is used to condense the ortho-primary alcohol into an ether bond (e.g., by dehydrating ethanol to an ether bond with dilute sulfuric acid at 140°C, while avoiding heating to 180°C (where elimination occurs)). This process itself is repeatable. Primary alcohols at the same tip of the tubular structure should be sufficiently far apart to avoid intramolecular reactions.

[0277] Figures 8F-8I The diagram illustrates a process for extending tubular structures associated with surfaces. A second tubular structure containing template molecules is adhered to an existing tubular structure, such as... Figure 8F As shown in the diagram. Then, a connection is formed between the added tubular structure and the tubular structure already associated with the surface.

[0278] exist Figure 8G In this process, a portion of the tubular structure cleaves from the rest of the tubular structure, while the rest of the tubular structure remains in place. For this to work, the tubular structure (or a portion thereof) must be constructed with selectively removable bridges. Bulk endcaps are also removed, possibly accompanied by the removal of a portion of the template molecule.

[0279] exist Figure 8H In the process, the large-volume endcaps are removed, and the tubular structures that were not trapped within the interstitial filling layer are subsequently released, leaving small tubular structures from which the template molecules associated with the threaded surfaces extend significantly. New tubular structures can then be attached to the template molecules.

[0280] exist Figure 8I In this process, large-volume endcaps and template molecules are removed from the surface, leaving a tubular structure trapped within the interstitial filling layer. New, longer template molecules can be used to thread through this tubular structure and extend it after associating with its surface. Alternatively, it can be extended as shown in the previous figures.

[0281] The foregoing examples of the extension tubes represent exemplary embodiments, and other mechanisms may be employed without departing from the scope of this disclosure. Furthermore, strategies for extending tubular structures (described above) that can typically be performed in solution can also be performed on the surface of a porous substrate, and vice versa, although some methods may be more effective in another situation, depending on the circumstances.

[0282] H. Methods to enhance channel verticality First, choose a smooth substrate surface to promote perpendicularity.

[0283] Secondly, the surface density of the tubular structures can be adjusted so that they will meet each other and will not 'adhere' parallel to the surface.

[0284] Third, the functional groups at the outer shell of the tubular structure can react with groups such as bulky / rigid / robust groups to help ensure they remain upright. This can be done multiple times. Such groups can also be attached to bulky end caps. Furthermore, groups that have not reacted with the molecules can be reacted before the interstitial filling layer is deposited.

[0285] In another approach, the surface of the substrate can be protected so that the tubular structures cannot 'adhere' parallel to the surface. This can be done multiple times. This can be done after an array of tubular structures exists on the surface and / or only after the template polymer is attached to the surface.

[0286] In another approach, the tubular structure can be attached to the surface using protected functional groups (which can react with the surface) near one or more of its tips. For example, if the surface is gold, the thiol-protected groups at the tips can be cleaved, and the reaction with the surface will occur immediately. Further deactivation of the deprotected thiol groups that do not react with the surface may be necessary, especially if such groups are not only present at the tips of the tubular structure. Another example is if the surface (has nucleophilic groups / can become nucleophilic after activation) and the tubular structure have leaving groups near one or more of their tips (or vice versa). Adding an activator, such as a base (gas or liquid phase), will promote the reaction between the surface and the leaving groups on the tubular structure.

[0287] Finally, less flexible template polymers can be used. For example, there are macrocycles that can form inclusion complexes with PEG, but also with polyphenylene and other less flexible molecules.

[0288] V. Gap filling A. Theory Gap filling can be performed using any known deposition process. In an exemplary embodiment, the gap filling process is atomic layer deposition (ALD). Other suitable processes include molecular layer deposition (MLD), MVD, CVD, PVD, thermal deposition of metals, sputtering, application of titanium followed by its oxidation, metal deposition of gold, spin coating, and dip coating, including dilute solutions of nanoparticles (metal or ceramic) molten after coating and solvent evaporation. In similar dip or spin coating processes, polymer chains can be dissolved in the mixture. Combinations of different processes are also possible.

[0289] In some embodiments, the gaps between the tubular structures are filled through a chemical process, creating a layer of molecules (optionally an adhesive) that grow iteratively from the substrate and / or associate with the substrate between the tubular structures. In some embodiments, gap filling begins with a portion of the 'bottom portion'—a portion closer to the surface of the tubular shell—where the tubular structures are close to each other and cover the entire substrate. In some embodiments, a combination of the first two methods is performed.

[0290] In some embodiments, the gaps between the tubular structures are filled with inorganic materials, such as titanium dioxide, using atomic layer deposition (ALD). In some embodiments, the gaps between the tubular structures are filled with organic materials, such as cross-linked polyamides using molecular layer deposition (MLD). Alternatively, a mixture of organic and inorganic materials may be used to fill the gaps between the tubular structures. In some embodiments, the gap-filling material is also chemically associated with the tubular structure (not just the substrate). The selection of the gap-filling layer and its formation process depend particularly on its mechanical properties, density / impermeability, chemical stability, thermal stability, and its ability to embed the tubular structures without covering them from above and without obstructing their cavities.

[0291] The gap-filling process requires several functional outcomes. Clearly, to form membranes with picometer-level pore sizes, it is necessary to adhere the gap-filling layer to the sides of the tubular structure in a virtually hermetically sealed manner. The degree of sealing depends on the type of molecules being filtered. Furthermore, the gap-filling process needs to be tuned to ensure that the gap-filling layer does not bury the openings of the tubular structure.

[0292] To achieve these and other goals, there are various strategies for modulating the interface between the tubular structure and the gap-filling layer.

[0293] In one example, the tubular structure is formed with a shell that can improve embedding during the gap-filling process. The shell can include bulk molecules associated with the shell using thin connecting molecules. These bulk molecules can act as anchors within the gap-filling layer.

[0294] Template molecules within the tubular structure (when present) can also be used to determine the properties of the tubular structure-gap-filler interface. Specifically, the template molecules cause a reduction in flexibility and physically form a barrier within the tubular structure, preventing the gap-filler structure from having any voids for penetration and growth.

[0295] The properties of the interface can be tuned by selecting the shape of the ligands for the atoms used in the ALD process. The ALD process can use different ligands for the same atom and / or change the choice of ligands from time to time during the process to control the properties of the tubular structure-interstitial filling layer interface.

[0296] In some embodiments, atoms or molecules, or mixtures thereof, first associate with the surface to initiate the gap-filling process, while having more functional groups that can react with ALD / MLD precursors. In some embodiments, such molecules are dendritic motifs that associate with the surface via their stems, while their 'leaves' can react with the ALD precursor. Such embodiments can reduce the encapsulation of the bottom portion of the tubular structure during gap filling.

[0297] In some embodiments, functional groups and / or bulky end-capping groups and / or template molecules at the shell of the tubular structure are protected prior to the gap-filling process. The cavity of the tubular structure can be protected by template molecules that optionally associate with the surface and optionally with bulky groups at one end. In some cases, if the bulky groups at the ends of the threaded template molecules react with the ALD precursor, an open pore can still be obtained after the template molecules are released along with a portion of the tubular structure.

[0298] Although ALD is sometimes considered a special case of chemical vapor deposition (“CVD”), the term ALD should be understood with its broadest known definition and is understood to include processes that enable ALD growth even under wet conditions and combinations of wet and dry conditions, as well as catalytic ALD.

[0299] Between and during ALD / MLD cycles, scavengers or etchants can be used to regenerate functional groups present at the shell of the tubular structure, reducing the likelihood of burying the tubular structure during the gap-filling process. This process can also be referred to as “super-cycling.” For example, suppose that prior to the gap-filling process, each tubular structure comprises one or more exposed alcohols on its outer periphery. The surface of the substrate (e.g., Al₂O₃) comprises Al-OH groups. During the first stage of ALD, Al(O-CH₂-CH₃)₃ is added. These molecules react with the alcohol groups on both the tubular structure and the aluminum hydroxide to generate Al(O-CH₂-CH₃)₂ groups on both the tubular structure and the substrate surface, with ethanol as a byproduct. Phenol or ethanol is then added as a scavenger. Phenol or ethanol undergoes ligand exchange, thereby cleaving the aluminum groups from the tubular structure and restoring the alcohols on the tubular structure. Phenol can also replace ethanol in the Al-O complex at the surface of the structure. These phenol groups can subsequently be replaced by aluminum oxide by mixing with water before the next step of ALD.

[0300] In some embodiments, after filling the gaps between the tubular structures, the shell of the tubular structure associates with groups once or repeatedly to thicken the shell. In some embodiments, with or without initially thickening the shell, the shell may associate with the surface of the gap-filling layer. The former can be achieved by activating groups on the shell and / or removing the protection of groups on the shell, as well as by other means, such as reacting the surface of the gap-filling layer with molecules that can later associate with the 'bottom' of the tubular shell. In some cases, the former molecules can selectively detach from the surface of the gap-filling layer while maintaining association with the bottom portion of the tubular shell. The remaining functional groups can be used to thicken the shell. In some embodiments, further gap filling can then be performed.

[0301] In some implementations, an additional layer is deposited on top of the gap-filling layer to prevent chemical attack and limit adhesion.

[0302] In some implementations, the gap-filling layer can enter from inside the orifices of the final device and can affect the throughput through these orifices.

[0303] When appropriate, gap-filling processes can be used to intentionally cover tubular structures. If a surface is associated with tubular structures that are not of uniform length—for example, because some of them have been successfully elongated while others have not—the gap-filling process can cover (“bury”) the shorter tubular structures while filling only the gaps between the longer ones. This process depends particularly on the differences in length between the tubular structures, their perpendicularity, flexibility, the significant presence of functional groups at their openings, and other properties.

[0304] The gap-filling layer can also induce surface association with the tubular structure, for example, by embedding some or all of their structure and / or by chemical association between the gap-filling layer and the tubular structure. If, for example (and with...) Figure 7A (Different examples) Before the gap-filling process, the tubular structures are not directly associated with the surface, and they are only associated with it via rotaxane / polyrotaxane association, which can be taken advantage of.

[0305] Furthermore, the gap-filling process can provide coaxial association between adjacent tubular structures, with or without chemical bonding between such a gap-filling layer and the tubular structure, for example, by forming chemical bonds between the portions of the tubular structure closer to the surface and / or between bridges used to associate adjacent tubular structures (if such adjacent tubular structures exist) and / or between openings of adjacent tubular structures. Therefore, the process in which the tubular structure is first extended and then the gaps are filled can be repeated. After each instance of adding a tubular structure, the gap-filling process is performed to fix the new tubular structure in place. This gap-filling process can construct existing solid material to at least partially encapsulate the new tubular structure. Alternatively, the gap-filling process can form a new solid layer that is not attached to the existing solid material but itself serves as a connection between the original tubular structure and the new tubular structure in a manner similar to the "partial gap-filling" process described below.

[0306] The following examples illustrate specific methods that can be used in gap-filling processes.

[0307] 1. Precursor If the substrate is a metal that can react with thiols, such as gold, a pre-deposition that aids ALD initiation can be deposited (by solution or vapor). Examples of molecules that can be used for such deposition are molecular binders, such as HS(CH2)3Si(OMe)3, which have or do not have methoxysilane groups for further conversion to silanols. Such deposition can be accomplished in a series of several reactions—forming multilayers rather than just a single layer. Such deposition does not completely destroy the array of tubular structures. Another method for generating ALD initiation sites is to wet the surface with water and then dry the water from the tubular structures (this can work with surfaces that have a stronger affinity for water than the tubular structures). Some ALD precursors, such as TDMAT, can be deposited directly on certain metallic surfaces, such as gold.

[0308] The precursor used for depositing interstitial filling layers ideally does not possess the kinetic energy that could damage the tubular structure during surface reactions.

[0309] Water-oil interfaces can also be used to form gap-filling layers. If one part of the tubular structure's shell is more hydrophobic than another, it can aid in such gap-filling processes, for example, if the portion closer to the surface is hydrophilic and the portion farther from the surface is hydrophobic (and water and oil are formed accordingly). Ceramics such as oxides, as well as cross-linked organic polymers, can be formed at the water-oil interface.

[0310] For some tubular structures, the gap filling layer can have a synergistic effect (especially in tubular structures where the outer shell is not tightly sealed, for example if there is a long distance between adjacent large rings) and can affect the throughput through the orifice of the final device.

[0311] 2. Regioselective ALD for embedding tubular structures without forming bonds Regioselective ALD can occur if the tubular structure does not contain groups that can react with the ALD precursor and its corresponding leaving groups / ligands, nor groups that can form adducts (Lewis acid-base bonds) with them. Key parameters for controlling the outcome include: the mobility of the tubular structures, their length, their perpendicularity, their density, their shell permeability, their flexibility, and all conventional ALD parameters. If the process is carried out in the gas phase, the unreacted precursors must be removed from the surface by heating, vacuum pumping, or carrier gas purging.

[0312] Deposition can occur simultaneously or sequentially. Temperature can be varied from one sequence to another. Heating and cooling can be rapid or gradual. Different materials can be grown simultaneously. Layers of different materials can be grown on top of other layers.

[0313] For TiO2 as an example, its ALD precursors are typically classified from high to low reactivity: TiCl4, Ti-nitrogen ligands (such as TDMAT), and Ti-oxygen ligands (such as Ti(isopropanol)4, Ti-(OMe)4, Ti-(OEt)4, and Ti-(OBu)4). In the experimental results, regioselective ALD was performed using TDMAT in the presence of THP ethers and other groups containing tubular structures.

[0314] Through this deposition, the interstitial filling layer and the tubular structure have no chemical bonds, but the tubular structure is still completely trapped in the interstitial filling layer.

[0315] If the tubular structure is a polyrotaxane (with a macrocycle, a macrocyclic dimer, and / or a macrocyclic trimer, etc.), and only the bulk end cap contains groups that can react with the ALD precursor, then ALD can still be used because the template molecule will eventually be removed along with the bulk end cap and optionally along with the top portion of the tubular structure.

[0316] 3. Functional groups on the tubular structure of ALD used to form bonds at the surface If functional groups for ALD are present in the portion of the tubular structure near the surface, the formation of the interstitial filling layer can be accomplished without obstruction from above and with chemical bonds between the interstitial filling layer and the tubular structure. This method also enhances the compactness of the interstitial filling layer around the tubular structure.

[0317] One way to perform this method is as follows: After an array of tubular structures (with functional groups for ALD on their shells) is present on a surface, the surface can be deposited to form a layer of molecules containing protected groups (such a layer can be multilayered in more than one single process), which, upon activation by a small, possibly nucleophilic, base, can react with ALD. Then, by activation with a large base (potentially a non-nucleophilic agent, and such as an alkylating agent), the functional groups of the tubular structures above the surface and not masked by the previously formed layers can become inert to ALD (the yield may not be 100%, but it is high, so that very few tubular structures will be covered from above). A small base can then destroy the protecting groups and expose the functional groups to ALD at the surface, and further, not mask the functional groups at the tubular structures near the surface.

[0318] In some implementations, the tubular structures have a temporary, thicker shell in regions near the surface-associated portion to control their surface patterning. Specifically, the thicker shell may be shaped like a dendritic motif (a dendritic polymer?) (if dendritic polymer is the name of a dendritic polymer with accessible stems in a tree shape, then you are probably referring to a dendritic polymer) to help ensure minimal spacing between adjacent tubular structures when they are patterned onto the surface. After surface patterning has occurred, this temporary shell can be selectively removed, leaving residues (such as alcohols) that can form bonds with the ALD layer.

[0319] Another option is similar to the former, but in which such a thicker shell near the surface-associated portion is not temporary, and it has groups that can form bonds with the ALD layer.

[0320] Furthermore, it is evident that, due to the design, tubular structures can 'naturally' possess such groups near the surface.

[0321] Another way to obtain similar results is by using molecular layer deposition as shown below. This illustration assumes the surface is gold and the tubular structure has alcohols as functional groups on its shell. The steps include: A) reacting the gold surface to produce a structure with HS-(CH2) n -NH3Cl -A) Add a monolayer (and add a base to activate the amine). B) Add a molecule having at least three alkyl halides. Alcohols with tubular structures will not attack such alkyl halides, but amines on the surface will, for example, be attacked under conditions of a weak base. The unreacted material is then removed. C) Add a strong base, such as NaH, so that the alcohol will now attack the remaining groups of the alkyl halides near them (this will only happen near the surface if the tubular structures are vertical enough). The base is then neutralized. D) Add a molecule having at least two amines. E) Repeat steps B, C, and D until necessary.

[0322] This method has many variations. For example, H2N(CH2)3Si(OMe)3 can be used for oxide surface initiation. Thiols and phenols can be used instead of amines. Instead of forming an "AB" cycle with leaving and attacking groups, a molecule with at least three functional groups can be used, wherein at least one functional group is a leaving group and at least one functional group is a protected attacking group. The attacking group loses its protection after or during the reaction of the alcohol with the leaving group.

[0323] Another option is to use phenols and / or secondary alcohols on the tubular shell, while using molecules with at least three primary alcohols to create an interstitial filling layer. After the molecules with three alcohols react with the surface, the remaining primary alcohols can be selectively converted to primary alkyl halides and react with the phenol / alcohol in the tubular shell.

[0324] Another version uses a tubular structure with a small random percentage of functional groups in its shell, and then after the gaps are filled, some will be covered from above, some will not be covered from above and will have chemical bonds with the gap-filling layer, and some will be retained as a whole without chemical bonds with the gap-filling layer.

[0325] Another version uses tubular structures, where only one side of the tubular structure has functional groups that can react during gap filling. If the arrays are not created to distinguish which side is closer to the surface, some will be covered from above after ALD is performed, while others will not.

[0326] These two versions may require some minimum distance between adjacent tubular structures.

[0327] Another option is to create tubular structures on the surface, which are two tubular [3]rotaxane / quasi-rotaxane structures, wherein one of their tips contains a group that can react during interstitial filling, and the two such tips face each other in the middle of the [3]rotaxane / quasi-rotaxane. Interstitial filling will crosslink the tubular structures and also create an interstitial filling layer. If the original tubular structure is a polyrotaxane / polyquasi-rotaxane containing more than two such tubular structures, then after interstitial filling, only the two tubular structures closest to the surface will retain a portion of the final device after the template polymer is removed.

[0328] In all the embodiments described above, a protecting group may be present at the opening of the tubular structure. The protecting group protects the opening of the tubular structure from reaction during gap filling and is subsequently removed to enable the elongation of the tubular structure. After this elongation, the gap filling process can be performed again, and chemical bonds may also form between one or both of the openings of the tubular structure associated during the elongation. This can occur more than once.

[0329] If the tubular structure has the protected functional groups as discussed, the formation of the interstitial filling layer can be accomplished without obstruction from above the tubular structure and with chemical bonds between the interstitial filling layer and the tubular structure. After some deposition of the interstitial filling layer, deposition can be stopped, the protection can be removed, and deposition can then continue. This can occur at least once when different protected groups present at different locations on the shell of the tubular structure are utilized.

[0330] Bonding between the tubular structure and the interstitial filling layer can also be achieved through several means after the deposition of the interstitial filling layer, rather than during its deposition. One example is to make a bifunctional reaction, in which one functional group can react with the tubular structure and the other functional group can react with the surface of the interstitial filling layer (this can be accomplished in one or more steps with protected groups).

[0331] One way to do this is to deposit an interstitial filling layer if functional groups that do not react with the ALD precursor still exist in the shell of the tubular structure, and then perform a final (or final few) ALD cycle with another precursor that will react with the functional groups in the shell.

[0332] Another approach is to pre-convert the functional groups at the outer shell of the tubular structure into protected groups. After the interstitial filling layer is deposited, the protection can be removed, and the tubular structure and the interstitial filling layer can be chemically bonded.

[0333] Another approach involves creating a gap-filling layer on an array of tubular structures of the following type: rotaxane / polyrotaxane / quasi-rotaxane / quasi-polyrotaxane, wherein the threaded structure is not threaded over a large portion of the template polymer: A) No further consideration is needed.

[0334] B) Before and / or after crosslinking, the groups of the tubular structures are transformed and deactivated so that they do not react with the precursors of ALD.

[0335] C) Applying crosslinks between macrorings can also attach macrorings to the surface.

[0336] D) Apply crosslinking (anchoring, see above method) between the tip and surface of the tubular structure.

[0337] E) Alternating heating and cooling of precursors during exposure (heating to remove excess precursors—if heating reaches temperatures that cause loosening—rotaxane and polyrotaxane are preferred).

[0338] F) Deposit molecules (vapor or solution) onto the surface that can react with the ALD precursor and retain at least a portion of the tubular structure relative to the surface (with or without self-condensation between adjacent such molecules). This can be accomplished in multiple steps with or without protecting groups.

[0339] G) At low temperatures, interstitial filling layers are formed, such as macrocycles of alcohols with tubular structures whose polyquadrorotaxanes are stabilized by hydrogen bonding. ALD of TiO2 can be carried out below 80 °C with precursors such as Ti-(OR)4. At those temperatures, growth is indeed slow. Another option is to use the same precursor, but to perform ALD-like growth in a combination of vapor and solution. If the substrate is an oxide, the vapor of the titanium precursor is introduced into the device, and the residue is then removed under a nitrogen flow. The device is then immersed in liquid water (if water does promote the composite between the tubular structure and the template polymer), and the residue is removed under a nitrogen flow, and the process is repeated.

[0340] In another possible approach, the interstitial filling layer is generated on an array of tubular structures containing a template polymer that is not rotaxane. The template polymer is shorter than the cavity of the tubular structure. ALD can be performed using thread-facilitating conditions. For example, a solvent can be used to perform wet ALD that facilitates threading, or gas-phase ALD at a temperature that maintains threading, or a combination of wet and gas-phase ALD. Another option is to first associate the tips of the tubular structure by means of associating more template molecules than the threading surface.

[0341] In another possible approach, if the tubular structure does indeed contain groups that can react with the ALD precursor to form adducts (through the formation of coordination / addition / Lewis acid-base bonds), then regioselective ALD can be performed by exposing the ALD deposition AB cycle to a competing agent / scavenger / etchant to form a supercycle. For example, ethers on the tubular structure can form adducts with trimethylaluminum (TMA). Exposure to phenol following TMA exposure can form triphenylaluminum and methane. Aluminum from CH3 - Ligand exchange with phenolates reduces the acidity of aluminum (in terms of Lewis acidity). Upon subsequent exposure to water, alumina will form a regioselective deposition. This method is advantageous when heating is required, as heating will damage the tubular structure and / or the rest of the device to disrupt the adduct, and also expands the range of functional groups present on the tubular structure.

[0342] There exist cases where the tubular structure contains groups that can react with the ALD precursor to form covalent bonds (not coordinate / addition / Lewis acid-base bonds) or ionic / static interactions. For example, an alkyl alcohol on the tubular structure can form a bond (metal alkoxide bond) with TMA. Similarly, exposure of phenol following exposure of TMA can form triphenylaluminum and convert the metal alkoxide back to an alkyl alcohol. Aluminum from RO - Ligand exchange (where R is an alkyl group) to phenolate reduces the acidity of aluminum (in terms of Lewis acidity). In addition, molecules with similar affinity to those forming undesirable interactions can be added, but in large excess, to induce ligand exchange and / or competition with the undesirable interactions in order to release ALD deposition from the tubular structure itself.

[0343] If ligand exchange produces a metal-ligand complex that cannot evaporate from the surface, then this method can be applied to wet ALD.

[0344] While this method can make ALD regioselective, it may potentially form bonds between the tubular structure and the ALD layer (because the metal may be less accessible during interstitial filling). Thus, the interstitial filling layer can be deposited without obstruction from above the tubular structure, and bonds exist between the tubular structure and the interstitial filling layer.

[0345] 4. Specific strategies for controlling the interface between the gap filler layer and the tubular structure Retaining template molecules within the tubular structure during gap filling can be beneficial, as the template molecules prevent the ALD precursor from permeating into certain tubular structures. Furthermore, the choice of template molecule is important, as thicker template molecules can prevent permeation more effectively than thinner ones.

[0346] As discussed, the groups at the outer shell of the tubular structure (and the actual design of the shell) prevent the spacer filling layer from getting too close to the tubular structure. These groups can be protective groups, which can be removed later (some will be buried inside the spacer filling layer and will be inaccessible).

[0347] If the interstitial filling layer is created via ALD, the deposition of the same material can be accomplished using more than one organometallic precursor. For example, if the desired material is Al₂O₃, Al(CH₃)₃ is not the only option; larger-volume ligands, such as Al(CH₂CH₃)₃, can be used. This method keeps the metal atoms at a greater distance from the tubular structure. They will also remain at a greater distance from the tubular structure after exposure to water to generate oxides. Combinations are also possible, i.e., simultaneously exposing a mixture of organometallic precursors and / or exposing pure Al(CH₃)₃ in one ALD cycle and pure Al(CH₂CH₃)₃ in other cycles. Another important factor is the condition and state of the ALD precursors under these conditions—some are monomers at certain temperatures, while others form dimers and even tetramers. These states can also affect the distance from the tubular structure.

[0348] Reducing the flexibility of the tubular structure facilitates the deposition of the gap-filling layer to better surround the tubular structure. This can be accomplished using one or more of the methods mentioned above.

[0349] Another method that can influence the interface is whether the tubular structure has groups that can react with the ALD precursor. Using small ALD precursors can also increase the tightness of the interstitial filling.

[0350] The interface between the gap filler layer and the tubular structure may be non-uniform. In some areas, the interface may be tighter or looser than in others.

[0351] B. Experimental Results Figure 9A Figure 9M illustrates the experimental results of preparing tubular structures and filling gaps on the surface covered with tubular structures using ALD.

[0352] The substrate used to demonstrate the following examples was 100 nm of gold (premium grade) coated onto a silicon wafer, with a few nanometers of chromium used as an adhesion layer between the gold and the oxide layer present on the Si-Cr-Au surface of the silicon wafer. The deposition method was thermal deposition or sputtering. After gold coating, the wafer was spin-coated with photoresist to protect the gold coating. The wafer was cut into 1 cm × 1 cm films. The films were held in Teflon-sealed containers. Before the experiment, the photoresist layer was removed by immersing the films in an acetone beaker under ultrasonic cleaning for approximately 3 minutes. The films were then washed with acetone, followed by isopropanol. The films were dried by purging with 0.3 μm filtered N2. The films were then cleaned under O2 plasma or a combination of O2 and inert gas (N2 or argon) plasma for 5–10 minutes. After plasma cleaning and until the start of the experiment, the films were stored in sealed vials containing deionized H2O covering the films. During sealing, the vial is purged with 0.3-micron filtered N2. The vial is then further sealed with a paraffin membrane.

[0353] Figure 9A Atomic force microscopy (AFM) characterization of plasma-cleaned Si-Cr-Au films is shown. All AFM characterizations were performed in air. The bottom of the figure is a graph illustrating the line profile of the layer across the length of the film. For the purpose of assessing height, peaks should be considered from the lowest measured height – that is, the “zero” height is the lowest height on the graph, not the height marked “0” on the scale.

[0354] The beaker (including its mouth and glass plate) was thoroughly cleaned with isopropanol and then washed with H2O. The beaker was dried by purging with 0.3-micron filtered N2 or by heating and then leaving it to cool under ambient conditions.

[0355] Except for immersion under heating, in all other cases, the beaker was sealed from above with a paraffin membrane, and the paraffin membrane was sealed around the mouth of the beaker with Teflon tape. In some experiments, the paraffin membrane sealing was performed under a 0.3-micron filtered N2 purging.

[0356] H2O is deionized and filtered out from micron-sized particles. The organic solvent is HPLC / MOS / CMOS grade.

[0357] Template polymer H2N-PEG 1.25k -NH2 is deposited onto the Si-Cr-Au surface to generate Si-Cr-Au-S-CH2-CONH-PEG. 1.25k -NH2 is completed in four steps: In the first step, the cleaned gold film is immersed in approximately 1-2 mg of HS-CH2-COO-PEG. 10k-OCH3 (COO indicates ester) was added to a diluted solution in 5 ml of H2O. The diluted solution was sonicated for several minutes before immersion. Immersion lasted approximately 10 minutes. After immersion, the membrane was washed with H2O and then sonicated for several minutes (using H2O as the solvent), followed by multiple washes with H2O.

[0358] In the second step, the gold film was immersed in a 0.1M NaOH aqueous solution for 10 minutes to allow for ester lysis. After immersion, the film and control film were washed with H2O and then ultrasonically cleaned for several minutes (using H2O as the solvent), followed by multiple washes with H2O. The vial was sealed and then additionally sealed with a paraffin film.

[0359] In step 3, a beaker (heated and then left at ambient conditions) after removing residue was filled with approximately 5 ml of acetone and 20-30 mg of 2-chloro-4,6-dimethoxy-1,3,5-triazine. This compound was added to convert the sodium salt of the carboxylic acid into the activated ester. The gold film was immersed in the beaker for approximately 15 minutes (optionally, a cleaning with acetone could be performed prior to this). The gold film was then washed with acetone, followed by washing with H2O, and then ultrasonically cleaned for several minutes (using H2O as the solvent), followed by more washes with H2O. The beaker used for ultrasonic cleaning was similarly cleaned of residue before placing the gold film into the beaker.

[0360] In the final step, the gold film is then placed in 5 ml of H2O and 1–3 mg of H2N-PEG. 1.25k -NH2(C 56 H 116 N2O 27 Immersion was performed for 15 minutes. Activated esters can react with amines to form amides. The beaker used was similarly cleaned of residue before placing the gold film into it. After immersion, the film was washed with H2O and then ultrasonically cleaned for several minutes (using H2O as the solvent), followed by multiple washes with H2O.

[0361] The polymer-coated surface was then immersed in a macrocyclic solution to generate polyquasi-rotaxanes on the surface. This process involved adding Si-Cr-Au-S-CH2-CONH-PEG. 1.25k The gold surface of the NH2 was immersed in a diluted solution of macrocyclic compounds (a few milligrams per few milliliters) to ensure complete immersion. The surface in the diluted solution was sonicated for 10 minutes and then held still for at least 1 hour prior to AFM characterization. Prior to characterization, the membrane was washed with H2O and then thoroughly purged with 0.3-micron filtered N2.

[0362] Figure 9BThe use of Si-Cr-Au-S-CH2-CONH-PEG in air was described. 1.25k AFM characterization of gold films containing α-CD polyquasi-rotaxanes with -NH2 as the template polymer on the surface. The bottom of the figure is a line profile, showing the presence of long tubular structures.

[0363] Next, the tip of the template polymer is reacted with a bulk end-cap to generate polyrotaxane on the surface. Approximately 25 mg of DNBS (sodium 2,4-dinitrobenzenesulfonate) is added to a beaker containing a few mL of the diluted macrocyclic solution. The solution is homogenized using sonication for several minutes. This mixture is then slowly and carefully added to the beaker containing the membrane (after keeping it still in the diluted macrocyclic solution for 1 hour). The beaker is left still overnight. In the morning, the beaker is gently stirred occasionally over a period of several hours. Immersion is stopped, and the membrane is washed with H2O and then sonicated for several minutes (using H2O as the solvent), followed by further washing with H2O.

[0364] Figure 9C XHR-SEM (Super-Resolution Scanning Electron Microscopy) characterization of a gold film of polyrotaxane with methylated α-CD in air was depicted. DNBS was used as a large-volume end cap. The sample is shown at 200,000x magnification. The sample was tilted at 45° to enhance the contrast between the tubular structures (small protrusions on the surface with electron shadows underneath) and the surface itself. As can be seen, the surface is covered with numerous vertical tubular structures.

[0365] Figure 9D A top view, with higher magnification, depicts the tubular structure. The top view does not provide as much contrast; however, it indicates the width of the tubular structure. Figure 9D At the bottom, AFM provides a view of another sample prepared using the same procedure.

[0366] Figure 9E AFM and XHR-SEM characterization of a gold film containing polyrotaxane with α-CD-OCH3 in air are shown. Specifically, all 18 alcohols in each α-CD are converted to O-methoxy groups. Some of these are highly parallel to the template polymer (PEG). 1.25k The length of DNBS. DNBS is used as a large-volume end cap (it looks like a version of 3 nm TiO2 after ALD...).

[0367] Of the eleven polyrotaxanes shown in the AFM plot, nine were measured. Combined with another region of the sample (where eleven polyrotaxanes were measured), the average height of the 20 polyrotaxanes was 11.1 nm. Note that the actual length of the stretched template polymer plus the bulky groups associated with its tip should be close to 11 nm.

[0368] After the tubular structure is formed, ALD is performed.

[0369] Table 1 summarizes the ALD procedures performed. The membranes are held in the chamber of the ALD (Atomic Layer Deposition) reactor for several minutes at a final temperature and a final vacuum to allow for cleaning. Differences in growth rates using the same metal source are most likely due to the conditions under which they are held, as different systems are used for different deposition processes.

[0370] Prior to ALD, the membrane is briefly immersed in a moderately alkaline aqueous solution (NaOH is the base used) to neutralize any possible acidic leaving groups on the polyrotaxane.

[0371] Program 1 was run on the Fiji ALD system. Program 2 was run on the Savannah ALD system.

[0372] Figure 9E The use of template polymer PEG is shown. 1.25k AFM characterization of a gold film deposited with polyrotaxanes (with α-CD-OCH3). DNBS was used as a bulk end cap, followed by ALD of 3 nm TiO2. Ten polyrotaxanes shown in the AFM were measured, and combined with two other polyrotaxanes measured in another region of the sample, resulting in an average height of 7.8 nm for the 12 polyrotaxanes. Note that the average height difference between these polyrotaxanes and those not deposited via ALD is 3.3 nm, which approximately corresponds to the 2.9 nm growth characterized in the control. Figure 9F and Figure 9G Views of the same sample were depicted using XHR-SEM.

[0373] Figure 9H The use of template polymer PEG is shown. 1.25k AFM characterization of gold films deposited with polyrotaxanes (with α-CD-OCH3). DNBS was used as a bulk end cap, followed by ALD of 6 nm TiO2. The ALD procedure is number 2 in Table 1. The average height of the 11 polyrotaxanes measured in the AFM region was 4.7 nm. Note that the average height difference between these polyrotaxanes and those not deposited by ALD was 6.4 nm, which approximately corresponds to the 6.1 nm growth characterized in the control. Figure 9I and Figure 9J Views of the same sample were depicted using XHR-SEM.

[0374] Compare surfaces that only have tubular structures ( Figure 9D ), with a surface having tubular structures deposited by 3 nm ALD ( Figure 9F and Figure 9G ) and a surface with tubular structures deposited by 6 nm ALD ( Figure 9I and Figure 9J The XHR-SEM view of the tubular structure is particularly useful. The comparison figure shows the decrease in contrast between the tubular structure and the surface, reflecting the surface rise caused by ALD, which reflects the gaps in the filling.

[0375] Figure 9K and Figure 9L The use of template polymer PEG is shown. 1.25k XHR-SEM characterization of the gold film containing α-CD polyrotaxane. DNBS was used as a bulk end-capping agent. The alcohol in α-CD was not methylated, allowing ALD to react with the tubular structure. ALD was then performed on 6 nm TiO2. The ALD procedure is number 2 in Table 1. The images clearly show the ALD reacting with the entire surface, including the polyrotaxane covering from above, which differs from the growth mechanism of polyrotaxane containing α-CD-OCH3, in which ALD only fills the gaps between the polyrotaxanes.

[0376] Therefore, the experiments first demonstrate that tubular structures can be constructed on the substrate in the described manner. Furthermore, the experiments demonstrate that if the tubular structures do not react during the ALD process, ALD can be performed to fill the gaps while maintaining the integrity of the tubular structures.

[0377] VI. Other processes A. Extraction of template molecules In most of the embodiments discussed above, the tubular structure forms around the template molecules. To allow material to pass through the tubular structure, it is necessary to remove the template molecules.

[0378] Template molecule removal can be achieved by treating the patterned surface regions with a material capable of selectively separating, dissociating, or removing the template material without affecting the stability or integrity of the tubular structure. Alternatively, the template molecules can be decomposed or dissolved without affecting the stability or integrity of the tubular structure. Chemical or physical methods or conditions enabling the decomposition, dissolution, or loosening / releasing of template molecules include heat treatment, the use of solvents or etching solutions, acoustic / ultrasonic treatment, and others such as the flux of material through the membrane.

[0379] Template molecules act as the binding agents for the tubular structures, ensuring their coaxial stacking. In the event of template molecule removal, a gap-filling layer is used for this purpose. In some embodiments, a portion of the tubular structure is also released along with the template molecules. For complete release of the template molecules, the template molecules should not even have a single functional group capable of binding to an internally accessible functional group of the tubular structure. In some embodiments, only some template molecules are completely released, while others are not fully released due to the former or any other issues. In some cases, portions of the template molecules used for such association can be further modified to release the template molecules due to etching of the substrate or a portion thereof.

[0380] In some implementations, template molecules are released without etching the substrate or a portion thereof.

[0381] In some implementations, if the template molecule / tubular structure is used for surface association of the tubular structure, it is also necessary to remove the cap from the tubular structure or remove the bulk end cap from the template molecule / tubular structure.

[0382] B. Etching of the sacrificial layer or attachment to the permanent substrate In an embodiment where the tubular structure is formed over a pore filled with a sacrificial material containing a permanent substrate ( Figures 1A-1H The sacrificial material is etched, leaving openings. The final etching is selective. For example, when the sacrificial material is gold or a gold alloy, iodine can etch gold / gold alloys without etching porous metal / silicon oxide, tubular structures, and layers filling the gaps between the tubular structures. The alternative etching processes have been discussed above in conjunction with the substrate description.

[0383] In an embodiment where the tubular structure is formed on a substrate that is not a permanent substrate ( Figures 2A-2D The embedded (surface) tubular structure layer is attached to the permanent substrate, or the permanent substrate is deposited on the embedded layer.

[0384] C. Etching of the gap filling layer Optionally, the interstitial filling layer can be etched to some extent (selectively or non-selectively) from the side closer to the initial substrate. If the interstitial filling layer is made of an oxide (TiO2, for example), this can be achieved by using an extremely diluted HF buffer solution. This potentially exposes the tubular structure better and increases accessibility. It can also increase the distance between the interstitial filling layer and the opening of the tubular structure, which can reduce molecular adhesion to it. This can also be achieved not only by slow, non-selective etching, but also by depositing two layers as the interstitial filling layer (first Si3N4 and then TiO2), and then removing the first layer or a portion thereof by selective etching after fabrication of the device (in this example, Si3N4 is less stable to HF vapor than TiO2). If the initial substrate is a metal such as gold, another option is to evaporate the gold before depositing the interstitial filling layer (gold adheres rather selectively to gold). This gold will be etched along with the gold on the initial substrate.

[0385] If a monolayer is deposited to induce an ALD for producing a gap-filling layer, and cleavable linkers exist within the molecules of the monolayer, then cleaving the cleavable linkers can also increase the distance between the gap-filling layer and the opening of the tubular structure.

[0386] D. Other modifications Protective groups at the shell and / or opening of the tubular structure can be removed and further modified. Reasons for protection / removal / modification after removal of protection may include promoting the selective formation of molecular bridges, which are no longer needed after the tubular structure is completed, and introducing anti-sticking groups to promote the patterning of the tubular structure, as will be discussed further herein.

[0387] The tubular structure can be disrupted using combustion / plasma / acid / etching to leave channels formed only by the surface. In such cases, the channels can be completely inorganic. Such pores can also be modified using, for example, atomic layer deposition (“ALD”). A gentle etching can be performed to achieve a specific diameter later, before altering the diameter by methods such as ALD that shorten it.

[0388] The sides of the encapsulated membrane can be sealed to prevent flux leakage from the sides.

[0389] E. Modification of tubular structures When the tubular structure reacts with protecting groups before initiating ALD, these protecting groups can be removed.

[0390] For example, Teflonization (protection with an anti-stick layer) can be performed before ALD. Teflonization involves reacting with fluorinated / perfluorinated compounds to prevent scaling / adhesion and increase the chemical stability of the tubular structure. Such modification can occur at the shell / orifice of the tubular structure, the surface of the interstitial filling layer, and combinations thereof. Such modification can involve reacting with a compound that has a Teflon portion near the portion that will react with the surface of the shell / orifice and / or interstitial filling layer of the tubular structure, and the portion further away may be water-soluble. Such Teflonization can also prevent ice formation on the membrane surface.

[0391] As discussed, the shell can react with the protecting group prior to ALD, which is subsequently cleaved. Cleavage may be desirable because if the bulky groups react with the reformed groups, or if the reformed groups react sequentially, they may affect the diameter of the tubular structure (e.g., reduce the diameter) and / or affect the flux through the tubular structure. Furthermore, they may affect the interface between the tubular structure and the interstitial filling layer.

[0392] Alternatively, some groups do not require protection before ALD / interstitial filling and can be reacted thereafter.

[0393] VII. Tubular structures are constructed after the initial deposition of solid materials. A. pit In the foregoing discussion, the method described herein is used to produce a tubular structure with through holes. In an alternative embodiment, the resulting structure is a recess with a solid bottom.

[0394] Figure 10A A schematic diagram illustrates the process for creating the pits. The process is performed using a substrate 100, to which a template polymer 104 has been attached, and a tubular structure 102 has been constructed, with a large-volume endcap 103 at the top of the tubular structure 102. Then, gap filling is performed as discussed. The tubular structure and the large-volume endcap are then removed, leaving template molecules associated with the bottom of the open pits.

[0395] In cases where all tubular structures are selectively removed, with or without selective removal of bulky groups (if such bulky groups are present), only the surface-associated template molecules remain inside the pits / pores. Note that non-flexible / rigid template molecules will not necessarily curl into the pits obtained after removing the tubular structures and bulky endcaps. The ends of the template molecules can associate with another molecule.

[0396] Subsequently, in some embodiments, a portion of the template molecule 104 is selectively removed, leaving long or short residues, a single residue per pit. The resulting residues can associate with another molecule, which can be very rigid. Some molecules may be more difficult to associate with others, thus an “AB cycle” can occur, where only a portion is associated at a time. If the reaction is with bulky terminal groups that cannot enter the pits between “AB cycles,” the uniformity of length can be increased, thus making association possible after the elongated molecule is long enough to extend out of the pit. Such bulky terminal groups can be removed before the final desired association.

[0397] In some implementations, the entire template molecule is removed by heating and / or oxidizing the surface, leaving a surface with hollow pits. The bottom of the pits may be made of a different material than the material used to fill the gaps between the tubular structures, thus obtaining a surface patterned with pits.

[0398] In some implementations, an additional layer may be deposited on top of the gap-filling layer before pit formation. Such a layer can be used in different processes, as described later. In some cases, this layer has protected functional groups.

[0399] The former method can be used not only to generate surfaces with empty pits, but also to generate surfaces with pits containing a single molecule for each pit. This can be achieved, for example, by using rod-shaped branched polymers / dendritic polymers, where the linkers between the main backbone chain and the branched / dendritic units are selectively cleavable, such as... Figure 10B As shown in the diagram. Figure 10B In this process, rod-shaped dendritic polymers associate with bulky groups. The gaps between these polymers are filled, and the dendritic units 105 can be selectively removed from the backbone chain. In some cases, the branched / dendritic units are also degradable under certain conditions, and their links to the backbone chain are selectively cleaved. If the resulting backbone chain is suspected of curling into pits, and it is desirable to prevent this, association with the bulky groups can prevent this. It is required that the bulky groups be larger than the resulting pits.

[0400] In some embodiments, the surface is patterned via functional groups at its stem using uniformly dendritic motifs. The gaps are filled, and the dendritic motifs are subsequently selectively etched to leave residues in each pit. Alternatively, the dendritic motifs can be completely removed to leave empty pits. Tubular structures containing even a single macrocycle (modified at its two openings) can be used for such patterning with or without template molecules.

[0401] Surfaces patterned with recesses can be used to associate tubular structures with the bottom of the recesses via single or multiple functional groups at the openings of the tubular structures. In some cases, the size of the recesses allows for the association of only a single tubular structure with each recess. The size of the recesses can contribute to the fundamental perpendicularity of the tubular structure. Surface association of tubular structures can also be achieved using template molecules associated with the bottom of the recesses.

[0402] In some embodiments, a layer may be deposited before pit formation. Such a layer may have non-stick properties, reducing the physical adhesion of the tubular structure to the surfaces between the pits, thereby enhancing accessibility to the pits. In some cases, even the non-stick coating may have protected functional groups. Unprotected functional groups may be used after association with the surfaces of the tubular structure, for example, to fill the gaps between the tubular structures. In some embodiments, a loosely stacked non-stick layer may leave pathways to sufficient surface sites for initiating gap filling. These two approaches may be combined. In some cases, only localized gaps between the tubular structure and the pit associated with it are filled. Depositing a monolayer on the bottom of the pit can enhance this gap filling and also enhance coverage of pits with no tubular structure associated with them. Other possible embodiments exist in which localized gap filling may be used, as described later.

[0403] Figure 10C The steps for filling the local gap between the tubular structure and the pit to which the tubular structure is associated are described. In this scheme, the tubular structure is associated with the bottom of the pit using a single connector between the opening of the tubular structure and the bottom of the pit. Diagonal 106 represents a layer that blocks growth. A local gap-filling material 107 is added around the top of the pit.

[0404] Associating a single molecule (which can be a tubular template molecule or another type of molecule, such as a rigid molecule) into an empty pit can be accomplished by associating a single residue with each pit and later associating that residue with another molecule. If the size of the dendrite and the pit size do not allow more than one dendrite to associate within the pit, a dendrite with selectively cleavable chemical bonds near its stem (where the tip of the stem has a single functional group for surface association) can be used to associate a single residue in each empty pit. The size of the dendrite and the size of the pit can guide association to the center of the pit to some extent. In some cases, the dendrite is also degradable under certain conditions, and it is not just a linker between its atoms that is selectively cleavable. Another method to guide the association of a single template molecule relative to the center of the pit is by growing a sacrificial layer around the pit. This may require forming another sacrificial layer at the bottom of the pit before the sacrificial layer is formed around the pit. In any case, after the sacrificial layer is formed around the pit, the bottom of the pit should be empty. Template molecules can associate with pits and selectively remove the sacrificial layer around the pits.

[0405] The surface, which contains a single molecule in each pit, can be further modified to enhance the embedding around such molecules. This surface can be rigid or flexible, with associated bulk groups at its ends. This can be done via another step of ALD. In some embodiments, particularly where such molecules are flexible, ALD can be performed under solution conditions, combined with stirring and / or acoustic / sonic treatment to stretch the molecules. In some cases, the end-associated bulk groups are also magnetic, and the molecules can be stretched by applying a magnetic field. In some cases, a layer is deposited before the pits are formed. Such a layer can block further ALD growth, thus guiding the gap filling to surround such molecules more without covering them. Note that in some cases, such embedding around molecules with non-tubular structures can be obtained simply by performing a gap-filling process without covering the top of such molecules onto a surface associated with a tubular structure threaded by a molecule associated with another molecule, or alternatively, a structural analog of a tubular structure associated with another molecule at its 'top' end. Such surfaces can be used for further steps, as they are embedded in tubular structures to form a membrane.

[0406] Figure 10D The diagram illustrates the steps to enhance the embedding of molecules. The diagonal lines represent layers that block growth.

[0407] The surface containing a single template molecule in each pit can associate with the tubular structure by forming an inclusion complex. In some cases, the opening of the tubular structure can reach the bottom of the pit, while in others it cannot. In some cases, the pit becomes narrower towards the bottom, for example, because the tubular structure or its structural analogue used to create the pit is wider in its upper portion, so the inclusion complex introduced between the tubular structures can reach a certain part within the pit. Another case that would lead to the former is when some of the outer shells of the tubular structure are wider.

[0408] Figure 10E The figure shows the different levels of containment of tubular structures 108a-108d within the pit.

[0409] Note that different conditions can cause the tubular structure to be wider in some parts. Figure 10E (The rightmost sketch in the image). It's possible that the tubular structure is wider in some sections, and the cavities in those sections are also wider. In this case, threading with template molecules might be impossible due to the varying ability of the cavities to form inclusion complexes. In another case, it's possible that all sections of the tubular structure will be able to form inclusion complexes with the template molecules because the cavities are identical, and some sections are wider due to differences in the shell.

[0410] As discussed, pits can be used to form various tubular structures. Figure 10F The following diagrams reveal some of the additional mechanisms used in this process.

[0411] Figure 10F The figure shows a basic schematic cross-section of the structure remaining after the removal of the tubular structure or another material used to form the pits. The composite substrate 801 has gold 802 filling the pores therein. The top of the substrate is covered with a gap-filling layer 803, which may be titanium dioxide. The pits 804 are located at the sites where the tubular structures were previously constructed.

[0412] Figure 10G A second possibility for generating the pit was disclosed. In this possibility, the tubular structure is removed from the pit, but the template molecule 805 remains.

[0413] Figure 10F and Figure 10G What they have in common is that the pits have a significantly narrower diameter than the pores in the composite substrate on which they are arranged. The diameter of the pits can be, for example, around 2 nanometers, or even smaller. In fact, sometimes two pits 804 can fit within the region of a single pore. It is significantly easier to incorporate a tubular structure surface, including asymmetric tubular structures, into pits of this size compared to the original pores of the composite substrate. (As in...) Figure 10HAs can be seen, the tubular structure 806 (with a large-volume end cap 807) can be selected to be wider than the tubular structure or other material used to create the pit 804. As a result, the tubular structure 806 can be bonded to the gap-filling layer rather than to the base of the pit 804.

[0414] Figure 10I The figure illustrates the adhesion of an asymmetric tubular structure 809 to a pit structure, and specifically highlights the benefits of protecting the deposited interstitial filling layer in doing so. In the upper left of the figure, a tubular structure with template molecules within the pit is shown, as in... Figure 10G In the upper right corner, the same structure is shown, featuring a monolayer 808 adhered to it. The monolayer can be polytetrafluoroethylene (PTFE) or any other fluorinated molecule. The monolayer can also have a surface—Si-CH2-CH2-X—to which a tubular structure can bond, where X is a leaving group. The monolayer helps ensure that the tubular structure adheres only to the template molecule, as shown on the upper right of the figure, rather than to the surface, as shown on the lower left of the figure.

[0415] B. Local gap filling Local gap filling can be used optionally, independent of the layer structure (i.e., tubular structures as in most of this disclosure, or pits as immediately following the previous section).

[0416] Localized gap filling can also be used if a surface with defined and uniform pores is selectively filled with another material within its pores. A tubular structure can associate with the surface of the filled pores. Then, a layer can be grown on the shell of the 'bottom' portion of the tubular structure. This layer is then associated with the surface between the filled pores. Finally, the material filling the initial pores is selectively removed. Note that filled pores that do not associate with the tubular structure can associate with layers to cover such future pores, thus blocking them after the materials filling them are selectively removed.

[0417] exist Figure 11 Another embodiment is illustrated, in which localized gap filling can be used. A pristine porous material 110 with defined pores is filled with another material 111. A tubular structure 112 is associated with the surface of the filled pores, including a bulk endcap 113 and template molecules 114, followed by a layer 115 grown around the shell of the tubular structure. This layer is then associated with the pristine surface 110, followed by selective removal of the material 111 filling the pores. The template molecules and / or bulk endcaps may be removed if such template molecules and / or bulk endcaps are present. This may also be feasible for asymmetric tubular structures.

[0418] VIII. Application While the materials described in this article can be primarily used for filtration (extracting smaller substances from mixtures), as discussed above, other applications are possible.

[0419] The structure formed by the process described herein alters the surface properties of the substrate. Surface properties that can be altered by constructing channels in the surface region can include surface roughness, increased surface area, hydrophobicity, hyperphobicity, hydrophilicity, wettability, surface area, electrostatic shielding, anti-stick properties, antifouling properties, anti-icing properties, self-cleaning, and any one or more of the following.

[0420] While the typical flow path of materials is from the “inlet” to the “outlet” of the channel, with the inlet located at the tip and the outlet at the pore of the substrate, reverse flow can also occur, such as in a process known as “backwashing”.

[0421] Non-limitingly, conditions affecting the passage through the membrane at different sides include: pressure difference, partial pressure difference, suction applied from one side and / or pressure applied from the other side, the presence of an adsorbent (chemisorbent and / or physisorbent) on one side, chemical reactions (including flare combustion), temperature difference (including temperatures low enough to liquefy / solidify gases), and combinations thereof.

[0422] Without limitation, the apparatus of this disclosure can be used in one or more of the following applications: Adsorption and extraction. Some macrocycles have a known ability to adsorb certain materials. Therefore, membranes containing macrocycles, primarily using suction from one side of the membrane, may potentially increase the amount of adsorbed material on that side of the membrane. Examples include: cyclodextrins and rare gases, molecular traps and argon, columnar aromatics and carbon dioxide, and calixar [4] aromatics and NO. x Gas nanotubes.

[0423] Sometimes, if both materials are smaller than the pore size, then considering the mixture of the two materials, the larger material will preferentially permeate through the membrane.

[0424] catalytic. If at least one product is smaller than all reactants, its removal (potentially sequential) may alter the equilibrium of such catalysis. Examples include: 0.5N₂ + 1.5H₂ NH3, 4H2 + CO2 CH4 + 2H2O, 3H2 + CO2 CH3OH + H2O and others. In other reactions, hydrogen is released from its support (which may be organic or liquid) or produced by the reaction of CO with steam. Utilizing this known phenomenon (Le Chatelier's principle), membranes can be coupled to the reactor, for example using catalysis, under conditions of suction from one side and / or pressure applied from the other, to separate / extract products from the reactants in real time and influence equilibrium. This can save energy by enabling catalysis to take place under milder conditions and thus better preserve the catalyst. It can also simplify the separations required for production.

[0425] The catalyst can be associated with the opening of the tubular structure, and catalysis and separation can be coupled by suction / applying pressure / both.

[0426] The passageway is through the tubular shell incorporated into the membrane. This involves blocking the entrance to the pores present at the tips of the tubular structure of the membrane, allowing passage only through the shell of the tubular structure. These blockings can be temporary or permanent by several means. One means is to react the group present only at the tip of the tubular structure with the group blocking its entrance (a sequential reaction may be required). If the group is protective, the blocking can be temporary. Another means that can be used, particularly if the group present at the tip of the tubular structure is also present at other locations, is to form an inclusion complex between the tubular structure and the template molecule, which has a bulky group attached to one side. Such an inclusion complex may be temporary and may need to be formed periodically. If the bulky group has a functional group that allows it to react with the group at the tip of the pore, this blocking can be permanent. However, if the linker between the bulky group and the tip is selectively cleavable, this blocking can be temporary. A pathway through the shell of the tubular structure may be of interest if, for example, an ortho-macrocycle is associated through a bridge that is itself a macrocycle, or if a pore of interest is formed.

[0427] A unique example of 'conditional blocking' is achieved by using a 'molecular valve' on one side of the membrane, thus allowing passage only from one side to the other. This can be accomplished by attaching a template polymer to one side of the membrane.

[0428] Note that one of the functions of the shell of the tubular structure is to prevent the deposition of the gap-filling layer within the tubular structure. Therefore, a tubular structure containing the shell of interest can be associated with a tubular structure already incorporated into the gap-filling layer.

[0429] Sensors / Identification.Surfaces serving as membrane precursors, such as those associated with tubular structures, can be used as sensor platforms. The tubular structures, even with some flexibility, are generally perpendicular to the surface and thus distanced from the surface and its potential contaminants. In some embodiments, the surface is modified to have anti-stick / anti-fouling / anti-icing properties, for example, by associating with hydrophobic / superhydrophobic / hyper-hydrophobic compounds (hydrocarbons / fluorocarbons / perfluorinated compounds), while the shell of the tubular structure is associated with antibodies / macrocycles / single-stranded DNA or RNA. In some embodiments, antibodies / macrocycles are associated with bulky endcaps, and the surface and / or shell of the tubular structure are modified to have anti-stick / anti-fouling / anti-icing properties. In some embodiments, some upper portions of the tubular structure are associated with antibodies / macrocycles, while the surface and / or some lower portions of the shell of the tubular structure are modified to have anti-stick / anti-fouling / anti-icing properties.

[0430] Adjusting the density and flexibility / rigidity of tubular structures that associate or do not associate with hydrophobic / superhydrophobic / excessively hydrophobic compounds can affect their anti-stick / anti-fouling / anti-icing properties. The presence of a gap-filling layer can be one means of achieving such adjustments. Gap-filling layers can also be used for other purposes, such as protecting underlying surfaces, embedding tubular structures, etc.

[0431] A particular instance of interest is where a macroloop associates with the tip of a tubular structure, with at least two external bridges at opposing or nearly opposing sites. Such association can alter the selectivity of the macroloop compared to other associations. In another instance, the macroloop serves as a bridge between adjacent macroloops of the tubular structure.

[0432] In some implementations, the sensor can be regenerated by solvent cleaning with or without heating / ultrasonic treatment.

[0433] A membrane can be used as a sensor by employing a pump and a pressure sensor. When one side of the membrane is held under negative pressure (once, continuously, or intermittently), exposure to one or more materials permeable to the membrane will increase the pressure on the other side, which can be detected by the pressure sensor. Regeneration of such a sensor can be accomplished by suction and adjusting the pressure back to the initial negative pressure. Further cleaning with a solvent, with or without heating / ultrasonic treatment, may be necessary.

[0434] When a large ring is associated with the tip of a tubular structure having at least two external bridges at opposite / almost opposite sites, the rest of the 'dual protection' device—its surface or gap filling layer and the outer shell of the tubular structure—is capable of providing unprecedented protection, regardless of whether the device is a sensor, a membrane, or both.

[0435] In some embodiments, partially formed devices manufactured according to the methods of this disclosure can be used as sensors. Such partially formed devices may include tubular structures attached to a porous substrate without a gap-filling layer. Such devices can also be used to modify the surface properties of the substrate.

[0436] Decompose embedded tubular structures or other types of molecules to produce derived membranes. By selectively removing the tubular structures / embedded molecules within the interstitial filling layer, prepared membranes with embedded tubular structures and previously described 'membrane-like' devices in which molecules are integrally embedded can be transformed into new types of membranes. In some embodiments, the tubular structures / embedded molecules are organic, and the interstitial filling layer is a metal / silica or another ceramic material. The organic portion can be selectively removed without damaging the ceramic portion by several means, such as strong acids, high-temperature combustion in an oxygen environment, oxidation by strong oxidants, plasma processes, piranha solutions, etc. The resulting membrane is entirely ceramic. The resulting membrane can be further modified, for example, by ALD. Note that ceramic membranes (pores of 1 nm and below) for nanofiltration are commercially available from only one company, although approximately 7,000 companies use them. In the proposed method, such ceramic membranes can be produced, for example, by using tubular structures of α-cyclodextrin having an outer diameter of approximately 1.5 nm, and after selective removal of these structures, the derived ceramic pores can be readily further tuned to 1 nm and below.

[0437] Ceramic films can also be etched under conditions of extremely diluted etch factors, for example, so that more pore space can later be used for different combinations of modifications, or for other possible modifications, such as subsequent modifications. The ceramic surface of the film can also be coated with hydrophobic / superhydrophobic / hyperhydrophobic molecules such as hydrocarbons / fluorocarbons / perfluorinated compounds by forming a monolayer or, sequentially, by forming multiple layers. These modifications can be used to control the smoothness of the film's pores. It is recommended to clean the ceramic surface with piranha or plasma before such coating. Potential applications will be described in the next section.

[0438] Desalination with water. The ability of ceramic nanofiltration membranes to desalinate water is discussed in this field. The ability of hydrophobic, smooth pores with a diameter of approximately 1 nanometer to desalinate water is also discussed in this field. The previously described methods (in which the removal of organic components and their further hydrophilic or hydrophobic / superhydrophobic / hyperhydrophobic modifications) can be used to fabricate both types of such membranes.

[0439] Furthermore, membranes incorporating tubular structures can have pores smaller than 1 nanometer, and thus enable water desalination. Macrorings with hydrophobic or hydrophilic cavities can associate with other macrorings having hydrophobic or hydrophilic cavities (ultimately, all cavities of the resulting tubular structure can be entirely hydrophobic, entirely hydrophilic, or a mixture thereof). Association between macrorings themselves can be achieved using hydrophobic or hydrophilic bridges or mixtures of bridges (the inner side of the bridge is the important side in this manner) and / or hydrophobic or hydrophilic gap-filling layers or mixtures of gap-filling layers.

[0440] Hydrogen will be transported using existing natural gas pipelines. Separating hydrogen from natural gas is important. Pure hydrogen can cause the steel that makes up natural gas distribution pipelines to crack. However, a mixture of hydrogen and natural gas will not cause the steel to crack. The use of membranes that allow hydrogen to pass through while simultaneously blocking natural gas can be used to transport hydrogen through those pipelines, while largely keeping the natural gas trapped inside such pipelines.

[0441] Hydrogen storage. Using membranes to separate hydrogen from its support (which is larger than hydrogen) can retain the potentially volatile support within the storage system. Hydrogen emission uses catalysis, so membranes allow for emission under milder conditions and / or better preservation of the catalyst and / or support and its derivatives.

[0442] If hydrogen is stored as CH3OH, it can be released in two ways. In the first way, CH3OH is exposed to a catalyst, following the equilibrium of CH3OH. 2H₂ + CO. The smaller amount of H₂ can be selectively removed / extracted using a membrane. The remaining CO can react with H₂O (possibly steam) to produce more H₂. A second option is to add water to CH₃OH and use a membrane to extract the resulting H₂.

[0443] When extracting H2 from a support in the presence of H2O less than H2, more membranes can be used, for example, H2O can be extracted from the mixture first, and / or additional water can be added to the support to release more H2 at once or from time to time. If H2O is added to react with the H2 support, it can be added in advance in precise amounts, once or more.

[0444] The released H2 can be consumed using a flame / internal combustion engine or, alternatively, a fuel cell. Even when using a fuel cell, the use of a membrane prevents the need for O2 and the support to be mixed, thus the membrane can keep the support and its derivatives locked in the storage system.

[0445] If NH3 is an H2 support, then even though NH3 is smaller than H2, a catalyst can be used to release H2 (and N2) from NH3, and after the catalyst is removed from the system, a membrane, possibly in combination with a flare combustion / adsorbent, can be used to selectively remove the remaining NH3.

[0446] Membranes can be used not only to remove H2 from its carrier, but also for other desired purifications before and / or after and / or during the release of H2 from its carrier and / or its derivatives, and / or for other desired purifications before and / or after and / or during the reaction of H2 with the excretion form of the carrier.

[0447] Gas diffusion. When the surface of the membrane faces the solution, the membrane can be used as a selective gas diffusion layer.

[0448] When extracting substances from a mixture, the pull (and push) piston can be placed in a chamber under negative pressure or vacuum to use less energy.

Claims

1. A filter configured to allow substance to flow from one side to the other and configured to separate substance passing through it, the filter comprising: Mechanically stable porous substrates; A solid material in contact with the porous substrate, the solid material defining a surface layer having at least one channel, each channel having at least one inlet at a surface of the surface layer and at least one outlet at a pore of the porous substrate; The inlet of each channel has a diameter of 3 nm or less.

2. The filter of claim 1, wherein the at least one channel comprises the solid material without any other material encapsulating it.

3. The filter of claim 1, wherein the at least one channel comprises the solid material, wherein one or more tubular structures comprising large rings cover the solid material.

4. The filter of claim 1, wherein the at least one channel comprises one or more tubular structures, the one or more tubular structures comprising large rings at least partially embedded within the solid material.

5. The filter of claim 4, wherein each tubular structure comprises a stack of coaxially associated large rings having a first inner diameter.

6. The filter according to claim 5, wherein the macrocycle comprises cyclodextrin, calixarene, columnar aromatics, porphyrin, crown ether, helical molecules, kubryan[n]arene, cucurbituril, nonspherical aromatics, Kekulene, cage molecules, metal macrocycles, carbon nanotubes, or any combination thereof.

7. The filter of claim 4, wherein the large ring has a generally frustum-shaped body.

8. The filter of claim 7, wherein the molecular orientation of adjacent macrocycles includes one or more of the following: wide-wide association, narrow-narrow association, and wide-narrow association.

9. The filter of claim 4, wherein each large ring or tubular structure in the stack is bonded to one or more adjacent large rings or tubular structures in the stack with a filler material.

10. The filter of claim 4, wherein each macroring or tubular structure in the stack is connected to an adjacent macroring or tubular structure in the stack by one or more molecular bridges.

11. The filter of claim 4, wherein the top portion of each channel includes an asymmetric tubular structure, wherein the asymmetric tubular structure includes at least one large ring having a second inner diameter narrower than the first inner diameter.

12. The filter of claim 11, wherein the at least one large ring having a second inner diameter is located at the tip of the asymmetric tubular structure such that the tip forms the entrance to the channel.

13. The filter of claim 12, wherein the surface layer extends above the height of the tip molecules but does not enclose the entrance to the channel.

14. The filter of claim 11, wherein at least one molecule having a second inner diameter is within the asymmetric tubular structure but not at its tip, such that the asymmetric tubular structure has an hourglass-shaped configuration.

15. The filter according to claim 11, wherein at least one molecule having a second molecular diameter is a crown ether.

16. The filter of claim 4 further comprises at least one end-capping molecule and an elongated molecule, the elongated molecule being attached to at least one end-capping body and inserted into the top of the uppermost tubular structure in the channel, such that the gap between the end-capping molecule, the elongated molecule and the top of the uppermost tubular structure is a second inner diameter, wherein the second inner diameter is narrower than a first inner diameter and forms the entrance of the channel.

17. The filter of claim 4, wherein the inlet of at least one channel is blocked due to at least one of the following: a) End capping molecules and elongated molecules, the elongated molecules being attached to at least one end capping body and inserted into the top of the uppermost tubular structure in the channel; b) Elongated molecules, said elongated molecules being attached to the solid material and inserted into the top of the uppermost tubular structure in the channel; and c) Deposit solid material in such a way that it covers the top of the uppermost tubular structure in the channel; Furthermore, a passage between adjacent large rings at the outer shell of at least one tubular structure defines a second inner diameter, wherein the second inner diameter is narrower than the first inner diameter and constitutes the entrance to the passage.

18. The filter of claim 4, further comprising at least one elongated molecule inserted into the top of the uppermost tubular structure in the channel and chemically associated with the uppermost tubular structure in the channel or with the solid material, such that the uppermost tubular structure and the at least one elongated molecule define a second inner diameter, wherein the second inner diameter is narrower than the first inner diameter and forms the entrance of the channel.

19. The filter of claim 4, wherein the surface layer encloses the lower portion of at least one tubular structure and does not enclose the upper portion of the at least one tubular structure; wherein the lower portion of the at least one tubular structure comprises large rings associated with each other in a manner that maintains a gap larger than the size of the inlet of the channel; and wherein the upper portion of each tubular structure comprises large rings associated with each other in a manner that reduces the gap between adjacent large rings to below the size of the inlet of the channel.

20. The filter of claim 4, wherein the solid material is embedded in at least one tubular structure without being chemically bonded to the at least one tubular structure.

21. The filter of claim 4, wherein the solid material is adhered to at least one tubular structure by at least one chemical binder.

22. The filter of claim 4, wherein at least one tubular structure further comprises one or more anti-sticking functional groups on its outer surface.

23. The filter of claim 1, wherein the at least one channel extends from the inlet of the at least one channel to the outlet of the at least one channel at a substantially uniform width in the pores of the porous substrate.

24. The filter of claim 1, wherein the at least one channel includes a narrower portion adjacent to the pores of the porous substrate.

25. The filter of claim 1, wherein the substrate comprises anodized aluminum oxide (AAO).

26. The filter of claim 1, wherein at least a portion of the solid material is deposited via atomic layer deposition.

27. The filter of claim 26, wherein the solid material deposited via atomic layer deposition is one or more of titanium dioxide, silicon dioxide, aluminum oxide, or silicon nitride.

28. The filter of claim 1, wherein at least a portion of the solid material is deposited via molecular layer deposition.

29. The filter of claim 1, wherein the diameter of the inlet is between 2.5 angstroms and 4.5 angstroms.

30. A method of manufacturing a filter, comprising: At least one tubular structure is constructed on at least one pore of a porous substrate filled with sacrificial pore filling material, each tubular structure comprising a coaxial stack of associated macrorings; Fill the gaps between tubular structures with a solid space-filling material; And removing the sacrificial pore filling material from the pores of the porous substrate; This creates at least one channel, wherein a solid material defines the surface layer, the entrance of each channel is at the surface of the surface layer, and the outlet of each channel is at a pore in the porous substrate. The inlet of each channel has a diameter of 3 nanometers or less.

31. The method of claim 30, further comprising, prior to the construction step, filling the pores of the porous substrate with the sacrificial pore-filling material.

32. The method of claim 31, further comprising, prior to the hole-filling step, laminating a sacrificial layer material on the porous substrate, wherein the sacrificial layer material is configured to associate with both the sacrificial hole-filling material and the porous substrate, wherein the hole-filling step comprises adhering the hole-filling material to the sacrificial layer material, and further comprising, after the hole-filling step, selectively etching the sacrificial layer material to leave the porous substrate having holes filled with the hole-filling material.

33. The method of claim 32, wherein the porous substrate is a high surface area ceramic material.

34. The method of claim 32, wherein the porous substrate is anodized aluminum oxide, the sacrificial pore filling material is gold, and the sacrificial layering material is silver.

35. The method of claim 30, further comprising, prior to the construction step, selecting a substrate comprising a sacrificial layering material; depositing a porous layer on the sacrificial substrate; and filling the pores of the porous layer with the sacrificial pore-filling material to adhere the pore-filling material to the sacrificial layering material, and selectively etching the sacrificial substrate.

36. The method of claim 35, wherein the porous substrate is a high surface area material.

37. The method of claim 35, wherein the porous substrate is ceramic.

38. The method of claim 30, wherein each tubular structure comprises a stack of coaxially associated large rings having a first inner diameter.

39. The method according to claim 38, wherein the macrocycle comprises cyclodextrin, calixarene, columnar aromatics, porphyrin, crown ether, helical molecule, kubryan[n]arene, cucurbituril, nonspherical aromatics, Kekulene, cage molecule, metal macrocycle, carbon nanotube or any combination thereof.

40. The method of claim 30, wherein the large ring has a generally frustum-shaped body.

41. The method of claim 30, wherein the molecular orientation of adjacent macrocycles includes one or more of the following: wide-wide association, narrow-narrow association, and wide-narrow association.

42. The method of claim 30, wherein the construction step comprises: Template molecules are patterned on the sacrificial pore filling material; And to thread at least a portion of at least one tubular structure around the template molecule.

43. The method of claim 42, wherein the step of patterning the template molecule comprises: Precursor molecules are attached to the sacrificial pore-filling material. The precursor molecules are formed of an XYZ structure, wherein the Z functional group is configured to bond with the pore-filling material, and the XY bond is cleavable. as well as This causes the XY bonds to break.

44. The method of claim 43 further comprises, after cleaving the XY bond, bonding the template molecule to the Y group.

45. The method of claim 43, wherein X is any type of branched polymer.

46. ​​The method of claim 42, further comprising forming at least one molecular bridge between the coaxial tubular structure and the adjacent tubular structure when the tubular structure is threaded onto the template molecule.

47. The method of claim 42, further comprising: A large-volume end cap is attached to the template molecule to form a rotaxane or polyrotaxane; When the bulk end cap is attached to the template molecule, at least one molecular bridge is formed; as well as Remove the bulk end cap and the template molecule.

48. The method of claim 42, wherein the threading step is performed while the tubular structure and the porous substrate are immersed in the solution.

49. The method of claim 48, further comprising one or more of ultrasonic treatment or heating of the solution.

50. The method of claim 48, wherein the solution is a dilute solution.

51. The method of claim 42, further comprising removing the template molecules after the step of filling the gap.

52. The method of claim 38 further comprises, after the step of filling the gap, elongating the template molecule and threading at least one additional macrocyclic or tubular structure onto the elongated template molecule.

53. The method of claim 52, wherein the step of elongating the template molecule is performed using click chemistry.

54. The method of claim 30, further comprising: Template molecules attached to a bulk endcap are threaded into the entrance of each channel, thereby defining the pathway into each channel based on the size of the entrance, the size of the bulk endcap, and the size of a portion of the template molecule near the entrance of each channel.

55. The method of claim 30, further comprising forming the tubular structure by forming molecular bridges between macrocycles in solution prior to the construction step.

56. The method of claim 55, wherein the step of constructing the tubular structure comprises introducing a macrocycle into a solution containing template molecules, thereby allowing the macrocycle to thread around the template molecules.

57. The method of claim 56 further comprises sonicating the solution.

58. The method of claim 56, wherein the solution is a saturated solution.

59. The method of claim 55, wherein the step of forming the molecular bridge comprises: At least one functional group of each macrocycle is modified; as well as Macrocyclic chains are generated by associating the macrocycles at modified functional groups to form a molecular bridge between adjacent macrocycles.

60. The method of claim 59, further comprising: The macrocyclic chain is threaded onto a template molecule, the template molecule having a large volume end cap that is removably attached at one end; A large-volume end cap is attached to the second end of the template molecule; At least a second molecular bridge is formed between adjacent macrorings, thereby creating a macroring ladder; Large-volume endcaps removable from the template molecule cleavage; as well as Remove the template molecule from the macrocyclic ladder.

61. The method of claim 55, further comprising forming bridges in sequential reactions, wherein each sequential reaction increases the proximity of different portions of the macrocycle to each other, thereby enabling subsequent reactions to proceed.

62. The method of claim 55 further comprises using a connector molecule to form a bridge having at least one branched bridge, the connector molecule forming a connection between adjacent macrocycles at two or more locations.

63. The method of claim 62, further comprising adding additional functional groups to the connector molecule after attaching the connector molecule to the adjacent macrocycle, and using the additional functional groups to add one or more additional bridges between the adjacent macrocycles.

64. The method of claim 55, wherein the tubular structure formed in the solution is an asymmetric tubular structure comprising a coaxial stack of associated large rings having substantially the same inner diameter and a large ring having a second inner diameter narrower than a first inner diameter of the large ring of the coaxial stack.

65. The method of claim 64, wherein the bridge between the macrorings adjacent to the tip molecule reduces the gap between the macrorings to less than the second inner diameter.

66. The method of claim 64, wherein the second inner diameter is between 2.5 angstroms and 4.5 angstroms.

67. The method of claim 64, further comprising elongating the asymmetric tubular structure in solution by associating the asymmetric tubular structure with a symmetric tubular structure.

68. The method of claim 67, wherein the elongation step comprises forming a hemirotaxane comprising a template molecule inserted into both the symmetrical tubular structure and the asymmetrical tubular structure, associating the asymmetrical tubular structure and the symmetrical tubular structure, and removing the template molecule.

69. The method of claim 55, further comprising: Prior to the construction step, the tubular structure is modified with anti-adhesion functional groups on the outer shell of the tubular structure.

70. The method of claim 55, further comprising modifying the tubular structure with a branched polymer prior to the construction step to promote spacing and perpendicularity of the tubular structure relative to the substrate, and removing the branched polymer prior to the filling step if the branched polymer does not form a chemical bond with the filler material.

71. The method of claim 30, wherein the construction step comprises directly patterning the at least one tubular structure onto the at least one hole.

72. The method of claim 71, wherein the patterning step comprises patterning a tubular structure containing at least one template molecule associated with at least one bulk end cap.

73. The method of claim 72, wherein the at least one bulk end cap is chemically attached to the at least one tubular structure.

74. The method of claim 30, wherein the filling step comprises performing atomic layer deposition (ALD).

75. The method of claim 74, wherein the solid interstitial material is one or more of titanium dioxide, silicon dioxide, aluminum oxide, or silicon nitride.

76. The method of claim 75, further comprising: Prior to the ALD, precursor molecules are attached to the tubular structure, such that the gap-filling material is directly connected to the tubular structure.

77. The method of claim 74, further comprising: Prior to the ALD, a protective group is attached to the tubular structure so that the gap-filling material does not adhere to at least some portions of the tubular structure.

78. The method of claim 74, further comprising: During the ALD process, a cleaner or etchant is used to regenerate the functional groups present in the outer shell of the tubular structure during the supercycle process.

79. The method of claim 30, wherein the filling step comprises performing molecular layer deposition.

80. The method of claim 30, further comprising sequentially extending the tubular structure after the filling step, and repeating the filling step with respect to the extended tubular structure.

81. The method of claim 30, further comprising: After the gap-filling step, the tubular structure is disassembled to obtain a channel with a surface layer formed solely of the solid material after the step of removing the sacrificial hole-filling material.

82. A method of manufacturing a filter, comprising: Select a sacrificial substrate that can attach to an organic compound; The template molecule is attached to the sacrificial substrate; At least one channel is constructed on the sacrificial substrate, each channel comprising one or more tubular structures comprising coaxial stacks of associated large rings; The gaps between the tubular structures are filled by adhering a solid gap-filling material to the sacrificial substrate; Attach the porous substrate to the open end of the tubular structure or one of the filler materials; as well as Remove the sacrificial substrate and the template molecule.

83. The method of claim 82, further comprising extending the channel by attaching an additional tubular structure to the end of the channel that has previously been associated with the sacrificial substrate.

84. A method for forming a tubular structure comprising macrocycles linked by molecular bridges in solution, comprising: Modification of at least one functional group of two or more macrocycles; as well as A macrocyclic chain is generated by associating the macrocycles at the modified functional groups to form a molecular bridge between the macrocycles.

85. The method of claim 84, further comprising: The macrocyclic chain is threaded onto a template molecule, the template molecule having a large volume end cap that is removably attached at one end; A large-volume end cap is attached to the second end of the template molecule; At least a second molecular bridge is formed between adjacent macrorings, thereby creating a macroring ladder; Large-volume endcaps removable from the template molecule cleavage; as well as Remove the template molecule from the macrocyclic ladder.

86. The method of claim 84, further comprising forming bridges in sequential reactions, wherein each sequential reaction increases the proximity of different portions of the macrocycle to each other, thereby enabling subsequent reactions to proceed.

87. The method of claim 84, further comprising using a connector molecule to form a bridge having at least one branched bridge, the connector molecule forming a connection between adjacent macrocycles at two or more locations.

88. The method of claim 84, wherein the tubular structure formed in the solution is an asymmetric tubular structure comprising a coaxial stack of associated macrocycles having substantially the same inner diameter and a molecule having a second inner diameter narrower than the first inner diameter of the macrocycles of the coaxial stack.

89. The method of claim 88, further comprising elongating the asymmetric tubular structure in solution by associating the asymmetric tubular structure with a symmetric tubular structure.

90. The method of claim 88, wherein the elongation step comprises forming a hemirotaxane comprising a template molecule inserted into both the symmetrical tubular structure and the asymmetrical tubular structure, associating the asymmetrical tubular structure and the symmetrical tubular structure, and removing the template molecule.

91. A method for filtering a mixture of two or more substances, comprising: Expose the mixture of substances through a filter according to any one of claims 1-29, wherein at least one of the substances is of a smaller size such that it is configured to pass through the channel, and at least a second of the substances is of a larger size such that it cannot pass through the channel; and At least one molecule of at least one smaller-sized substance is passed through the filter.

92. The method of claim 91, wherein the mixture is in chemical equilibrium.

93. The method of claim 91, wherein the mixture is in contact with the catalyst.

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