High-performance barrier or optical materials developed through programming of entropy-driven nanosheet growth

Abstract

A nanocomposite material is provided comprising nanoparticles, small molecules, and block copolymer (BCP)-based supramolecules. The nanoparticles, small molecules, and BCP-based supramolecules self-assemble into multiple nanosheets that form a multilayer nanocomposite material. The nanoparticles, small molecules, and BCP-based supramolecules can be ZrO2, 3-pentadecylphenol (PDP), and polystyrene-block-poly(4-vinylpyridine)(PDP)1, respectively. A method for producing the nanocomposite material is also provided by contacting the nanoparticles, small molecules, and BCP-based supramolecules with a solvent, drying to remove the solvent, and allowing them to self-assemble. The nanocomposite material provided herein can be used as a barrier material against volatile organic compounds, water, oxygen, or electrons, and can be used as a coating and packaging material for various substrates, or as an optical material.

Description

Technical Field

[0001] Cross-Reference to Related Applications This application claims priority to U.S. Provisional Application No. 63 / 519,162, filed on August 11, 2023, the contents of which are incorporated herein by reference in their entirety. Statement on Government Support This invention was made with government support under Contract No. DE-AC02-05CH11231 awarded by the U.S. Department of Energy. The government has certain rights in this invention. The present disclosure generally relates to nanocomposites and barrier or optical materials.

Background Art

[0002] Two-dimensional nanosheets are a common motif in natural materials. Despite extensive efforts to develop layered self-assemblies of nanosheets based on block copolymers (BCP) and nanoparticles or liquid crystals, a mismatch remains between what is produced and what is required. Materials based on readily available nanosheets with a thickness of several to tens of nanometers generally have insufficient functionality when serving as viable components for optical, barrier and dielectric applications.

[0003] Engineering nanomaterials, while not limited, must meet essential requirements at a system level, including feature size, chemistry, multifunctionality, processing, integration compatibility, scalability, and lifecycle. However, these essential requirements limit design freedom. Non-linear chain structures like stars or bottlebrushes can expand the range of available feature sizes and overcome the dynamic barriers associated with long-chain entanglement, but their synthesis is difficult. Current designs, driven by optimizing intermolecular interactions, are too rigid to accommodate new chemical functionalities and cannot mitigate state differences during integration. Despite extensive optimization of building blocks and processing, access to nanostructures with the required feature size and chemistry remains difficult. Programming their growth across the nano- to macro hierarchy also remains challenging. The rigidity of existing designs limits the growth of programmable nanomaterials. [Overview of the project]

[0004] This specification provides high-performance barrier coatings and methods for producing such coatings by programming a growth sequence from micro to nano using a ternary nanocomposite blend. The coatings have a defect density of <0.056 μm. -2The nanocomposite consists of stacked nanosheets (sheet thickness, approximately 125 nm) with an efficiency of approximately 98% when controlling defect types. High molecular weight polymers (approximately 500 kDa) are used as the matrix of the nanocomposite. Contrary to common perception, polymer chain entanglement is advantageous in achieving long-range order, accelerating the manufacturing process (<30 minutes), and meeting specific requirements to advance multilayer film technology. In particular, the coatings exhibit high-performance barrier properties against volatile organic compounds, water, and oxygen for use as packaging materials. They can also be applied as electron barriers used as dielectric capacitors. These composite coatings are inherently recyclable, providing a solution to the recycling problems associated with existing metallized multilayer films. Long-chain entanglement provides mechanical durability without the need for chemical crosslinking. They are suitable for assembly, disassembly, and reassembly cycles without compromising structural integrity, highlighting the advantages of bottom-up material synthesis.

[0005] In one embodiment, this specification provides a nanocomposite material comprising nanoparticles, small molecules, and a block copolymer (BCP)-based supramolecule, which self-assemble into a plurality of nanosheets forming a nanocomposite material. The BCP-based supramolecule contains BCP and small molecules. In some embodiments, each BCP-based supramolecular comprises BCP and small molecules bonded to BCP via non-covalent bonds. In some embodiments, BCP has a molecular weight of about 130 kDa to about 600 kDa. In certain embodiments, BCP is a high molecular weight polymer (for example, having a molecular weight of about 500 kDa or more). In some embodiments, the small molecules are organic molecules. In several embodiments, the small molecules contain a molar mass of approximately 50 g / mol to approximately 1500 g / mol.

[0006] 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 are approximately 3 nm to 50 nm in size, approximately 3 nm to 9 nm in size, or approximately 6 nm in size. In certain embodiments, the nanoparticles contain ZrO2. In certain embodiments, the small molecule contains 3-pentadecylphenol (PDP). In certain embodiments, BCP contains polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP). In certain embodiments, the BCP-based supramolecular molecule contains PS-b-P4VP(PDP)1, which contains PDP bonded to the pyridine side chain of PS-b-P4VP via hydrogen bonds. In some embodiments, nanoparticles account for approximately 3–20 volume% of the nanocomposite material, small molecules for approximately 10–25 volume%, and BCP-based supramolecules for approximately 65–75 volume%. Examples of nanocomposite material compositions are shown in Table 1.

[0007] In some embodiments, each nanosheet has a thickness of approximately 50 nm to approximately 410 nm, for example, approximately 50 nm to approximately 150 nm, or approximately 125 nm. In some embodiments, the nanocomposite material comprises a number of nanosheets of about 20 to about 100, about 20 to about 200, or about 200 or more. In some embodiments, the nanocomposite material is approximately 0.06 μm thick. -2 It has the following defect density and efficiency in controlling approximately 98% of defect types. In some embodiments, the nanocomposite materials provided herein have improved barrier functionality against volatile organic compounds (VOCs), water, oxygen, and / or electrons compared to control materials. In some embodiments, the nanocomposite materials have a VOC removal efficiency of 40% or more, 8 gm -2 day -1 The following water vapor transmission rate (WVTR) is 500 MV / m³. -1 The dielectric breakdown strength is 3 Jcm. -3The above maximum discharged energy density, and / or 3 min μm -1 The encapsulant has the above-mentioned lifespan.

[0008] In some embodiments, the nanocomposite material has multiple nanosheets having a gradient layer thickness, for example, thinner layers toward the substrate-nanocomposite interface and thicker layers away from the substrate. In some embodiments, the thickness of the nanosheets in the nanocomposite material is in the range of approximately 65 nm to approximately 135 nm (e.g., approximately 72 nm to approximately 126 nm), approximately 120 nm to approximately 280 nm (e.g., approximately 151 nm to approximately 223 nm), approximately 120 nm to approximately 250 nm (e.g., approximately 127 nm to approximately 221 nm), or approximately 120 nm to approximately 410 nm (e.g., approximately 135 nm to approximately 370 nm).

[0009] In some embodiments, the nanocomposite material has alternating layers of nanosheets rich in nanoparticles and nanosheets poor in nanoparticles. In one aspect of this disclosure, a method for producing a nanocomposite material is provided herein. The method comprises contacting an initial blend of nanoparticles, small molecules, and a block copolymer (BCP)-based supramolecule with a solvent to form a mixture, and drying the mixture to remove the solvent, thereby forming a nanocomposite material comprising a plurality of nanosheets containing nanoparticles, small molecules, and a BCP-based supramolecule via a self-assembly process. The BCP-based supramolecule contains BCP and small molecules. In some embodiments, the solvent is chloroform or benzene. In some embodiments, contact involves contacting an initial blend of nanoparticles, small molecules, and BCP-based supramolecules with a solvent that constitutes about 95% to about 100% by volume, or about 97.5% by volume, of the mixture (i.e., the initial blend constitutes less than or equal to about 5% by volume, or about 2.5% by volume, of the mixture). In some embodiments, drying involves removing the solvent to initiate a self-assembly process with a volume percentage of solvent in the mixture of about 70% to about 80% or less. The self-assembly process can occur when the volume percentage of solvent in the mixture is about 70% to about 80% or less.

[0010] In some embodiments, the drying process takes approximately 20 minutes to 3 days. 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 nanosheets. A slower drying rate or a higher proportion of solute in the mixture can produce thicker and / or redder colored nanosheets. In some embodiments, the mixture is drop-cast onto a substrate before drying. In some embodiments, the substrate is a solid, lens, film, or wafer made of Teflon, polyester, silicon, or glass. In some embodiments, each of the BCP-based supramolecules comprises BCP and a small molecule bound to BCP via non-covalent bonds. In some embodiments, BCP has a molecular weight of approximately 130 kDa to approximately 600 kDa. In some embodiments, the small molecules are organic molecules having a molar mass of approximately 50 g / mol to approximately 1500 g / mol.

[0011] 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 are approximately 3 nm to 50 nm in size, approximately 3 nm to 9 nm in size, or approximately 6 nm in size. In certain embodiments, the nanoparticles contain ZrO2. In certain embodiments, the small molecule contains 3-pentadecylphenol (PDP). In certain embodiments, BCP contains polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP). In certain embodiments, the BCP-based supramolecule contains PS-b-P4VP(PDP)1, which contains PDP bonded to the pyridine side chain of PS-b-P4VP via hydrogen bonds. In some embodiments, each nanosheet has a thickness of approximately 50 nm to approximately 410 nm, for example, approximately 50 nm to approximately 150 nm, or approximately 125 nm. In some embodiments, the nanocomposite material comprises a number of nanosheets of about 20 to about 100, about 20 to about 200, or about 200 or more.

[0012] In some embodiments, the nanocomposite material is approximately 0.06 μm thick. -2 It has the following defect density and efficiency in controlling approximately 98% of defect types. In some embodiments, nanoparticles account for approximately 3–20 volume% of the initial blend, small molecules for approximately 10–25 volume%, and BCP-based supramolecules for approximately 65–75 volume%. Examples of initial blend compositions are shown in Table 1. In some embodiments, forming involves creating alternating layers of nanosheets rich in nanoparticles and nanosheets poor in nanoparticles. In one aspect of this disclosure, a nanocomposite material produced by a method provided herein is provided. In one aspect of this disclosure, a product is provided which contains a nanocomposite material provided herein or a nanocomposite material produced by a method provided herein, wherein the product is a barrier product or an optical product.

[0013] In some embodiments, the product includes, and can be used as, volatile organic compound barriers, water barriers, oxygen barriers, electron barriers, dielectric capacitors, lens coatings, and / or packaging materials (e.g., food packaging materials), optical filters, planar lenses, and zone plates.

[0014] Details of one or more embodiments of the subject matter described in this specification are shown in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from the following description, drawings, and claims. Note that the relevant dimensions in the following drawings may not be drawn to a constant scale. A patent or application file must contain at least one color drawing. A copy of this published patent or patent application, including the color drawing, will be provided by the Office upon request and payment of the required fees. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1A schematically illustrates the systems engineering of layered nanosheets as a barrier material. To transform stacked nanosheets into a high-performance barrier coating, the aggregate must meet numerous requirements. Figure 1B depicts sequential nanosheet growth during film casting. Sequential growth follows a sequence from nano to micro to macro, forming the smallest feature size when system mobility is highest. Figure 1C shows programmed nanosheet growth during film casting. Programmed growth matches system mobility to the targeted feature size, organizing molecular aggregates into a microframework when system mobility is high. The nanostructure then grows within the microframework by short-range diffusion when system mobility is low. [Figure 2]Figures 2A–2I show transmission electron microscope (TEM) images of changes with respect to S2 / NP blend formulations. Figure 2A shows an S2 supramolecule containing 6 vol% 5 nm iron oxide nanoparticles. Figure 2B shows a 330-b-125 kDa supramolecule formed using different hydrogen-bonded small molecules I-PDP (insert). This is the blend used for the energy-dispersive X-ray spectroscopy (EDS) analysis in Figure 3. Figure 2C shows a 330-b-125 kDa supramolecule formed using blends of hydrogen-bonded small molecules (PDP) and non-hydrogen-bonded small molecules (DID) in molar ratios of 1 and 0.6, respectively. Figures 2D–2I show S2 / NP blends self-assembled on various substrates: Teflon beaker (Figure 2D), porous Teflon film (Figure 2E), polyester film (Figure 2F), thick silicon wafer (Figure 2G), thin silicon wafer (Figure 2H), and glass (Figure 2I). [Figure 3] Figure 3 shows EDS analysis of the small molecule distribution of an S2 / NP blend using iodine-labeled PDP (I-PDP). Structural and chemical information was acquired using a high-angle annular dark-field setup, and therefore the contrast is inverted compared to other TEM images provided herein. The brightest pixels are those with the strongest scattering, and thus domains filled with nanoparticles are brighter than domains containing only organic molecules. The iodine map shows that I-PDP is distributed across all microdomains despite the enthalpy driving force attempting to separate them into P4VP(PDP) domains. In comparison, ZrO2 nanoparticles are strictly separated into P4VP(PDP) domains. This imaging method does not distinguish between hydrogen-bonded and unbonded small molecules, and therefore P4VP(PDP) domains have a higher overall concentration of small molecules. [Figure 4]Figures 4A–4C show the quantification of the nanosheet growth dynamic pathway. Figure 4A shows the SANS profiles of 5 vol% and 10 vol% S2 / NP solutions in deuterated chloroform fitted to the Guinier-Porod model. Figure 4B shows the USANS profile of the 10 vol% S2 / NP solution. The inset shows liquid cell TEM images of ribbon-like aggregates. Scale bar, 500 nm. Figure 4C shows the USAXS profiles of 10 vol% S2 / NP and S3 / NP solutions. At this concentration, the S3 / NP solution formed microscale aggregates indicated by the presence of low-q features. Figures 4D–4F show results from in-situ SAXS-XPCS experiments used to quantify system mobility during nanosheet growth. Roman numerals i–v indicate the aggregation stage during solvent drying. Figure 4D shows the SAXS profile showing the structural evolution from dilute solution to highly ordered lamellae. Figure 4E shows the evolution of nanoparticle diffusion modes during the S2 / NP assembly process based on Kohlrausch index γ values ​​derived using dynamic data from qs to ql. Each data point is indicated by a black 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 chronologically by white circles. Figure 4F shows a comparison of relaxation times τs (qs=0.3nm⁻¹) and τl (ql=0.03nm⁻¹) for each assembly stage during nanosheet growth. Figure 4G shows in situ GTSAXS of the S1cyl / NP solution under optimized dry conditions. Δt is used to indicate the elapsed time after aggregate formation (leftmost panel). Figure 4H shows cross-sectional TEM of S2 / NP films quenched with the indicated solvent fractions. Scale bar, 1 μm. The lower right panel is a pseudocolor image of the film quenched with 28 vol%, and the color is used to indicate the length of each nanosheet extending beyond the image boundary. au, arbitrary unit. [Figure 5] Figure 5A shows an example of automated sheet length analysis, and Figure 5B shows a semi-automated defect density analysis, both performed on S2 film frozen at 40 vol%. Junctions and ends were automatically identified. U-turn defects were manually labeled. [Figure 6]Figures 6A–6F show programmed nanosheet growth that induces long-range order and defect control. Figure 6A shows a cross-sectional TEM image of an S2 / NP coating containing more than 200 stacked nanosheets. Within an image area of ​​approximately 2,660 μm², there are only 149 defects: 146 paired ends (blue circles), 2 paired U-turns (pink squares), and 1 junction (gold triangle). A photograph of the S2 / NP coating on a polyester film is shown in the insert. Figure 6B shows a higher magnification TEM image of an S2 / NP film showing high aspect ratio nanosheets containing densely packed nanoparticles. Figure 6C shows higher magnification TEM images of each defect type. Figure 6D shows a comparison of defect density from cross-sectional TEM images of S1 / NP and S2 / NP with literature values ​​from BCP thin films. Figure 6E shows a cross-sectional TEM image of an S2 / NP blend that was dried too rapidly for microframework formation; disordered microdomains and nanoparticle aggregates are observed. Figure 6F shows a cross-sectional TEM image of an S3 / NP film with 20 vol% nanoparticles and a microdomain periodicity of 174 nm. Scale bar: 100 nm. [Figure 7]Figures 7A-7H show the performance evaluation of nanocomposite coatings as barrier materials. Figures 7A-7D show representative TEM images of S2 / NP (Figure 7A), S2dis / NP (Figure 7B), S2 (Figure 7C), and S1 / NP (Figure 7D) used to establish the chemical-structural-barrier property relationship. Scale bar, 500 nm. Figure 7E shows the VOC barrier performance of S2 / NP, S2dis / NP, S2, and S1 / NP coatings on a porous Teflon film. Removal efficiency for five types of VOC molecules is shown. n=2 for each bar. Figure 7F shows the WVTR of PET films with S2 / NP, S2dis / NP, S2, and S1 / NP coatings. The S2 / NP coating has the lowest water permeability rate. n=3 for each bar. Figure 7G shows the dielectric breakdown strength (filled bars) and maximum discharge energy density (blank bars) for S2 / NP, S2dis / NP, S2, and S1 / NP coatings. Biaxially oriented polypropylene (BOPP) is shown as a control. n=10 for each bar. Figure 7H shows the encapsulant lifetime of S2 / NP and two types of commercially available UV-curing epoxy, measured using electrocalcium testing. Results are normalized by barrier layer thickness. n=3 for each bar. In all panels, error bars represent ±1 standard deviation. [Figure 8] Figures 8A-8D show the stability analysis of the nanocomposite coating. Figure 8A shows that when the film is dried, redissolved, and then recast, it forms the same lamellar structure as before. Figure 8B shows nanoindentation results demonstrating that the S2 / NP film is mechanically stable despite the lack of interlayer chemical crosslinking. Figure 8C shows a periodic buckling test (n=600) of S2 / NP on a PET film, showing that the film remains intact without any delamination from the substrate. Figure 8D shows disordered nanocomposite (S2dis / NP) and lamellae without nanoparticles (S2), and despite all test films having the same thickness and being supported by the same PET film, all exhibited inferior properties to S2 / NP (Figure 8B). [Figure 9]Figures 9A–9E illustrate the formation of gradient layer thickness in lamellar nanocomposites. Figure 9A schematically shows a supramolecular nanocomposite system that is diluted in a non-selective solvent and drop-cast to produce an ordered lamellar structure. The concentration gradient present in the film during drop-casting affects the gradient layer thickness of the nanocomposite. The parameter L, used to describe the local layer thickness, is visually defined in the rightmost panel. Figure 9B shows an image of a well-dried lamellar nanocomposite film taken under normal laboratory lighting. The various structural colors indicate process-dependent nanostructures. From left to right, the self-assembly time of the samples increased. Each sample is approximately 1.5 cm to its horizontal edge. Figures 9C–9E show cross-sectional TEM images of selected nanocomposites. As suggested by their structural colors, the dried films have substantially different internal structures. Each film also exhibits a height-dependent L gradient. The images are oriented so that the substrate-film interface is at the bottom and the film-air interface is at the wavy upper boundary. All scale bars are 1 μm. [Figure 10]Figures 10A–10D show the scattering characteristics evaluation of L gradient formation. Figure 10A shows the in situ SAXS profile of a slowly dried supramolecular nanocomposite solution. The yellowish-brown lines indicate the evolution from correlation holes to ordered lamellae. The golden lines indicate the first signs of L gradient formation. The brown lines indicate the evolution of stronger L gradients. Figure 10B shows the combined SAXS and USAXS profiles of dried nanocomposite films with various nanostructures, vertically shifted for clarity. The curves are colored by the structural color of the dried samples shown in the lower right panel. Peaks i and i* are derived from the USAXS results and define the average L over the film thickness. Peak ii is derived from 6 nm nanoparticles. Figure 10C shows the WAXS profile derived from solution measurements using capillaries with spatially varied solvent concentrations. Structural color was used to label the position on the capillary where each measurement was collected; the capillaries are shown in the upper right panel. Peak iii indicates the amount of crystallized PDP present in the sample. Peaks iv and v originate from the NP ligand, and their intensity is roughly proportional to the solute concentration. Figure 10D shows the WAXS profile of the same sample as shown in Figure 10B. [Figure 11]Figures 11A–11G show the gradient structure at the nanoscale, microscale, and macroscale. Figure 11A shows a cross-sectional TEM image of a film with different periodic gradients and no NPs. Figure 11B shows the measured domain widths for the coil, comb, and overall L over the same region shown above. Figure 11C shows raw domain size data plotted as coil and comb portions of the overall microdomain volume. The dashed lines were calculated directly from the sample composition for comparison with experimental data. From the bottom to the top of the film, most unbound PDPs move from the coil domains to the comb domains. Figure 11D shows an optical micrograph of the rough texture observed in the L gradient film. Figure 11E shows an optical micrograph of the substrate edge (lower black boundary) of the dried film. As the film dried, it receded from the edge rather than remaining fixed. This effect is more pronounced in slowly dried films and may be a macroscopic side effect of the upper layer shrinking laterally. Figure 11F shows a TEM image of the top surface of the gradient film. End defects are labeled with blue teardrops oriented along the continuous lamellae. Paired end-to-end defects are not observed. Figure 11G shows a TEM image of the bottom interface of the gradient film. A mixture of paired end-to-end defects and isolated end defects is observed. [Figure 12]Figures 12A-12H show optical micrographs of six compositional control films and descriptions of their surface textures. Figure 12A shows a smooth film with no NPs and no excess PDP, rapidly dried. Figure 12B shows a smooth film with NPs, no excess PDP, rapidly dried. Figure 12C shows a film with no NPs and excess PDP, rapidly dried, and with a subtle texture. Figure 12D shows a film with no NPs and no excess PDP, slowly dried, and with a subtle texture. Figure 12E shows a smooth film with NPs and no excess PDP, slowly dried. Figure 12F shows a film with no NPs and excess PDP, slowly dried, and with a significant texture. Figure 12G shows a cross-sectional TEM image of the film shown top-down in Figure 12D; there is no obvious L-slope and the surface is locally smooth. Figure 12H shows a cross-sectional TEM image of a lower molecular weight S2 supramolecular under slow-drying conditions; an L-slope is clearly present. Figure 12I shows a cross-sectional TEM image of a lower molecular weight S3 supramolecular under slow drying conditions; a morphological transition to cylindrical domains occurs. Figure 12J shows a cross-sectional TEM of an S1 supramolecular dried over 3 days; a high L structure is achieved throughout the entire film thickness, and therefore no gradient is present. Figure 12K shows a cross-sectional TEM of an S1 / NP nanocomposite dried over 3 days; no visible gradient structure is present. In the insert, the elongated comb domains form a three-layered structure as the NPs become more tightly packed, pushing out other NPs while leaving some NPs at the coil-comb interface. [Figure 13] Figure 13 shows solvent fraction versus time curves for gradient and non-gradient films. Solvent fraction values ​​during film drying are based on Filmmetrics F20 interferometry measurements. The upper curve represents slow drying over 60 minutes, which would cause gradient formation. The two lower curves represent faster drying processes that would not cause gradient formation. The data are fitted with an exponential decay function for interpolation. [Figure 14]Figure 14A shows the reflectance spectrum collected for a thicker gradient film. Insert: The film is approximately 3 mm wide and 30 μm thick. The spectra are colored with the structural color observed for each reflectance measurement. Figure 14B shows an optical microscope image of the region from which the reflectance spectrum was collected. [Modes for carrying out the invention]

[0016] Herein, we refer in detail to several specific embodiments of the present invention, including the best mode conceivable by the inventors for carrying out the invention. Examples of these specific embodiments are shown in the accompanying drawings. While the present invention is described in relation to these specific embodiments, it will be understood that the invention is not intended to be limited to the embodiments described. Rather, it is intended to include alternatives, modifications, and equivalents that may fall within the spirit and scope of the invention as defined by the accompanying claims.

[0017] In the following description, numerous specific details are provided to provide a complete understanding of the invention. Certain exemplary embodiments of the invention may be carried out without some or all of these specific details. In other examples, well-known process operations have not been described in detail so as not to unnecessarily obscure the invention. Various techniques and mechanisms of the present invention are sometimes described in singular form for clarity. However, unless otherwise noted, some embodiments may include multiple iterations of a certain technique or multiple instances of a certain mechanism.

[0018] The terms "approximately" or "about" are synonymous and are used to indicate that the value modified by these terms has a known range, which can be ±20%, ±15%, ±10%, ±5%, or ±1%. The terms "substantially" are used to indicate that a value is close to a target value, where "close" can mean, for example, that the value is within 80%, 85%, 90%, 95%, or 99% of the target value.

[0019] When used herein in relation to parameters, the terms “decreased,” “decreasing,” “decrease,” “reduced,” “(reducing),” “reduce,” or “lower” mean a detectable negative change in a parameter from an established normal or reference level or an established standard control (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%). Thus, the terms “decreased,” “reduce,” etc., encompass both partial and complete reductions compared to the control.

[0020] When used herein in relation to parameters, the terms “increased,” “increasing,” “increase,” “enhanced,” “enhancing,” “enhance,” or “greater” mean a detectable positive change in the parameter from an established normal or reference level or an established standard control (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%) from a comparison control such as the parameter’s established normal or reference level or an established standard control.

[0021] A. Nanocomposite materials This specification provides nanocomposite materials comprising nanoparticles, small molecules, and block copolymer (BCP)-based supramolecules, which self-assemble into multiple nanosheets forming a nanocomposite material. The BCP-based supramolecules contain BCP and small molecules. As used herein, “nanocomposite” material refers to a heterogeneous material in which the characteristic length scale of the filler material is typically in the nanometer range, for example, a material formed by a blend of nanoparticles, small molecules, and BCP-based supramolecules provided herein. The novel nanomaterial designs provided herein offer improvements over previously available nanosheet science and technology by (1) the ability of entropy-driven assemblies to accept changes in reactant composition and pair interactions during processing and integration, and (2) providing system mobility matched with the diffusion of building blocks necessary to form the targeted structure. As shown in Figure 1B, previously available techniques of continuous growth follow a nano-to-micro growth process, where the smallest structural features are generated when system mobility is highest, and vice versa. In contrast, the growth pathway provided herein proceeds in an inverted micro-first-nano-later order (Figure 1C): the microstructure is first defined when the system has the highest mobility, and then nanostructure formation occurs through the local organization of building blocks. The entropy-driven phase behavior helps realize this large-to-small growth pathway. When the system is mobile enough to organize large-scale structures, it allows the system to form microscopic aggregates in dilute solutions. Thermodynamically, the entropy-driven phase behavior observed in high-entropy alloys provides compounding adaptability while maintaining structural fidelity. Thus, target nanostructures can be generated using many combinations of locally available components when system mobility is low. The coatings exhibit high-performance barrier properties against volatile organic compounds, water, and oxygen for use as packaging materials, and against electrons for use as dielectric capacitors.

[0022] BCP can have a molecular weight of approximately 130 kDa to approximately 600 kDa, for example, approximately 130 kDa, approximately 200 kDa, approximately 300 kDa, approximately 400 kDa, approximately 450 kDa, approximately 500 kDa, approximately 560 kDa, or approximately 600 kDa. Specifically, BCP can have molecular weights of 134 kDa, 455 kDa, and 557 kDa, as listed in Table 1. In certain embodiments, BCP is a high molecular weight polymer (for example, having a molecular weight of approximately 100, 200, 300, 400, or 500 kDa or more). The entanglement of long polymer chains, brought about by high molecular weight polymers, plays several roles: namely, matching the system's mobility to its stage of structural evolution and programming dynamic pathways to modulate local defect morphology. By using high molecular weight building blocks, the blend forms molecular aggregates in dilute solutions. This provides sufficient system mobility to organize the molecular aggregates into a wide range of microframeworks for subsequent nanostructure formation. Long-chain entanglement increases the dynamic stability and integrity of the aggregates during subsequent growth and organization. Long-chain entanglement can slow down local reorganization at defect sites, thus maintaining end-to-end defect morphology.

[0023] Each BCP-based supramolecular may have a BCP and small molecules bonded to the BCP via non-covalent bonds. For example, a BCP-based supramolecular can be constructed by non-covalently bonding small molecules to polymer side chains. The presence of small molecules eliminates the need to modify either the nanoparticle ligand or the polymer for nanoparticle incorporation and to improve interparticle ordering within the BCP microdomain. 1-, 2-, and 3-D nanoparticle arrays can be obtained in thin films of supramolecular nanocomposites via solvent annealing to a range of nanoparticles or nanoparticle mixtures. Dynamically, the presence of small molecules also provides an opportunity to manipulate the energy landscape of the assembly process and accelerate assembly dynamics, thereby preserving the intrinsic properties of the nanoparticles and enabling continuous thin-film processing techniques for device fabrication.

[0024] The small molecule can be an organic molecule. The small molecule can contain a molar mass of approximately 50 g / mol to approximately 1500 g / mol. In certain embodiments, the small molecule contains 3-pentadecylphenol (PDP). For example, BCP can be polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP). A BCP-based supramolecular can be PS-b-P4VP(PDP)1, which contains PDP bonded to the pyridine side chain of PS-b-P4VP via hydrogen bonds. PS-b-P4VP contains two random-coil blocks, forming a spherical microdomain of P4VP surrounded by a PS matrix. Without being bound by a specific theory, when PDP hydrogen bonds to the pyridine ring, the P4VP block is stretched to form a rigid comb-block. This structure occupies considerably more volume, and therefore the supramolecular forms a lamellar microdomain rather than a spherical one. By bonding to the pyridine ring, PDP also forms a periodic lamellar structure, resulting in a lamellar-intralamellar hierarchical morphology.

[0025] Small PDP molecules add mobility to the system by diluting BCP entanglement and increasing the volume of P4VP blocks. PDP has solubility parameters between BCP blocks and NP ligands, and therefore free PDP can relax undesirable interfaces between blocks or around NPs, stabilizing large surface area morphologies. Free PDP can also be redistributed over relatively large distances to accept constraints. The intermediate strength of hydrogen bonds gives PDP some degree of freedom to rearrange. Much of the self-regulating behavior of nanocomposite systems can be attributed to small molecules. The nanoparticles can be metal oxide nanoparticles [e.g., zirconium oxide (ZrO2)], noble metal nanoparticles (e.g., gold), or inorganic molecules such as silica nanoparticles. In some embodiments, the nanoparticles are about 3 nm to about 50 nm in size, about 3 nm to about 9 nm, or about 6 nm in size. In certain embodiments, the nanoparticles contain ZrO2 about 6 nm in size.

[0026] Table 1 provides examples of formulations and compositions of the nanocomposite materials provided herein. These nanocomposite materials include BCPs with molecular weights of 134 kDa, 455 kDa, and 557 kDa. These nanocomposite materials form lamellar or cylindrical microdomains with periodicity in the range of approximately 60 nm (S1 / NP) to approximately 170 nm (S3 / NP). PDP molecules are dispersed in both PS-rich and P4VP (PDP)-rich microdomains; spatially resolved energy dispersive X-ray spectroscopy (EDS) of S2 / NP with iodine-labeled small molecules (I-PDP) is shown in Figure 3. The dispersed PDP molecules are essential for screening undesirable interactions between PS and P4VP (PDP) and for realizing entropy-driven phase behavior such as formulation adaptability. The S3 / NP blend based on 557-kDa PS-b-P4VP can accommodate up to 20 vol% of nanoparticles in parallel layers. In the nanocomposite materials provided herein, nanoparticles may constitute about 3–20 volume% of the nanocomposite material (e.g., about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 volume%), small molecules may constitute about 10–25 volume% (e.g., about 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 volume%), and BCP-based supramolecules may constitute about 65–75 volume% (e.g., about 65, 66, 67, 68, 69, 70, 71, 72, 83, 74, or 75 volume%).

[0027] Nanoparticles, small molecules, and BCP-based supramolecules (collectively referred to as solutes) can be dissolved in a solvent and can self-assemble into multilayer nanosheets during the drying process. The solvent can be any solvent that is suitable for dissolving the solutes (i.e., small molecules and BCP-based supramolecules) and producing nanocomposites. For example, the solvent can be chloroform, which dissolves PS and P4VP almost equally well, and also dissolves PDP. The solvent can also be benzene, which has lower X-ray absorption than chloroform. The solutes can be dissolved in the solvent to form a solution with 1 to 20 volume percent (e.g., 1 to 5, 5 to 10, 10 to 15, 15 to 20, or 20 volume percent or more). The overlap concentration of a polymer solution in a good solvent N -1.8 is scaled as, estimated to be >20 volume percent for solutes containing 134-kDa BCP, and approximately 2.7 volume percent for solutes containing 455-kDa BCP, respectively.

[0028] Each nanosheet of the nanocomposite can have a thickness of about 50 nm to about 410 nm, for example, about 50 to 100, 50 to 150, 50 to 200, 200 to 300, 300 to 410 nm, or about 150, 100, 125, 150, 200, 250, 300, 350, 400, or 410 nm. The nanocomposite can contain about 20 to about 100, about 20 to about 200, about 100 to about 200, or about 200 or more nanosheets. A larger number of nanosheets can provide greater functionality of the nanocomposite, such as those used as barrier materials or optical materials.

[0029] The initial microscopic structure determines the degree of long-range order (i.e., defect density) of the nanostructure. Stepwise changes in the diffusion mode and system mobility of nanoparticles identify a processing window for programming growth, where the microscopic growth is first and the nanoscopic growth is later. As shown in Figure 4H, when solvent removal occurs at a solute concentration of 23 vol%, long-range order is poor, and this solute concentration is too dilute to drive the condensation of molecular aggregates despite high system mobility. Rapid solvent removal at 40 vol% generated different nanosheets, but with a high defect density and an aspect ratio of less than 40. This suggests that the generation of nanostructures may compete with and interfere with the generation of microframeworks. The best long-range order is achieved by quenching the film at 28%, slightly lower than the concentration at which the nanosheets were generated. The nanosheets are several tens of micrometers long and have an aspect ratio greater than 500. Thus, long-range order, i.e., defect density, can be regulated by optimizing the organization of sheet-like aggregates before the generation of nanostructures.

[0030] Defect types also determine barrier performance, as different defects have diverse effects on transport pathways. The proliferation of various defect types is determined by short-range diffusion during the final stage of assembly. Blends based on lower molecular weights, such as S1, have more circular microdomains between nanosheets, and sharply curved microdomains, which we have named "U-turn" defects, are rare. These defect morphologies are the result of local reorganization, indicating that the system is mobile enough to reorganize BCP-based supramolecules and release packing frustration. However, in the case of high molecular weight building blocks, such as S2 / NP and S2-based blends, most defects are paired terminal and U-turn types. Some nanosheets proceed in a zigzag manner, resulting in several consecutive U-turns (Figures 5A-5B). There is considerable energy loss associated with bending nanosheets at such sharp angles. However, the entanglement of long chains increases the energy barrier against local reorganization and dynamically traps these defects after the formation of the microframework. U-turn defects can be eliminated by increasing the rigidity of the nanosheet, for example by adding nanoparticles or by driving the system to a lower solvent fraction to further enhance long-range order. Paired end defects sever transport pathways, which is desirable for engineering barrier materials. Thus, the ability of long-chain entanglement to separate defect operations from the generation of nanostructures is advantageous in controlling the proliferation of various defect types.

[0031] The nanocomposite materials provided herein are 0.2 μm -2 Below, 0.1μm -2 Below, 0.09μm -2 Below, 0.08μm -2 Below, 0.07μm -2 Below, 0.06μm -2 The following, or 0.05 μm -2 The following defect densities may be present. In a particular embodiment, the nanocomposite material has a defect density of approximately 0.06 μm. -2 It has the following defect density and efficiency in controlling approximately 98% of defect types.

[0032] The multilayer nanocomposite materials provided herein are competitive barrier materials that are comparable to or superior to current industry standards, offering significant advantages in their material chemistry and programmable lifecycle. The nanocomposite materials provided herein possess inherent recyclability, providing a solution to the recycling problems associated with existing metallized multilayer films. Long-chain entanglement provides mechanical durability without the need for chemical crosslinking. The nanocomposite materials provided herein are suitable for assembly, disassembly, and reassembly cycles without compromising structural integrity, highlighting the advantages of bottom-up material synthesis (see embodiments in Figures 8A–8D).

[0033] The nanocomposite materials provided herein have improved barrier functionality against volatile organic compounds (VOCs), water, oxygen, and / or electrons compared to control materials. In some embodiments, the nanocomposite materials have a VOC removal efficiency of 40% or more, 8 gm -2 day -1 The following water vapor transmission rate (WVTR) is 500 MV / m³. -1 The dielectric breakdown strength is 3 Jcm. -3 The above maximum discharge energy density, and / or 3 min μm -1 The sealing material has the above lifespan. For example, when coated on a porous Teflon film, a 30 μm S2 / NP coating reduces the permeation of common volatile organic compounds (VOCs) with removal efficiencies of 100 ± 0% (kinetic diameter dk ≥ 5.3 Å) for 2-butanone and hexaldehyde, 96 ± 0% (dk = 5.0 Å) for acetaldehyde, 94 ± 9.2% (dk = 4.4 Å) for acetone, and 55 ± 4.2% (dk = 3.7 Å) for formaldehyde (Figure 7E). This performance is comparable to a wet scrubber based on an electrochemical cell with a removal efficiency of 95% at similar VOC concentrations. A 30 μm S2 / NP coating on a 127 μm polyester film showed more consistent barrier performance over a 3-week test, reducing its water vapor transmission rate (WVTR) to 11.5 ± 5.7 gm². -2 day -1 ~5.3±0.6gm-2 day -1 This can be substantially reduced (Figure 7F).

[0034] With 98% efficiency in defect control, nanocomposites with stacked nanosheets also serve as excellent barriers to electrons, making them high-performance dielectric materials for energy storage. The S2 / NP film is 650 MVm. -1 It has an energy efficiency of 91.2%, a charge / discharge efficiency exceeding 90%, and a discharge energy density of 6.2 Jcm². -3 This is the case (Figure 7G). This performance is comparable to current industry-standard dielectrics, including biaxially oriented polypropylene (BOPP) (Figure 7G). The high dielectric breakdown strength of the nanocomposite films is another piece of evidence for the importance of their low defect density and high efficiency in defect type control.

[0035] Organic electronic devices, including organic light-emitting diodes and solar cells, must be encapsulated to prevent degradation by oxygen and water vapor; irregular device topologies present specific challenges. Calcium films oxidize rapidly under ambient conditions, and their relative conductance makes them a convenient proxy against long-term device degradation. Using electrocalcium testing, the barrier properties of S2 / NP nanocomposites were compared with two standard UV-curable epoxies, DELO Katiobond LP655 and Ossila E132 (Figure 7H). Despite considerable differences in barrier thickness, their performance was comparable. The 50% relative conductance of the encapsulated calcium film was reached after 241±27 minutes for DELO Katiobond LP655 (approx. 119 μm), 367±53 minutes for Ossila E132 (approx. 218 μm), and 79±11 minutes for S2 / NP (approx. 35 μm). When normalized by film thickness, the S2 / NP barrier takes almost twice as long for the calcium film to reach 0% relative conductance. Thus, self-assembled nanosheets can produce thinner and more flexible organic electronic devices, and their inherent recyclability can contribute to better control throughout the lifecycle of organic electronic devices.

[0036] The performance of barrier materials is determined by their composition and structure: layer composition and dimensions, defect type and density, long-range order, mechanical properties, and geometric fit. Nanoparticles help to 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 essential for realizing the benefits of functional nanomaterials. Ordering of nanocomposites also has a significant effect on their mechanical properties. Supramolecules formed by high molecular weight BCPs contribute to the high performance of the nanocomposites provided herein. Contrary to the common notion that chain entanglement is detrimental to aggregate dynamics, high molecular weight building blocks are favorable and essential for achieving programmable rapid growth of nanosheets with long-range order and defect control. Superior barrier performance relies on the thick nanosheets they assemble into.

[0037] Nanocomposite materials can have a hierarchically ordered structure. For example, a nanocomposite material may have alternating layers of regions rich in conductive (or semiconducting) nanoparticles and regions poor in nonconductive nanoparticles. A nanocomposite material may have alternating layers of nanosheets of nanoparticles (or nanosheets rich in nanoparticles) and nanosheets of BCP-based supramolecules (or nanosheets rich in BCP-based supramolecules). When nanosheets of nanoparticles (or nanosheets rich in them) and nanosheets of BCP-based supramolecules (or nanosheets rich in them) are present in a nanocomposite material, each nanosheet of nanoparticles may have a thickness of approximately 50 nm to 410 nm, or 50 nm to 150 nm, and each nanosheet of BCP-based supramolecules may have a thickness of 50 nm to 410 nm, or approximately 50 nm to 150 nm. Each nanosheet of nanoparticles may have approximately the same thickness as each nanosheet of BCP-based supramolecules. Alternatively, each nanosheet of nanoparticles may be thicker than each nanosheet of BCP-based supramolecules. The nanocomposite material may also contain regions rich in one of the two polymers of BCP, and regions rich in the other polymer of BCP, for example, regions rich in PS, and regions rich in P4VP (PDP).

[0038] The nanocomposite materials provided herein have broad applicability as coatings or barrier materials. For example, a substrate (e.g., about 10-15 cm in length and width, or smaller or larger) can be coated with the nanocomposite materials provided herein. Surfaces of any texture (rough or smooth) can be coated with the nanocomposite materials 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 equipment packaging materials and can be incorporated into consumer packaging materials (e.g., food packaging materials). The advantage of the coating compositions provided herein is that they encompass barrier function relative to their thickness due to their large number of layers, providing a barrier function that competes with much thicker barrier layers created with fewer layers. Furthermore, the coating compositions provided herein can have improved recyclability because the material can be dissolved and recast as a single waste stream. The mechanical stability of the coating compositions provided herein is derived from physical chain entanglement rather than chemical crosslinking. The coating compositions provided herein are manufactured via a self-assembly process without chemical transformation and are completely reversible. The nanocomposite materials provided herein can also be used for purposes other than coatings or barrier materials, for example, as optical materials further provided herein.

[0039] B. Nanocomposite materials with a gradient structure Spatial gradients are a valuable element in nanoscale design: they are frequently used to improve the mechanical, optical, or stimulus-responsive properties of biological nanostructures. This specification provides nanocomposites having functional gradient motifs generated by self-assembly. While self-assembly typically involves uniform or periodic nanostructures, here a single BCP-based supramolecular nanocomposite can be used to generate numerous ordered multilayer structures. Layer thicknesses of 72–400 nm can be achieved using various drying procedures between drop-cast films of the same nanocomposite solution. The nanocomposites provided herein can have 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.

[0040] Layered nanocomposites with gradient periodicity can be produced by adjusting processing conditions and composition, such as the concentration of small molecules (e.g., PDP), the ratio of unbonded and hydrogen-bonded small molecules, the molecular weight of BCP (e.g., PS-b-P4VP), and the drying rate and conditions. Generally, slower drying rates and / or higher solute proportions in the solute / solvent mixture provide thicker nanosheets that appear redder in color. Furthermore, the mobility of small molecules (chemical or crosslinking) can be adjusted to obtain nanocomposites in forms of interest. The nanocomposites provided herein, in particular those with gradient layer thickness and properties, possess unique optical properties and can be used as optical materials such as light filters, planar lenses, and zone plates.

[0041] Nanocomposite materials can have multiple nanosheets having a gradient of layer thickness, for example, with thinner layers facing the substrate-nanocomposite interface and thicker layers away from the substrate. In some embodiments, the thickness of the nanosheets in the nanocomposite material is in the range of approximately 65 nm to approximately 135 nm (e.g., approximately 72 nm to approximately 126 nm), approximately 120 nm to approximately 280 nm (e.g., approximately 151 nm to approximately 223 nm), approximately 120 nm to approximately 250 nm (e.g., approximately 127 nm to approximately 221 nm), or approximately 120 nm to approximately 410 nm (e.g., approximately 135 nm to approximately 370 nm). For example, during the drying of a drop-cast film, the solute concentration is a function of both time and depth (Figure 9A). Therefore, at every point until the film is completely dry, the solute and solvent fractions form a smooth gradient throughout the film thickness. Using high molecular weight supramolecular nanocomposite blends, the characteristic layer width L varies considerably by changing the drying rate and duration of the film. Rapidly dried nanocomposite films have relatively small domain thicknesses, while slowly dried films exhibit considerably larger L values ​​(Figures 9B-9E). In addition to substantial differences between samples, a significant L gradient exists within individual samples. Drying over three days can produce nanosheets with a thickness of approximately 280-340 nm (Figure 12K). All samples shown in Figures 9B-9E have the same composition, film thickness, and initial concentration. The underlying mechanism of gradient multilayers involves a combination of entropy, enthalpy, and kinetic factors.

[0042] C. Methods for producing nanocomposite materials A method for producing nanocomposite materials provided herein may include contacting an initial blend of nanoparticles, small molecules, and block copolymer (BCP)-based supramolecules with a solvent to form a mixture, and drying the mixture to remove the solvent and forming a nanocomposite material comprising multiple nanosheets containing nanoparticles, small molecules, and BCP-based supramolecules via a self-assembly process. The BCP-based supramolecules contain BCP and small molecules.

[0043] Nanoparticles, small molecules, and BCP-based supramolecules (collectively known as solutes) can be dissolved in a solvent and self-assembled into multilayer nanosheets during a drying process. The solvent can be any solvent suitable for dissolving the solute (i.e., small molecules and BCP-based supramolecules) and producing nanocomposites. For example, the solvent can be chloroform, which dissolves PS and P4VP almost equally well and also dissolves PDP. The solvent can also be benzene, which dissolves the solute and has lower X-ray absorption than chloroform, making it suitable for SAXS and XPCS studies. The solute can dissolve in the solvent to form solutions of 1–20 vol% (e.g., 1–5, 5–10, 10–15, 15–20, 20 vol% or more). The overlapping concentration of the polymer solution is N in a good solvent. -1.8 Scaled as such, it is estimated to be >20 vol% for solutes containing 134-kDa BCP and approximately 2.7 vol% for solutes containing 455-kDa BCP.

[0044] Contacting an initial blend of nanoparticles, small molecules, and block copolymer (BCP)-based supramolecules with a solvent may include contacting the initial blend of nanoparticles, small molecules, and BCP-based supramolecules with a solvent that constitutes about 95% to about 100% by volume of the mixture, or about 97.5% by volume (i.e., the initial blend constitutes less than about 5% of the mixture, or about 2.5% by volume).

[0045] The drying process may include removing the solvent to initiate the self-assembly process. Solutes can begin to aggregate in a solution of approximately 3–10 (e.g., 5) vol% (i.e., solvent is 90–97 vol%, e.g., 95 vol%). The self-assembly process can occur as the volume percentage of solvent in the mixture decreases and the solute volume percentage increases. For example, self-assembly can occur when the solvent volume percentage is approximately 70%–80% or less (i.e., the solute volume percentage is approximately 20%–30% or more). For example, as shown in Figure 4H, nanostructures can be generated with solutes of 23 vol%, 28 vol%, and 40 vol%. However, long-range order is insufficient when solvent removal occurs at 23 vol%. This solute concentration is too dilute to drive the condensation of molecular aggregates despite high system mobility. Rapid solvent removal at 40 vol% generated different nanosheets, but with high defect density and an aspect ratio of less than 40. This suggests that the generation of nanostructures may compete with and interfere with the generation of microframeworks. The best long-range order can be achieved by quenching the film at 28%, slightly lower than the concentration at which the nanosheets were generated. The drying process can take approximately 20 minutes to 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. If the nanocomposite material dries too rapidly, the microdomains may become disordered, and a microframework may not be formed (e.g., Figure 6E).

[0046] The method may further include adjusting the drying rate, the depth of the mixture, and / or the solute / solvent ratio in the mixture to adjust the thickness and / or color of the nanosheets. Generally, slower drying rates or higher solute ratios in the mixture can produce thicker and / or redder colored nanosheets. The method provided herein can produce nanocomposite materials having gradient multilayers by adjusting parameters and using a self-assembly mechanism. Before drying, the mixture may be drop-cast onto the substrate. The substrate can be any material in any surface state, including solids, lenses, films, or wafers made of Teflon, polyester, silicon, or glass. The BCP-based supramolecules used in the method include BCP and small molecules bound to BCP via non-covalent bonds.

[0047] BCP can have a molecular weight of approximately 130 kDa to approximately 600 kDa, for example, approximately 130 kDa, approximately 200 kDa, approximately 300 kDa, approximately 400 kDa, approximately 450 kDa, approximately 500 kDa, approximately 560 kDa, or approximately 600 kDa. Specific examples include BCPs having molecular weights of 134 kDa, 455 kDa, and 557 kDa, as listed in Table 1. In certain embodiments, BCP is a high molecular weight polymer (for example, having a molecular weight of approximately 100, 200, 300, 400, or 500 kDa or more). Each BCP-based supramolecule can include BCP and small molecules bonded to BCP via non-covalent bonds. For example, BCP-based supramolecules can be constructed by non-covalently bonding small molecules to polymer side chains.

[0048] The small molecule can be an organic molecule. The small molecule can contain a molar mass of approximately 50 g / mol to approximately 1500 g / mol. In certain embodiments, the small molecule has 3-pentadecylphenol (PDP). For example, BCP can be polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP). A BCP-based supramolecular can be PS-b-P4VP(PDP)1, which contains PDP bonded to the pyridine side chain of PS-b-P4VP via hydrogen bonds. PS-b-P4VP contains two random-coil blocks, forming a spherical microdomain of P4VP surrounded by a PS matrix. Without being bound by a specific theory, when PDP hydrogen bonds to the pyridine ring, the P4VP block is stretched to form a rigid comb-block. This structure occupies considerably more volume, and therefore the supramolecular forms a lamellar microdomain rather than a spherical one. By bonding to the pyridine ring, PDP also forms a periodic lamellar structure, resulting in a lamellar-intralamellar hierarchical morphology.

[0049] The nanoparticles can be metal oxide nanoparticles [e.g., zirconium oxide (ZrO2)], noble metal nanoparticles (e.g., gold), or inorganic molecules such as silica nanoparticles. In some embodiments, the nanoparticles are about 3 nm to about 50 nm in size, about 3 nm to about 9 nm, or about 6 nm in size. In certain embodiments, the nanoparticles contain ZrO2 about 6 nm in size. Table 1 provides examples of formulations and compositions of the initial blends provided herein. PDP molecules are dispersed in both PS-rich and P4VP(PDP)-rich microdomains. The dispersed PDP molecules screen for undesirable interactions between PS and P4VP(PDP) and realize entropy-driven phase behavior such as formulation adaptability. An S3 / NP blend based on 557-kDa PS-b-P4VP can accommodate up to 20 vol% of nanoparticles in parallel layers.

[0050] In the methods provided herein, nanoparticles may be about 3–20 volume percent (e.g., about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 volume percent) of the initial blend of nanoparticles, small molecules, and BCP-based supramolecules; small molecules may be about 10–25 volume percent (e.g., about 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 volume percent); and BCP-based supramolecules may be about 65–75 volume percent (e.g., about 65, 66, 67, 68, 69, 70, 71, 72, 83, 74, or 75 volume percent).

[0051] The method may include drying the mixture to remove the solvent and forming a material having alternating layers of conductive (or semiconducting) nanoparticle-rich regions and non-conductive nanoparticle-poor regions via a self-assembly process. The method can produce a nanocomposite material having alternating layers of nanoparticle nanosheets (or nanoparticle-rich nanosheets) and BCP-based supramolecular nanosheets (or BCP-based supramolecular-rich nanosheets). When nanoparticle nanosheets (or nanoparticle-rich nanosheets) and BCP-based supramolecular nanosheets (or nanoparticle-rich nanosheets) are present in the nanocomposite material, each nanoparticle nanosheet may have a thickness of approximately 50 nm to 410 nm, or 50 nm to 150 nm, and each BCP-based supramolecular nanosheet may have a thickness of 50 nm to 410 nm, or approximately 50 nm to 150 nm. Each nanoparticle nanosheet may be approximately the same thickness as each BCP-based supramolecular nanosheet. Alternatively, each nanoparticle nanosheet may be thicker than each BCP-based supramolecular nanosheet. The method can also be used to produce nanocomposite materials having regions rich in PS and regions rich in P4VP (PDP) within a nanocomposite material containing regions rich in one of the two polymers of BCP, and regions rich in the other polymer of BCP, for example, PPS-b-P4VP.

[0052] Nanocomposite materials produced by the methods provided herein are also provided. The nanocomposite material may have approximately 20 to approximately 100, approximately 20 to approximately 200, or approximately 200 or more nanosheets, each nanosheet having a thickness of approximately 50 nm to approximately 410 nm, for example, approximately 50 to 100, 50 to 150, 50 to 200, 200 to 300, 300 to 410 nm, or approximately 150, 100, 125, 150, 200, 250, 300, 350, 400, or 410 nm. The nanocomposite material is approximately 0.06 μm thick. -2 The following defect densities and efficiency in controlling approximately 98% of defect types can be achieved. The nanocomposite material may have improved barrier functionality against volatile organic compounds (VOCs), water, oxygen, and / or electrons compared to the control material, and / or any other features provided herein.

[0053] Furthermore, this specification also provides barrier materials containing 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 coatings in a variety of applications, including, but are not limited to, volatile organic compound barriers, water barriers, oxygen barriers, electron barriers, dielectric capacitors, optical materials (e.g., optical filters, planar lenses, zone plates), and / or packaging materials for consumer products (e.g., as food packaging materials). [Examples]

[0054] (Example 1) Functional composites created by programming entropy-driven nanosheet growth The current challenges in fabricating 2D nanosheets were addressed by introducing a novel nanomaterial design with two elements: (1) utilizing the ability of entropy-driven assemblies to accept changes in reactant composition and pair interactions during processing and integration, and (2) matching the diffusion of building blocks required to form the targeted structure with system mobility. As shown in Figure 1B, continuous growth follows a nano-to-micro growth process in which the smallest structural features are generated when system mobility is highest, and vice versa. The growth pathway provided herein proceeds in a reversed micro-first-to-nano order (Figure 1C): the microstructure is defined first when the system has the highest mobility, and then the generation of nanostructure occurs through the local organization of building blocks. The entropy-driven phase behavior helps realize this large-to-small growth pathway. When the system is mobile enough to organize large-scale structures, it allows the system to form microscopic aggregates in dilute solutions. Thermodynamically, the entropy-driven phase behavior observed in high-entropy alloys provides compounding adaptability while maintaining structural fidelity. Thus, target nanostructures can be generated using many combinations of locally available components when system mobility is low. This novel design leads to 0.056 μm -2 A coating consisting of more than 200 stacked nanosheets (sheet thickness 125 nm) was fabricated, exhibiting a lower defect density and approximately 98% efficiency in defect control. The coating shows high-performance barrier properties against volatile organic compounds, water, and oxygen for use as a packaging material, and against electrons for use as a dielectric capacitor.

[0055] System Selection An entropy-driven assembly approach was tested using composite blends exhibiting entropy-driven self-assembly. The specific blend consists of 6-nm zirconium oxide (ZrO2) nanoparticles, 3-pentadecylphenol (PDP) small molecules, and a BCP-based supramolecular (abbreviated as PS-b-P4VP(PDP)1) constructed by hydrogen bonding PDP to the pyridine side chains of polystyrene-block-poly(vinylpyridine) (PS-b-P4VP). As shown in Figures 2A-2I, these blends self-assemble with formulation adaptability and structural fidelity similar to that observed in high-entropy alloys. These blends form nanostructures when effective interactions between PS-rich and P4VP(PDP)-rich microdomains are near zero or zero. Thus, components can readily diffuse across interfaces even at low system mobility. P4VP chemistry is beneficial for optimizing the substrate adhesion of coatings.

[0056] With engineering-related coating materials as the ultimate goal, high molecular weight BCP-based supramolecules were selected to access the thick nanosheets required for mechanical durability and good barrier resistance. Compound blend formulations based on BCP with molecular weights of 134 kDa, 455 kDa, and 557 kDa are listed in Table 1. They form lamellar or cylindrical microdomains with periodicity ranging from approximately 60 nm (S1 / NP) to approximately 170 nm (S3 / NP). PDP molecules are dispersed in both PS-rich and P4VP (PDP)-rich microdomains; spatially resolved energy dispersive X-ray spectroscopy (EDS) of S2 / NP using iodine-labeled small molecules (I-PDP) is shown in Figure 3. Dispersed PDP molecules are essential for screening undesirable interactions between PS and P4VP (PDP) and for realizing entropy-driven phase behavior such as formulation adaptability. Although the unique ligand chemistry of ZrO2 nanoparticles is unknown, an S3 / NP blend based on 557-kDa PS-b-P4VP can accept up to 20 vol% of nanoparticles in parallel layers.

[0057] The entanglement of long polymer chains plays several roles: namely, matching the system's mobility to its stage of structural evolution and programming dynamic pathways to regulate local defect morphology. The critical overlap concentration of polymer solutions is N in a good solvent. -1.8 Scaled as such, the concentrations are estimated to be >20 vol% for S1 and approximately 2.7 vol% for S2, based on BCPs of 134-kDa and 455-kDa, respectively. By using high molecular weight building blocks, the blend forms molecular aggregates in more dilute solutions. This provides sufficient system mobility to organize the molecular aggregates into a wide range of microframeworks for subsequent nanostructure generation. Long-chain entanglement increases the dynamic stability and integrity of the aggregates during subsequent growth and organization. Long-chain entanglement can slow local reorganization at defect sites, thus maintaining end-to-end defect morphology.

[0058] [Table 1]

[0059] Nanocomposite material generation: dynamic pathways To program nanosheet growth, S1 / NP, S2 / NP, and S3 / NP blends were studied to identify solution concentrations that form molecular aggregates and lamellar microdomains / nanosheets, and system mobility was quantified 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 distinct lamellae and specific nanoparticle resolution in P4VP (PDP)-rich regions, where approximately 10 vol%, is present, at a solute concentration of 30 vol%. Figure 4A shows the SANS profiles of S2 / NP at solute concentrations of 5 vol% and 10 vol%. Guinier-Porod analysis shows that at 5 vol%, S2 / NP forms cottony molecular aggregates approximately 100 nm in size, with no preferential resolution of nanoparticles. At 10 vol%, the molecular aggregates become better defined with sharper aggregate / solvent interfaces, and nanoparticles preferentially reside in P4VP (PDP)-rich regions. However, the lamellar microdomains have not yet assembled. Ultrasmall-angle neutron scattering (USANS) is q = 3.8 × 10⁻¹⁶. -3 nm -1 The slope transition (Figure 4B) suggests the presence of larger aggregates with an Rg of 453 nm. Randomly arranged aggregates were also observed in liquid cell transmission electron microscopy (TEM) studies (Figure 4B, inset).

[0060] The heterogeneous distribution of nanoparticles in 10 vol% S2 / NP was confirmed using SAXS, which exhibits broad correlated holes with a characteristic size of approximately 114 nm (q = 0.055 nm⁻¹). This is consistent with the ultrasmall-angle X-ray scattering (USAXS) profile in Figure 4C. The S3 / NP blend is based on a 557-kDa BCP and forms molecular aggregates at much lower solute concentrations than S2 / NP. This is indeed the case: the USAXS profile of S3 / NP at a 10 vol% solute concentration shows large-scale aggregates, evidenced by the emerging nanostructures (Figure 4C) described by strong scattering in the low-q region and a scattering peak at q = 0.043 nm⁻¹. In-situ SAXS studies showed that well-ordered lamellar microdomains with a periodicity of 126 nm and a Scherrer particle size of approximately 1.73 μm are generated almost immediately as the S2 / NP solution concentration approaches approximately 30 vol% (Figure 4D). The aggregates can rapidly convert into nanosheets. Thus, microscopically arranged molecular aggregates can template nanosheet growth and regulate the long-range order of nanocomposites. However, this requires considerable system mobility.

[0061] X-ray photon correlation spectroscopy (XPCS) was used to quantify S2 / NP system mobility and investigate the spatial distribution of ZrO2 nanoparticles throughout the in-situ drying process (Figure 4E). Based on the fitting of the Kohlrausch exponent γ, nanoparticle diffusion changes from subdiffusive (γ≈3.5) to diffusive (γ≈2) motion as the solute concentration increases from 10 vol%. This is consistent with SANS results and suggests that the nanoparticles leave the entangled PS mesh and selectively enrich regions rich in P4VP (PDP). Relaxation time at two length scales: q = 0.3 nm -1 τ at s and q=0.03nm -1 τ at l By determining (Figure 4F), the nanoparticle diffusivity was further quantified at the nano and microscales. When molecular aggregates are formed at approximately 10 vol%, the blend exhibits good mobility for both nanoscale and microscopic diffusion, and τ sis τ l (10 -3 (10) is approximately 100 times faster than (10 -5 s). However, when nanosheets are formed (approximately 30 vol%), the relaxation time increases sharply (τ l ≈1,000s and τ s (approximately 100 seconds), proportional to the diffusion length scale they describe. System mobility is too limited to alter the templated microstructure. Subsequent nanostructure generation must rely on short-range diffusion to locally organize various building blocks.

[0062] The generality of this assembly process is demonstrated by S1, which generates cylindrical microdomains with a periodicity of approximately 80 nm. cyl Evaluation was performed using the / NP blend. S1 cyl The drying conditions for processing the / NP film were adjusted to vary the incubation time (Δt) between molecular aggregate formation and nanostructure formation. In-situ glazing transmission small-angle X-ray scattering (GTSAXS) was used to characterize the structural evolution throughout the complete solution / film thickness over an estimated beam path length of approximately 1.5 mm. When Δt was sufficiently long (approximately 11 minutes for this blend), diffraction peaks of several orders of magnitude appeared rapidly, supporting the idea that mobility-based nanostructure growth can induce a high degree of long-range ordering in non-lamellar forms (Figure 4G).

[0063] Long-range ordering and defect optimization The initial microscopic structure determines the degree of long-range order in the nanostructure. Stepwise changes in the diffusion mode and system mobility of nanoparticles identify a processing window for programming growth, with the microscopic structure being the first and the nanoscopic structure the second. The microscopic structure determines the degree of long-range order achieved by the nanostructure. Nanocomposite films were kinetically captured at specific solute concentrations selected from scattering results using rapid solvent removal. Representative cross-sectional TEM images of S2 / NP films quenched at 23 vol%, 28 vol%, and 40 vol% are shown in Figure 4H. For all samples, nanostructures are clearly generated despite rapid solvent removal. This again supports the idea that nanostructure generation is not the rate-limiting step for hierarchical growth of nanosheets. When solvent removal occurs at 23 vol%, long-range order is insufficient. The solute concentration is too dilute to drive condensation of molecular aggregates despite high system mobility. Rapid solvent removal at 40 vol% generated different nanosheets, but with a high defect density and an aspect ratio of less than 40. This suggests that the generation of nanostructures may compete with and interfere with the generation of microframeworks. The best long-range order is achieved by quenching the film at 28%, slightly lower than the concentration at which the nanosheets were generated. The nanosheets are tens of micrometers in length and have an aspect ratio greater than 500. Thus, long-range order, i.e., defect density, can be regulated by optimizing the organization of sheet-like aggregates before the generation of nanostructures.

[0064] Defect types also determine barrier performance, as different defects have diverse effects on transport pathways. The proliferation of various defect types is determined by short-range diffusion during the final stage of assembly. Complete defect densities are provided in Table 2. Blends based on lower molecular weights, e.g., S1, have more circular microdomains between nanosheets, and sharply curved microdomains, which we have named "U-turn" defects, are rare. These defect morphologies are the result of local reorganization, indicating that the system is mobile enough to reorganize BCP-based supramolecules and release packing frustration. However, in the case of high molecular weight building blocks, e.g., S2 / NP and S2-based blends, most defects are paired terminal and U-turn types. Some nanosheets proceed in a zigzag manner, resulting in several consecutive U-turns (Figures 5A-5B). There is considerable energy loss associated with bending nanosheets at such sharp angles. However, long-chain entanglement increases the energy barrier against local reorganization and dynamically traps these defects after the formation of the microframework. U-turn defects can be eliminated by increasing the rigidity of the nanosheet, for example by adding nanoparticles or by driving the system to a lower solvent fraction to further enhance long-range order. Paired end defects sever transport pathways, which is desirable for engineering barrier materials. Thus, the ability of long-chain entanglement to separate defect operations from the generation of nanostructures is advantageous in controlling the proliferation of various defect types.

[0065] [Table 2]

[0066] Programmed composite coating manufacturing Macroscopic nanocomposite coatings were fabricated on commercially available films by optimizing the evaporation of the S2 / NP solution to maximize the time spent between 23 vol% and 28 vol%, followed by rapid drying. Figures 6A-6B show cross-sectional TEM images of an S2 / NP film with a thickness of approximately 35 μm. The film contains more than 200 parallel lamellae with a periodicity of 127 nm. Most nanosheets are continuous within and beyond the 90-μm field of view. A similar degree of long-range order extends in other regions of the film, approximately 2,660 μm. 2 There were only 149 defects within the image area (Figure 6C). Since there is no reported defect density for stacked nanosheets, the defect density of a 60-nm thick cross-section was compared to that of a BCP thin film (Figure 6D). 0.056 μm -2 The S2 / NP defect density is the density obtained after multi-step annealing (3.5 μm). -2 ) or topographic self-assembly (0.267 μm -2 This is only a small part of it.

[0067] Almost all defects were paired terminals (146 out of N=149, approximately 98%); the remaining defects were paired U-turns (N=2) and single junctions (N=1). Nanoparticles influence the defect density, which will then contribute to the long-range order and the properties of the coating. The incorporation of nanoparticles substantially increases the stiffness and flexural modulus of the layer. They result in straight nanosheets with a high aspect ratio and low defect density, and bias the defect type distribution away from U-turns and junctions. Dynamic control may more than compensate for the increased entanglement of higher molecular weight supramolecules. When the incubation time Δt decreased, only poorly ordered S1 / NP and S2 / NP films were observed; a sufficiently long Δt led to a highly ordered S3 / NP film with a periodicity of 174 nm and a nanoparticle packing density of 20 vol% (Figures 6E-6F).

[0068] When engineered at the system level, these nanocomposite films actually meet numerous essential requirements as functional barrier coatings. Due to their long-range order and high molecular weight building blocks, S2 / NP films are flexible and mechanically robust; their vivid structural color is a bonus for their relatively large feature size. They have an elastic modulus of 512 ± 122 MPa and a hardness of 13.6 ± 3.3 MPa as measured using nanoindentation. Thanks to their entropy-driven phase behavior, stacked nanosheets can be formed on a variety of substrates despite variations in substrate chemistry (silicon, glass, polyester, and Teflon) as well as roughness and morphological irregularities (Figures 2A-2I). Periodic elongation and buckling tests (N=600) were performed on a polyester substrate (127 μm thick, McMaster-Carr) coated with S2 / NP, and the coating maintained its integrity without delamination or crack formation.

[0069] High-performance nanocomposite barrier Barrier materials, essential for product preservation and longevity, are the cornerstone of sustainability. Multilayer nanocomposite coatings are competitive barrier materials that rival or surpass current industry standards, offering significant advantages in their material 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, providing a solution to the recycling problems associated with existing metallized multilayer films. Long-chain entanglement provides mechanical durability without the need for chemical crosslinking. They are suitable for assembly, disassembly, and reassembly cycles without compromising structural integrity, highlighting the advantages of bottom-up material synthesis (Figures 8A-8D).

[0070] When coated on a porous Teflon film, a 30-μm S2 / NP coating allows the permeation of common volatile organic compounds (VOCs) of 100±0% (dynamic diameter d) for 2-butanone and hexaldehyde. k (≥5.3 Å), 96±0% (d) relative to acetaldehyde k =5.0Å), 94±9.2% (d) relative to acetone. k =4.4 Å) and 55 ± 4.2% (d) relative to formaldehyde. k The VOCs are reduced with a removal efficiency of 3.7 Å (Figure 7E). This performance is comparable to a wet scrubber based on an electrochemical cell that has a removal efficiency of 95% at similar VOC concentrations. The barrier performance of the composite coating was tested for water vapor permeability as a substitute for multilayer packaging film. A 30-μm S2 / NP coating on a 127-μm polyester film showed more consistent barrier performance over a 3-week test, with a water vapor transmission rate (WVTR) of 11.5 ± 5.7 gm -2 day -1 ~5.3±0.6gm -2 day -1 This can be substantially reduced (Figure 7F).

[0071] With 98% efficiency in defect control, nanocomposites with stacked nanosheets also serve as excellent barriers to electrons, making them high-performance dielectric materials for energy storage. The S2 / NP film has a thickness of 650 MVm. -1 It has an energy efficiency of 91.2%, a charge / discharge efficiency exceeding 90%, and a discharge energy density of 6.2 Jcm². -3 This is the case (Figure 7G). This performance is comparable to current industry-standard dielectrics, including biaxially oriented polypropylene (BOPP) (Figure 7G). The high dielectric breakdown strength of the nanocomposite films is another piece of evidence for the importance of their low defect density and high efficiency in defect type control. Organic electronic devices, including organic light-emitting diodes and solar cells, must be encapsulated to prevent degradation by oxygen and water vapor; irregular device topologies present specific challenges. Calcium films oxidize rapidly under ambient conditions, and their relative conductance makes them a convenient proxy against long-term device degradation. Using electrocalcium testing, the barrier properties of S2 / NP nanocomposites were compared with two standard UV-curable epoxies, DELO Katiobond LP655 and Ossila E132 (Figure 7H). Despite considerable differences in barrier thickness, their performance was comparable. The 50% relative conductance of the encapsulated calcium film was reached after 241±27 minutes for DELO Katiobond LP655 (approx. 119 μm), 367±53 minutes for Ossila E132 (approx. 218 μm), and 79±11 minutes for S2 / NP (approx. 35 μm). When normalized by film thickness, the S2 / NP barrier takes almost twice as long for the calcium film to reach 0% relative conductance. Thus, self-assembled nanosheets can produce thinner and more flexible organic electronic devices, and their inherent recyclability can contribute to better control throughout the lifecycle of organic electronic devices.

[0072] Systematic control studies confirm the importance of holistic nanomaterial design to achieve technically relevant nanomaterials (Figures 7E-7H). The performance of barrier materials is determined by all aspects of their composition and structure: layer composition and dimensions, defect type and density, long-range order, mechanical properties and geometric fit. Nanoparticles help to 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 essential to realizing the benefits of functional nanomaterials. S2 dis Poorly ordered S2 / NP composites, represented as / NP, have a discharge energy density of 6.2 to 4.3 Jcm². -3 It showed a reduction of more than 30%, and could not function as an effective water barrier coating. Furthermore, the ordering of the nanocomposite material had a significant impact on its mechanical properties. Insufficiently ordered S2dis The S1 / NP composite had 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 supramolecules formed by high molecular weight BCP are decisive for high performance in all applications tested in this study. Contrary to the common idea that chain entanglement is detrimental to aggregate dynamics, high molecular weight building blocks are favorable and essential for achieving programmable rapid growth of nanosheets with long-range order and defect control. Superior barrier performance relies on the thick nanosheets they assemble into. When the nanosheet is only 60 nm thick, the barrier efficiency of S1 / NP drops to 20-36% for all VOCs and <10% for water, and the dielectric breakdown strength is 637 to 469 MVm -1 As a result, the maximum discharge energy density was reduced by more than 50%.

[0073] summary The successful conversion of nanosheets into high-performance barrier materials highlights the importance and necessity of engineered nanomaterials at the system level. The results provided herein support the feasibility of creating nanomaterials that meet multifaceted requirements by transforming limitations in previous designs into unique advantages. This example demonstrates that properly engineered nanomaterials are inherently multifunctional and, when thoughtfully designed, ultimately harness the power of nanoscience to advance technology.

[0074] Materials and methods Materials. Poly(styrene)-b-poly(4-vinylpyridine) was purchased from Polymer Source, Inc. (polydispersibility index = 1.1-1.2). 3-n-pentadecylphenol (90-95% purity) was purchased from Acros Organics. Chloroform was purchased from Fisher Scientific, and HCl was not detected by NMR. Deuterated chloroform was purchased from Cambridge Isotope Laboratories. (6±2 nm) zirconium dioxide nanoparticles dispersed in toluene were purchased from Pixelligent. All materials were used as received without further purification. In the following manner, the block copolymer is abbreviated as PS-b-P4VP, and the small molecule as PDP. The supramolecular is abbreviated as PS-b-P4VP(PDP) to indicate hydrogen bonding between PDP and 4VP monomers. PDP was added in excess of the possible binding sites, and therefore there is one more than one PDP molecule per 4VP monomer. The ratios of each blend are provided in Table 1.

[0075] Sample solution preparation. Dissolve PS-b-P4VP and PDP powder in chloroform to make 25 mg / ml solution. -1 A (2.5 vol%) supramolecular solution was prepared. 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 using a pipette pump. For SANS and USANS studies, the same preparation was performed using deuterated chloroform. For SAXS and XPCS studies, the same preparation was performed using benzene due to the high X-ray absorption of chloroform. Cross-sectional TEM images confirmed that the self-assembly pathways were consistent in benzene and chloroform.

[0076] Dropcast film sample preparation. For each dropcast film, a 50 μl droplet of 2.5 vol% solution was placed on a 1.5 cm surface. 2The material was applied to a square silicon substrate. To slow down the drying process, the substrate was sealed in a 125 ml glass jar with a cap along with a 70 μl container of pure solvent. The solution was allowed to dry for a predetermined length of 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. All remaining solvent evaporated within approximately 3 seconds, effectively "freezing" the microstructure of the nanocomposite. The film thickness was measured as a function of its drying time using a white light interferometer (Filmetrics F20). At the beginning of the drying process, the film thickness was outside the interferometer's measurement range. These thickness values ​​were evaluated by interpolating between a known initial film thickness (calculated from solvent volume and substrate area) and an exponentially decaying fit of the data dried later. The thickness values ​​were converted to solvent or solute portions to compare results across various experiments.

[0077] Bulk sample preparation. To prepare the bulk sample, 1 ml of 2.5 vol% polymer solution was dried at room temperature in a 1 ml Teflon beaker. The beaker was not sealed or coated, so the solvent evaporated freely. Due to the larger volume of solvent, the sample was left to dry overnight. Once dry, the nanocomposite was peeled from the Teflon beaker using tweezers. To prepare a deliberately disordered sample, a jet of N2 was applied across the opening of the beaker. This accelerated the drying process to approximately 30 minutes.

[0078] Static solution SANS and USANS experiments. The EQ-SANS instrument at the Spallation Neutron Source of Oak Ridge National Laboratory was used for SANS experiment 47. The temperature of the sample, housed in a cylindrical quartz cuvette, was maintained at 25 ± 0.1 °C. Each sample was measured using three settings for sample-detector distance and minimum wavelength: 9 m / 15 Å, 4 m / 10 Å, and 2.5 m / 2.5 Å. In summary, these three configurations provided a momentum transfer q within a certain range of 0.002 Å. -1 <q<0.7Å -1The data from the sample and solvent were corrected for wavelength-dependent transmission, incident flux, detector sensitivity, shape effects, and signals from an empty quartz cell, then averaged by azimuthal nuclei and converted to 1D I(q) vs q using standard procedures performed in drtsans software 48. During data reduction, the data were measured at 1 cm using a calibrated porous silica standard 49. -1 The intensity was scaled to absolute intensity. Then, data from the three instrument configurations were combined into a single dataset. The combined dataset was used for data analysis. 5 × 10 -5 ~3×10 -3 Å -1 To cover the wave vector q range, USANS measurements were performed at the BL-1A USANS instrument of the spallation neutron source using three wavelengths: 1.2, 1.8, and 3.6 Å. Samples were loaded into a 2-mm Hellma cell. Data were reduced using an empty cell background correction and expressed in absolute intensity units.

[0079] Guinier-Porod model information and fitting approach. The Guinier-Porod fit follows the approach originally described by Hammouda, 2010 J. Appl Crystallography 43, 716-719, doi:10.1107 / S0021889810015773. This method was chosen because it can accept the coexistence of poorly defined and / or non-spherical structures, and the fitting parameters have a reasonable physical explanation. The Guinier-Porod model is empirical overall. Further details on the Guinier-Porod model information and fitting approach are described in Vargo et al. 2023 Nature 623:724-731, https: / / doi.org / 10.1038 / s41586-023-06660-x, Supplementary Information Section 1.

[0080] Static solution USAXS. Fully calibrated USAXS and SAXS experiments were performed at beamline 9-ID in the Advanced Photon Source, Argonne National Laboratory. The combined q range was 1 × 10⁻⁶. -4 Å -1 ~1.3 Å -1 The equation is given by q = 4π / λsin(θ), where λ is the wavelength and θ is half the scattering angle. The X-ray energy was 21 keV (λ = 0.5895 Å). The X-ray photon flux was approximately 5 × 10⁻¹⁶ throughout the 0.5 × 0.5 mm beam size. 12 mm -2 s -1 This is equivalent to the data being reduced using USAXS instrument data reduction software and desmeared from slit-smeared collimation of the Bonse-Hart USAXS system.

[0081] In-situ SA-XPCS. In-situ small-angle X-ray scattering and X-ray photon correlation spectroscopy (SA-XPCS) experiments were performed at beamline 8-ID-I in the Advanced Photon Source, Argonne National Laboratory. The X-ray energy was 10.9 keV; the horizontal beam size, defined by the upstream guard slit, was 15 μm, and the vertical beam size was 10 μm. To perform the drying experiment, a 10-vol% S1 / NP solution was loaded into a quartz capillary (2 mm outer diameter, Charles Supper). The capillary seal was removed 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 was collected every 15 minutes. Liquid diffusion within 15 minutes was sufficient to avoid visible beam damage. Local solution concentrations, other than the known starting concentrations, could not be measured during the drying process. 2D scattering intensities were collected using a Rigaku XSPA-500k detector. Fast dynamics (initial drying stage) were captured with a frame rate of 50 kHz and a total acquisition time of up to 2 s. Slow dynamics (later drying stage) were captured with a frame rate of 100 Hz and an adjustable total acquisition time (50 s in this study) matched to the sample duration. SA-XPCS analysis was performed on high-performance clusters using the APS Data Management System workflow. Both SAXS and XPCS results were visualized, fitted, and plotted using the graphics module and function libraries provided by pyXPCSviewer.

[0082] GTSAXS. GTSAXS measurements were performed at beamline 8-ID-E in the Advanced Photon Source, Argonne National Laboratory. The X-ray wavelength was 1.687 Å, and the scattering intensity distribution was captured with 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. To slow the drying process, a chloroform container of a selected volume (here, 350 or 500 μl) was placed in the chamber, and then 100 μl of sample solution was drop-cast onto the substrate. GTSAXS measurements were performed at an incidence angle of 0.8°.

[0083] TEM sample preparation and imaging. Bulk samples were embedded in resin (Araldite 502, Electron Microscopy Sciences) and cured overnight at 60°C. Film samples were coated with resin and cured overnight at 60°C. The silicon substrate was removed by immersing the resin-coated films in liquid nitrogen; due to the mismatched thermal expansion coefficients, the nanocomposite film peeled away from the silicon but remained bonded to the resin. Sections approximately 60 nm thick were prepared using an RMC MT-X ultramicrotome (Boeckeler Instruments), floated on water, and picked up onto a copper TEM grid. In samples without nanoparticles, the P4VP region was selectively stained using iodine vapor. Thin sections were imaged using an FEI Tecnai 12 at an accelerating voltage of 120 kV. To generate high-resolution composite images (Figure 6A), overlapping TEM images were collected and manually aligned in Photoshop using lower-magnification reference images.

[0084] Automated nanosheet length and defect analysis. An approach translated from ADAblock, using an ImageJ plugin developed by Murphy et al., was employed to execute image analysis code in Python. In short, grayscale TEM images were binarized using the local Otsu thresholding technique. Using the binarized images, a 1-pixel-thickness skeleton describing the connectivity of each layer's cross-section was drawn. Defects were labeled using the eight nearest neighbors of each skeleton pixel. Skeleton pixels with two nearest neighbors were considered defect-free, those with only one nearest neighbor were labeled as terminal defects, and those with three or more nearest neighbors were labeled as junctions. Concatenated junctions were avoided by avoiding double counting. U-turn defects were not counted in this automated image analysis method as they do not affect connectivity. Each terminal defect was manually inspected, and U-turn defects were labeled where applicable.

[0085] To perform sheet length analysis, all junction pixels were removed from the skeleton, leaving a set of isolated 1D sheets. The length of each sheet was recorded in the pixels and then converted to micrometers using the magnification of each image.

[0086] VOC removal efficiency test. S2 / NP, S2 disFilms of / NP, S2, and S1 / NP were prepared on a circular 47 mm diameter polytetrafluoroethylene air sampling membrane (Pall, part number R2PJ047). In each test, the edge of the test specimen was tightly held between the two flanges of a Teflon filter holder to which a 1 / 4” Teflon tube was attached. On one side, the filter holder was connected to a Teflon bag pre-filled with air enriched with a mixture of formaldehyde (70–230 ppb), acetaldehyde (10–90 ppb), acetone (1.9–4.3 ppm), 2-butanone (35–90 ppb), and hexaldehyde (40–95 ppb). Water vapor was added to the bag to achieve a relative humidity of 5–50%. The experiment was conducted at room temperature (20–23°C). Temperature and relative humidity were measured with an in-line digital T / RH sensor (HIH6100 series, Honeywell). On the other side of the filter holder, 80–90 ml -1 Air was drawn from the bag through the specimen using a peristaltic pump operating at a flow rate of . Once the airflow through the specimen reached a steady state, samples were simultaneously collected upstream and downstream of the specimen by drawing air through a silica gel cartridge (Waters Corp., part number WAT047205) impregnated with 2,4-dinitrophenylhydrazine (DNPH) for a period of 15 to 50 minutes. The DNPH cartridge was then extracted with 2 ml of carbonyl-free acetonitrile (Honeywell) and submitted to the United States Environmental Protection Agency. 53 Extracts were analyzed by high-performance liquid chromatography with UV detection (Agilent 1200) according to the TO-11 method. VOCs were identified based on the retention times of their corresponding dinitrophenylhydrazine derivatives (Sigma-Aldrich) and true standards. These standards were used to create calibration curves for quantification. The reported values ​​are the average of two sequentially obtained determination values. Retention efficiency E of each compound i i is compound i

[0087]

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[0088] WVTR test. The WVTR test procedure is specified by ASTM E96-00: 'Standard Test Methods for Water Vapor Transmission of Materials'54. In each test, an aluminum jar (80 mm diameter, Joywee) was filled with 4 g of desiccant pellets (DampRid Moisture Absorber). A polyester sheet (127 μm thick, McMaster-Carr) was heat-sealed around the mouth of the jar to form a circular dish with a 5 mm rim. After cooling, the circular dish was removed from the jar and filled with 2.5 ml of 2.5-vol% sample solution. After the film dried, the polyester dish was inverted and sealed to the jar filled with desiccant using 5 Minute Epoxy (Devcon). A control sample was prepared using the same procedure with 2.5 ml of pure chloroform instead of the sample solution.

[0089] After bonding the samples to a cured dish with commercially available epoxy, the initial mass of the samples was directly collected. Then, all samples were placed on a perforated plastic stand over salt-saturated water in a sealed plastic container at ambient temperature and pressure to create a 75% relative humidity environment. After measuring the initial mass, mass measurements were taken once every 24-48 hours to measure the mass increase of the desiccant water using the test film over a three-week period. The WVTR value was calculated by finding the least squares fit of the sample mass versus collection time data. For the jar used here, the film area A = 40π mm² 2 The slope of the fit was converted to WVTR by dividing by [a certain factor]. The standard deviation of the WVTR was calculated in the same way.

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[0090] Calcium conductivity test. The barrier properties of nanocomposites were compared to commercially available UV-curable epoxy using an electrocalcium test. Each sample was prepared on a 125-μm polyethylene terephthalate (PET) substrate by a series of thermal deposition steps. A pair of silver traces (100 nm thick, 2 × 15 mm in size) were used. 2 Calcium (thickness 100 nm, area 8 × 8 mm) was thermally deposited onto a PET substrate. 2 ) is thermally deposited onto silver (at a pressure of 2-5 × 10 -6 Toll, deposition rate <0.8 Ås -1 The two traces were electrically connected, resulting in an initial conductance <0.1S. Each sample was then prepared with the specified sealant and covered with a 125-μm PET cap. The decreasing conductance of the calcium sample is a result of oxidation in the presence of oxygen and moisture. 2Be + O2 = 2BeO Ca + 2H2O = Ca(OH)2 + H2O The commercially available epoxies tested were DELO Katiobond LP655 and Ossila E132 epoxy. After applying the epoxy and PET caps, each sample was exposed to a UV lamp until fully cured before measurement. Approximately 20 μl of S2 / NP solution was drop-cast onto the nanocomposite samples, covered with PET caps, and allowed to assemble for approximately 1 hour before measurement. The conductance of the encapsulated samples was measured over time in a closed environment chamber (Associated Environmental Systems BHS-503, Acton) maintained at 20% relative humidity and 20°C (Keysight DAQ970A). The approximate barrier thickness against the commercially available encapsulants was calculated based on repeated mass measurements of the applied droplets and the volume density reported by the manufacturer.

[0091] Dielectric strength test. Device fabrication. Glass substrates coated with indium tin oxide (ITO) (2~3Ω / sq -1 , Thin Film Devices, Inc.) were sequentially cleaned in advance using soap water, deionized (DI) water, acetone and isopropanol. The substrate was then heated at 100°C for at least 4 h before use, followed by UV / O3 treatment for 20 minutes. Nanocomposite films were drop-cast onto the ITO substrate as described above. After the films were completely dried, they were placed in a vacuum chamber overnight to remove any residual solvent or moisture. A typical film thickness was about 2 μm. Gold electrodes (1.13 mm 2 in area, approximately 20 nm thick) were deposited onto the top surface of the film sample using a thermal evaporation system (MBRAUN). The ITO conductive coating was grounded using conductive silver paint (Ted Pella, Inc.). For comparison, benchmark BOPP (capacitor grade, about 3~4 μm thick) was obtained from PolyK Technologies, LLC. Gold electrodes (1.13 mm 2 in area, approximately 20 nm thick) were deposited on both sides of the BOPP film using the same thermal evaporation system (MBRAUN).

[0092] Device breakdown strength. Dielectric breakdown strength was measured using a Trek 610D instrument amplifier as the voltage source based on the electrostatic pull-down method, where a DC voltage ramp of 200 V s-1 was applied to the film sample until dielectric breakdown occurred. Experimental dielectric breakdown measurements were analyzed by two-parameter Weibull statistics, which can be described by the following formula: P(E)=1-exp(-(E / α)^β) β where P(E) is the cumulative probability of dielectric breakdown, E is the measured breakdown field, the scale parameter α is the characteristic breakdown strength (i.e., Weibull breakdown strength), which corresponds to a failure probability of 63.2%, and the shape parameter β is related to the distribution of the data. A higher β value indicates narrower data spread. At least 10 measurements were performed for each Weibull fitting.

[0093] Dielectric energy storage characteristics. Electrical displacement-electric field (DE) loops were collected under various applied electric fields using a modified Sawyer-Tower circuit integrated with PolyK Technologies, LLC's PK-CPE1801 high-voltage test system. A voltage with a unipolar triangular waveform was applied to the film sample at a frequency of 100 Hz. Dielectric energy storage characteristics, including discharge energy density and charge / discharge efficiency, were derived from the DE loops.

[0094] 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 chip (TI-0039-1, 50 nm chip radius). The coating was bonded to a silicon wafer using crystal bond and left overnight under ambient conditions for indentation. Maximum load 1,000 μN and loading speed 20 μNs -1 Twenty-five indentations were performed per sample. The film was subjected to quasi-static indentation with a holding time of 30 s before load removal. The applied tip-area function was fitted using polycarbonate, a reference material provided by Hysitron. The reduced modulus and hardness were determined using the Oliver and Pharr methods. The reduced modulus was

number

[0095] Periodic buckling test. The periodic buckling test was performed on the nanocomposite coating at room temperature using an MTS Tytron 250 test machine (MTS Systems Corp.). The film was bent and stretched for a total of 600 cycles within a range of ±0.75 mm at a frequency of 1 Hz. Recycling test. Bulk nanocomposite samples were 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 with chloroform; the volume of chloroform was selected to produce a 2.5-vol% solution. The bulk sample appeared to dissolve immediately, and the solution was stirred overnight to ensure complete dissolution. The following day, another bulk sample was prepared as described above. TEM imaging confirmed that the recycled sample had the same lamellar structure as the original sample (Figures 8A-8D).

[0096] STEM tomography. 3D electron tomography projections were collected using a 200kV FEI TitanX 60-300 microscope with a 10-mrad probe and half-focus angle at the National Center for Electron Microscopy (NCEM) facility at Molecular Foundry. A series of TEM images were obtained using a Hummingbird heavy tomography holder with tilt angles ranging from ±70° and angular intervals of 1°. The tilted series were aligned and reconstructed using eTomo software from the IMOD tomography package. Reconstruction was performed using a weighted-back-5 projection method. 3D visualization was performed using Tomviz 1.3.1. The materials, methods, and results provided in this embodiment are further described, including extensive data figures and tables and supplementary information, in Vargo et al. 2023 Nature 623:724-731, https: / / doi.org / 10.1038 / s41586-023-06660-x. The entire contents of the above material are incorporated herein by reference.

[0097] (Example 2) Gradient structure in self-assembling multilayer nanocomposites The spontaneous generation of layer thickness gradients has been studied in self-assembling nanocomposite systems. As provided in Example 1, the self-assembling nanocomposite systems provided herein generated a rich map of their self-assembly process from dilute solution to dried composite. Among other unique behaviors, it is well supported that the final ordered nanostructure is determined by the processing conditions, i.e., the drying rate, in addition to the system's composition. This processing dependence is particularly pronounced at high molecular weights, probably due to the large number of possible polymer arrangements and the stabilizing effect of chain entanglement. Transmission electron microscopy (TEM) imaging of cross-sections showed that a single high molecular weight lamellar nanocomposite can form features anywhere from 72 nm to over 300 nm, compared to a "bulk" periodicity of 127 nm, under various drying conditions. Within a single nanocomposite film, layer thickness can also vary spatially, increasing smoothly from the film-substrate interface towards the upper film-air interface.

[0098] The nanocomposite blend consists of 6 nm ZrO2 nanoparticles, 3-pentadecylphenol (PDP) small molecules, and a coil-comb supramolecule constructed from PDP and polystyrene-block-poly(vinylpyridine) (PS-b-P4VP) block copolymer. The supramolecular comb blocks spontaneously form when PDP molecules hydrogen-bond to 4VP units within the BCP. Unbonded and hydrogen-bonded PDP were distinguished because the two populations play different roles in the self-assembly process and act essentially as two different components. Chloroform was chosen as the solvent because it is a good solvent for PS coil blocks and produces a loose chain structure at low concentrations. Small molecule PDP adds mobility to the system by diluting the entanglement of BCP and increasing the volume of P4VP blocks. Since PDP has solubility parameters between BCP blocks and NP ligands, free PDP can relax undesirable interfaces between blocks or around NPs, stabilizing morphologies with a large surface area. Free PDPs can also redistribute over relatively large distances and accept constraints. The intermediate strength of hydrogen bonds gives PDPs some degree of freedom to rearrange, and the exchange between the 4VP-bound and free states is a subject for study. 61 This is an open topic. Much of the self-regulating behavior of this complex system may be attributable to small molecules.

[0099] Within a drying drop-cast film, the solute concentration is a function of both time and depth (Figure 9A). Thus, at every point until the film is completely dry, the solute and solvent fractions form a smooth gradient throughout the film thickness. Using high molecular weight supramolecular nanocomposite blends, the characteristic layer width L can be varied by changing the drying rate and duration of the film. Rapidly dried nanocomposite films have relatively small domain thicknesses, while slowly dried films exhibit considerably larger L values ​​(Figures 9B-9E). In addition to substantial differences between samples, we also observe a significant L gradient within individual samples. The system may be dynamically trapped in lower L states by the collapse of microdomains during rapid solvent removal. However, the existence of higher L states cannot be explained by the same mechanism. All samples shown in Figures 9B-9E have the same composition, film thickness, and initial concentration. The underlying mechanism involves a combination of entropy, enthalpy, and dynamic factors.

[0100] Structural property evaluation by X-ray scattering The strong dependence of the gradient structure on the processing history suggests that they are in a state of dynamic capture rather than thermodynamic equilibrium. However, in situ small-angle X-ray scattering (SAXS) suggests additional factors for the mechanism. The assembly process of the nanocomposite was observed from a starting concentration of 10 vol%, mapping the complete structural evolution (Figure 10A). If the solution has time to dry slowly after the appearance of sharp lamellar structure factor peaks, the peaks eventually broaden and shift to lower q values. The shift in q is easily interpreted: the volume-average feature size grows larger. Broadening structure peaks are less common and often correspond to the formation of smaller particles, as described by the Scherrer equation. However, technically, this simply means that the nanocomposite structure deviates completely from periodic lamellae. Cross-sectional imaging of the dried samples confirms that they maintain a nearly perfect domain orientation (i.e., a particle size larger than the X-ray probe) that appears around a solute concentration of approximately 30%. Thus, broadening structure factor peaks were used to identify the appearance of gradient structures. In particular, the gradient appears only after the formation of highly ordered, larger particles of oriented lamellae with uniform microdomain periodicity. This suggests either that the gradient structure is energetically preferable to the periodic lamellar structure, or that the energy theory of the system changes after the formation of the periodic lamellae.

[0101] In addition to in-situ studies, static USAXS, SAXS, and WAXS measurements of fully dried films with and without gradient structures were collected on probe features with angstrom-μm length scales (Figures 10B-10D). The USAXS-SAXS scattering profiles provided satisfactory answers to a couple of disparate questions. First, they confirm that we are indeed seeing a net increase in lamellar thickness; the increase at the top edge of the film is not compensated for by a decrease elsewhere. Also, the various periodicities observed in the cross-sectional TEM images are representative because USAXS examines a much larger sample volume. The scattering results verify that the gradient is not an optical illusion caused by the inclined lamellae.

[0102] WAXS peaks describe angstrom-level small molecule behavior corresponding to PDP and NP ligand organization. In addition to static WAXS performed on dried samples, solution WAXS data was collected using capillaries filled with solution (Figure 10C). Due to their long aspect ratio, capillaries contain a range of solvent concentrations that are clearly distinguishable by their structural color. Thus, static samples could be used to approximate in-situ studies of small molecule behavior throughout the drying process. Peak iii in Figures 10C and 10D is consistent with the 4.17 Å WAXS feature of crystallized PDP (MC Luyten et al. 1999 Macromolecules 32, 13, 4404-4410). Peaks iv and v were matched to NP ligands using a control sample containing only NPs. Since NPs do not aggregate in slowly dried samples, the volumetric NP concentration is expected to be proportional to the solute concentration. Therefore, the relative height of peak iii compared to peaks iv and v indicates the amount of PDP crystallization relative to a fixed amount of solute.

[0103] As the solution dries, the crystallized PDP peak intensity overtakes the NP peak intensity in the WAXS data, suggesting that the increasing length of the P4VP backbone becomes fully saturated with hydrogen-bonded small molecules. The relative amount of PDP is fairly consistent between the driest solution sample and three of the four fully dried samples. Based on their structural color and cross-sectional TEM imaging, these three samples have an average domain spacing below the previously reported "bulk" periodicity. However, the fourth dried sample, whose red color suggests a much larger L on the top of the film, has substantially less crystallinity of PDP. The WAXS results suggest that gradient formation is associated with a net decrease in the amount of crystallized PDP.

[0104] Structural property evaluation using image analysis The direction of PDP redistribution can be identified by simply re-examining the existing library of cross-sectional TEM images. Assuming that lamellar sections are representative samples, 2D thin sections can be expanded to 3D structures. From the 3D structure, the distribution of all components can be calculated by making the following three assumptions: each component is incompressible and its density remains constant; PS and P4VP are sufficiently separated across microdomain boundaries; and there is no long-range (multi-domain) PDP redistribution. In a cross section without a gradient, assuming nearly equal domain widths of approximately 64 nm, it was found that almost all unbound PDP was not crystallized together within the comb inside the PS domains. This is consistent with the conclusion that high molecular weight self-assembly is entropy-driven. As discussed in Example 1, small molecules are miscible in both blocks and increase the potential mixing entropy of the system, thus reducing the enthalpy driving force. As the solvent evaporates, enthalpy becomes more important: small molecules prefer to reside within comb domains, where alkyl molecules can stack via favorable van der Waals interactions. The supramolecular nanocomposite described herein and previously studied, PDP small molecules in a molar ratio of 1.6 (330-β-125 kDa), are expected to form a PS cylinder when all small molecules are sequestered within comb domains. The lamellae themselves, though not of the finest order, are the result of entropy-driven self-assembly.

[0105] Performing the same analysis on samples with different L gradients revealed that the increasing fraction of unbound PDP self-separated into comb domains (Figures 11A-11C). The microdomains became larger and increasingly asymmetrical: for example, a 108 nm coil domain paired with a 225 nm comb domain. At the highest L values, all PDP was estimated to be within the comb domains. This behavior can be qualitatively understood as variation related to the dilution approximation used for BCP solutions. To calculate the effective χ of BCP partially mediated by non-selective solvent molecules, one can simply multiply the χ of molten BCP by the solute fraction. As the solvent fraction approaches 100%, the effective χ approaches 0, and undesirable interactions are completely shielded by the solvent molecules. In nanocomposite systems, PDP behaves like a solvent despite being more selective. Based on this understanding of enthalpy in BCP solutions, we expect PDP redistribution to occur through a "positive feedback loop". The decreasing solvent fraction creates an increasing enthalpy preference for small molecules to distribute only within the comb domains. As the small molecules begin to separate into the comb domains, the supramolecules shift their positions along both axes on the BCP phase diagram. χN increases because the PDP molecules no longer act as a solvent. f also changes as one block loses volume (small molecules) while the other gains volume (Figure 11C). Since the solvent concentration in the drying film changes spatially, being lower at the top and higher at the bottom, the degree of PDP redistribution follows a corresponding gradient across the entire thickness of the film.

[0106] Importantly, this explanation of PDP behavior does not directly refer to the formation of an L-gradient: instead, it suggests that the system undergoes a morphological transition from lamellar to cylindrical. Here, finally, we assume that we are observing the dynamic effect of high molecular weight in the supramolecular. The morphological transformation from lamellar to cylindrical requires a large-scale rearrangement of the BCP itself. At approximately 500 kDa, high molecular weight BCPs are effectively pinned along the domain boundary by coil-coil entanglement. In response to the increasing cross-sectional mismatch between smaller coil domains and larger comb domains, the supramolecular cannot form a curved interface. Instead, we predict that the comb domains extend away from the coil-comb interface. A high small molecule content within the domain means that this rearrangement can be performed without too much undesirable chain extension; small molecules can fill the volume as needed.

[0107] This mechanism explains all the scattering data and the asymmetry of large L microdomains. It also explains seemingly unrelated observations: drop-cast films with a prominent gradient structure have a rough, scaly surface texture (Figures 11D-11E). Cross-sectional TEM images show a very large number of isolated terminal defects toward the upper surface of the gradient film (Figures 11F-11G). The paired terminal defects that characterize the non-gradient structure may act like "sliding doors" to reduce the stress of shape changes in the upper layer. As many individual defects move away from each other, the smooth film surface breaks down into irregular terraces.

[0108] Controlled studies using related systems The presence of surface texture is a convenient proxy for the presence of gradient structures along the cross-section of the film. We tested the proposed mechanism of PDP redistribution by performing a series of control experiments. Six control samples were studied to determine whether excess PDP and / or NPs were essential for the formation of gradient structures (Figures 11A-11F). As expected, samples without excess PDP showed considerably less surface roughness; NPs did not have a significant effect on the formation of gradient structures. Cross-sectional TEM of low-PDP samples showed ordered, uniform lamellae (Figure 11G). The system without excess PDP, defined by the stoichiometric 1:1 4VP:PDP ratio, still had unbound PDPs that appeared to aid in their assembly. As discussed above, longer polymers cannot accept as many small molecules as shorter polymers of the same monomer chemistry due to their reduced free volume. However, the amount of unbound PDP was too small to induce a considerably large number of morphological transitions.

[0109] Next, we explored the role of kinetics using a similar system with a lower molecular weight. For simplicity, we did not use NPs, as previous control studies suggested that NPs did not play a significant role in gradient formation. Supramolecules constructed with 104-b-30 and 50-b-17 kDa BCPs had similar coil-comb ratios, as summarized in Table 3. S2 and S3 self-assembled under slow drying conditions. Cross-sectional structures showed evidence of the same PDP redistribution process observed in S1 (Figures 12H-12I). The S2 blend formed layers with a pronounced L gradient, with L values ​​ranging from 48 nm at the bottom of the film to 102 nm at the top, representing a 113% increase. The S3 blend, on the other hand, had larger particles of cylindrical microdomains. At this lower molecular weight, the system could partially achieve its thermodynamically determined structure without needing to form an L gradient.

[0110] [Table 3]

[0111] Finally, the effect of a slow, multi-day drying process was studied. Dropcast films dried over a 3-day period showed consistently high L values ​​of 251–311 nm throughout their overall thickness (Figure 12J–12K). No significant surface structure was observed at the film-air interface. In cross-section, regions of pinched-off lamellae suggest that the system had nearly sufficient mobility to undergo a complete morphological transition to cylindrical domains. For comparison, the films shown in Figures 9C–9E were slowly dried for 1 day in a solvent-rich atmosphere and then rapidly transferred to solvent-free conditions. While the top of the samples appeared dry after 1 day, the different structures of the 3-day films support the idea that solvent still remained in the lower layers of the film. Based on simultaneous structural color and film thickness measurements, gradient formation is estimated to begin when the film contains an average of 20–30% solvent by volume (Figure 13). However, as discussed, the film density changes spatially throughout the entire drying process, making it difficult to accurately determine the precise transition point.

[0112] Gradient film as a photonic crystal The film layer thicknesses are equivalent to the wavelengths of visible light, and their vivid structural colors suggest that they cause constructive and destructive interference at specific wavelengths. Periodic lamellar nanocomposites with a single, consistent L are an example of 1D photonic crystals. Somewhat aperiodic structures, such as L-gradient films, are more optically complex. Given the nearly continuous transitions between layer thicknesses, they can exhibit interference over a range of wavelengths rather than a single wavelength. In the optical world, this geometry is called a chirp photonic crystal, and its optical properties are not fully understood. However, because they can interact simultaneously over a range of wavelengths, they appear useful as broadband filters.

[0113] Reflectance measurements were performed on nanocomposite films with periodic gradients (Figures 14A-14B). To prevent thin-film interference peaks in the reflectance spectrum, the films were thicker than usual: approximately 30 μm. Due to the increased thickness, the drying rate was not easily controlled, so the dried films exhibited an L-gradient in the plane of the substrate in addition to the usual L-gradient perpendicular to the substrate (Figure 14A, inset). Most areas of the gradient films were able to filter wavelengths approximately 50-100 nm wide. In particular, the regions with the most pronounced gradients, identifiable by their red structural color, exhibited nearly uniform reflectance in the visible range. They can be very far from the periodic structure to satisfy the Bragg condition and no longer function as photonic crystals. Alternatively, their rough surfaces scatter light, reducing the reflectance. In addition to serving as optical filters, L-gradient films may possess other useful optical properties. For example, planar lenses and zone plates focus light using concentric rings with gradient widths.

[0114] summary The relative free energy of various forms of nanocomposites can be evaluated. The relative free energy is a function of solute concentration due to the changing PDP distribution. Due to the high molecular weight of supramolecules, polymers begin to interact at solute concentrations below 10 vol%. At such high solvent concentrations, PDPs do not exhibit interblock enthalpy preference and are distributed almost uniformly throughout the domains. The effective block ratio f of the nanocomposite is... コイル Since the value is approximately 0.48, lamellae are a preferred form. The lamellae are stabilized by chain entanglement and rapidly orderly. When the sample is rapidly dried in this state, the result is macroscopically oriented, homogeneous lamellae. Despite being highly ordered and homogeneous, homogeneous lamellae are energetically undesirable once the solvent evaporates. As the solvent continues to evaporate, the effective χ between coil and comb domains increases, and the PDP molecules begin to separate into comb domains. Their redistribution further increases the χ value, and the effective block ratio increases to f コイルThis shifts to =0.29. The cylinder is the lowest energy structure, but requires overall rearrangement beyond the microdomain boundary. Asymmetric and stretched lamellae are a compromise: not as advantageous as the cylinder, but possible through short-range rearrangement.

[0115] Layered nanocomposites with gradient periodicity can be produced by adjusting processing conditions and composition, such as the concentration of small molecules (e.g., PDP), the ratio of unbonded and hydrogen-bonded small molecules, the molecular weight of BCP (e.g., PS-b-P4VP), and the drying rate and conditions. Generally, slower drying rates and / or higher solute proportions in the solute / solvent mixture provide thicker, redder (lighter blue) nanosheets. Furthermore, the mobility of small molecules (chemical or crosslinking) can be adjusted to obtain nanocomposites in forms of interest. The nanocomposites provided herein, in particular those with gradient layer thickness and properties, possess unique optical properties and can be used as optical materials such as light filters, planar lenses, and zone plates.

[0116] The above specification describes the present invention with reference to specific embodiments. However, as will be apparent to those skilled in the art, various modifications and changes can be made without departing from the scope of the invention as set forth in the following claims. Accordingly, the specification and figures are intended to be illustrative rather than restrictive, and all such modifications are intended to fall within the scope of the invention.

Claims

1. A nanocomposite material comprising nanoparticles, small molecules, and block copolymer (BCP)-based supramolecules, BCP-based supramolecules contain BCP and small molecules. Nanocomposite materials are formed by nanoparticles, small molecules, and BCP-based supramolecules self-assembling into multiple nanosheets that make up the nanocomposite material.

2. Each BCP-based supramolecular contains BCP and a small molecule bound to BCP via a non-covalent bond, or BCP has a molecular weight of approximately 130 kDa to approximately 600 kDa. The nanocomposite material according to claim 1.

3. The nanocomposite material according to claim 1, wherein the small molecules are organic molecules having a molar mass of about 50 g / mol to about 1500 g / mol.

4. The nanoparticles are inorganic molecules having a size of approximately 3 nm to approximately 50 nm, approximately 3 nm to approximately 9 nm, or approximately 6 nm, or Nanoparticles, metal oxides, zirconium oxide (ZrO 2 ), including nanoparticles of precious metals, gold, or silica, The nanocomposite material according to claim 1.

5. Nanoparticles are ZrO 2 Includes, The small molecule contains 3-pentadecylphenol (PDP), BCP contains polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP), PS-b-P4VP (PDP) contains a BCP-based supramolecular that is bonded to the pyridine side chain of PS-b-P4VP via hydrogen bonds. 1 including, The nanocomposite material according to claim 1.

6. The nanocomposite material according to claim 1, wherein nanoparticles account for approximately 3 to 20 volume percent of the nanocomposite material, small molecules account for approximately 10 to 25 volume percent, and BCP-based supramolecules account for approximately 65 to 75 volume percent.

7. Each nanosheet has a thickness of approximately 50 nm to 410 nm. The nanocomposite material contains more than 200 nanosheets. The nanocomposite material is approximately 0.06 μm -2 The following defect densities are present: The nanocomposite material according to claim 1.

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

9. VOC removal efficiency of 40% or more, 8 gm -2 day -1 a water vapor transmission rate (WVTR) of or below, 500 MV / m -1 dielectric breakdown strength of or above, 3 J cm -3 a maximum discharge energy density of or above, or 3 min μm -1 The nanocomposite material according to claim 8, which has an encapsulant life of or longer.

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

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

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

13. A step of contacting an initial blend of nanoparticles, small molecules, and block copolymer (BCP)-based supramolecules with a solvent to form a mixture, wherein the BCP-based supramolecules include BCP and small molecules, The process involves drying the mixture to remove the solvent and forming a nanocomposite material comprising multiple nanosheets containing nanoparticles, small molecules, and BCP-based supramolecules via a self-assembly process. A method for producing nanocomposite materials, including [the specified element].

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

15. The method according to claim 13, wherein contact is made of an initial blend with a solvent that is about 95% to about 100% by volume, or about 97.5% by volume, of the mixture.

16. Drying involves removing the solvent and initiating the self-assembly process with a volume percentage of solvent in the mixture of approximately 70% to approximately 80% or less. This includes drying time of approximately 20 minutes to 3 days. The method according to claim 13.

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

18. The method according to claim 13, wherein the mixture is drop-cast onto a substrate before the mixture dries.

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

20. Each BCP-based supramolecule contains BCP and a small molecule bound to BCP via a non-covalent bond, BCP has a molecular weight of approximately 130 kDa to approximately 600 kDa, or Small molecules are organic molecules with a molar mass ranging from approximately 50 g / mol to approximately 1500 g / mol. The method according to claim 13.

21. The nanoparticles are inorganic molecules having a size of approximately 3 nm to approximately 50 nm, approximately 3 nm to approximately 9 nm, or approximately 6 nm, or Nanoparticles, metal oxides, zirconium oxide (ZrO 2 ), including nanoparticles of precious metals, gold, or silica, The method according to claim 13.

22. Nanoparticles are ZrO 2 Includes, The small molecule contains 3-pentadecylphenol (PDP), BCP contains polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP), PS-b-P4VP (PDP) contains a BCP-based supramolecular that is bonded to the pyridine side chain of PS-b-P4VP via hydrogen bonds. 1 including, The method according to claim 13.

23. Each nanosheet has a thickness of approximately 50 nm to 410 nm. The nanocomposite material contains more than 200 nanosheets. The nanocomposite material is approximately 0.06 μm -2 The following defect densities are present: The method according to claim 13.

24. The method according to claim 13, wherein nanoparticles account for approximately 3 to 20 volume percent of the initial blend, small molecules for approximately 10 to 25 volume percent, and BCP-based supramolecules for approximately 65 to 75 volume percent.

25. The method according to claim 13, wherein forming includes forming alternating layers of nanosheets rich in nanoparticles and nanosheets poor in nanoparticles.

26. A nanocomposite material produced by the method described in claim 13.

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

28. The product according to claim 27, comprising a volatile organic compound barrier, a water barrier, an oxygen barrier, an electron barrier, a dielectric capacitor, a lens coating, a packaging material, an optical filter, a planar lens, and a zone plate.

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

30. The product according to claim 29, comprising a volatile organic compound barrier, a water barrier, an oxygen barrier, an electron barrier, a dielectric capacitor, a lens coating, a packaging material, an optical filter, a planar lens, and a zone plate.

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