High performance barrier or optical materials obtained by entropy driven nanosheet growth procedure

Abstract

Nanocomposites comprising nanoparticles, small molecules, and block copolymer (BCP)-based supramolecules are provided. The nanoparticles, small molecules, and BCP-based supramolecules self-assemble into a plurality of nanosheets that form a multilayer nanocomposite. The nanoparticles, small molecules, and BCP-based supramolecules can be Zr02, 3-pentadecylphenol (PDP), polystyrene-b-poly(4-vinylpyridine) block copolymer (PDP) 1, respectively. b A method of producing a nanocomposite by contacting nanoparticles, small molecules, and BCP-based supramolecules with a solvent and drying to remove the solvent to allow self-assembly is also provided. The nanocomposites provided herein can be used as a barrier material against volatile organic compounds, water, oxygen, or electrons, and can be used as a coating on various substrates and as a packaging material, or as an optical material.

Description

[0001] Cross-references to related applications This application claims priority to U.S. Provisional Application No. 63 / 519,162, filed August 11, 2023, the entire contents of which are incorporated herein by reference.

[0002] Government Support Statement This invention was completed with government support under contract number DE-AC02-05CH11231 issued by the U.S. Department of Energy. The government holds certain rights to this invention. Technical Field

[0003] This disclosure generally relates to nanocomposite materials and barrier or optical materials. Background Technology

[0004] 2D nanosheets are common structural motifs in natural materials. Despite extensive efforts to design layered self-assemblies of nanosheets based on block copolymers (BCPs) and nanoparticles or liquid crystals, a mismatch remains between what is manufactured and what is needed. Materials based on readily available nanosheets (thicknesses ranging from a few nanometers to tens of nanometers) often perform poorly, for example, when used as viable components in optical, barrier, and dielectric applications.

[0005] Nanomaterials require engineered design to meet a variety of system-level requirements, including but not limited to feature size, chemical properties, multifunctionality, processability, integration compatibility, scalability, and lifespan. However, these requirements narrow the range of design options. While BCPs with nonlinear chain structures (e.g., star-shaped or bottle brush-shaped) can expand the range of accessible feature sizes and overcome kinetic barriers associated with long-chain entanglement, their synthesis is highly demanding. Driven by the optimization of intermolecular interactions, current designs are too rigid to incorporate new chemical functional groups and cannot mitigate condition differences during integration. Despite extensive optimization of building blocks and processing, obtaining nanostructures with the desired feature sizes and chemical properties remains difficult. Programming their growth at the nanoscale to macroscale levels also remains challenging. The rigidity of existing designs limits the programmable growth of nanomaterials. Summary of the Invention

[0006] This paper presents a high-performance barrier coating and a method for fabricating such a coating by programming a micron-then-nano growth sequence in a ternary nanocomposite blend. The coating consists of >200 stacked nanosheets (approximately 125 nm thick) with a defect density <0.056 μm.-2 The efficiency of controlling defect types is approximately 98%. High molecular weight polymers (nearly 500 kDa) are used as the matrix for nanocomposites. Contrary to common belief, polymer chain entanglement facilitates long-range ordering, accelerates the manufacturing process (<30 minutes), and meets specific requirements for advancing multilayer membrane technology. Specifically, the coatings exhibit high-performance barrier properties against volatile organic compounds, water, and oxygen for packaging applications. They can also serve as electronic barriers for dielectric capacitors. These composite coatings possess inherent recyclability and offer solutions to recycling issues associated with existing metallized and multilayer membranes. The long-chain entanglement provides mechanical stability, eliminating the need for chemical crosslinking. They are suitable for cycling through assembly, disassembly, and reassembly without compromising structural integrity, highlighting the advantages of bottom-up material synthesis.

[0007] In one aspect, this article provides a nanocomposite material comprising nanoparticles, small molecules, and a block copolymer (BCP)-based supramolecular structure, wherein the nanoparticles, small molecules, and BCP-based supramolecular structure self-assemble into multiple nanosheets forming the nanocomposite material. The BCP-based supramolecular structure comprises BCP and small molecules.

[0008] In some embodiments, each of the BCP-based supramolecular molecules comprises a BCP and a small molecule bound to the BCP via non-covalent bonds. In some embodiments, the BCP comprises a molecular weight of about 130 kDa to about 600 kDa. In specific embodiments, the BCP is a high molecular weight polymer (e.g., having a molecular weight of about 500 kDa or greater).

[0009] In some embodiments, the small molecule is an organic molecule. In some embodiments, the small molecule has a molar mass of about 50 g / mol to about 1500 g / mol.

[0010] In some embodiments, the nanoparticles are inorganic molecules, such as metal oxide nanoparticles [e.g., zirconium oxide (ZrO2)], noble metal nanoparticles (e.g., gold), or silica nanoparticles. In some embodiments, the nanoparticles have a size of about 3 nm to about 50 nm, a size of about 3 nm to about 9 nm, or a size of about 6 nm.

[0011] In a specific embodiment, the nanoparticles comprise ZrO2. In a specific embodiment, the small molecule comprises 3-pentadecanylphenol (PDP). In a specific embodiment, the BCP comprises polystyrene- b - Poly(4-vinylpyridine) block copolymer (PS- b -P4VP). In a specific embodiment, the BCP-based supramolecular component contains PS- b-P4VP(PDP)1, which contains PS- via hydrogen bonding b -P4VP pyridine side chain bound PDP.

[0012] In some embodiments, the nanoparticles comprise about 3%-20% of the nanocomposite material, the small molecules comprise about 10%-25% of the nanocomposite material, and the BCP-based supramolecular components comprise about 65%-75% of the nanocomposite material. Example compositions of the nanocomposite materials are listed in Table 1.

[0013] In some embodiments, each nanosheet has a thickness of about 50 nm to about 410 nm, for example, about 50 nm to about 150 nm or about 125 nm.

[0014] In some embodiments, the nanocomposite material comprises about 20 to about 100, about 20 to about 200, or about 200 or more nanosheets.

[0015] In some embodiments, the nanocomposite material contains approximately 0.06 μm -2 Or even lower defect density, and approximately 98% defect type control efficiency.

[0016] In some embodiments, the nanocomposite materials provided herein possess improved barrier properties against volatile organic compounds (VOCs), water, oxygen, or electrons compared to control materials. In some embodiments, the nanocomposite materials exhibit a VOC removal efficiency of 40% or higher and a molecular weight of 8 gm³. -2 sky -1 Or even lower water vapor transmission rate (WVTR), 500 MV / m -1 Or greater dielectric breakdown strength, 3 J cm -3 Or greater maximum discharge energy density and / or 3 minutes μm -1 Or a longer encapsulant lifetime.

[0017] In some embodiments, the nanocomposite material comprises a plurality of nanosheets having a gradient layer thickness, for example, a thinner layer toward the substrate-nanocomposite interface and a thicker layer away from the substrate. In some embodiments, the thickness of the nanosheets in the nanocomposite material ranges from about 65 nm to about 135 nm (e.g., about 72 nm to about 126 nm), about 120 nm to about 280 nm (e.g., about 151 nm to about 223 nm), about 120 nm to about 250 nm (e.g., about 127 nm to about 221 nm), or about 120 nm to about 410 nm (e.g., about 135 nm to about 370 nm).

[0018] In some embodiments, the nanocomposite material has alternating layers of nanosheets rich in nanoparticles and nanosheets lacking nanoparticles.

[0019] In one aspect of this disclosure, a method for producing nanocomposite materials is provided. The method includes: contacting an initial blend of nanoparticles, small molecules, and a block copolymer (BCP)-based supramolecular structure with a solvent to form a mixture; drying the mixture to remove the solvent; and forming the nanocomposite material via a self-assembly process. The nanocomposite material comprises a plurality of nanosheets, each nanosheet comprising the nanoparticles, the small molecules, and the BCP-based supramolecular structure. The BCP-based supramolecular structure comprises BCP and the small molecules.

[0020] In some embodiments, the solvent is chloroform or benzene.

[0021] In some embodiments, contacting includes contacting an initial blend of nanoparticles, small molecules, and BCP-based supramolecular molecules with a solvent comprising about 95% to about 100% or about 97.5% of the mixture (i.e., the initial blend comprising about 5% or less, or about 2.5% of the mixture).

[0022] In some embodiments, drying includes removing the solvent when the volume percentage of the solvent in the mixture is about 70% to about 80% or less to initiate the self-assembly process. The self-assembly process can occur when the volume percentage of the solvent in the mixture is about 70% to 80% or less.

[0023] In some implementations, the drying process takes about 20 minutes to about 3 days.

[0024] In some embodiments, the method further includes adjusting the drying rate and / or the solute / solvent ratio in the mixture to adjust the thickness and / or color of the multiple nanosheets. A slower drying rate or a higher solute ratio in the mixture can produce thicker and / or redder nanosheets.

[0025] In some embodiments, the mixture is drop-cast onto a substrate before drying. In some embodiments, the substrate is a solid, lens, film, thin film, or wafer made of Teflon, polyester, silicon, or glass.

[0026] In some implementations, each of the BCP-based supramolecular molecules comprises a BCP and a small molecule bound to the BCP via a non-covalent bond.

[0027] In some implementations, the BCP contains a molecular weight of about 130 kDa to about 600 kDa.

[0028] In some embodiments, the small molecule is an organic molecule containing a molar mass of about 50 g / mol to about 1500 g / mol.

[0029] In some embodiments, the nanoparticles are inorganic molecules, such as metal oxide nanoparticles [e.g., zirconium oxide (ZrO2)], noble metal nanoparticles (e.g., gold), or silica nanoparticles. In some embodiments, the nanoparticles have a size of about 3 nm to about 50 nm, a size of about 3 nm to about 9 nm, or a size of about 6 nm.

[0030] In a specific embodiment, the nanoparticles comprise ZrO2. In a specific embodiment, the small molecule comprises 3-pentadecanylphenol (PDP). In a specific embodiment, the BCP comprises polystyrene- b - Poly(4-vinylpyridine) block copolymer (PS- b -P4VP). In a specific embodiment, the BCP-based supramolecular component contains PS- b -P4VP(PDP)1, which contains PS- via hydrogen bonding b -P4VP pyridine side chain bound PDP.

[0031] In some embodiments, each nanosheet has a thickness of about 50 nm to about 410 nm, for example, about 50 nm to about 150 nm, or about 125 nm.

[0032] In some embodiments, the nanocomposite material comprises about 20 to about 100, about 20 to about 200, or about 200 or more nanosheets.

[0033] In some embodiments, the nanocomposite material contains approximately 0.06 μm -2 Or even smaller defect density, and approximately 98% efficiency in controlling defect types.

[0034] In some embodiments, the nanoparticles comprise about 3%-20% of the initial blend, the small molecules comprise about 10%-25% of the initial blend, and the BCP-based supramolecular molecules comprise about 65%-75% of the initial blend. Example compositions of the initial blend are listed in Table 1.

[0035] In some embodiments, the formation includes forming alternating layers of nanosheets rich in nanoparticles and nanosheets lacking nanoparticles.

[0036] In one aspect of this disclosure, nanocomposite materials produced by the methods provided herein are provided.

[0037] In one aspect of this disclosure, products containing the nanocomposite materials provided herein or products containing nanocomposite materials produced by the methods provided herein are provided, wherein said products are barrier products or optical products.

[0038] In some embodiments, the product includes and can be used as a volatile organic compound barrier, a water barrier, an oxygen barrier, an electronic barrier, a dielectric capacitor, a lens coating and / or packaging (e.g., food packaging material), a filter, a plane lens, and a zone plate.

[0039] Detailed descriptions of one or more embodiments of the subject matter described herein are set forth in the accompanying drawings and the following description. Other features, aspects, and beneficial effects will become apparent from the description, drawings, and claims. It should be noted that the relative dimensions in the following figures are not drawn to scale.

[0040] Brief description of the attached figures The patent or application document contains at least one color drawing. Upon request and payment of the necessary fees, the U.S. Patent and Trademark Office will provide a copy of the patent or application publication document with the color drawing.

[0041] Figure 1A The system engineering of layered nanosheets as barrier materials is schematically depicted. To transform stacked nanosheets into high-performance barrier coatings, the assemblies need to meet numerous requirements. Figure 1B The sequential growth of nanosheets during film casting is depicted. The sequential growth follows a sequence from nanometer to micrometer to macrometer, and the smallest feature size is formed when the system mobility is highest. Figure 1C The programmed growth of nanosheets during cast film deposition is described. Programmed growth matches the system mobility to the target feature size and organizes molecular aggregates into microframeworks when the system mobility is high. When the system mobility is low, the nanostructures then grow within the microframeworks via short-range diffusion.

[0042] Figures 2A-2I Transmission electron microscopy (TEM) images depicting the formulation changes of S2 / NP blends. Figure 2A S2 supramolecular structures with 6 volume % 5 nm iron oxide nanoparticles were depicted. Figure 2B A 330-b-125 kDa supramolecular structure formed using different hydrogen-bonded small molecule I-PDPs (illustrated) is depicted. This is for... Figure 3 The blends were analyzed by energy dispersive X-ray spectroscopy (EDS). Figure 2C A 330-b-125 kDa supramolecular structure was depicted using blends of hydrogen-bonded small molecules (PDPs) and non-hydrogen-bonded small molecules (DIDs) in molar ratios of 1 and 0.6. Figure 2D-Figure 2IS2 / NP blends self-assembled on various substrates are depicted: Teflon beakers ( Figure 2D ), porous Teflon membrane ( Figure 2E ), polyester film ( Figure 2F ), thick silicon wafers ( Figure 2G thin silicon wafers Figure 2H ), and glass ( Figure 2I ).

[0043] Figure 3 EDS analysis depicting the distribution of small molecules in S2 / NP blends with iodine-labeled PDPs (I-PDPs) was performed. Structural and chemical information was collected using a high-angle annular dark-field apparatus, resulting in contrast that is opposite to other TEM images presented in this paper. The brightest pixels are those with the strongest scattering, thus the domains filled with nanoparticles are brighter than those containing only organic matter. The iodine distribution map shows that, despite the presence of enthalpy-driven forces that induce them to separate into the P4VP (PDP) domains, I-PDPs are distributed throughout all microdomains. In contrast, ZrO2 nanoparticles are tightly partitioned into the P4VP (PDP) domains. This imaging technique does not distinguish between hydrogen-bonded and unbonded small molecules, therefore the P4VP (PDP) domains exhibit a higher overall concentration of small molecules.

[0044] Figures 4A-4C Quantitatively describing the growth kinetics of nanosheets. Figure 4A The SANS curves of 5 vol% and 10 vol% S2 / NP solutions in deuterated chloroform, fitted using the Guinier-Porod model, were plotted. Figure 4B USANS curves were plotted for a 10 volume % S2 / NP solution. The inset shows a liquid-cell TEM image of the ribbon-like aggregates. Scale bar: 500 nm. Figure 4C USAXS plots were generated for 10 volume % S2 / NP and S3 / NP solutions. At this concentration, the S3 / NP solution had formed microscale aggregates, indicated by the presence of low-q characteristics. Figures 4D-4F Results from in-situ SAXS-XPCS experiments used to quantify the system mobility during nanosheet growth are depicted. The Roman numeral iv indicates the assembly stage during solvent drying. Figure 4D SAXS curves depicting the structural evolution from dilute solutions to highly ordered sheets are presented. Figure 4E The evolution of nanoparticle diffusion modes during S2 / NP assembly is depicted based on Kohlrausch exponent γ values ​​extracted using kinetic data from qs to ql. Each data point is marked with a solid circle. Note that γ for stages iii and v could not be calculated due to the presence of sharp scattering peaks. These stages are marked with hollow circles in chronological order. Figure 4FThe relaxation time τs for each assembly stage during nanosheet growth is depicted (at qs = 0.3 nm). -1 ) and τL (at ql=0.03nm) -1 A comparison of ). Figure 4G The description of S1 under optimized drying conditions cyl In-situ GTSAXS of / NP solution. Δt is used to indicate the time elapsed after aggregate formation (leftmost figure). Figure 4H A cross-sectional TEM image of the S2 / NP film quenched at the labeled solvent fraction is depicted. The scale bar is 1 μm. The lower right image is a false-color image of the film quenched at 28% volume; for this image, colors are used to indicate the length of each nanosheet extending beyond the image boundary. au, arbitrary units.

[0045] Figure 5A An example of automated sheet length analysis is described, and Figure 5B Semi-automatic defect density analysis was performed on S2 films frozen at 40% volume. Junctions and ends were automatically identified. U-turn defects were manually marked. Figures 6A-6F Depicting programmed nanosheet growth that leads to long-range order and defect control. Figure 6A Cross-sectional TEM images depicting an S2 / NP coating comprising over 200 stacked nanosheets are shown. At approximately 2660 μm... 2 Within the imaging area, there were only 149 defects: 146 paired ends (blue circles), two paired U-shaped bends (pink squares), and one connecting knot (gold triangle). The illustration shows a photograph of the S2 / NP coating on the polyester film. Figure 6B High-magnification TEM images of the S2 / NP film were depicted, showing a high aspect ratio nanosheet containing densely packed nanoparticles. Figure 6C High-magnification TEM images of each defect type were depicted. Figure 6D The defect density of cross-sectional TEM images from S1 / NP and S2 / NP is compared with literature values ​​from BCP films. Figure 6E Cross-sectional TEM images of S2 / NP blends that were dried too quickly to form microframeworks were depicted; disordered microdomains and nanoparticle aggregates were observed. Figure 6F A cross-sectional TEM image of an S3 / NP film with 20 volume% nanoparticles and a micro-domain periodicity of 174 nm is depicted. Scale bar is 100 nm.

[0046] Figures 7A-7H Describe the performance evaluation of nanocomposite coatings as barrier materials. Figures 7A-7D Describing S2 / NP (for establishing chemical-structure-barrier properties) Figure 7A S2dis / NP ( Figure 7B S2 Figure 7C ) and S1 / NP ( Figure 7D A representative TEM image of ( ). Scale bar is 500 nm. Figure 7E S2 / NP and S2 on porous Teflon membranes were depicted. dis VOC barrier properties of S1 / NP, S2, and S1 / NP coatings. Removal efficiencies for five VOC molecules are shown. For each strip, n=2. Figure 7F Depicting S2 / NP, S2 dis WVTR of PET films with S1 / NP, S2, and S1 / NP coatings. The S2 / NP coating has the lowest water permeability. For each strip, n=3. Figure 7G S2 / NP and S2 are described dis Dielectric breakdown strength (solid bar) and maximum discharge energy density (hollow bar) of the / NP, S2, and S1 / NP coatings are shown. Biaxially oriented polypropylene (BOPP) is shown as a reference. For each bar, n=10. Figure 7H Encapsulant lifetimes for S2 / NP and two commercially available UV-cured epoxy resins, measured using an electrocalcium test, are depicted. Results are normalized by barrier layer thickness. For each bar, n=3. Error bars in all figures represent ±1 standard deviation.

[0047] Figures 8A-8D Eight stability analyses of the nanocomposite coating were described. Figure 8A It is depicted that when the film dries, is redissolved, and then recoated, it forms the same layered structure as before. Figure 8B The nanoindentation results were depicted, showing that the S2 / NP film is mechanically stable despite the lack of chemical crosslinking between the layers. Figure 8C Cyclic buckling tests (n=600) of S2 / NP on PET film were depicted, showing that the film remained intact and no delamination with the substrate occurred. Figure 8D The disordered nanocomposite material (S2) was described dis The performance of S2 / NP and the non-nanoparticle sheet (S2) is inferior to that of S2 / NP. Figure 8B Although all the films tested had the same thickness and were supported by the same PET film.

[0048] Figures 9A-9E The formation of gradient layer thickness in layered nanocomposites was described. Figure 9A A supramolecular nanocomposite system is schematically depicted, which is diluted in a non-selective solvent and drop-cast to produce an ordered layered structure. The concentration gradient present in the film during drop-casting affects the gradient layer thickness in the nanocomposite. Parameters used to describe the local layer thickness are... The diagram on the far right is defined visually. Figure 9BImages of fully dried layered nanocomposite films, taken under normal laboratory lighting, are depicted. Different structural colors represent processing-dependent nanostructures. From left to right, the self-assembly time of the samples increases. Each sample is approximately 1.5 cm along its horizontal edge. Figures 9C-9E Cross-sectional TEM images depicting the selected nanocomposites. As indicated by their structural colors, the dried films exhibit substantially different internal structures. Each film also shows a high degree of correlation. Gradient. Images are oriented such that the substrate-film interface is at the bottom and the film-air interface has a wavy top boundary. All scale bars are 1 µm.

[0049] Figures 10A-10D Depicting Scattering characteristics of gradient formation. Figure 10A In-situ SAXS curves of a slowly drying supramolecular nanocomposite solution were plotted. The brown lines indicate the evolution from correlated pores to ordered sheets. The gold lines indicate... The first sign of gradient formation. The brown line indicates a stronger gradient. The evolution of gradients. Figure 10B SAXS and USAXS curves for combinations of dried nanocomposite films with different nanostructures were plotted, with vertical shifts made for clarity. The curves are colored with the structural colors of the dried samples, as shown in the lower right figure. Peaks i and i* are from the USAXS results and define the average film thickness. Peak ii originates from 6 nm nanoparticles. Figure 10C WAXS curves of the solution measured on a capillary with spatially varying solvent concentrations are plotted. Structure colors are used to mark the location on the capillary where each measurement was collected; the capillary is shown in the upper right figure. Peak iii depicts the amount of crystalline PDP present in the sample. Peaks iv and v originate from NP ligands, and their intensities are approximately proportional to the solute concentration. Figure 10D Depicting the middle Figure 10B The WAXS curves for the same samples are shown below.

[0050] Figures 11A-11G Depict gradient structures at the nanoscale, microscale, and macroscale. Figure 11A Cross-sectional TEM images of a membrane with a distinct periodic gradient and no NP were depicted. Figure 11B The text describes the curl, comb-like, and total curl measured over the entire same area shown above. The width of the domain. Figure 11C The raw domain size data, plotted as the fraction of curled and comb-like structures as part of the total microdomain volume, are depicted. Dashed lines are calculated directly from the sample composition for comparison with experimental data. From the bottom to the top of the membrane, most of the unbonded PDPs transition from the curled domains to the comb-like domains. Figure 11D Depicting in Optical micrograph of the rough texture observed in the gradient film. Figure 11E An optical micrograph depicting the substrate edge (lower black border) of the dried film. As the film dries, it recedes from the edge instead of remaining fixed. This effect is noticeable in slowly drying films and may be a macroscopic side effect of the lateral shrinkage of the top layer. Figure 11F A TEM image depicting the top surface of the gradient film is shown. End defects are marked with blue teardrops pointing along the continuous layers. No paired end-to-end defects were observed. Figure 11G TEM images depicting the bottom interface of the gradient film were shown. A mixture of paired end-to-end defects and isolated end defects was observed.

[0051] Figures 12A-12H Optical micrographs of six component-controlled films are depicted, along with descriptions of their surface textures. Figure 12A The membrane is described as having no NP, no excess PDP, and rapid drying; it is smooth. Figure 12B A membrane with NP, no excess PDP, and rapid drying is described; it is smooth. Figure 12C The film depicts a membrane without NP, with excess PDP, and rapid drying; it has a fine texture. Figure 12D It depicts a membrane without NP, without excess PDP, and with slow drying; with a delicate texture. Figure 12E A membrane with NP, no excess PDP, slow drying, and smooth surface is described. Figure 12F The film is depicted as having no NP, excess PDP, and slow drying; with significant texture. Figure 12G Depicting Figure 12D The TEM images of the membrane cross-section shown from top to bottom are in the middle; no obvious cross-sections are visible. Gradient, localized smoothness of the surface. Figure 12H Cross-sectional TEM images of low molecular weight S2 supramolecular molecules under slow drying conditions were depicted; it is clear that... gradient. Figure 12I Cross-sectional TEM images of the lowest molecular weight S3 supramolecular molecules under slow drying conditions were depicted; a morphological transformation to cylindrical domains has occurred. Figure 12J A cross-sectional TEM image of the S1 supramolecular membrane after three days of drying was created; high resolution was achieved throughout the entire membrane thickness. The configuration is such that there is no gradient. Figure 12K A cross-sectional TEM image of the Si / NP nanocomposite after 3 days of drying is depicted; no visible gradient structure is observed. In the inset, extended comb-like domains leave some NPs at the curl-comb interface as they pack more tightly and eject other NPs, forming a 3-layer structure.

[0052] Figure 13The solvent fraction vs. time curves are plotted for gradient and non-gradient membranes. The solvent fraction values ​​in the dried membranes are based on Filmetrics F20 interferometry. The top curve shows slow drying at 60-minute intervals, which leads to gradient formation. The two bottom curves show a faster drying process that does not lead to gradient formation. The data are fitted with an exponential decay function for interpolation.

[0053] Figure 14A The reflectance spectra collected on a relatively thick gradient film are depicted. Inset: The film diameter spans approximately 3 mm, and the thickness is 30 µm. For each reflectance measurement, the spectrum is colored with the observed structural color. Figure 14B Optical microscope images depicting each domain of the reflectance spectrum are presented. Detailed Implementation

[0054] Reference is now made in detail to certain specific embodiments of the invention, including the inventors' preferred methods for carrying out the invention. Examples of these specific embodiments are illustrated in the accompanying drawings. While the invention has been described in conjunction with these specific embodiments, it should be understood that this is not intended to limit the invention to the described embodiments. Rather, it is intended to cover alternatives, modifications, and equivalents that may be included within the spirit and scope of the invention as defined by the appended claims.

[0055] In the following description, numerous specific details are set forth to provide a thorough understanding of the invention. Specific exemplary embodiments of the invention may be practiced without some or all of these specific details. In other instances, well-known processes have not been described in detail to avoid unnecessarily obscuring the invention.

[0056] For clarity, the various techniques and mechanisms of the present invention will sometimes be described in the singular. However, it should be noted that some embodiments involve multiple iterations of the techniques or multiple instantiations of the mechanisms, unless otherwise stated.

[0057] The terms “about / approximately” or “approximately” are synonyms and are used to indicate that the value modified by the term has an intelligible range associated with it, wherein the range may be ±20%, ±15%, ±10%, ±5%, or ±1%. The terms “substantially” are used to indicate that a value is close to a target value, wherein close to can mean, for example, that the value is within 80%, 85%, 90%, 95%, or 99% of the target value.

[0058] As used in this document regarding parameters, the terms “decreased,” “decreasing,” “decrease,” “reduced,” “reducing,” “reduce,” or “lower” refer to a detectable (e.g., at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100%) negative change in a parameter relative to a control (e.g., a predetermined normal or reference level or a predetermined standard control). Therefore, the terms “decreased,” “decrease,” etc., encompass both partial and complete reductions compared to a control.

[0059] As used in this article with respect to parameters, the terms “increase” or “enhance” or “greater” refer to a detectable (e.g., at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 200%, 300%, 400%, 500%, 600%, 700%, 800%, 900%, or 1000%) positive change in a parameter relative to a comparison control (e.g., a predetermined normal or reference level or a predetermined standard control of the parameter).

[0060] A. Nanocomposites This document provides a nanocomposite material comprising nanoparticles, small molecules, and block copolymer (BCP)-based supramolecular structures, wherein the nanoparticles, small molecules, and BCP-based supramolecular structures self-assemble into multiple nanosheets forming the nanocomposite material. The BCP-based supramolecular structures comprise both BCP and small molecules. As used herein, a “nanocomposite” material refers to a heterogeneous material in which the characteristic length scale of the filler material is typically in the nanometer range, such as a material formed from a blend of the nanoparticles, small molecules, and BCP-based supramolecular structures provided herein.

[0061] By providing (1) the ability to adapt to changes in reactant composition and pairing interactions during entropy-driven assembly processing and integration, and (2) system mobility matching the necessary diffusion of building blocks to form the target structure, the novel nanomaterial design presented in this paper offers an improvement over previously available nanosheet technologies. Figure 1BAs shown, previously available sequential growth techniques follow a nanometer-to-micrometer growth process, where the smallest structural features are formed when the system mobility is highest, and vice versa. In stark contrast, the growth pathway presented in this paper proceeds in the opposite order, first micrometer-then nanometer. Figure 1C When the system has the highest mobility, the microstructure is first defined, and then the nanostructure is formed through the local organization of building units. Entropy-driven phase behavior facilitates this growth path from large to small. When the system is mobile enough to organize large-scale structures, it allows the system to form micro-aggregates in dilute solutions. Thermodynamically, the entropy-driven phase behavior observed in high-entropy alloys provides formulation flexibility while maintaining structural fidelity. Therefore, when the system mobility is low, many combinations of locally available components can be used to form the target nanostructure. The coating exhibits high-performance barrier properties against volatile organic compounds, water, and oxygen used as packaging, as well as high-performance barrier properties against electrons used as dielectric capacitors.

[0062] BCPs can contain molecular weights from about 130 kDa to about 600 kDa, such as about 130 kDa, about 200 kDa, about 300 kDa, about 400 kDa, about 450 kDa, about 500 kDa, about 560 kDa, or about 600 kDa. As specific examples, BCPs can have molecular weights of 134 kDa, 455 kDa, and 557 kDa, as listed in Table 1. In specific embodiments, BCPs are high molecular weight polymers (e.g., having molecular weights of about 100, 200, 300, 400, 500 kDa, or greater).

[0063] Long polymer chain entanglements provided by high molecular weight polymers serve several functions: they program the kinetic pathway to match the system's mobility to its structural evolution stage and regulate local defect morphology. By using high molecular weight building blocks, blends form molecular aggregates in dilute solutions. This provides sufficient system mobility to organize the molecular aggregates into extended microframeworks for subsequent nanostructure formation. During subsequent growth and organization, long chain entanglements increase the kinetic stability and integrity of the aggregates. Long chain entanglements can mitigate local reorganization at defect sites, thus maintaining end-to-end pair-defect morphology.

[0064] Each of the BCP-based supramolecular components can contain a BCP and small molecules bound to the BCP via non-covalent bonds. For example, BCP-based supramolecular components can be constructed by non-covalently attaching small molecules to polymer side chains. The presence of small molecules eliminates the need to modify nanoparticle ligands or polymers for nanoparticle incorporation and to improve interparticle order within the BCP microdomains. 1-D, 2-D, and 3-D nanoparticle arrays can be obtained in films of supramolecular nanocomposites by solvent annealing of a series of nanoparticles or mixtures of nanoparticles. Kinetically, the presence of small molecules also provides opportunities to manipulate the energy landscape of the assembly process and accelerate assembly kinetics, allowing the preservation of the intrinsic properties of the nanoparticles and enabling continuous thin-film processing techniques for device fabrication.

[0065] The small molecule can be an organic molecule. The small molecule can have a molar mass of about 50 g / mol to about 1500 g / mol. In a specific embodiment, the small molecule comprises 3-pentadecanylphenol (PDP).

[0066] For example, BCP can be polystyrene- b - Poly(4-vinylpyridine) block copolymer (PS- b -P4VP). BCP-based supramolecular molecules can be PS- b -P4VP(PDP)1, which contains PS- via hydrogen bonding b PDP bound to the pyridine side chain of -P4VP. PS- b -P4VP comprises two randomly coiled blocks, forming spherical microdomains of P4VP surrounded by a PS matrix. Unbound by any particular theory, when PDP hydrogen-bonded to the pyridine ring, the P4VP blocks are stretched to form rigid comb-like blocks. This structure occupies a significantly larger volume, thus the supramolecular form layered rather than spherical microdomains. Through binding with the pyridine ring, PDP also forms a periodic layered structure, resulting in a hierarchical morphology of lamellae-within-lamellae.

[0067] Small-molecule PDPs increase the mobility of the system by diluting BCP entanglements and increasing the volume of P4VP blocks. The solubility parameter of PDPs lies between that of BCP blocks and NP ligands; therefore, free PDPs can relax unfavorable interfaces between blocks or around NPs and stabilize morphologies with large surface areas. Free PDPs can also redistribute over relatively large distances to adapt to constraints. Moderate-strength hydrogen bonds give PDPs a degree of rearrangement freedom. Much of the self-regulating behavior of the nanocomposite system can be attributed to small molecules.

[0068] Nanoparticles can be inorganic molecules, such as metal oxide nanoparticles [e.g., zirconium oxide (ZrO2)], noble metal nanoparticles (e.g., gold), or silica nanoparticles. In some embodiments, the nanoparticles have a size of about 3 nm to about 50 nm, a size of about 3 nm to about 9 nm, or a size of about 6 nm. In a specific embodiment, the nanoparticles comprise ZrO2 with a size of about 6 nm.

[0069] Table 1 provides example formulations and compositions of the nanocomposites presented herein. These nanocomposites include BCPs with molecular weights of 134 kDa, 455 kDa, and 557 kDa. They form periodic layered or cylindrical microdomains ranging from about 60 nm (S1 / NP) to about 170 nm (S3 / NP). PDP molecules are dispersed in PS-rich microdomains and P4VP-rich (PDP)-rich microdomains; Figure 3 Spatial-resolved energy-dispersive X-ray spectroscopy (EDS) of S2 / NPs with iodine-labeled small molecules (I-PDPs) is shown. The dispersed PDP molecules screen for unfavorable interactions between PS and P4VP (PDPs) and are essential for achieving entropy-driven phase behavior, such as formulation flexibility. Based on 557-kDa PS- b -P4VP's S3 / NP blends can accommodate up to 20% by volume of nanoparticles within parallel layers.

[0070] In the nanocomposites provided herein, nanoparticles may constitute about 3-20% of the nanocomposites by volume (e.g., about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20% by volume), small molecules may constitute about 10-25% of the nanocomposites by volume (e.g., about 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25% by volume), and BCP-based supramolecular molecules may constitute about 65-75% of the nanocomposites by volume (e.g., about 65, 66, 67, 68, 69, 70, 71, 72, 83, 74 or 75% by volume).

[0071] Nanoparticles, small molecules, and BCP-based supramolecular materials (collectively referred to as solutes) can be dissolved in solvents and can self-assemble into multilayer nanosheets during drying. Solvents can be any solvent that dissolves the solute (i.e., small molecules and BCP-based supramolecular materials) and is suitable for preparing nanocomposites. For example, a solvent can be chloroform, which dissolves PS and P4VP almost as well, and also PDP. A solvent can also be benzene, which has lower X-ray absorption than chloroform. Solutes can be dissolved in solvents to form solutions of 1–20 vol% (e.g., 1–5, 5–10, 10–15, 15–20, or greater than 20 vol%). The overlap concentration of polymer solutions in good solvents is... N –1.8 For solutes containing 134-kDa BCP, the estimate is >20% by volume, and for solutes containing 455-kDa BCP, the estimate is approximately 2.7% by volume.

[0072] Each nanosheet of the nanocomposite material can be about 50 nm to about 410 nm thick, for example, about 50-100, 50-150, 50-200, 200-300, 300-410 nm thick, or about 150, 100, 125, 150, 200, 250, 300, 350, 400 or 410 nm thick.

[0073] Nanocomposites may contain about 20 to about 100, about 20 to about 200, about 100 to about 200, or about 200 or more nanosheets. A greater number of nanosheets can provide greater functionality to the nanocomposites, such as for use as barrier materials or optical materials.

[0074] The early microstructure determines the long-range order (i.e., defect density) of the nanostructure. The diffusion mode of nanoparticles and the stepwise change in system mobility define the processing window for achieving micro-first-nano-later growth. Figure 4H As shown, when solvent removal occurs at a solute concentration of 23 vol%, long-range order is poor; despite high system mobility, this solute concentration is too dilute to drive the condensation of molecular aggregates. With rapid solvent removal at 40 vol%, different nanosheets are formed, but with high defect density and an aspect ratio of less than 40. This indicates that nanostructure formation can compete with and disrupt microframework formation. Optimal long-range order is achieved by quenching the film at 28% (slightly lower than the concentration at which nanosheets are formed). The nanosheets are tens of micrometers long with an aspect ratio greater than 500. Therefore, long-range order, i.e., defect density, can be tuned by optimizing the organization of the sheet-like aggregates prior to nanostructure formation.

[0075] The type of defect also determines the barrier performance, as different defects have different effects on the transport pathway. The prevalence of different defect types is determined by short-range diffusion in the final stage of assembly. Blends based on lower molecular weights (e.g., S1) exhibit more circular microdomains between nanosheets, while sharply curved microdomains (which we term "U-turn" defects) are less common. These defect morphologies are the result of local recombination and indicate that the system has sufficient mobility to recombine BCP-based supramolecular structures to release stacking frustration. However, for blends based on high molecular weight building blocks (e.g., S2 / NP and S2), most defects are paired ends and U-turn types. Some nanosheets bend into several consecutive U-turns (…). Figures 5A-5B Significant energy losses exist associated with bending nanosheets at such sharp angles. However, the entanglement of long chains raises the energy barrier for local reorganization and dynamically traps these defects after microframework formation. U-shaped bend defects can be eliminated by increasing the stiffness of the nanosheets, for example, by adding nanoparticles or driving the system to a lower solvent fraction to further enhance long-range order. Paired end defects break the transport path and are desirable for barrier material engineering. Therefore, the ability of long-chain entanglement to decouple defect manipulation from nanostructure formation is advantageous for controlling the prevalence of different defect types.

[0076] The nanocomposite material provided in this paper has a diameter of 0.2 μm. -2 or smaller, 0.1 μm -2 Or smaller, 0.09 μm -2 Or smaller, 0.08 μm -2 Or smaller, 0.07 μm -2 or smaller, 0.06 μm -2 Or smaller, or 0.05 μm -2 Or even smaller defect density. In a specific embodiment, the nanocomposite material contains approximately 0.06 μm -2 Or even smaller defect density, and approximately 98% efficiency in controlling defect types.

[0077] The multilayer nanocomposites presented in this paper are competitive barrier materials with performance comparable to or superior to current industry standards, and offer significant advantages in their materials chemistry and programmable lifecycle. These multilayer nanocomposites possess inherent recyclability and offer a solution to recycling challenges associated with existing metallization and multilayer films. The entanglement of long chains provides mechanical stability, eliminating the need for chemical crosslinking. They are suitable for cycling through assembly, disassembly, and reassembly without compromising structural integrity, highlighting the advantages of bottom-up material synthesis (see [link to article]). Figures 8A-8D Implementation methods (as described in the text).

[0078] The nanocomposites provided herein can possess improved barrier properties against volatile organic compounds (VOCs), water, oxygen, or electrons compared to control materials. In some embodiments, the nanocomposites exhibit VOC removal efficiencies of 40% or higher and 8 gm -2 sky -1 Or even lower water vapor transmission rate (WVTR), 500 MV / m -1 Or a greater dielectric breakdown strength, 3J cm -3 Or greater maximum discharge energy density and / or 3 minutes μm -1 Or a longer encapsulant lifetime.

[0079] For example, when coated on porous Teflon membranes, the 30-μm S2 / NP coating reduces the permeation of common volatile organic compounds (VOCs), with removal efficiencies of 100±0% for 2-butanone and hexanal (kinetic diameter dk≥5.3 Å), 96±0% for acetaldehyde (dk=5.0 Å), 94±9.2% for acetone (dk=4.4 Å), and 55±4.2% for formaldehyde (dk=3.7 Å). Figure 7E This performance is comparable to that of wet scrubbers based on electrochemical cells, achieving a removal efficiency of 95% at similar VOC concentrations. A 30-μm S2 / NP coating on a 127-μm polyester membrane can increase its water vapor transmission rate (WVTR) from 11.5 ± 5.7 gm. -2 sky -1 Significantly reduced to 5.3 ± 0.6 gm -2 sky -1 It exhibits more consistent barrier performance over three weeks of testing. Figure 7F ).

[0080] With a defect type control efficiency of 98%, the stacked nanosheet nanocomposite material is also an excellent electron barrier, making it a high-performance dielectric material for energy storage. The S2 / NP film at 650 MV m... -1 The energy efficiency is 91.2%, the charge / discharge efficiency exceeds 90%, and the discharge energy density is 6.2 J / cm³. -3 ( Figure 7G This performance is comparable to current industry benchmark dielectrics, including biaxially oriented polypropylene (BOPP). Figure 7G The high dielectric breakdown strength of nanocomposite films further demonstrates their importance in defect type control due to their low defect density and high efficiency.

[0081] Organic electronic devices (including organic light-emitting diodes and photovoltaic devices) must be encapsulated to prevent degradation by oxygen and water vapor; irregular device topologies present a particular challenge. Calcium films oxidize rapidly under environmental conditions, and their relative conductivity conveniently characterizes long-term device degradation. Electrocalcium tests were used to compare the barrier properties of S2 / NP nanocomposites with two standard UV-cured epoxy resins, DELO Katiobond LP655 and Ossila E132. Figure 7H Despite significant differences in barrier thickness, their performance was comparable. DELO Katiobond LP655 (approximately 119 μm) achieved 50% relative conductivity after 241 ± 27 minutes, Ossila E132 (approximately 218 μm) after 367 ± 53 minutes, and S2 / NP (approximately 35 μm) after 79 ± 11 minutes. When normalized by film thickness, the S2 / NP barrier nearly doubled the time required for the calcium film to reach 0% relative conductivity. Therefore, self-assembled nanosheets can lead to thinner and more flexible organic electronic devices, and their inherent recyclability can contribute to better control over the lifecycle of organic electronic devices.

[0082] The properties of barrier materials are determined by their composition and structure: layer composition and size, defect type and density, long-range order, mechanical properties, and geometric conformity. Nanoparticles help modulate defect types, achieve entropy-driven phase behavior, and improve barrier, dielectric, and mechanical properties. Long-range order and local defect control of nanostructures are crucial for realizing the benefits of functional nanomaterials. The order of nanocomposites also significantly affects their mechanical properties. Supramolecular structures formed from high-molecular-weight BCPs contribute to the high performance of the nanocomposites presented in this paper. Contrary to the common view that chain entanglement is detrimental to assembly kinetics, high-molecular-weight building blocks are advantageous and necessary for the programmable rapid growth of nanosheets with long-range order and defect control. Excellent barrier properties depend on the thick nanosheets they assemble into.

[0083] Nanocomposites can have hierarchically ordered structures. For example, a nanocomposite can have alternating layers of conductive (or semi-conductive) nanoparticle-rich regions and non-conductive nanoparticle-deficient regions. A nanocomposite can have alternating layers of nanosheets (or nanoparticle-rich nanosheets) and BCP-based supramolecular nanosheets (or BCP-based supramolecular nanosheets). In the presence of nanosheets (or nanoparticle-rich nanosheets) and BCP-based supramolecular nanosheets (or BCP-based supramolecular nanosheets) in a nanocomposite, each nanosheet of the nanoparticles can be about 50 nm to 410 nm thick, or 50 nm to 150 nm thick, and each nanosheet of the BCP-based supramolecular nanosheets can be 50 nm to 410 nm thick, or about 50 nm to 150 nm thick. Each nanosheet of the nanoparticles can be approximately as thick as each nanosheet of the BCP-based supramolecular nanosheets. Alternatively, each nanosheet of the nanoparticles can be thicker than each nanosheet of the BCP-based supramolecular nanosheets. Nanocomposites can also contain regions of one of the two polymers rich in BCP and regions of the other polymer rich in BCP, for example, containing PPS- b - P4VP nanocomposites contain PS-rich regions and P4VP (PDP-rich regions).

[0084] The nanocomposites provided herein have broad applicability as coatings or barrier materials. For example, the nanocomposites provided herein can be coated onto substrates (e.g., lengths and widths of about 10 cm to 15 cm, or smaller or larger). Surfaces of any texture (rough or smooth) can be coated with the nanocomposites provided herein. The coating can be used as a barrier against VOCs, water vapor, and oxygen, as well as as an electrical insulator and dielectric capacitor. The coating compositions provided herein can be readily applied as dielectric films or as electronic packaging and can be incorporated into consumer-facing packaging (e.g., food packaging paper). The advantages of the coating compositions provided herein include competitive barrier performance relative to their thickness due to their numerous layers, compared to much thicker barrier layers made of fewer layers. Furthermore, the coating compositions provided herein can have improved recyclability, as the material can be dissolved and recast as a single waste stream. The mechanical stability of the coating compositions provided herein stems from physical chain entanglement rather than chemical crosslinking. The coating compositions provided herein are manufactured via a self-assembly method, requiring no chemical conversion, and are completely reversible. As further provided herein, the nanocomposites provided herein can also be used for purposes other than as coatings or barrier materials, such as for optical materials.

[0085] B. Nanocomposites with gradient structures Spatial gradients are a valuable element in nanoscale design: they are frequently used to improve the mechanical, optical, or stimulus-responsive properties of bio-nanostructures. This paper presents nanocomposites with functionally gradient motifs generated through self-assembly. Self-assembly is typically associated with homogeneous or periodic nanostructures, but here, a single BCP-based supramolecular nanocomposite can be used to generate a rich variety of ordered multilayer structures. Layer thicknesses ranging from 72 to 400 nm can be achieved between drop-coated films of the same nanocomposite solution using different drying procedures. The nanocomposites presented in this paper can exhibit significant gradients within many individual films, with an increase in layer thickness of ≤175% observed from the bottom to the top interface of the film.

[0086] Layered nanocomposites with gradient periodicity can be fabricated by controlling processing conditions and composition, such as the concentration of small molecules (e.g., PDP), the ratio of unbonded to hydrogen-bonded small molecules, and BCPs (e.g., PS-). b -P4VP) molecular weight, as well as drying rate and conditions. Generally, a slower drying rate and / or a higher solute ratio in the solute / solvent mixture provides thicker and redder nanosheets. Furthermore, the mobility of small molecules (chemical or cross-linked) can be tuned to obtain nanocomposites of interest in specific morphologies. The nanocomposites presented herein, particularly those with gradient layer thicknesses and properties, possess unique optical properties and can be used as optical materials such as filters, flat lenses, and zone plates.

[0087] Nanocomposites can comprise multiple nanosheets with gradient layer thicknesses, for example, a thinner layer toward the substrate-nanocomposite interface and a thicker layer away from the substrate. In some embodiments, the thickness of the nanosheets in the nanocomposite ranges from about 65 nm to about 135 nm (e.g., about 72 nm to about 126 nm), about 120 nm to about 280 nm (e.g., about 151 nm to about 223 nm), about 120 nm to about 250 nm (e.g., about 127 nm to about 221 nm), or about 120 nm to about 410 nm (e.g., about 135 nm to about 370 nm).

[0088] For example, in a dry drop-coated film, the solute concentration is a function of both time and depth. Figure 9A Therefore, at each time point before the membrane is completely dry, the solute and solvent fractions form a smooth gradient across the membrane thickness. Using high molecular weight supramolecular nanocomposite blends, the width of the characteristic layer can be varied by changing the membrane drying rate and duration. Rapidly dried nanocomposite films exhibit relatively small domain thicknesses, while slowly dried films show significantly larger ones. value( Figures 9B-9EIn addition to substantial differences between samples, there are also significant differences within each individual sample. Gradient. When drying for more than 3 days, nanosheets with a thickness of 280-340 nm can be formed. Figure 12K ). Figures 9B-9E Each sample shown has the same composition, film thickness, and initial concentration. The underlying mechanism of gradient multilayers involves a combination of entropy, enthalpy, and kinetic factors.

[0089] C. Methods for producing nanocomposite materials The method for preparing the nanocomposite materials provided herein may include: contacting an initial blend of nanoparticles, small molecules, and block copolymer (BCP)-based supramolecular molecules with a solvent to form a mixture, and drying the mixture to remove the solvent, thereby forming the nanocomposite material via a self-assembly process. The nanocomposite material comprises a plurality of nanosheets, each nanosheet comprising the nanoparticles, the small molecules, and the BCP-based supramolecular molecules. The BCP-based supramolecular molecules comprise BCP and small molecules.

[0090] Nanoparticles, small molecules, and BCP-based supramolecular materials (collectively referred to as solutes) can be dissolved in solvents and can self-assemble into multilayer nanosheets during the drying process. Solvents can be any solvent that dissolves the solute (i.e., small molecules and BCP-based supramolecular materials) and is suitable for preparing nanocomposites. For example, a solvent could be chloroform, which dissolves PS and P4VP almost as well, and also PDP. A solvent could also be benzene, which dissolves the solute and has lower X-ray absorption than chloroform, making it suitable for SAXS and XPCS studies. Solutes can be dissolved in solvents to form solutions of 1–20 vol% (e.g., 1–5, 5–10, 10–15, 15–20, or greater than 20 vol%). The overlap concentration of polymer solutions in good solvents is... N –1.8 For solutes containing 134-kDa BCP, the estimate is >20% by volume, and for solutes containing 455-kDa BCP, the estimate is approximately 2.7% by volume.

[0091] Contacting an initial blend of nanoparticles, small molecules, and BCP-based supramolecular materials with a solvent may include contacting the initial blend of nanoparticles, small molecules, and BCP-based supramolecular materials with a solvent comprising about 95% to about 100% or about 97.5% of the mixture (i.e., the initial blend comprises about 5% or less, or about 2.5% of the mixture).

[0092] The drying process may include removing the solvent to initiate a self-assembly process. The solute may begin to aggregate in a solution of about 3-10 (e.g., 5) volume % (i.e., 90-97 volume % solvent, e.g., 95 volume %). Self-assembly can occur as the volume percentage of solvent in the mixture decreases and the volume percentage of solute increases. For example, self-assembly can occur when the volume percentage of solvent is about 70% to about 80% or less (i.e., about 20% to about 30% or more solute). For example, as... Figure 4H As shown, nanostructures can be formed at solute concentrations of 23%, 28%, and 40% vol%. However, when solvent removal occurs at 23% vol, long-range order is poor. Despite high system mobility, the solute concentration is too dilute to drive the condensation of molecular aggregates. With rapid solvent removal at 40% vol, different nanosheets are formed, but with high defect density and an aspect ratio less than 40. This indicates that nanostructure formation can compete with and disrupt microframework formation. Optimal long-range order can be achieved by quenching the film at 28% vol (slightly lower than the concentration used to form nanosheets).

[0093] The drying process can take from approximately 20 minutes to approximately 3 days (e.g., 20 minutes, 30 minutes, 60 minutes, 90 minutes, 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 1 day, 2 days, 3 days), and can be adjusted based on the process speed and the desired nanocomposite material. When the nanocomposite material dries too quickly, the microdomains may be disordered and may not form a microframework (e.g., Figure 6E ).

[0094] This method may also include adjusting the drying rate, mixture depth, and / or solute / solvent ratio in the mixture to adjust the thickness and / or color of multiple nanosheets. Generally, a slower drying rate or a higher solute ratio in the mixture can produce thicker and / or redder nanosheets. The method presented herein can produce nanocomposites with gradient multilayers by adjusting parameters and using a self-assembly mechanism.

[0095] The mixture can be drop-coated onto a substrate before drying. The substrate can be any material with any surface condition, including solids, lenses, films, thin films, or wafers made of Teflon, polyester, silicon, or glass.

[0096] The BCP-based supramolecular used in this method comprises BCP and small molecules bound to the BCP via non-covalent bonds.

[0097] BCPs can contain molecular weights from about 130 kDa to about 600 kDa, such as about 130 kDa, about 200 kDa, about 300 kDa, about 400 kDa, about 450 kDa, about 500 kDa, about 560 kDa, or about 600 kDa. As specific examples, BCPs can have molecular weights of 134 kDa, 455 kDa, and 557 kDa, as listed in Table 1. In specific embodiments, BCPs are high molecular weight polymers (e.g., having molecular weights of about 100, 200, 300, 400, 500 kDa, or greater).

[0098] Each of the BCP-based supramolecular molecules may contain a BCP and a small molecule bound to the BCP via non-covalent bonds. For example, a BCP-based supramolecular molecule can be constructed by non-covalently attaching a small molecule to a polymer side chain.

[0099] The small molecule can be an organic molecule. The small molecule can have a molar mass of about 50 g / mol to about 1500 g / mol. In a specific embodiment, the small molecule comprises 3-pentadecanylphenol (PDP).

[0100] For example, BCP can be polystyrene- b - Poly(4-vinylpyridine) block copolymer (PS- b -P4VP). BCP-based supramolecular molecules can be PS- b -P4VP(PDP)1, which contains PS- via hydrogen bonding b PDP bound to the pyridine side chain of -P4VP. PS- b -P4VP comprises two randomly coiled blocks, forming spherical microdomains of P4VP surrounded by a PS matrix. Unbound by any particular theory, when PDP hydrogen-bonded to the pyridine ring, the P4VP blocks are stretched to form rigid comb-like blocks. This structure occupies a significantly larger volume, thus the supramolecular form layered rather than spherical microdomains. Through binding with the pyridine ring, PDP also forms a periodic layered structure, resulting in a hierarchical morphology of lamellae-within-lamellae.

[0101] Nanoparticles can be inorganic molecules, such as metal oxide nanoparticles [e.g., zirconium oxide (ZrO2)], noble metal nanoparticles (e.g., gold), or silica nanoparticles. In some embodiments, the nanoparticles have a size of about 3 nm to about 50 nm, a size of about 3 nm to about 9 nm, or a size of about 6 nm. In a specific embodiment, the nanoparticles comprise ZrO2 with a size of about 6 nm.

[0102] Table 1 provides example formulations and compositions of the initial blends presented herein. PDP molecules are dispersed in PS-rich and P4VP-rich microdomains (PDP). The dispersed PDP molecules screen for unfavorable interactions between PS and P4VP (PDP) and achieve entropy-driven phase behavior (e.g., formulation flexibility). Based on 557-kDa PS- b -P4VP's S3 / NP blends can accommodate up to 20% by volume of nanoparticles within parallel layers.

[0103] In the method provided herein, nanoparticles may comprise about 3-20% by volume (e.g., about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20% by volume) of the initial blend of nanoparticles, small molecules, and BCP-based supramolecular molecules; small molecules may comprise about 10-25% by volume (e.g., about 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25% by volume) of the initial blend of nanoparticles, small molecules, and BCP-based supramolecular molecules; and BCP-based supramolecular molecules may comprise about 65-75% by volume (e.g., about 65, 66, 67, 68, 69, 70, 71, 72, 83, 74, or 75% by volume) of the initial blend of nanoparticles, small molecules, and BCP-based supramolecular molecules.

[0104] This method may include drying a mixture to remove solvent, forming a material comprising alternating layers of conductive (or semi-conductive) nanoparticle-rich regions and non-conductive nanoparticle-deficient regions via a self-assembly process. This method can produce nanocomposites having alternating layers of nanoparticle-rich nanosheets and BCP-based supramolecular nanosheets. In the presence of both nanoparticle-rich and BCP-based supramolecular nanosheets in the nanocomposite, each nanosheet may be approximately 50 nm to 410 nm thick, or 50 nm to 150 nm thick, and each BCP-based supramolecular nanosheet may be approximately 50 nm to 410 nm thick, or approximately 50 nm to 150 nm thick. Each nanosheet may be approximately as thick as each BCP-based supramolecular nanosheet. Alternatively, each nanosheet of the nanoparticles can be thicker than each nanosheet of the BCP-based supramolecular polymer. This method can also produce nanocomposites having regions of one of two BCP-rich polymers and regions of another BCP-rich polymer, for example, containing PPS- b- P4VP nanocomposites contain PS-rich regions and P4VP (PDP-rich regions).

[0105] Nanocomposites produced by the methods described herein are also provided. The nanocomposites may comprise about 20 to about 100, about 20 to about 200, or about 200 or more nanosheets, each nanosheet being about 50 nm to about 410 nm thick, for example, about 50-100, 50-150, 50-200, 200-300, 300-410 nm thick, or about 150, 100, 125, 150, 200, 250, 300, 350, 400, or 410 nm thick. The nanocomposites may have a thickness of about 0.06 μm. -2 Or even lower defect density, and approximately 98% efficiency in controlling defect types. Nanocomposites can possess improved barrier properties against volatile organic compounds (VOCs), water, oxygen, or electrons compared to control materials, and / or any other properties provided herein.

[0106] This document also provides barrier materials comprising nanocomposite materials produced by the methods provided herein. Nanocomposite materials produced by the methods provided herein can be used as barrier materials, optical materials, or coating materials in a variety of applications, including but not limited to use as volatile organic compound barriers, water barriers, oxygen barriers, electronic barriers, dielectric capacitors, optical materials (e.g., filters, flat lenses, zone plates), and / or for packaging consumer products (e.g., as food packaging paper).

[0107] Example Example 1: Functional composite materials that enable programmed entropy-driven nanosheet growth This addresses the current challenges in fabricating 2D nanosheets by introducing novel nanomaterial designs with two key elements: (1) the ability of entropy-driven assemblies to adapt to changes in reactant composition and pairing interactions during processing and integration, and (2) system mobility that matches the necessary diffusion of building blocks to form the target structure. Figure 1B As shown, sequential growth follows a nanometer-to-micrometer growth process, where the smallest structural features are formed when the system mobility is highest, and vice versa. The growth pathway presented in this paper proceeds in the opposite order, first micrometer-then nanometer. Figure 1CWhen the system has the highest mobility, the microstructure is first defined, and then the nanostructure is formed through the local organization of the building blocks. Entropy-driven phase behavior facilitates this large-to-small growth path. It allows the system to form micro-aggregates in dilute solutions when the system is mobile enough to organize large-scale structures. Thermodynamically, the entropy-driven phase behavior observed in high-entropy alloys provides formulation flexibility while maintaining structural fidelity. Therefore, when the system mobility is low, many combinations of locally available components can be used to form the target nanostructure. Guided by this novel design, a coating consisting of more than 200 stacked nanosheets (125 nm thick) was fabricated with a defect density of less than 0.056 μm. -2 Furthermore, it exhibits a defect control efficiency of approximately 98%. The coating demonstrates high-performance barrier properties against volatile organic compounds, water, and oxygen used in packaging, as well as high-performance barrier properties against electrons used in dielectric capacitors.

[0108] System Selection Entropy-driven assembly methods were tested using complex blends exhibiting entropy-driven self-assembly. A specific blend consisted of 6 nm zirconium oxide (ZrO2) nanoparticles, 3-pentadecanylphenol (PDP) small molecules, and BCP-based supramolecular (abbreviated as PS-) b -P4VP(PDP)1) constitutes the PS- b -P4VP(PDP)1 is achieved by hydrogen bonding PDP to polystyrene- b - Poly(vinylpyridine) block copolymer (PS- b It is constructed on the pyridine side chain of (-P4VP). Figures 2A-2I As shown, these blends are self-assembled, exhibiting formulation flexibility and structural fidelity similar to those observed in high-entropy alloys. They form nanostructures when the effective interaction between PS-rich microdomains and P4VP-rich (PDP)-rich microdomains approaches or equals zero. Therefore, components can readily diffuse across the interface, even when system mobility is low. The P4VP chemistry is beneficial for optimizing substrate adhesion of the coating.

[0109] The ultimate goal is to design technology-related coating materials, selecting supramolecular materials based on high molecular weight BCP to obtain the thick nanosheets required for mechanical robustness and good barrier properties. Table 1 lists formulations of complex blends based on BCP with molecular weights of 134 kDa, 455 kDa, and 557 kDa. They form periodic layered or cylindrical microdomains ranging from approximately 60 nm (S1 / NP) to approximately 170 nm (S3 / NP). PDP molecules are dispersed in PS-rich microdomains and P4VP-rich (PDP)-rich microdomains; Figure 3Spatial-resolved energy-dispersive X-ray spectroscopy (EDS) of S2 / NPs with iodine-labeled small molecules (I-PDPs) is shown. The dispersed PDP molecules screen for unfavorable interactions between PS and P4VP (PDPs) and are essential for achieving entropy-driven phase behavior, such as formulation flexibility. The specific ligand chemistry of zirconium dioxide (ZrO2) nanoparticles is not yet clear, but is based on 557-kDa PS- b -P4VP's S3 / NP blends can accommodate up to 20% by volume of nanoparticles within parallel layers.

[0110] Long polymer chain entanglements play several roles: they program kinetic pathways to match the system's mobility to its structural evolution stages and regulate local defect morphology. The overlap concentration of polymer solutions in good solvents exhibits... N –1.8 Furthermore, for S1, the estimate is >20% by volume, and for S2 based on 134-kDa and 455-kDa BCPs, it is estimated to be approximately 2.7% by volume. By using high molecular weight building blocks, the blends form molecular aggregates in a more dilute solution. This provides sufficient system mobility to organize the molecular aggregates into extended microframeworks for subsequent nanostructure formation. During subsequent growth and organization, long-chain entanglement increases the kinetic stability and integrity of the aggregates. Long-chain entanglement can mitigate local reorganization at defect sites, thereby maintaining end-to-end pair-defect morphology.

[0111] Table 1. Formulations and composition of the blends studied The supramolecular identifier includes the molecular weights of the PS and P4VP blocks. It is expected that the PDP molecule is hydrogen-bonded to the 4VP monomer in a 1:1 ratio, denoted as P4VP(1).

[0112] Formation of nanocomposites: kinetic pathways To program the growth of nanosheets, blends of S1 / NP, S2 / NP, and S3 / NP were investigated to identify the solution concentrations that form molecular aggregates and layered microdomains / nanosheets, and to quantify the system mobility at the nano and micro scales. Using small-angle neutron scattering (SANS) and small-angle X-ray scattering (SAXS), it was found that S2 / NP forms molecular aggregates with specific nanoparticle distributions, forms P4VP-rich regions at approximately 10 vol% solute concentration, and forms well-defined sheets at 30 vol% solute concentration. Figure 4ASANS curves for S2 / NP at solute concentrations of 5 vol% and 10 vol% are shown. Guinier-Porod analysis indicates that at 5 vol%, S2 / NP forms fuzzy molecular aggregates with a size of approximately 100 nm, and there is no preferential partitioning of nanoparticles. At 10 vol%, the molecular aggregates become clearer, with a more defined aggregate / solvent interface, and nanoparticles preferentially occupy regions rich in P4VP (PDP). However, layered microdomains are not yet assembled. Ultrasmall-angle neutron scattering (USANS) indicates the presence of larger aggregates. q =3.8 × 10 -3 nm -1 Estimate from the inflection point of the slope R g is 453 nm ( Figure 4B Randomly arranged aggregates were also observed in liquid pool transmission electron microscopy (TEM) studies. Figure 4B ,illustration).

[0113] The non-uniform distribution of nanoparticles in 10 volume% S² / NP was confirmed using SAXS, revealing wide correlated pores with a characteristic size of approximately 114 nm (q = 0.055 nm⁻¹). This is consistent with... Figure 4C The ultrasmall angle X-ray scattering (USAXS) curves of the S3 / NP blends are consistent. The S3 / NP blends are based on a 557-kDa BCP and form molecular aggregates at much lower solute concentrations than S2 / NP. Indeed, at a 10 vol% solute concentration, the USAXS curves of S3 / NP show large-scale assemblies demonstrated by strong scattering in the low q region and a scattering peak at q = 0.043 nm⁻¹, indicating emerging nanostructures. Figure 4C In-situ SAXS studies showed that when the S2 / NP solution concentration approached approximately 30% by volume, ordered layered microdomains with a periodicity of 126 nm and a Scherrer grain size of approximately 1.73 μm formed almost immediately. Figure 4D Aggregates can be rapidly transformed into nanosheets. Therefore, microscopically arranged molecular aggregates can be used to template the growth of nanosheets and modulate the long-range order of nanocomposites. However, achieving this requires a large system mobility.

[0114] The mobility of the S2 / NP system was quantified using X-ray photon correlation spectroscopy (XPCS) to examine the spatial distribution of ZrO2 nanoparticles throughout the in-situ drying process. Figure 4EBased on the fitted Kohlrausch exponent γ, as the solute concentration increased from 10 vol%, the diffusion of nanoparticles changed from subdiffusion (γ≈3.5) to diffusion (γ≈2). This is consistent with the SANS results and indicates that nanoparticles leave the tangled PS network to selectively enrich regions rich in P4VP (PDP). The diffusivity of nanoparticles was further quantified at the nano and micro scales by measuring the relaxation time at two length scales: at q=0.3 nm. -1 τ at time s and at q=0.03 nm -1 τ at time l ( Figure 4F When molecular aggregates reach approximately 10% by volume, the blend exhibits good mobility for both nano- and micro-diffusion, τ. s (10) -5 s) is approximately greater than τ l (10) -3 The relaxation time is 100 times faster than the τ-s. However, when nanosheets are formed (approximately 30% by volume), the relaxation time increases dramatically (τ). l ≈1000 s and τ s The diffusion time is approximately 100 s and is proportional to the diffusion length scale they describe. The system mobility is too limited to alter the templated microstructure. Subsequent nanostructure formation must rely on short-range diffusion to locally organize the different building blocks.

[0115] Using S1 cyl The / NP blend was used to assess the generality of the assembly process, which forms cylindrical microdomains with a periodicity of approximately 80 nm. The processing of S1 was controlled. cyl The drying conditions of the / NP film were adjusted to alter the incubation time (Δ) between the formation of molecular aggregates and the formation of nanostructures. t In-situ grazing transmission small-angle X-ray scattering (GTSAXS) was used to characterize the structural evolution over the entire solution / film thickness at an estimated beam path length of approximately 1.5 mm. When Δ t Sufficient time (approximately 11 minutes for this blend) was observed, and diffraction peaks of several orders of magnitude rapidly appeared, confirming that mobility-based nanostructure growth can lead to a high degree of long-range order in morphologies other than lamellar structures. Figure 4G ).

[0116] Long-range ordering and defect optimization The early microstructure determines the long-range order of the nanostructure. The diffusion mode of the nanoparticles and the stepwise change in system mobility define the processing window for micro-first-nano-later growth. The microstructure determines the long-range order achieved in the nanostructure. Rapid solvent removal is used to kinetically capture nanocomposite films at specific solute concentrations selected from the scattering results. Figure 4H Representative cross-sectional TEM images of S2 / NP films quenched at 23 vol%, 28 vol%, and 40 vol% are shown. For all samples, nanostructures were clearly formed despite rapid solvent removal. This again confirms that nanostructure formation is not the rate-limiting step in the hierarchical growth of nanosheets. When solvent removal occurs at 23 vol%, long-range order is poor. Although the system mobility is high, the solute concentration is too dilute to drive the condensation of molecular aggregates. With rapid solvent removal at 40 vol%, different nanosheets were formed, but with high defect density and an aspect ratio of less than 40. This indicates that nanostructure formation can compete with and disrupt microframework formation. Optimal long-range order was achieved by quenching the film at 28% (slightly lower than the concentration at which nanosheets are formed). The nanosheets are tens of micrometers in length and have an aspect ratio greater than 500. Therefore, long-range order, i.e., defect density, can be tuned by optimizing the organization of sheet-like aggregates prior to nanostructure formation.

[0117] The type of defect also determines the barrier performance, as different defects have different effects on the transport pathway. The prevalence of different defect types is determined by short-range diffusion in the final stage of assembly. The complete defect density is provided in Table 2. Blends based on lower molecular weights (e.g., S1) exhibit more circular microdomains between nanosheets, while sharply curved microdomains (which we term "U-turn" defects) are less common. These defect morphologies are the result of local reorganization and indicate that the system has sufficient mobility to reorganize BCP-based supramolecular structures to release stacking frustration. However, for blends based on high molecular weight building blocks (e.g., S2 / NP and S2), most defects are paired ends and U-turn types. Some nanosheets bend into several consecutive U-turns ( Figures 5A-5BSignificant energy losses exist associated with bending nanosheets at such sharp angles. However, the entanglement of long chains raises the energy barrier for local reorganization and dynamically traps these defects after microframework formation. U-shaped bend defects can be eliminated by increasing the stiffness of the nanosheets, for example, by adding nanoparticles or driving the system to a lower solvent fraction to further enhance long-range order. Paired end defects break the transport path and are desirable for barrier material engineering. Therefore, the ability of long-chain entanglement to decouple defect manipulation from nanostructure formation is advantageous for controlling the prevalence of different defect types.

[0118] Table 2. Output of full defect analysis for thick and thin films The composite material image is divided into five sub-images of approximately equal size. The defect density of each sub-image is calculated, and the standard deviation of the density is also calculated.

[0119] Programmatic composite coating manufacturing Macroscopic nanocomposite coatings were prepared on commercial films by adjusting the evaporation time of the S2 / NP solution to maximize the time between 23 vol% and 28 vol%, followed by rapid drying. Figures 6A-6B A cross-sectional TEM image of an S2 / NP film with a thickness of approximately 35 μm is shown. The film comprises over 200 parallel sheets with a period of 127 nm. Most of the nanosheets are continuous within and beyond a 90 μm field of view. A similar degree of long-range order extends to other areas of the film. Within an imaging region of approximately 2660 μm², only 149 defects are observed. Figure 6C Due to the lack of reports on the defect density of stacked nanosheets, the defect density of a 60 nm thick cross-section was compared with that of a BCP film. Figure 6D The S2 / NP defect density is 0.056 μm. -2 It is a multi-step annealing process (3.5 μm) -2 ) or morphology-oriented self-assembly (0.267 μm) -2 (This refers to a portion of the density obtained after the process.)

[0120] Almost all defects are in pairs at the ends ( N =146 out of 149, approximately 98%; the remaining defects are paired U-turns ( N =2) and a single connection ( N=1). Nanoparticles influence long-range order and defect density, which in turn contributes to the coating's performance. The incorporation of nanoparticles significantly increases the layer's stiffness and flexural modulus. They result in straight nanosheets with high aspect ratio and low defect density, and decouple the defect type distribution from U-turns and junctions. Kinetic control can adequately compensate for the increase in high-molecular-weight supramolecular entanglement. When the incubation time Δ t Reduced, only poorly ordered S1 / NP and S2 / NP films were observed; sufficiently long Δ t This results in a highly ordered S3 / NP film with a periodicity of 174 nm and a nanoparticle loading of 20% by volume. Figures 6E-6F ).

[0121] When designed at the system level, these nanocomposite films do indeed meet many of the requirements for functional barrier coatings. With their long-range ordered and high-molecular-weight building blocks, S2 / NP films are flexible and mechanically robust; their vibrant structural colors are an added bonus due to their relatively large feature size. Measured using nanoindentation, their elastic modulus is 512 ± 122 MPa, and their hardness is 13.6 ± 3.3 MPa. Due to their entropy-driven phase behavior, stacked nanosheets are formed on various substrates, despite differences in substrate chemical composition (silicon, glass, polyester, and Teflon) and roughness and shape irregularities. Figures 2A-2I Cyclic tensile and buckling tests ( N =600) was applied to an S2 / NP coated polyester substrate (127 μm thickness, McMaster-Carr), and the coating maintained its integrity without delamination or crack formation.

[0122] High-performance nanocomposite barrier Barrier materials are crucial for product preservation and lifespan, forming the core pillar of durability. Multilayer nanocomposite coatings are competitive barrier materials with performance comparable to or superior to current industry standards, offering significant advantages in their materials chemistry and programmable lifecycle. Within each nanosheet of the S2 / NP film, the nanoparticle-rich region is approximately 70 nm thick and contains 10-15 layers of densely packed ZrO2 nanoparticles, reminiscent of miniaturized metallized films. Figure 7A However, these composite coatings possess inherent recyclability and offer a solution to the recycling challenges associated with existing metallized and multilayered membranes. The entanglement of long chains provides mechanical stability, eliminating the need for chemical crosslinking. They are suitable for cycling through assembly, disassembly, and reassembly without compromising structural integrity, highlighting the advantages of bottom-up material synthesis. Figures 8A-8D ).

[0123] When coated onto porous Teflon membranes, the 30-μm S2 / NP coating reduces the permeation of common volatile organic compounds (VOCs), such as 2-butanone and hexanal (kinetic diameter). d The removal efficiency of ≥5.3 Å was 100±0%, and that of acetaldehyde ( d k =5.0 Å) was 96±0%, acetone ( d k =4.4 Å) was 94±9.2%, formaldehyde ( d k =3.7 Å) is 55±4.2% ( Figure 7E This performance is comparable to that of wet scrubbers based on electrochemical cells, achieving a removal efficiency of 95% at similar VOC concentrations. As an alternative to multilayer packaging films, the water vapor transmission rate (WVTR) barrier properties of the composite coating were tested. A 30-μm S2 / NP coating on a 127-μm polyester film reduced its WVTR from 11.5 ± 5.7 gm. -2 sky -1 Significantly reduced to 5.3 ± 0.6 gm -2 sky -1 It exhibits more consistent barrier performance over three weeks of testing. Figure 7F ).

[0124] With a defect type control efficiency of 98%, the stacked nanosheet nanocomposite material is also an excellent electron barrier, making it a high-performance dielectric material for energy storage. The S2 / NP film at 650 MV m... -1 The energy efficiency is 91.2%, the charge / discharge efficiency exceeds 90%, and the discharge energy density is 6.2 J / cm³. -3 ( Figure 7G This performance is comparable to current industry benchmark dielectrics, including biaxially oriented polypropylene (BOPP). Figure 7G The high dielectric breakdown strength of nanocomposite films further demonstrates their importance in defect type control due to their low defect density and high efficiency.

[0125] Organic electronic devices (including organic light-emitting diodes and photovoltaic devices) must be encapsulated to prevent degradation by oxygen and water vapor; irregular device topologies present a particular challenge. Calcium films oxidize rapidly under environmental conditions, and their relative conductivity serves as a convenient surrogate indicator of long-term device degradation. Electrocalcium testing was used to compare the barrier properties of S2 / NP nanocomposites with two standard UV-cured epoxy resins, DELO Katiobond LP655 and Ossila E132. Figure 7HDespite significant differences in barrier thickness, their performance was comparable. DELO Katiobond LP655 (approximately 119 μm) achieved 50% relative conductivity after 241 ± 27 minutes, Ossila E132 (approximately 218 μm) after 367 ± 53 minutes, and S2 / NP (approximately 35 μm) after 79 ± 11 minutes. When normalized by film thickness, the S2 / NP barrier nearly doubled the time required for the calcium film to reach 0% relative conductivity. Therefore, self-assembled nanosheets can lead to thinner and more flexible organic electronic devices, and their inherent recyclability can contribute to better control over the lifecycle of organic electronic devices.

[0126] Systematic comparative studies have confirmed the importance of holistic nanomaterial design for realizing technology-related nanomaterials. Figures 7E-7H The properties of barrier materials are determined by every aspect of their composition and structure: layer composition and size, defect type and density, long-range order, mechanical properties, and geometric conformity. Nanoparticles help tune defect types, achieve entropy-driven phase behavior, and improve barrier properties, dielectric properties, and mechanical properties. Long-range order and local defect control of nanostructures are crucial for realizing the benefits of functional nanomaterials. Poorly ordered S2 / NP composites are denoted as S2. dis / NP, its discharge energy density decreased by more than 30%, from 6.2 Jcm to 4.3 Jcm. -3 Furthermore, it cannot serve as an effective water barrier coating. The orderliness of nanocomposites also significantly affects their mechanical properties. Poorly ordered S2... dis The S1 / NP composite exhibits an elastic modulus of 303 ± 129 MPa, which is 60% of the ordered value, and a hardness of 1.4 ± 1.4 MPa, which is only about 10% of the ordered value. The supramolecular structure formed from high molecular weight BCPs is crucial for the high performance of each application tested in this study. Contrary to the common view that chain entanglement is detrimental to assembly kinetics, high molecular weight building blocks are advantageous and necessary for achieving programmable rapid growth of nanosheets with long-range order and defect control. Excellent barrier properties depend on the thick nanosheets they assemble into. When the nanosheet thickness is only 60 nm, the barrier efficiency of S1 / NPs drops to 20–36% for all volatile organic compounds, less than 10% for water, and the dielectric breakdown strength decreases from 637 MV m. -1 Reduced to 469 MV m -1 The maximum discharge energy density decreased by more than 50%.

[0127] Overview The successful transformation of nanosheets into high-performance barrier materials highlights the importance and necessity of engineered nanomaterials at the system level. The results presented in this paper demonstrate the feasibility of converting limitations in previous designs into unique advantages, resulting in nanomaterials that meet diverse requirements. This example shows that properly engineered nanomaterials are inherently multifunctional and, if designed correctly, will ultimately leverage the power of nanoscience to advance technology.

[0128] Materials and methods Material: Polystyrene b - Poly(4-vinylpyridine) block copolymer was purchased from Polymer Source, Inc. (polydispersity index = 1.1-1.2). 3- n - Pentadecylphenol (90-95% purity) was purchased from Acros Organics. Chloroform was purchased from Fisher Scientific; HCl was not detected by NMR. Deuterated chloroform was purchased from Cambridge Isotope Laboratories. Zirconia nanoparticles (6±2 nm) dispersed in toluene were purchased from Pixelligent. All materials were used as received without further purification. In the following methods, block copolymers are abbreviated as PS- b -P4VP, and the abbreviation for small molecules is PDP. The abbreviation for supramolecular molecules is PS-. b -P4VP(PDP) is used to denote the hydrogen bonding between PDP and 4VP monomers. More PDP than possible bonding sites are added, resulting in more than one PDP molecule per 4VP monomer. The ratios for each blend are provided in Table 1.

[0129] Sample solution preparation. PS- b -P4VP and PDP powders were dissolved in chloroform to form 25 mg / ml -1 (2.5 vol%) supramolecular solution. The solution was stirred overnight. For samples containing particles, a separately prepared nanoparticle suspension (25 mg mL ZrO2 nanoparticles in chloroform) was added to the supramolecular solution and mixed by pipetting. For the SANS and USANS studies, the same preparation was performed using deuterated chloroform. For the SAXS and XPCS studies, the same preparation was performed using benzene due to the high X-ray absorption of chloroform. Cross-sectional TEM imaging confirmed that the self-assembly pathway was consistent in both benzene and chloroform.

[0130] Sample preparation for drop-coated films: For each drop-coated film, a 50 μL droplet of a 2.5 v / v solution was deposited onto a 1.5 cm² square silicon substrate. To slow the drying process, the substrate was sealed together with a 70 μL stock solution of pure solvent in a capped 125 ml glass jar. The solution was allowed to dry for a predetermined time (20, 30, 60, or 90 minutes). At the end of the drying time, the jar was opened and the substrate was quickly removed from the jar. Any remaining solvent evaporated within approximately 3 seconds, effectively “freezing” the microstructure of the nanocomposite.

[0131] The film thickness was measured as a function of its drying time using a white light interferometer (Filmetrics F20). At the start of the drying process, the film thickness was outside the interferometer's measurement range. These thickness values ​​were estimated by interpolating between a known initial film thickness (calculated from solvent volume and substrate area) and an exponential decay fit of subsequent drying data. The thickness values ​​were converted to solvent or solute fractions to compare results from different experiments.

[0132] Bulk sample preparation. To prepare the bulk sample, 1 mL of a 2.5 vol% polymer solution was dried in a 1 mL Teflon beaker at room temperature. The beaker was not sealed or covered, thus allowing the solvent to evaporate freely. Due to the large volume of solvent, the sample was left to dry overnight. After drying, the nanocomposite was peeled off the Teflon beaker using tweezers. To prepare a deliberately disordered sample, a jet of N2 was directed across the opening of the beaker. This accelerated the drying process to approximately 30 minutes.

[0133] Static Scheme SANS and USANS Experiments. SANS experiments were conducted using the EQ-SANS instrument at the Spallation Neutron Source of Oak Ridge National Laboratory.47 The temperature of the samples contained in cylindrical quartz cuvettes was maintained at 25 ± 0.1 °C. Each sample was measured using three settings for sample-to-detector distance and minimum wavelength: 9 m / 15 Å, 4 m / 10 Å, and 2.5 m / 2.5 Å. Overall, these three configurations covered 0.002 Å. -1 <q<0.7Å -1 The momentum transfer range q. Before azimuth averaging and binning of the sample and solvent data to 1D I(q) and q using the standard procedure implemented in drtsans software 48, corrections were made for wavelength-dependent transmittance, incident flux, detector sensitivity, geometric effects, and the signal from the empty quartz cell. During data reduction, the data were scaled to 1 cm using a calibrated porous silica standard 49. -1The absolute intensity was then measured. Data from the three instrument configurations were then merged into a single dataset. The merged dataset was used for data analysis. The USANS measurements were performed on the BL-1A USANS instrument at the spallation neutron source, using three wavelengths of 1.2, 1.8, and 3.6 Å to cover 5 × 10⁻⁶ Å. -5 Up to 3 × 10 -3 Å -1 The wave vector q range was determined. Samples were loaded into 2 mm Hellma cuvettes. Data were reduced by empty cell background correction and presented in absolute intensity units.

[0134] Guinier-Porod model information and fitting method. Guinier-Porod fitting follows Hammouda, 2010. J. Appl Crystallography The method was first described in 43, 716-719, doi:10.1107 / S0021889810015773. This method was chosen because it is compatible with the coexistence of poorly defined and / or non-spherical structures, and because the fitted parameters have a reasonable physical interpretation. The Guinier-Porod model is entirely empirical. Vargo et al. 2023 Nature The Supplementary Information Section 1 of 623:724-731, https: / / doi.org / 10.1038 / s41586-023-06660-x further describes the details of the Guinier-Porod model information and fitting methods.

[0135] The static solution USAXS. Absolutely calibrated USAXS and SAXS experiments were performed on beamline 9-ID at the Advanced Photon Source, Argonne National Laboratory. The combined q range is 1 × 10⁻⁶. -4 Å -1 and 1.3Å -1 Between; here q = 4π / λsin(θ), where λ is the wavelength and θ is half the scattering angle. The X-ray energy is 21 keV (λ = 0.5895 Å). Through a beam of size 0.5 × 0.5 mm, the X-ray photon flux is approximately 5 × 10⁻⁶. 12 mm -2 s -1The data was reduced using USAXS instrument data restoration software and desmeared from the slit-smeared collimation of the Bonse-Hart USAXS system.

[0136] In-situ SA-XPCS. In-situ small-angle X-ray scattering and X-ray photon correlation spectroscopy (SA-XPCS) experiments were conducted on beamline 8-ID-I of the Advanced Photon Source at Argonne National Laboratory. The X-ray energy was 10.9 keV; the horizontal beam size was 15 μm and the vertical beam size was 10 μm, defined by the upstream guard slit. For the drying experiment, a 10 vol% S1 / NP solution was loaded into a quartz capillary (2 mm outer diameter, Charles Supper). The capillary was opened to allow the solvent to evaporate freely. Due to the small surface area of ​​the capillary, the drying process took approximately 12 hours. Scattering data were collected every 15 minutes. The diffusion of the liquid within 15 minutes was sufficient to avoid visible beam damage. Local solution concentrations could not be measured during the drying process, except for the known initial concentration. 2D scattering intensities were collected using a Rigaku XSPA-500k detector. Fast dynamics (early stages of drying) were captured at a frame rate of 50 kHz, with a total acquisition time of up to 2 seconds. Slow-motion (late drying stage) data was captured at a frame rate of 100 Hz, with the total acquisition volume matched to the timescale of the samples (50 seconds in this study). SA-XPCS analysis was performed on a high-performance cluster using the APS data management system workflow. The graphics modules and function libraries provided by pyXPCSviewer were used to visualize, fit, and plot the SAXS and XPCS results.

[0137] GTSAXS experiments were conducted on beamline 8-ID-E of the Advanced Photon Source at Argonne National Laboratory. X-rays were emitted at a wavelength of 1.687 Å, and the scattered intensity distribution was captured by a Pilatus 1M detector. A 2 × 2 cm silicon substrate was placed in a chamber designed for in-situ measurements and aligned with the beam. A selected volume (350 or 500 μL in this case) of chloroform stock solution was injected into the chamber to slow the drying process, and then 100 μL of sample solution was drop-coated onto the substrate. GTSAXS measurements were performed at an incident angle of 0.8°.

[0138] TEM Sample Preparation and Imaging. The bulk sample was embedded in resin (Araldite 502, Electron Microscopy Sciences) and cured overnight at 60°C. A resin-coated film sample was then applied and cured overnight at 60°C. The silicon substrate was removed by immersing the resin-coated film in liquid nitrogen; due to the mismatch in thermal expansion, the nanocomposite film peeled off the silicon and remained attached to the resin. Segments approximately 60 nm thick were cut using an RMC MT-X microtome (Boeckeler Instruments), floated on water, and picked up on a copper TEM grid. For samples without nanoparticles, the P4VP region was selectively stained with iodine vapor. The thin segments were imaged using a FEI Tecnai 12 at an accelerating voltage of 120 kV. To produce high-resolution synthetic images… Figure 6A Collect overlapping TEM images and manually align them in Photoshop using reference images at a lower magnification.

[0139] Automated Nanosheet Length and Defect Analysis. The image analysis code is executed in Python, using methods derived from ADAblock, an ImageJ plugin developed by Murphy et al. In short, the grayscale TEM image is binarized using a local Otsu thresholding technique. The binarized image is used to draw a 1-pixel-thick skeleton describing the connectivity of each layer's cross-section. The eight nearest neighbors of each skeleton pixel are used to label defects. Skeleton pixels with two nearest neighbors are considered defect-free, those with only one nearest neighbor are labeled as ends, and those with three or more nearest neighbors are labeled as junctions. Connected junctions are merged to avoid double counting. U-turn defects are not counted in this automated image analysis program because they do not affect connectivity. Each end defect is manually checked, and U-turn defects are labeled where applicable.

[0140] To perform sheet length analysis, all connecting pixels are removed from the skeleton, leaving a set of isolated 1D sheets. The length of each sheet is calculated in pixels and then converted to micrometers using the magnification of each image.

[0141] VOC removal efficiency testing. S2 / NP and S2 were prepared on a circular polytetrafluoroethylene air sampling membrane (Pall, part number R2PJ047) with a diameter of 47 mm. dis / NP, S2, and S1 / NP. In each test, the edge of the sample was held tightly between two flanges of a Teflon filter holder fitted with 1 / 4″ Teflon tubing. On one side, a filter holder was connected to a pre-filled Teflon bag rich in a mixture of formaldehyde (70-230 ppb), acetaldehyde (10-90 ppb), acetone (1.9-4.3 ppm), 2-butanone (35-90 ppb), and hexanal (40-95 ppb). Water vapor was added to the bag to achieve a relative humidity of 5-50%. The experiments were conducted at room temperature (20-23°C). Temperature and relative humidity were measured using an online digital T / RH sensor (HIH6100 series, Honeywell). On the other side of the filter holder, a peristaltic pump was used to extract air from the bag through the sample at a rate of 80-90 ml / min. -1 The flow rate was controlled. Once the gas flow through the sample reached steady state, the sample was simultaneously collected upstream and downstream of the sample over a period of 15–50 minutes by pulling air through a silica gel cartridge (Waters Corp., part number WAT047205) impregnated with 2,4-dinitrophenylhydrazine (DNPH). The DNPH cartridge was then extracted with 2 ml of carbonyl-free acetonitrile (Honeywell), and the extract was analyzed by high-performance liquid chromatography (HPLC) with UV detection (Agilent 1200) according to the US Environmental Protection Agency's TO-11 method. VOCs were identified based on retention times corresponding to their dinitrophenylhydrazine derivatives (Sigma-Aldrich). These standards were used to develop calibration curves for quantification. The reported values ​​are the average of consecutively obtained repeated determinations. The retention efficiency E for each compound was determined as follows: ,in and These are the upstream and downstream concentrations of compound i, measured simultaneously.

[0142] WVTR Test. The WVTR test setup is provided by ASTM E96-00: 'Standard Test Methods for Water Vapor Transmission of Materials'54. For each test, an aluminum can (80 mm diameter, Joywee) is filled with 4 g of desiccant granules (DampRid desiccant). A polyester sheet (127 μm thick, McMaster-Carr) is heat-sealed around the can opening to form a circular disc with a 5 mm edge. After cooling, the disc is removed from the can and filled with 2.5 ml of 2.5 vol% sample solution. After the film dries, the polyester disc is inverted and bonded to the desiccant-filled can with 5 minute epoxy (Devcon) to form a seal. A control sample is prepared following the same procedure, using 2.5 ml of pure chloroform instead of the sample solution.

[0143] After the samples were bonded to the cured disc with commercial epoxy resin, the initial weight of the samples was measured directly. The samples were then placed on a perforated plastic platform above salt-saturated water, all samples were kept in a sealed plastic container at ambient temperature and pressure to create a 75% relative humidity environment. Weight measurements were taken every 24–48 hours for three weeks following the initial weight measurement to measure the increase in desiccant water mass passing through the test membrane. The WVTR value was calculated by finding a least-squares fit of the sample mass to the acquisition time data. The slope of the fit was converted to WVTR by dividing by the film area, for the container used here. A = 40π mm 2 The standard deviation of WVTR is calculated in the same manner.

[0144] WVTR (gm) -2 sky -1 )= Calcium conductivity testing. An electro-calcium test was used to compare the barrier properties of the nanocomposite material with those of commercially available UV-cured epoxy resin. Each sample was prepared on a 125 μm polyethylene terephthalate (PET) substrate via a series of thermal evaporation steps. A pair of silver traces (100 nm thick, 2 × 15 mm in size) were used. 2 Calcium (4 mm spacing) was thermally evaporated onto a PET substrate. (100 nm thick, 8 × 8 mm) 2 The area) is thermally evaporated on top of the silver (pressure 2-5×10). -6 Torr, deposition rate <0.8 Å s -1Two traces were electrically connected, resulting in an initial conductivity <0.1 s⁻¹. Each sample was then prepared with a specified sealant and capped with a 125 μm PET cap. The decrease in conductivity of the calcium samples was a result of oxidation in the presence of oxygen and moisture. The commercial epoxy resins tested were DELO Katiobond LP655 and Ossila E132. After applying the epoxy resin and PET cap, each sample was exposed to a UV lamp until fully cured before measurement. For the nanocomposite samples, approximately 20 μL of S2 / NP solution was dropped onto the sample, covered with a PET cap, and left to assemble for approximately 1 hour before measurement. The electrical conductivity of the encapsulated samples was measured over time in a closed environmental chamber (Associated Environmental Systems BHS-503, Acton) maintained at 20% relative humidity and 20°C (Keysight DAQ970A). The approximate barrier thickness of the commercial sealant was calculated based on repeated weight measurements of the applied droplets and the manufacturer-reported bulk density.

[0145] Dielectric testing. Device manufacturing. The indium tin oxide (ITO) coated glass substrate (2-3 Ω sq, Thin Film Devices, Inc.) was pre-cleaned sequentially with soapy water, deionized (DI) water, acetone, and isopropanol. The substrate was then heated at 100°C for at least 4 hours, followed by a UV / O3 treatment for 20 minutes before use. The nanocomposite film was drop-coated onto the ITO substrate as described above. After the films were completely dry, they were placed in a vacuum chamber overnight to remove any residual solvent or moisture. Typical film thickness was approximately 2 μm.

[0146] A gold electrode (1.13 mm) was deposited on the top surface of the film sample using a thermal evaporator (MBRAUN). 2 The area and thickness are approximately 20 nm. The ITO conductive coating was electrically connected to ground using conductive silver paint (Ted Pella, Inc.). For comparison, a benchmark BOPP (vessel-grade, approximately 3-4 μm) was obtained from PolyK Technologies, LLC. Gold electrodes (1.13 mm thick) were deposited on both sides of the BOPP film using the same thermal evaporator (MBRAUN). 2 (Area, thickness approximately 20nm).

[0147] Device breakdown strength.The dielectric breakdown strength was measured using a Trek 610D instrumentation amplifier as a voltage source based on the electrostatic pull-down method, where a DC voltage ramp of 200 Vs⁻¹ was applied to the film sample until dielectric failure. The experimental dielectric breakdown measurements were analyzed using two-parameter Weibull statistical analysis, which can be described as follows: ,in P ( E ) is the cumulative probability of dielectric failure. E For the measured dielectric breakdown field, scaling parameters α The characteristic breakdown strength (i.e., Weibull breakdown strength) corresponds to a failure probability of 63.2%, and the shape parameter... β Related to the distribution of the data. Higher β The value refers to a narrower data distribution. For each Weibull fit, at least ten measurements are performed.

[0148] Dielectric energy storage properties. Electric displacement-electric field was collected under different applied electric fields using an improved Sawyer-Tower circuit. D – E This circuit is integrated with PolyK Technologies, LLC's PK-CPE1801 high-voltage test system. A voltage with a unipolar triangular waveform is applied to the membrane sample at a frequency of 100 Hz. D – E The energy storage characteristics of the dielectric were derived cyclically, including discharge energy density and charge / discharge efficiency.

[0149] Mechanical testing. Nanoindentation. Nanoindentation was performed to measure the reduced modulus and hardness of the nanocomposite coating. We used a Hysitron TI-950 Triboindenter with a Berkovich tip (TI-0039-1, 50 nm tip radius). The coating was attached to a silicon wafer using crystalline bonding and left overnight under ambient conditions for indentation. Each sample underwent 25 indentations with a maximum load of 1000 μN and a loading rate of 20 μN / s. Quasi-static indentation with a holding time of 30 seconds was performed before unloading. The applied tip area function was fitted using polycarbonate, a reference material provided by Hysitron.

[0150] The Oliver and Pharr method is used to determine the reduced modulus and hardness. Reduced modulus is defined as... The elastic modulus E indenter is 1,140 GPa, and the Poisson's ratio ν indenter is 0.07. The Poisson's ratio of the sample is assumed to be 0.34 to convert the measured reduced modulus to the elastic modulus.

[0151] Cyclic buckling test.Cyclic buckling tests on the nanocomposite coating were performed at room temperature using an MTS Tytron 250 testing machine (MTS Systems Corp.). The membrane was bent and stretched for a total of 600 cycles within a range of ±0.75 mm at a frequency of 1 Hz.

[0152] Recovery Test. A bulk nanocomposite sample was prepared as described above. After drying, a portion of the sample was removed using a razor blade and prepared for TEM imaging. The remaining bulk sample was weighed and placed in a 20 ml glass vial. The dried sample was dissolved in chloroform; the volume of chloroform was chosen to produce a 2.5 vol% solution. The bulk sample appeared to dissolve immediately; the solution was stirred overnight to ensure complete dissolution. The next day, another bulk sample was prepared as described above. TEM imaging confirmed that the recovered sample had the same layered structure as the original sample. Figures 8A-8D ).

[0153] STEM Tomography. Projected images for 3D electron tomography were acquired at 200 kV using a FEI TitanX 60-300 microscope with a 10-mrad probe semi-convergence angle at the National Center for Electron Microscopy (NCEM) facility at the Molecular Foundry. A series of TEM images were acquired using a hummingbird heavy-duty tomography rig with tilt angles ranging from ±70° at 1° intervals. The tilt series was aligned and reconstructed using eTomo software within the IMOD tomography package. Reconstruction was performed using a weighted back-5 projection method. 3D visualization was performed using Tomviz 1.3.1.

[0154] The materials, methods, and results provided in this embodiment are further described in Vargo et al., Nature 623:724-731, https: / / doi.org / 10.1038 / s41586-023-06660-x, including extended data figures and tables, and supplementary information. The entire contents of the foregoing materials are incorporated herein by reference.

[0155] Example 2: Gradient Structure in Self-Assembled Multilayer Nanocomposites The spontaneous formation of layer thickness gradients was explored in self-assembled nanocomposite systems. As provided in Example 1, the self-assembled nanocomposite systems presented herein have yielded a rich map of their self-assembly process from dilute solutions to dried composites. Among other unique behaviors, in addition to the system composition, the final ordered nanostructure is determined by processing conditions (i.e., drying rate). This processing dependence is particularly pronounced at high molecular weights, likely due to the stabilizing effect of a larger number of possible polymer configurations and chain entanglements. Cross-sectional transmission electron microscopy (TEM) imaging has shown that, under different drying conditions, a high molecular weight layered nanocomposite can form features ranging from 72 nm to over 300 nm, compared to a “bulk” periodicity of 127 nm. Within a single nanocomposite film, layer thickness can also vary spatially, smoothly increasing from the film-substrate interface to the upper film-air interface.

[0156] The nanocomposite blend consists of 6 nm ZrO2 nanoparticles, 3-pentadecanylphenol (PDP) small molecules, and a mixture of PDP and polystyrene. b The system is composed of coiled-comb supramolecular structures made up of poly(vinylpyridine) block copolymers (PS-b-P4VP). The comb-like blocks of the supramolecular structure spontaneously form when PDP molecules hydrogen-bond with the 4VP units in the BCP. Unbound and hydrogen-bonded PDPs are distinguished because these two groups play different roles in the self-assembly process and essentially act as two distinct components. Chloroform was chosen as the solvent because it is a good solvent for PS coiled blocks, resulting in a loose chain conformation at low concentrations. Small-molecule PDPs increase the system's mobility by diluting the BCP entanglements and increase the volume of the P4VP blocks. The solubility parameter of PDPs lies between the solubility of the BCP blocks and the solubility of the NP ligands; therefore, free PDPs can relax unfavorable interfaces between blocks or around NPs and stabilize the morphology with a large surface area. Free PDPs can also redistribute over relatively large distances to accommodate constraints. The moderate strength of the hydrogen bonds gives PDPs some freedom for rearrangement; the exchange between the 4VP bound and free states is an open research topic. 61 Much of the self-regulating behavior of such complex systems can be attributed to small molecules.

[0157] In dry drop-coated films, the solute concentration is a function of both time and depth. Figure 9A Therefore, at each time point before the membrane is completely dry, the solute and solvent fractions form a smooth gradient across the membrane thickness. Using high molecular weight supramolecular nanocomposite blends, the width of the characteristic layer can be varied by changing the membrane drying rate and duration. Rapidly dried nanocomposite films exhibit relatively small domain thicknesses, while slowly dried films show significantly larger ones. value( Figures 9B-9E In addition to substantial differences between samples, we also observed significant differences within each individual sample. Gradient. After rapid solvent removal, the system can achieve a lower gradient through microdomain collapse. The state is dynamically captured. However, the same mechanism cannot explain the higher states. The existence of a state. Figures 9B-9E Each sample shown has the same composition, film thickness, and initial concentration. The underlying mechanism involves a combination of entropy, enthalpy, and kinetic factors.

[0158] Structural characterization using X-ray scattering The strong dependence of gradient structures on processing history suggests they are kinetically trapped states rather than thermodynamic equilibrium. However, in-situ small-angle X-ray scattering (SAXS) reveals other factors in this mechanism. The assembly process of the nanocomposite was observed starting from an initial concentration of 10 vol%, mapping the complete structural evolution. Figure 10A If the solution is allowed to dry slowly after the appearance of a sharp layered structure factor peak, the peak will eventually broaden and move to a lower level. q The value is shifted in direction. This is easy to explain. q Displacement: The volume-average feature size increases. The broadening of the structural peaks is more unusual. This typically corresponds to the formation of small grains, as described by the Scherrer equation. However, technically, this only means that the structure of the nanocomposite deviates from perfectly periodic lamellar structures. Cross-sectional imaging of the dried samples confirmed that they maintained near-perfect domain orientation (i.e., larger than the grain size of the X-ray probe) near approximately 30% solute concentration. Therefore, the broadening of the structure factor peak was used to identify the emergence of gradient structures. Notably, the gradient only appears after the formation of large grains with highly ordered, oriented lamellar structures exhibiting uniform micro-domain periodicity. This implies that gradient structures are energetically superior to periodic layered structures, or that the energy of the system changes after the formation of periodic lamellar structures.

[0159] In addition to in-situ studies, static USAXS, SAXS, and WAXS measurements of completely dry films (with and without gradient structures) were collected to probe features on length scales from angstroms to micrometers. Figures 10B-10D The USAXS-SAXS scattering curves, though simple, provide satisfactory answers to some peripheral questions. First, they confirm that we do indeed see a net increase in sheet thickness; the increase at the top of the film is not compensated for by a decrease elsewhere. They also confirm that the different periodicities observed in the cross-sectional TEM images are representative, given the much larger sample volume probed by USAXS. The scattering results verify that the gradient is not an optical illusion caused by the tilted sheet.

[0160] WAXS peaks describe the behavior of small molecules at the angstrom level, corresponding to the organization of PDP and NP ligands. In addition to static WAXS on dried samples, solution-filled WAXS data were collected using a capillary filled with solution. Figure 10C Due to its aspect ratio, the capillary contains a range of solvent concentrations, clearly distinguishable by its structural color. Therefore, static samples can be used for approximately in-situ studies of small molecule behavior throughout the drying process. Figure 10C and Figure 10D peak iii Consistent with the WAXS characteristics of crystalline PDP at 4.17 Å (MC Luyten et al., 1999) Macromolecules 32, 13, 4404–4410). Using a control sample with only NP, the peaks... iv and v Matching with NP ligands. The volumetric NP concentration is expected to be proportional to the solute concentration because NP does not aggregate in slowly drying samples. Therefore, with peak... iv and v In comparison, peak iii The relative height describes the amount of PDP crystallization relative to a fixed amount of solute.

[0161] As the solution dried, the intensity of the PDP peak in the crystallized sample exceeded that of the NP peak in the WAXS data, indicating that the increased P4VP backbone length became fully saturated with hydrogen-bonded small molecules. The relative amounts of PDP were fairly consistent between the driest solution sample and three of the four completely dried samples. Based on their structural color and cross-sectional TEM imaging, the average domain spacing of these three samples was less than or equal to the previously reported “bulk” periodicity. However, the fourth dried sample, with its red color, indicated a larger [domain spacing] at the top surface of the film. It has significantly fewer crystalline PDPs. WAXS results indicate that gradient formation is associated with a net reduction in the amount of crystalline PDPs.

[0162] Structural characterization based on image analysis The direction of PDP redistribution can be identified by simply re-examining an existing library of cross-sectional TEM images. Assuming the layered cross-section is representative of the sample, 2D slices can be extended to 3D structures. Based on the 3D structure, the distribution of each component can be calculated by making three assumptions: each component is incompressible and its density remains constant; PS and P4VP are completely separated at the microdomain boundaries; and there is no long-range (multi-domain) PDP redistribution. In a cross-section without gradients, given nearly equal domain widths of ~64 nm, almost all unbonded PDPs were found to be within the PS domains, rather than co-crystallized within the comb. This is consistent with the conclusion that high molecular weight self-assembly is entropy-driven. As discussed in Example 1, small molecules reduce the enthalpy-driven force because they are miscible in both blocks and increase the potential mixing entropy of the system. Enthalpy becomes more important as the solvent evaporates: small molecules are preferred in the comb domains, where alkyl molecules can stack through favorable van der Waals interactions. If all small molecules are isolated in the comb domains, then the supramolecular nanocomposites (330-) explored here and previously are expected to be similar. b -125kDa and 1.6 molar ratio of PDP small molecules form PS cylinders. The sheets themselves are not only the result of their excellent order, but also the result of entropy-driven self-assembly.

[0163] When the pairs have different When samples with varying gradients were analyzed in the same way, an increasing number of unbonded PDPs were found to self-separate into comb-like structural domains. Figures 11A-11C The microdomains are becoming larger and increasingly asymmetric: for example, a 108 nm coiled domain pairs with a 225 nm comb-like domain. At the largest... At this value, it is estimated that all PDPs reside within the comb domains. This behavior can be qualitatively understood as a change in the dilution approximation used for BCP solutions. To calculate the effectiveness χ for BCP mediated by non-selective solvent molecules, the χ of the BCP melt can be simply multiplied by the solute fraction. When the solvent fraction approaches 100%, the effective χ approaches 0 – unfavorable interactions are completely shielded by solvent molecules. In nanocomposite systems, PDPs also act like solvents, albeit more selectively. Based on this understanding of enthalpy in BCP solutions, we expect the redistribution of PDPs to undergo a “positive feedback loop.” Reducing the solvent fraction produces an increased enthalpy preference for small molecules to distribute only within the comb domains. As small molecules begin to separate into the comb domains, supramolecular structures shift positions along both axes on the BCP phase diagram. χN increases because PDP molecules no longer act like solvents. f Changes have also occurred, as one block is losing volume (small molecule), while another block is gaining volume. Figure 11CBecause the solvent concentration inside the dry membrane varies spatially (lower at the top and higher at the bottom), the degree of PDP redistribution follows a corresponding gradient across the membrane thickness.

[0164] Importantly, this explanation of PDP behavior does not directly point to... Gradient formation: Conversely, it implies that the system will undergo a morphological transition from lamellar to cylindrical. Finally, here we assume we observe the kinetic effects of high molecular weight supramolecular BCPs. The lamellar-to-cylindrical morphological transition requires large-scale rearrangement of the BCPs themselves. At nearly 500 kDa, high molecular weight BCPs are effectively anchored along domain boundaries by coil-coil entanglements. In response to the increased cross-sectional mismatch between smaller coiled domains and larger comb-like domains, supramolecular BCPs cannot form curved interfaces. Instead, we predict that comb-like domains extend away from the coil-comb interface. The high content of small molecules within the domains means that this rearrangement can occur without much adverse chain stretching; small molecules can fill the volume as needed.

[0165] This mechanism explains all the scattering data, as well as the large... The asymmetry of the micro-domains. It also explains a seemingly unrelated observation: drop-coated films with a pronounced gradient structure exhibit a rough, scaly surface texture. Figures 11D-11E Cross-sectional TEM images show an unusually high number of isolated end defects toward the top surface of the gradient film. Figures 11F-11G In non-gradient structures, paired end defects that dominate can alleviate stress from top-layer shape changes, much like "sliding doors." As many individual defects pull apart, the smooth film surface is broken into irregular terraces.

[0166] Comparative study of related systems The presence of surface texture conveniently characterizes the existence of gradient structures along the cross-section of the film. We conducted a series of control experiments to test the proposed PDP redistribution mechanism. Six control samples were studied to determine whether excess PDP and / or NP is necessary for the formation of gradient structures. Figures 11A-11F As expected, samples without excess PDP exhibited significantly lower surface roughness; NP had no significant effect on the formation of gradient structures. Cross-sectional TEM of the low-PDP samples revealed ordered, uniform flakes. Figure 11G As defined by a stoichiometric 1:1 4VP:PDP ratio, a system without excess PDP may still have unbonded PDP to aid its assembly. As mentioned above, due to the reduced free volume, longer polymers cannot accommodate as many small molecules as shorter polymers with the same monomer chemistry. However, the amount of unbonded PDP is too small to cause a substantial morphological transformation.

[0167] Next, a similar system was used at lower molecular weights to probe the role of kinetics. For simplicity, NPs were not used because previous control studies have shown they do not play a significant role in gradient formation. Using 10⁴- b -30 and 50- b The supramolecular structures constructed from -17kDa BCP exhibited similar coil-to-comb ratios, as summarized in Table 3. S2 and S3 self-assembled under slow-drying conditions. The cross-sectional structures showed evidence of the same PDP redistribution process observed in S1. Figures 12H-12I The S2 blend formed a distinct... The gradient layer, its The value ranged from 48 nm at the bottom of the film to 102 nm at the top, an increase of 113%. On the other hand, the S3 blends possess large particles with cylindrical microdomains. At this lower molecular weight, the system is able to partially achieve its thermodynamically determined structure without the need for the formation of... gradient.

[0168] Table 3. Composition of the blends studied The supramolecular identifier includes the molecular weights of the PS and P4VP blocks. It is expected that the PDP molecule is hydrogen-bonded to the 4VP monomer in a 1:1 ratio, denoted as P4VP(1).

[0169] Finally, the effect of a slow, multi-day drying process was investigated. The drop-coated film, dried for 3 days, exhibited a constant high viscosity of 251–311 nm across its entire thickness. value( Figures 12J-12K No obvious surface texture was observed at the membrane-air interface. In cross-section, the regions of the clipped lamellar layers indicate that the system possesses nearly sufficient mobility to undergo a complete morphological transformation to a cylindrical domain. For comparison, Figures 9C-9E The membrane shown was slowly dried in a solvent-rich environment for one day, then rapidly transferred to solvent-free conditions. Although the top of the sample appeared dry after one day, the different structures of the membrane over three days confirmed that solvent residue remained in the lower layers of the membrane. Based on simultaneous structural color and membrane thickness measurements, it was estimated that a gradient began to form when the membrane had an average volume of 20-30% solvent. Figure 13 However, as discussed, the concentration of the film varies spatially throughout the drying process, making it difficult to pinpoint the exact transition point.

[0170] Gradient films as photonic crystals These films have a thickness comparable to the wavelength of visible light, and their vibrant structural colors confirm that they induce both constructive and destructive interference at specific wavelengths. They possess a single constant... Periodic layered nanocomposites are an example of 1D photonic crystals. Slightly aperiodic structures, such as gradient films, are optically more complex. Given the almost continuous transitions between layer thicknesses, they can exhibit interference at a range of wavelengths rather than a single wavelength. In the optical community, this geometry is called chirped photonic crystals, and their optical properties are not yet fully understood. However, they appear to be potential applications as broadband filters because they can interact with a range of wavelengths simultaneously.

[0171] The reflectance of a nanocomposite film with a periodic gradient was measured. Figures 14A-14B To prevent interference peaks in the reflection spectrum, the film is thicker than usual: ~30 μm. Due to the increased thickness, the drying rate is not easily controlled, therefore the dried film, in addition to being perpendicular to the substrate as usual... In addition to gradients, it also exhibits properties within the plane of the substrate. gradient( Figure 14A (Illustration). Most regions of the gradient film can filter a wavelength band of approximately 50-100 nm. Notably, the regions with the most significant gradient, identified by their red structural color, have almost uniform reflectivity in the visible light range. They may deviate too far from a periodic structure to satisfy the Bragg condition and no longer function as photonic crystals. Alternatively, their rough surfaces may cause light scattering, reducing reflection intensity. Besides serving as filters, Gradient films can also possess other useful optical properties. For example, flat lenses and zone plates use concentric rings with gradient widths to focus light.

[0172] Overview The relative free energy of various morphologies of nanocomposites can be estimated. Due to variations in PDP distribution, the relative free energy is a function of solute concentration. Because of the high molecular weight of supramolecular polymers, polymers begin to interact at solute concentrations below 10% by volume. At such high solvent concentrations, PDPs exhibit no enthalpy preference between blocks and are distributed almost uniformly throughout the domain. The effective block ratio of nanocomposites... f 卷曲 With a value of approximately 0.48, lamellar structures are the preferred morphology. Lamellar structures are stabilized through chain entanglement and rapidly ordered. If the sample undergoes rapid drying in this state, the result is macroscopically oriented, uniform lamellar structures. Despite their high order and uniformity, uniform lamellar structures are energy-disadvantageous once the solvent evaporates. As the solvent continues to evaporate, the effective χ² between the coiled and comb-like domains increases, and PDP molecules begin to separate into the comb-like domains. Their redistribution further increases the χ² value and shifts the effective block ratio to [value missing]. f 卷曲=0.29. A cylinder is the lowest-energy structure, but requires global rearrangement across microdomain boundaries. Asymmetric stretched sheets are a compromise: less advantageous than cylinders, but achievable via short-range rearrangement.

[0173] Layered nanocomposites with gradient periodicity can be fabricated by controlling processing conditions and composition, such as the concentration of small molecules (e.g., PDP), the ratio of unbonded to hydrogen-bonded small molecules, and BCPs (e.g., PS-). b -P4VP) molecular weight, as well as drying rate and conditions. Generally, a slower drying rate and / or a higher solute ratio in the solute / solvent mixture provides thicker nanosheets with a redder color (less blue). Furthermore, the mobility of small molecules (chemical or cross-linked) can be tuned to obtain nanocomposites of interest in specific morphologies. The nanocomposites presented herein, particularly those with gradient layer thicknesses and properties, possess unique optical properties and can be used as optical materials such as filters, flat lenses, and zone plates.

[0174] The invention has been described above with reference to specific embodiments. However, those skilled in the art will understand that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims. Therefore, the specification and drawings are considered illustrative rather than restrictive, and all such modifications are intended to be included within the scope of the invention.

Claims

1. A nanocomposite material comprising nanoparticles, small molecules, and supramolecular components based on block copolymers (BCPs). The BCP-based supramolecular structure comprises BCP and small molecules, and The nanoparticles, the small molecules, and the BCP-based supramolecular self-assemble to form multiple nanosheets of the multilayer nanocomposite material.

2. The nanocomposite material as described in claim 1, Each of the BCP-based supramolecular molecules comprises BCP and a small molecule bound to the BCP via a non-covalent bond; or The BCP described therein contains a molecular weight of approximately 130 kDa to approximately 600 kDa.

3. The nanocomposite material of claim 1, wherein the small molecule is an organic molecule comprising a molar mass of about 50 g / mol to about 1500 g / mol.

4. The nanocomposite material as described in claim 1, The nanoparticles are inorganic molecules with a size of about 3 nm to about 50 nm, about 3 nm to about 9 nm, or about 6 nm; or The nanoparticles contain metal oxides, zirconium oxide (ZrO2), noble metals, gold, or silicon dioxide.

5. The nanocomposite material as described in claim 1, The nanoparticles contain ZrO2; The small molecule mentioned above contains 3-pentadecanylphenol (PDP); The BCP contained in the BCP was polystyrene. b - Poly(4-vinylpyridine) block copolymer (PS- b -P4VP); and The BCP-based supramolecular contains PS- b -P4VP(PDP)1, which contains PS- via hydrogen bonding b -P4VP pyridine side chain bound PDP.

6. The nanocomposite material of claim 1, wherein the nanoparticles account for about 3%-20% of the nanocomposite material, the small molecules account for about 10%-25% of the nanocomposite material, and the BCP-based supramolecular molecules account for about 65%-75% of the nanocomposite material.

7. The nanocomposite material as described in claim 1, Each nanosheet has a thickness of approximately 50 nm to approximately 410 nm; The nanocomposite material comprises approximately 200 or more nanosheets; and The nanocomposite material contains approximately 0.06 μm -2 Or even smaller defect density.

8. The nanocomposite material of claim 1, having improved barrier properties against volatile organic compounds (VOCs), water, oxygen, or electrons compared to the control material.

9. The nanocomposite material as described in claim 8, having a VOC removal efficiency of 40% or higher and 8 gm -2 sky -1 Or even lower water vapor transmission rate (WVTR), 500 MV / m -1 Or greater dielectric breakdown strength, 3 J cm -3 Or a higher maximum discharge energy density or 3 minutes μm -1 Or a longer encapsulant lifespan.

10. The nanocomposite material of claim 1, comprising the plurality of nanosheets having a gradient layer thickness.

11. The nanocomposite material of claim 10, wherein the thickness of the nanosheets in the nanocomposite material is in the range of about 65 nm to about 135 nm, about 120 nm to about 280 nm, about 120 nm to about 250 nm, or about 120 nm to about 410 nm.

12. The nanocomposite material of claim 1, comprising alternating layers of nanosheets rich in nanoparticles and nanosheets lacking nanoparticles.

13. A method for producing nanocomposite materials, the method comprising: An initial blend of nanoparticles, small molecules, and block copolymer (BCP)-based supramolecular components is contacted with a solvent to form a mixture, wherein the BCP-based supramolecular components comprise BCP and small molecules; as well as The mixture is dried to remove the solvent, and the nanocomposite material is formed via a self-assembly process. The nanocomposite material comprises multiple nanosheets, which contain the nanoparticles, the small molecules, and the BCP-based supramolecular material.

14. The method of claim 13, wherein the solvent is chloroform or benzene.

15. The method of claim 13, wherein contacting comprises contacting the initial blend with the solvent comprising about 95% to about 100% or about 97.5% by volume of the mixture.

16. The method of claim 13, The drying process includes removing the solvent from the mixture when the volume percentage of the solvent in the mixture is about 70% to about 80% or less to initiate the self-assembly process; and The drying process takes approximately 20 minutes to approximately 3 days.

17. The method of claim 13, wherein the method further comprises adjusting the drying rate or the solute / solvent ratio in the mixture to adjust the thickness or color of the plurality of nanosheets, wherein a slower drying rate or a higher solute ratio in the mixture produces thicker or redder nanosheets.

18. The method of claim 13, wherein the mixture is drop-coated onto a substrate prior to drying the mixture.

19. The method of claim 18, wherein the substrate is a solid, lens, film, thin film, or wafer made of Teflon, polyester, silicon, or glass.

20. The method of claim 13, Each of the BCP-based supramolecular molecules comprises BCP and a small molecule bound to the BCP via a non-covalent bond; The BCP described therein contains a molecular weight of approximately 130 kDa to approximately 600 kDa; or The small molecule mentioned therein is an organic molecule containing a molar mass of about 50 g / mol to about 1500 g / mol.

21. The method of claim 13, The nanoparticles are inorganic molecules with a size of about 3 nm to about 50 nm, about 3 nm to about 9 nm, or about 6 nm; or The nanoparticles contain metal oxides, zirconium oxide (ZrO2), noble metals, gold, or silicon dioxide.

22. The method of claim 13, The nanoparticles contain ZrO2; The small molecule mentioned above contains 3-pentadecanylphenol (PDP); The BCP contained in the BCP was polystyrene. b - Poly(4-vinylpyridine) block copolymer (PS- b -P4VP); and The BCP-based supramolecular contains PS- b -P4VP(PDP)1, which contains PS- via hydrogen bonding b -P4VP pyridine side chain bound PDP.

23. The method of claim 13, Each nanosheet has a thickness of approximately 50 nm to approximately 410 nm; The nanocomposite material comprises approximately 200 or more nanosheets; and The nanocomposite material contains approximately 0.06 μm -2 Or even smaller defect density.

24. The method of claim 13, wherein the nanoparticles comprise about 3%-20% of the initial blend, the small molecules comprise about 10%-25% of the initial blend, and the BCP-based supramolecular molecules comprise about 65%-75% of the initial blend.

25. The method of claim 13, wherein forming comprises forming alternating layers of nanosheets rich in nanoparticles and nanosheets lacking nanoparticles.

26. A nanocomposite material produced by the method of claim 13.

27. A product comprising the nanocomposite material of claim 1, wherein the product is a barrier product or an optical product.

28. The product of claim 27, comprising volatile organic compound barrier, water barrier, oxygen barrier, electron barrier, dielectric capacitor, lens coating, packaging, filter, plane lens, and zone plate.

29. A product comprising the nanocomposite material of claim 26, wherein the product is a barrier product or an optical product.

30. The product of claim 29, comprising volatile organic compound barriers, water barriers, oxygen barriers, electron barriers, dielectric capacitors, lens coatings, packaging, filters, plane lenses, and zone plates.

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