Textile composites

Abstract

A textile composite is disclosed, including a textile material; a plurality of linkers covalently bonded to the textile material; a layer of nanostructures covalently bonded to the plurality of linkers; and a coating covalently bonded to the layer of nanostructures; wherein the layer of nanostructures is disposed between the textile material and the coating. A method of making such textile composite is also disclosed.

Description

TEXTILE COMPOSITESRELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 63 / 645,041, entitled ‘"TEXTILE COATINGS,” filed May 9, 2024, which is incorporated by reference herein in its entirety.COPYRIGHT NOTICE

[0002] This patent disclosure may contain material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves any and all copyright rights.FIELD OF THE INVENTION

[0003] The present disclosure relates to coatings, and more specifically to textile coatings and textile composites.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0004] This invention was made with government support under 2011754 and 1922321 awarded by National Science Foundation (NSF). The government has certain rights in this invention.BACKGROUND[0005} Water repellency offers comfort and protection from hypothermia for extreme users in the sailing, fishing, and outdoors industries, while medical and firefighting professionals depend on water-repellent fabrics for protection against hazardous substances. Many modern applications that require water repellency utilize per- and polyfluoroalkyl compounds (PFAs or PFAS), substances with low surface energies that offer lyophobicity' to both water and oil. Due to their excellent surfactant, stain resistant, and water-repellentproperties, PF As have been ubiquitously applied in apparel, food packaging, electronics, oil and water separation membranes, anti-icing, firefighting foams, and anti-corrosive coatings. The high stability, water repellency, and oil repellency of PF As translated well as durable water-repellent finishes on synthetic fibers such as polyester and nylon and found widespread applications including on carpets, furniture, shoes, and clothing.

[0006] However, recent research has shown that PFAs may pose risks to human health by causing adverse carcinogenic, immune, metabolic, and developmental effects. In particular, perfluorooctanoic acid (PFOA) was classified in 2023 as a human carcinogen. Over 50% of the global use of PFAs is in coatings for textiles, and PFAs in textiles find their way into the environment at every stage in a garment’s lifecycle: production, use and wear, and disposal at end of life. The manufacture and use of PFA-based finishing chemicals for garment production can lead to atmospheric or aquatic release, while pattern offcuts from garment construction and built garments that do not make it to market are put in landfills, from which PFA-contaminated leachates can be released into waterways and the environment. Garment use, wear, and laundering produce PFA-coated microfibers and abrade garment coatings, leading PFAs to contaminate dust, wastewater, drinking water, and the environment. Once these compounds have entered the environment as nanoparticles or liquid contaminants, they can enter the human body. As a consequence of their pervasive use, PFAs have been found in the blood serum of over 98% of the United States population. Consequently, new solutions are urgently required to dramatically reduce the quantity of and dependency on PFAs.

[0007] While a certain amount of hydrophobicity can be achieved without chemical finishes by combining the inherent water-repellent properties of synthetic fibers with reduced fabric porosity by developing fabrics with denser weave and yam thicknesses, this can inevitably impact the breathability and hand feel of the fabric, reducing comfort andwearability. Of existing coating solutions, PFA-free polymer coatings fall short of the performance expectations created by PF As for superhydrophobicity, comfort hand feel, manufacturability, breathability and flexibility. Bioinspired coatings, such as Slippery Liquid Infused Porous Surfaces (SLIPS) have sufficient superhydrophobic performance, but are impractical for most wearable fabric applications because their functional lubricants feel wet to the touch.SUMMARY

[0008] In one aspect, a textile composite is described, including a textile material; a plurality of linkers covalently bonded to the textile material; a layer of nanostructures covalently bonded to the plurality of linkers; and a coating covalently bonded to the layer of nanostructures ; wherein the layer of nanostructures is disposed between the textile material and the coating.

[0009] In any one of the embodiments disclosed herein, the textile material comprises a woven material, a knit material, a nonwoven material, or a combination thereof.

[0010] In any one of the embodiments disclosed herein, the textile material comprises a woven polyester material.

[0011] In any one of the embodiments disclosed herein, the linkers comprise a ligand.

[0012] In any one of the embodiments disclosed herein, the textile material comprises a synthetic fiber, synthetic film, natural fiber, bio-based material, bioderived material, or combinations thereof.

[0013] In any one of the embodiments disclosed herein, the linkers comprise a silane or a thiol.

[0014] In any one of the embodiments disclosed herein, the linkers comprise a silane.

[0015] In any one of the embodiments disclosed herein, the linkers comprise 3- aminopropyltriethoxysilane (APTES) or 3 -aminopropyltrimethoxysilane (APTMS).

[0016] In any one of the embodiments disclosed herein, the nanostructures comprise silica, copper oxide, titania, silver oxide, zirconia, nanocellulose, diatoms, structurally colored particles, pigments, copper, titanium, silver, gold, polymer nanoparticles, semiconductor nanoparticles, or a combination thereof.

[0017] In any one of the embodiments disclosed herein, the nanostructures comprise silica.

[0018] In any one of the embodiments disclosed herein, the nanostructures comprise a metal oxide, metal, or a combination thereof.

[0019] In any one of the embodiments disclosed herein, the nanostructures comprise nanoparticles of different sizes.

[0020] In any one of the embodiments disclosed herein, the nanostructures comprise large nanoparticles having a diameter of about 500 to 1,000 nanometers and small nanoparticles having a diameter of about 10 to 300 nanometers.

[0021] In any one of the embodiments disclosed herein, the coating is hydrophobic, oleophobic, UV-resistant, antibacterial, antimicrobial, hydrophilic, thermoregulating, moisture wicking, photo switching, vapor permeable, gas permeable, color switching, antiabrasive, anticorrosive, or a combination thereof.

[0022] In any one of the embodiments disclosed herein, the coating is hydrophobic.

[0023] In any one of the embodiments disclosed herein, the coating is oleophobic.

[0024] In any one of the embodiments disclosed herein, the plurality of linkers are covalently bonded to the textile material by one or more of silicon-oxygen bond, ester bond, metal-sulfur bond, metal-oxygen bond, and amide bond.

[0025] In any one of the embodiments disclosed herein, the layer of nanostructures is covalently bonded to the plurality of linkers by one or more of silicon-oxygen bond, ester bond, metal-sulfur bond, metal-oxygen bond, and amide bond.

[0026] In any one of the embodiments disclosed herein, the coating is covalently bonded to the layer of nanostructures by one or more of silicon-oxygen bond, ester bond, metal-sulfur bond, metal-oxygen bond, and amide bond.

[0027] In any one of the embodiments disclosed herein, the textile composite is perfluoroalkyl and polyfluoroalkyl (PFA)-free.

[0028] In another aspect, a method for making a textile composite is described, the method comprising the following sequential steps: providing a textile material; covalently bonding a plurality of linkers to the textile material; covalently bonding a layer of nanostructures to the plurality of linkers; covalently bonding a coating to the layer of nanostructures to produce the textile composite; wherein the layer of nanostructures is disposed between the textile material and the coating.

[0029] In any one of the embodiments disclosed herein, covalently bonding the plurality of linkers to the textile material comprises immersing the texting in a solution containing the plurality of linkers.

[0030] In any one of the embodiments disclosed herein, the textile material comprises a woven material, a knit material, a nonwoven material, or a combination thereof.

[0031] In any one of the embodiments disclosed herein, the layer of nanostructures comprises a group of large nanostructures and a group of small nanostructures, wherein the group of large nanostructures are covalently bonded to the plurality of linkers first.

[0032] In any one of the embodiments disclosed herein, the nanostructures are dried and cured after being covalently bonded to the plurality of linkers.

[0033] In any one of the embodiments disclosed herein, the textile material comprises synthetic fibers, synthetic films, natural fibers, bio-based materials, bioderived materials, or combinations thereof.

[0034] In any one of the embodiments disclosed herein, the linkers comprise 3- aminopropyltriethoxysilane (APTES) or 3 -aminopropyltrimethoxysilane (APTMS).

[0035] In any one of the embodiments disclosed herein, the nanostructures comprise silica, copper oxide, titania, silver oxide, zirconia, nanocellulose, diatoms, structurally colored particles, pigments, copper, titanium, silver, gold, polymer nanoparticles, semiconductor nanoparticles, or a combination thereof.

[0036] In any one of the embodiments disclosed herein, the nanostructures comprise large nanoparticles having a diameter of about 500 to 1,000 nanometers and small nanoparticles having a diameter of about 10 to 300 nanometers.

[0037] In any one of the embodiments disclosed herein, the plurality of linkers is covalently bonded to the textile material by one or more of silicon-oxygen bond, ester bond, metal-sulfur bond, metal-oxygen bond, and amide bond.

[0038] In any one of the embodiments disclosed herein, the layer of nanostructures is covalently bonded to the plurality of linkers by one or more of silicon-oxygen bond, ester bond, metal-sulfor bond, metal-oxygen bond, and amide bond.

[0039] In any one of the embodiments disclosed herein, the coating is covalently bonded to the layer of nanostructures by one or more of silicon-oxygen bond, ester bond, metal-sulfur bond, metal-oxygen bond, and amide bond.

[0040] In any one of the embodiments disclosed herein, the textile composite is perfluoroalkyl and polyfluoroalkyl (PFA)-free.

[0041] While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detaileddescription, which shows and describes illustrative embodiments of the disclosure.Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.BRIEF DESCRIPTION OF THE DRAWINGS

[0042] For a more complete understanding of various embodiments of the disclosed subject matter, reference is now made to the following descriptions taken in connection with the accompanying drawings, in which:

[0043] FIG. 1 illustrates a cross section of a textile composite, according to one or more embodiments disclosed herein.

[0044] FIG. 2A illustrates a method of making a textile composite, according to one or more embodiments disclosed herein.

[0045] FIG. 2B illustrates a process of making a textile composite, according to one or more embodiments disclosed herein.[0046} FIG. 3 illustrates examples of coated and uncoated textiles, according to one or more embodiments disclosed herein.

[0047] FIG. 4A illustrates SEM images of certain textiles, according to one or more embodiments disclosed herein.

[0048] FIG. 4B illustrates Fourier Transform Infrared Spectroscopy measurements of certain textiles, according to one or more embodiments disclosed herein.

[0049] FIGs. 5A-5D illustrate measurements of water sliding or contact angles, according to one or more embodiments disclosed herein.

[0050] FIG. 6A illustrates measurements of silica content in certain textile composites, according to one or more embodiments disclosed herein.

[0051] FIGs. 6B-6C illustrate measurements of water sliding or contact angles, according to one or more embodiments disclosed herein.

[0052] FIG. 7 A illustrates measurements of mass loss for samples of textiles with untreated fabric, PET with silica alone, PET with Midori RP alone, PET with silica and HDTMS, and PET with silica and Midori RP, according to one or more embodiments disclosed herein.

[0053] FIG. 7B illustrates average permeance P [kg m-2 s-1 Pa-1] measurements (a function of the water vapor transmission rate through the samples over time at the saturation vapor temperature of the test temperature (21.5 °C) according to a Modified version of ASTM E96-E water vapor transmission test to determine the impact on the breathability of the treated fabric sample) for samples of textiles with untreated fabric, PET with silica alone, PET with Midori RP alone, PET with silica and HDTMS, and PET with silica and Midori RP, according to one or more embodiments disclosed herein.

[0054] FIG. 7C illustrates results of a spray test for samples of textiles with untreated fabric, PET with silica alone, PET with Midori RP alone, PET with silica and HDTMS, and PET with silica and Midori RP, according to one or more embodiments disclosed herein.

[0055] FIG. 7D illustrates results of repellency testing for samples of textiles with untreated fabric, PET with silica alone, PET with Midori RP alone, PET with silica and HDTMS, and PET with silica and Midori RP, according to one or more embodiments disclosed herein.

[0056] FIG. 7E illustrates results of water flow testing through for samples of textiles with untreated fabric, PET with silica alone, PET with Midori RP alone, PET with silica and HDTMS, and PET with silica and Midori RP, according to one or more embodiments disclosed herein.

[0057] FIG. 7F illustrates results of water absorption testing for samples of textiles with untreated fabric, PET with silica alone, PET with Midori RP alone, PET with silica andHDTMS, and PET with silica and Midori RP, according to one or more embodiments disclosed herein.

[0058] FIG. 8A illustrates flexibility testing for samples treated with silica and HDTMS or silica and Midori RP, according to one or more embodiments disclosed herein.

[0059] FIGs. 8B-8C illustrate results of flexibility testing for samples of textiles with untreated fabric, textile with silica alone, textile with Midori RP alone, textile with silica and HDTMS, and textile with silica and Midori RP, according to one or more embodiments disclosed herein.

[0060] FIGs. 9A-9C illustrate measurements of silica content in samples of PET with APTES, PET with APTES and HDTMS, PET without APTES, PET without APTES and with HDTMS, cotton without APTES, and cotton without APTES and with HDTMS, before and after washing, according to one or more embodiments disclosed herein.

[0061] FIGs. 10A-10D illustrate results of analyses of water sliding or contact angles for textiles including PET with APTES, PET without APTES, and cotton without APTES, according to one or more embodiments disclosed herein. Water sliding and contact angles are tested for “washed” textiles: Samples were subjected to 65 wash cycles to compare the longevity of hydrophobic performance of PET fabric coated with silica and HDTMS with and without an APTES linker to bind the silica to the PET. A cotton sample coated in silica and HDTMS without a linker was also wash tested.

[0062] FIGs. 11 A-11C illustrate results of analyses of water sliding or contact angles and spray tests of textile samples including PET, APTES, SiNPs, and HDTMS, compared to textiles treated with different commercially available technologies, according to one or more embodiments disclosed herein.

[0063] FIG. 12 illustrates results of water sliding or contact angle analyses of textiles treated with the same NP solution several times, according to one or more embodimentsdisclosed herein. In some embodiments, the same NP, APTES, and HDMTS solutions were also reused.

[0064] FIGs. 13A-13C illustrate SEM imaging of untreated textiles, textiles treated with Stober method NPs, and textiles treated with commercial NPs, according to one or more embodiments disclosed herein.

[0065] FIGs. 14A-14B illustrate water sliding or contact angle analyses of new substrates incorporated into textile composites, according to one or more embodiments disclosed herein.

[0066] FIG. 15 illustrates results of a size distribution analysis of different nanoparticles in solution, according to one or more embodiments disclosed herein.

[0067] While the disclosure is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the disclosure to the particular embodiments described. On the contrary, the disclosure is intended to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure as described and as defined by the appended claims.DETAILED DESCRIPTION

[0068] In one aspect, a textile composite is described, including a textile material, a plurality of linkers covalently bonded to the textile material, a layer of nanostructures covalently bonded to the plurality of linkers, and a coating covalently bonded to the layer of nanostructures, wherein the layer of nanostructures is disposed between the textile material and the coating.

[0069] According to some embodiments, as shown in FIG. 1, textile composite 100 can include a textile 102 that is covalently bonded to a linker, or a plurality of linkers, 104. The linker or linkers 104 are covalently bonded to the textile 102 on one end of the linker 104 andcovalently bonded to a nanostructure 106 on the other end. In some embodiments, the nanostructure 106 is covalently bonded to the linker 104 and to a coating 108.

[0070] In some embodiments, the textile 102 can be a fabric. In some embodiments, the textile 102 can be a different material used to make clothing, for example, a woven material, a knit material, a nonwoven material, or a combination thereof. In some embodiments, the textile can comprise synthetic fibers, synthetic films, natural fibers, bio-based materials, bioderived materials, combinations thereof, or the like.

[0071] In some embodiments, the textile 102 can be chosen based on certain properties such as water repellence, durability, breathability, flexibility, or other characteristics. In some embodiments, the textile composite can be applied to the textile to provide certain functionality to the garment made of the textile (for example, water repellence).

[0072] In some embodiments, a plurality of linkers 104 can be coupled to the textile 102, for example, by covalent bonding. The linkers can contain different functional groups based on the desired properties of the textile composite or the specific application. For example, in some embodiments, the linkers can include a silane group, a thiol group, a hydroxyl group, or a different silica-containing group. In some embodiments, the linkers can include 3- aminopropyltriethoxysilane (APTES) or 3-aminopropyltrimethoxysilane (APTMS).

[0073] In some embodiments, covalently bonding the linkers 104 to the textile 102 can improve the durability and performance of the textile composite 100. For example, in some embodiments, covalent bonding can be stronger than alternative methods, such as through electrostatic coupling or Van der W aals coupling, resulting in a material with superior durability. Similarly, covalent bonding of the linkers to the nanostructures and covalent bonding of the nanostructures to the coating 108 can, in some embodiments, be advantageous over other methods of coupling.

[0074] In some embodiments, the covalent bonds throughout the textile composite 100, e.g., between textile 102 and linker 104, linker 104 and nanostructure 106, and nanostructure 106 and coating 108, can be formed through silicon-oxygen bonds, amide bonds, ester bonds, metal-oxygen bonds, metal-sulfur bonds or the like. In some embodiments, the covalent bonds between textile 102 and linker 104, are silicon-oxygen bonds, amide bonds, ester bonds, metal-oxygen bonds, metal-sulfur bonds or the like. In some embodiments, the covalent bonds between linker 104 and nanostructure 106 are silicon-oxygen bonds, amide bonds, ester bonds, metal-oxygen bonds, metal-sulfur bonds or the like. In some embodiments, the covalent bonds between nanostructure 106 and coating 108 are silicon- oxygen bonds, amide bonds, ester bonds, metal-oxygen bonds, metal-sulfur bonds or the like.

[0075] In some embodiments, nanostructures 106 can be covalently bonded to the linkers 104. In some embodiments, the nanostructures can include silica, copper oxide, titania, silver oxide, zirconia, nanocellulose, diatoms, structurally colored particles, pigments, copper, titanium, silver, gold, polymer nanoparticles, semiconductor nanoparticles, metal oxide particles, metals, or a combination thereof. The specific nanoparticles can, in certain embodiments, be selected based on desired performance or desired characteristics of the textile composite. For example, in some embodiments, the nanoparticles can be selected based on the desired textile, the desired linker, or the desired coating to be used in the textile composite. In some embodiments, the nanoparticles are selected to result in superior hydrophobicity, breathability, strength, and / or durability of the textile composite.

[0076] In some embodiments, the terms nanostructures and nanoparticles are used interchangeably.

[0077] In some embodiments, nanoparticles 106 can include nanoparticles of different sizes. For example, in some embodiments, nanoparticles 106 can have a size of about 5, 10,20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320,340, 360, 380, 400, 420, 440, 460, 480, 500, 520, 540, 560, 580, 600, 650, 700, 750, 800,850, 900, 950, or 1000 nanometers, or, in some embodiments, nanoparticles 106 can have a size in a range bounded by any two values disclosed herein. In some embodiments, nanoparticles can be provided in multiple size ranges, where each of the multiple size ranges is bound by any two values disclosed herein.

[0078] In some embodiments, providing differently sized nanoparticles 106, also referred to as “hierarchical” nanoparticles in some embodiments, can have several advantageous effects. For example, in some embodiments, hierarchical nanoparticles can provide surface roughness, or generally a surface with a non-uniform plane, to the textile composite 100. In some embodiments, hierarchical nanoparticles can provide increased hydrophobicity or omniphobic ity to the textile coating. Further, in some embodiments, hierarchical nanoparticles provide advantageous coupling sites for coatings 108 used in the textile composite, increasing the bonding strength of the coating to the nanoparticles. For example, in some embodiments, the hierarchical NP structure enables a more thorough coating of NPs over the linkers and textile material, which provides more bonding sites for the coating.Also, in some embodiments, the hierarchical surface topography created by the hierarchical NPs allows for a higher effective surface of area of the coating to be bonded to the textile composite.

[0079] In some embodiments, the use of hierarchical nanoparticles provides a lotus leaf effect to the textile composite 100. As used herein, “lotus leaf effect” refers to the scenario where a material’s surface roughness can improve the material’s hydrophobicity, as the surface roughness can help minimize water contact with the surface.

[0080] In some embodiments, the use of hierarchical nanoparticles 106 is advantageous in providing a more complete coating of nanoparticles over the linkers or the overall textile surface. For example, in some embodiments, smaller nanoparticles can be advantageous infilling in gaps that remain after larger nanoparticles have been coupled to the linkers or textile surface.

[0081] In some embodiments, different nanoparticles can be used in the textile composite. The use of different nanoparticles can be advantageous in some embodiments, for example, by providing different functional groups for effectively bonding to different textiles, linkers, or coatings.

[0082] In some embodiments, the nanoparticles can include large nanoparticles and small nanoparticles, wherein the diameters of the large nanoparticles and the small nanoparticles can be bound by ranges disclosed herein.

[0083] In some embodiments, the covalent bonding of nanoparticles 106 to linkers 104 can provide a much more robust attachment of the nanoparticles compared to other methods of coupling such as thermal, electrostatic, Van der Waals, or other types of bonding.

[0084] In some embodiments, results showing a textile including “silica” indicates the sample was treated with both APTES or a silica linker, as well as silica nanoparticles.

[0085] In some embodiments, the coating 108 can be covalently bonded to nanoparticles 106. Coating 108 can, in some embodiments, be chosen based on the desired properties of the textile composite 100. For example, in some embodiments, coating 108 can be hydrophobic, oleophobic, UV-resistant, antibacterial, antimicrobial, hydrophilic, thermoregulating, moisture wicking, photo switching, vapor permeable, gas permeable, color switching, anti-icing, anti-abrasion, and anticorrosive, or a combination thereof. In some embodiments, the covalent bonding of nanoparticles 106 to coating 108 can provide a much more robust and durable attachment of the nanoparticles and coating compared to other methods of coupling such as thermal, electrostatic, Van der Waals, or other types of bonding.

[0086] In some embodiments, the coating 108 can be applied to a garment made of the textile, and the textile coating does not alter or significantly impair the natural characteristics of the garment (for example, water repellence or other properties discussed above).

[0087] In some embodiments, coating 108 can include multiple coating layers.

[0088] Further, coating 108 can, in some embodiments, be chosen based on the chemical composition of the textile, the linkers, or the nanoparticles.

[0089] In some embodiments, coating 108 can be selectively applied to different portions of the textile composite 100. In some embodiments, coating 108 is HDTMS, Midori RP, 1 ',3'-Dihydro- 1 ',3 ',3 '-trimethyl-6-nitrospiro[2H- 1 -benzopyran-2,2'-(2H)-indole], PEG (2- [methoxy(polyethyleneoxy) 9-12] propyl-trimethoxysilane, 1,3-dichloro tetramethyldisiloxane (“DCTEMS”), or the like.

[0090] In some embodiments, the textile composite as described here has a multi-layer structure, e.g., including a layer of textile, a layer of linkers, a layer of nanostructures and a layer of coating, wherein the layers are sequentially disposed. It has been surprisingly found that the textile composite disclosed herein exhibited superior durability, breathability, flexibility, and hydrophobicity. Particularly, it was surprisingly found that textile composites as disclosed herein have excellent hydrophobicity in comparison to other treated textiles. For example, textile composites as described herein, using a coating (e.g., HDTMS or Midori RP), had surprisingly better hydrophobicity (as shown by the measured water static contact angles and water sliding angles) when compared to textiles that were exposed to just HDTMS or Midori RP without the application of linkers or nanoparticles. See, e.g., FIGs. 5A-5D.

[0091] Also, surprisingly, it was found that textile composites as disclosed herein, in some embodiments, have excellent breathability. For example, textile composites as described herein using a coating (e.g., HDTMS or Midori RP) have essentially the same breathability performance compared to textiles that are untreated, and to textiles that are onlyexposed to HDTMS or Midori RP without exposure to linkers or nanoparticles. See, e.g., FIGs. 7A-7C.

[0092] Furthermore, surprisingly, it was found that textile composites according to some embodiments as disclosed herein have excellent durability and performance over multiple wash cycles. For example, textile composites as described herein, in some embodiments, a textile composite described herein comprising polyethylene terephthalate (PET) as the textile material, APTES as the linker, silica nanoparticles, and an HDTMS costing, had excellent retention of water static contact angles and water sliding angles over 65 washes when compared to the same PET and to cotton, where both were exposed to the same HDTMS solution but were not exposed to APTES or the silica nanoparticles. See, e.g., FIGs. 10A- 10D.

[0093] In another aspect, a method of making a textile composite is described, the method comprising the following sequential steps: providing a textile material; covalently bonding a plurality of linkers to the textile material; covalently bonding a layer of nanostructures to the plurality of linkers; covalently bonding a coating to the layer of nanostructures to produce the textile composite; wherein the layer of nanostructures is disposed between the textile material and the coating.

[0094] FIG. 2A demonstrates a method 200 of making a textile composite according to one or more embodiments described herein.

[0095] In some embodiments, step 210 comprises providing a textile material.

[0096] In some embodiments, step 215 comprises covalently bonding a plurality of linkers to the textile material.

[0097] In some embodiments, step 220 comprises covalently bonding a layer of nanostructures to the plurality of linkers.

[0098] In some embodiments, step 225 comprises covalently bonding a coating to the layer of nanostructures to produce the textile composite.

[0099] In some embodiments, the layer of nanostructures is disposed between the textile material and the coating.

[0100] FIG. 2B illustrates a specific method 250 of making a textile composite, according to some embodiments.

[0101] In some embodiments, step 255 comprises providing a clean fabric or textile substrate.

[0102] In some embodiments, step 260 comprises functionalizing the textile byimmersing the textile in a solution containing APTES. In some embodiments, APTES can act as a linker and covalently bond to the textile. In some embodiments, the functionalized textile can be removed from the solution used in step 260 and prepared for further processing by drying, curing, or other processing.

[0103] In some embodiments, step 265 comprises immersing the functionalized textile in a first solution of nanoparticles. The first solution can contain nanoparticles that covalently bond to the linkers. In some embodiments, the first solution can contain nanoparticles of a first size, or a first size range, according to embodiments disclosed herein. In some embodiments, the nanoparticles in the first solution are larger than the nanoparticles in the second solution. In some embodiments, the nanoparticles in the first solution are smaller than the nanoparticles in the second solution. After immersing the functionalized textile into the first solution, in some embodiments, the textile can be removed from the first solution and dried, cured, or further processed before proceeding to step 270. The product of step 265 is a textile exposed to first nanoparticles.

[0104] In some embodiments, step 270 comprises immersing the textile exposed to first nanoparticles in a second solution containing second nanoparticles. The second solution can contain second nanoparticles that covalently bond to the linkers. The second nanoparticles can be smaller than the first nanoparticles. In some embodiments, exposing the textile and linkers to first nanoparticles and then to second nanoparticles can create a hierarchical nanoparticle layer on the linkers. In some embodiments, in step 270, after immersion into the second solution, the textile is then removed from the second solution and dried, cured, or otherwise processed and prepared for step 275. In other emoluments, other non-immersion processes include padding, roll to roll coating, or additional methods can be used.

[0105] In some embodiments, step 275 comprises immersing the textile from step 270 into a surface functionalization solution. The surface functionalization solution can contain a coating. In some embodiments, the coating covalently bonds to the nanoparticles, which in some embodiments includes first and second nanoparticles. In other emoluments, other nonimmersion processes include padding, roll to roll coating, or additional methods can be used.

[0106] In some embodiments, as described herein, textile coating can be created using a layered approach. In some embodiments, a layered approach comprises adding each of the textile, the linkers, the nanoparticles, and the coating in successive steps. In some embodiments, using a layered approach is advantageous compared to other processes, including a one-pot process, because a layered approach allows for the controlled application and creation of each successive layer. In some embodiments, a layered approach creates a more durable or robust textile composite as compared to other methods such as a one-pot method, where, for example, all other materials and the coating can be mixed into one pot to attempt to create a textile composite.

[0107] In some embodiments, a layered approach to creating a textile composite has surprisingly advantageous effects of creating a textile composite with enhancedhydrophobicity, breathability, durability, and environmental friendliness as described herein. In some embodiments, the textile, linkers, nanoparticles and coatings are all PFA-free, thus resulting in a safe and environmentally friendly or environmentally responsible material.

[0108] According to some embodiments, to enhance the performance of hydrophobic coatings, an engineered surface topography can be applied to a textile (e.g., a fabric) to introduce surface roughness that mimics the water-repellent properties found in plants. The waterproofing strategies of the lotus leaf have inspired “lotus leaf effect” bumpy interfaces, where micro- and nanostructured surface topography can be combined with hydrophobic surface chemistry to trap air at the liquid-substrate interface to produce a superhydrophobic surface, a phenomenon referred to as the Cassie-Baxter effect. “Hierarchical” topographies with surface textures on multiple length scales (e.g. micro-, nano-) can result in more effective and stable hydrophobicity. However, chemical functional groups resulting in low surface energies can be used on the surface regardless of the underlying topography; traditionally, these have been PF As. Efforts to reduce PF As’ use have generally offered solutions in two categories: hydrocarbons such as naturally occurring waxes or silicone-based compounds such as silanes bearing long alkyl chains that impart hydrophobicity. In a comprehensive study to assess the environmental impact of PF As and substitute chemicals, Holmquist and colleagues demonstrate that compounds with non-fluorinated side chains offer significantly reduced human toxicity. Silanes offer strong chemical bonds to a variety of substrates with hydroxylated surfaces and the ability to break down in the environment.

[0109] In some embodiments, to facilitate the lotus leaf effect, a bumpy hierarchical surface topography can be achieved in several ways, such as destructive mechanical abrasion or the addition of material to the surface. Mechanical abrasion, like the shearing process used to create fleece, creates micro-scale texture but weakens the integrity of fibers and increases the possibility of microfiber loss and pollution. Accordingly, additive approaches to creatingtopography, such as the addition of nanoparticles, are preferable over destructive ones, as these reduce microfiber pollution and retain structural integrity in the fabric. Incorporating added particles at the fiber level is possible during fiber extrusion, the earliest process in textile production, but fiber-level interventions generally require large production runs for low-cost / high-volume output, while low-volume runs may be prohibitively expensive for small brands. Applying material to prefabricated fabric rather than at the fiber level provides brands and manufacturers affordable design versatility.

[0110] In some embodiments, to retain textile qualities such as hand feel, visual appeal, fabric drape, and flexibility, it can be helpful to carefully consider the design of the surface topography. Within the realm of the lotus leaf effect, the addition of several kinds of nanoparticles have been investigated, including copper, zinc, titanium, silver, aluminum, graphene, polymer particles, or combinations therein. Of these, in some embodiments, silica nanoparticles lend themselves well to textile applications for their overall transparency, ease of production, affordability when compared to other nanoparticles, their ability to covalently bond to many functional chemical finishes because of their readily available surface hydroxyl groups, and relatively benign environmental impacts. Amorphous, non-crystalline silica nanoparticles such as those produced from sol-gels, a process of condensing monomers in a solution into a solid or gel network, can be less harmful than crystallized nanoparticles such as naturally occurring quartz because the production method can enable control in their chemical makeup, size, shape, and porosity. Further, inhalation potential during production of sol-gels can be low as the colloids produced are contained within their solutions or matrices. The design of silica nanoparticles or nanostructures (“NPs”) can impact their overall toxicity, as well as exposure quantity. Toxicity can decrease with increase in size, particularly as NPs move from the “ultrafine” (<.1 pm) size range to the “fine” size range(<2.5 gm). The functional chemical coating of silica nanoparticles can impact their toxicity, where more hydrophilic silica particles result in greater cellular toxicity.

[0111] In some embodiments, the geometry of particles adhered to the surface can also be considered to optimize for fabric hand feel and fabric stiffness. Some approaches to create surface topography coat the fabric with a solid silica layer produced from a sol-gel, but this layer can shear on flexure to expose non-functionalized areas on the substrates, which can decrease the water-repellent performance. Crack formation in some solutions produced by sol-gel coatings to create topography can reduce the effectiveness of functional chemistry finishes applied to the sol-gel when the underlying fabric is exposed. This can, in some embodiments, indicate a necessity for discrete particles strongly adhered to the substrate surface, allowing the substrate to flex without disturbing the coating.

[0112] In some embodiments, particles physically adhered to the surface of a fabric to create topography can be subject to torsion, abrasion, and mechanical wear from daily use and washing. For the longevity of a garment coated in NPs, it can be advantageous if the fabric-NP bond is robust. Many of the textile approaches adopting the lotus leaf effect use electrostatic interactions as an attachment mechanism for particles, resulting in a fragile coating unable to withstand regular wash and use. Covalent bonds between the NP and the substrate material can help prevent detachment upon laundering.

[0113] Synthetic fibers such as polyester, acrylic, and nylon constitute over two thirds of global textile production because of the tunability inherent to both polymer chemistry and the fiber extrusion process, allowing for sufficient facile parameter variation to design for features such as lightness, breathability, wicking, and thermal regulation. Of the synthetic fibers, polyester represented over half of global fiber use in 2022, the largest volume of global fiber materials production. Synthetic fiber use is only projected to grow due to the properties the material offers.

[0114] In some embodiments, multi-step deposition rather than one-coat or one-pot production can allow more effective adhesion and bonding of the particles to the substrate. A design system that comprises substrate surface activation to covalently bind NPs, discrete NPs that move independently on torsion, and surface chemistry to functionalize the NPs can, in some embodiments, more effectively meet the need for durable hydrophobic or omniphobic fabric coatings for apparel.

[0115] Some embodiments disclosed herein include an environmentally responsible coating that imparts significant water repellency, without significantly impacting fabric functionality, breathability, or flexibility. In some embodiments, two sizes of silica NPs were bound to PET fabric that had been pre-activated with APTES to achieve a lotus leaf-like topography. These particles served as a site for further chemical functionalization by HDTMS or a PF A- free liquid acrylate copolymer to help control surface energy; the presence of the particles as a topography-enhancing scaffold helped improve the water-repellent performance of both compounds compared to direct application to particle-free fabric. In some embodiments, for a reliable analysis of durability, normal garment wash and use cycles were replicated, including extensive machine wash testing after 65 laundering cycles in accordance with the American Association of Textile Chemists and Colorists Lab Procedure 1 (AATCC LP1). In some embodiments, such testing has indicated that the coating can maintain its superhydrophobicity after many rounds of washing. In some embodiments, a layered fabrication approach can be a platform for further surface functionalization without impacting other important fabric characteristics.

[0116] FIG. I represents a schematic diagram of the layered system according to some embodiments. As shown, in some embodiments, a functional surface layer 108 can be applied to two sizes of nanoparticles 106. Nanoparticles 106 can be bonded by APTES linkers 104 to a flexible substrate 102.

[0117] In some embodiments, the samples can be first produced at small scale as 9 cm; then scaled up by over 40 times to 400 cm2squares to test for scalability, wash resiliency, and to conduct several textile industry standard water repellency tests, which are discussed herein. In some embodiments, samples can be analyzed by Fourier Transform Infrared (FTIR) spectroscopy to further verify the presence of chemical bonds in each step of the process.

[0118] In some embodiments, after the APTES application, a new peak can be observed on the polyester at 3400 cm'1, indicating a primary amine NH? stretching mode. In some embodiments, with the addition of the SiNPs, peaks between 900-1200 cm'1can be observed, indicating Si-O-Si bonds, and in some embodiments, the final addition of the functional finishes can demonstrate peaks in the 2800-3000 cm'1region, which can confirm CH2 stretching modes. In some embodiments, the coating applied to a textile comprises four sequential steps as illustrated in FIG. 2B.

[0119] In some embodiments, two distinct populations of silica NPs via the Stober method can be prepared with different average sizes. See, e.g.. Figure 15.

[0120] In some embodiments, hierarchical silica NPs can be produced with two distributions of silica particle sizes, one with an average of 144 ± 45.6 nm (Solution A or Sol. A) and the other with an average of 590 ± 104.5 nm (Sol B). For Sol A, 8.6% v / v tetraethylorthosilicate (TEOS, Sigma Aldrich) can be slowly added to ethanol (VWR) and stirred at 300 RPM at room temperature for 5 minutes. 5% v / v ammonium hydroxide (Sigma Aldrich) can be added dropwise and stirred at 25 degrees C for a minimum of 12 hours. To prepare Sol B, 14.3% v / v TEOS can be added to ethanol and stirred 300 RPM at room temperature for 5 minutes. A solution of 49% DI water, 33% ethanol, and 18% ammonium hydroxide can be added slowly and stirred for a further 2 hours. Samples can be first immersed in the larger particles (Solution B or Sol B) for 5 minutes, removed and immersed in an ethanol rinse, followed by drying at 80°C for 5 minutes and curing at 120 degrees C for2 minutes. Samples can then be immersed in the smaller particles (Sol A) for 5 minutes, removed and immersed in an ethanol rinse, followed by drying at 80°C for 5 minutes and curing at 120 degrees C for 2 minutes.

[0121] In some embodiments, a tightly woven fabric can be functionalized with 3- aminopropyltriethoxysilane (APTES) whose amine group forms covalent amide bonds with the fiber via nucleophilic attack of the ester groups in the fabric. The triethoxysilyl group on the other end of the APTES molecule can react with surface silanol groups on the silica particles to create a covalent linkage from the particle to the fiber. In some embodiments, a 70:30 ethanokdeionized water solution can be used to prevent clusters or oligomers of APTES functional groups.

[0122] In some embodiments, the linker can include 3-aminopropyltriethoxysilane (APTES) or 3 -aminopropyltrimethoxy silane (APTMS).

[0123] In some embodiments, the clean polyester fabric substrate (black line represents a side view) is immersed in APTES to functionalize the textile surface through transamidation reaction.

[0124] In some embodiments, to activate the surface and add active functional groups to textiles via a transamidation process without degrading the polyester, a 1% v / v solution of 3- aminopropyltriethoxysilane (Sigma Aldrich) in a 70:30 (by volume) DI waterethanol mixture can be prepared and stirred at 400 RPM at room temperature for 30 minutes. Samples can be added to the prepared solution and stirred for 1 hour, removed and rinsed with DI water, followed by dipping in a 1% v / v aqueous acetic acid solution in DI water (pH 4) to drive the condensation reaction for the subsequent silica attachment.

[0125] In some embodiments, the pretreated fabric can be immersed in the NP solution, helping to bind the particles to the fabric via an APTES I inker to help form a conformal coating on and within the fabric. In some embodiments, the functionalized surface can beadded to solutions of nanoparticles of two different sizes: first the larger size is applied, dried, and cured (Sol B), and subsequently a second coating of smaller NPs (Sol A) is added to fill in the gaps, decorating the textile fibers with a conformal coating.

[0126] In some embodiments, the exposed silica surface can be further functionalized to produce a flexible superhydrophobic, oleophobic, omniphobic coating, or the like.

[0127] In some embodiments, samples can be coated with HDTMS or Midori RP, a PFA- free liquid acrylate copolymer from Beyond Surface Technology (BST), to create a hydrophobic functional layer. In some embodiments, the NP coating is functionalized with a water-repellent finish.

[0128] In some embodiments, 3% v / v hexadecyltrimethoxysilane (HDTMS, Sigma Aldrich) in ethanol can be stirred at 400 RPM for 5 min. Samples can be stirred in the solution for 24 hours at room temperature, rinsed in ethanol and air dried, then cured for 1 hour at 120 degrees C.

[0129] In some embodiments, 120 g / L Midori RP 5.0 (Beyond Surface Technology), 5 g / L Invadine PBN (Hunstman), and 10 g / L 10% acetic acid (Brenntag Chemicals) can be applied to samples. 9 cm2samples can be dip-coated in the mixture, and 400 cm2samples can be coated by roll padder. Samples coated with Midori RP can be weighed before and after roll padding to determine their wet pickup absorption. Midori RP-coated samples can be dried for 1 minute at 120 degrees C and cured 1 minute 160 degrees C.

[0130] FIG. 3 shows imaging of textiles according to some embodiments. As shown therein, a silica-free control has an indistinguishable appearance from a textile with silica applied, indicating that silica NPs at this size are effectively transparent. In some embodiments, this feature may allow' manufacturers the flexibility to apply desired colors, prints, and finishes prior to the application of the silica NPs and the functional finish layer.

[0131] According to some embodiments, as shown in FIG. 3, 9 cm2 samples of black polyester without silica (left) and with silica treatment (right) were visually compared side by side, showing lack of visible change in color due to coating.

[0132] In some embodiments, silica NPs were applied to black and white swatches of the same woven polyester fabric. The visual appearance of the treated fabrics was indistinguishable from the untreated fabrics by the naked eye; the original color of the fabric remained white or black (photographs of the black substrate with and without silica NPS can be seen in FIG. 3), indicating that silica NPs at this size are effectively transparent. This feature may allow manufacturers the flexibility to apply desired colors, prints, and finishes prior to the application of the silica NPs and the functional finish layer.

[0133] As shown in FIGs. 4A and 4B, according to some embodiments, to verify the presence of the silica NPs and visualize their distribution, the samples were examined with scanning electron microscopy (SEM) and FTIR. SEM imaging confirms the deposition of silica NPs of two sizes in some embodiments. Fourier Transform Infrared Spectroscopy (FIG. 4B) and the SEM (FIG. 4A) further confirm the presence of the hydrophobic finishes. There is likely a lack of applicable groups in the Midori RP to covalently bind to the silica: instead the SEM images in FIG. 4A show a polymer matrix is formed over the NPs.

[0134] FIG. 4A shows SEM imaging of the fibers, according to some embodiments, at three scales: 250 pm (left), 10 pm (middle), and 2 pm (right). The top row is BST’s Midori RP on polyester alone. In the bottom three rows containing silica NPs, lower magnification images show uniformity of coating; higher magnification shows hierarchical roughness arising from bimodal size distribution of silica NPs.

[0135] According to some embodiments, as shown in FIG. 4B, shown therein is an FTIR analysis of the fabric at each production stage: clean untreated polyester, following the addition of APTES, following the addition of Silica NPS, and after finishing with eitherHDTMS or BST's Midori RP. The insets in the bottom 3 rows represent a subtraction of thePET substrate to emphasize the peaks that differentiate the coating from the polyester substrate.Exemplary analysis methodsWater static contact and sliding angles:

[0136] In some embodiments, 10 mL droplets can be deposited in five positions per sample using a Kruss DS A 100 Drop Shape Analyzer. Static water contact angles can be measured using the Young-Laplace fitting method. Sliding angles can be measured at the angle at which the droplet fully detached from the surface, tested on both the warp and weft directions.Energy’ dispersive X-ray spectroscopy:

[0137] In some embodiments, relative carbon, oxygen, and silicon elemental concentrations for the as-generated and washed fabric samples can be measured with a Tescan Vega GMU scanning electron microscope equipped with a Bruker XFlash 5030 dualdetector EDS system. Each fabric sample can be imaged in its native state (uncoated) and each corresponding EDS spectrum can be collected for 60 seconds from an area measuring 16 square millimeters under low vacuum conditions (15 Pa) and an acceleration voltage of 20 keV.Breathability: ASTM E96-E water vapor transmission:

[0138] In some embodiments, four fabric samples of each condition can be stretched and pinned to a padded board. Acrylic rings can be laser cut to match the shape of the lip of an aluminum cup and can be adhered to the stretched fabric using 3M Marine Grade Silicone Sealant. This assembly can be left to dry overnight, removed and glued to the cups using the silicone sealant to sandwich the fabric between the cup lip and the acrylic ring. A hole can be punctured in the side of the cup, 150 mL deionized water can be inserted, and the hole can besealed with the silicone sealant. The samples can be weighed initially, and subsequently weighed twice a day while recording ambient temperature, humidity, and air pressure using an ExTech Datalogger.Machine wash testing:

[0139] In some embodiments, three 400 cm2samples of each condition can be produced using the following methods: PET fabric with APTES, silica NPs and HDTMS; PET fabric without APTES, with silica NPs and HDTMS; cotton fabric without APTES, with silica NPs and HDTMS, as well as one of each sample without an HDTMS coating. All samples can be washed together following the American Association of Textile Chemists and Colorists Lab Procedure (AATCC LP1 ) in an AATCC standard top loading washing machine, an SDL Atlas Vortex M6. They can be washed with 66 grams of AATCC powder textile standard reference detergent without brightener at 44 ± 2 degrees C for 45 minutes with a 41b load weight (Type 3 ballast comprised of cotton and polyester). Samples can be dried with an AATCC dryer on an “extra dry” setting for half an hour, and cured 20 minutes in an oven at 85°C. Samples can be measured for contact and sliding angles every fifth wash cycle, totaling 65 washes.Water repellency testing:

[0140] A surface can be considered superhydrophobic if a static droplet of water sitting on its surface has a contact angle greater than 150 degrees and hydrophobic if the contact angle is greater than 90 degrees.

[0141] FIG. 5 A shows the results of measurements of the static contact angle of water droplets on 9 cm2 fabric samples, according to some embodiments. For each sample, five measurements were taken in different locations from the same sample. According to some embodiments, photographs of a representative static droplet for each sample are displayed in FIGs. 5B and 5C. All coated samples were hydrophobic, and samples coated with BSTMidori RP or NPs with functional coatings demonstrated superhydrophobicity, with watercontact angles above 150 degrees. On its own, the BST Midori RP on polyester without silica NPs performed as a superhydrophobic material, with an average contact angle of 151 ± 6.7 degrees. The introduction of the silica NPs improved the performance of the BST Midori RP by an average of 5 ± 5.6 degrees. Silica coatings with HDTMS were the most water- repellent samples overall, with average contact angles of 171 ± 1 degrees. This is also a performance improvement over the HDTMS coating without silica, where contact angles averaged 129 ± 5.3 degrees. It can be concluded that the addition of a silica NP substrate before application improves the overall performance of HDTMS. Contact angles could not be measured for untreated polyester fabric or for fabric treated with silica alone, as water droplets were absorbed upon contact.

[0142] According to some embodiments, as shown in FIGs. 5B and 5C, shown therein are static contact angle Images. In FIG. 5B, contact angle images of 9 cm2 (top row) and 400 cm2 (bottom row) samples of silica alone, silica with HDTMs, Silica and Midori RP, and Midori RP alone on PET. In FIG. 5C, 400 cm2 samples tested over the course of 65 wash cycles. Conditions include Cotton sample coated in silica and HDTMS without a linker (first row), PET fabric coated with silica and HDTMS without (second row) and with (third row) an APTES linker to bind the silica to the PET.

[0143] As shown in FIG. 5D, the water sliding angle was also measured according to some embodiments.

[0144] According to some embodiments, in FIGS. 5A and 5D, hydrophobic performance metrics of PET fabric with water-repellent coatings (HDTMS, a non-fluorinated silane, andMidori RP, a PFA-free commercial product) were compared against the performance of fabrics functionalized first with silica NPs and subsequently with the coatings. For each graph, N = 5. Measurements were taken in different locations from the same sample.According to some embodiments, 5A shows static contact angles of water on polyester fabric with various surface treatments. Untreated fabric absorbed water and could not be measured. High water contact angles indicate higher repellency. According to some embodiments, 5D shows sliding angles of water on polyester fabric with the same surface treatments. Polyester that was untreated or treated with silica alone absorbed the water and could not be measured. Lower sliding angle indicates higher water repellency.

[0145] Apparel is one of the most common commercial applications of water-repellent finishes, so tests of these coatings should reflect the modalities in which they are used and worn, in some embodiments. While on the body, at times a negligible amount of fabric remains horizontal or static for the duration of the garment’s use. In order to more accurately reflect the conditions of water-repellent clothing during wear, the sliding angle of water droplets on fabric samples can be measured, which can quantify the tilt angle at which water droplets roll off the surface of the fabric. A lower sliding angle indicates higher hydrophobicity.

[0146] In some embodiments, due to the surface topography of fabrics, which includes irregularities such as fibrillar protrusions, some pinning of the droplet may occur prior to the droplet’s full release from the sample. In the results shown in FIG. 5C, the sliding angle was measured as the angle of the plate at the moment the droplet became fully unpinned from the surface, according to some embodiments. The sliding angles of the coated samples followed a similar trend to the static contact angle results, showing a higher degree of water repellency when silica NPs had been added to the fabrics prior to the functional coatings. For each sample in FIG. 5C, five measurements were taken in different locations from the same sample. HDTMS alone had the highest sliding angle with an average of 39 ± 5.3degrees, Midori alone had an average of 30 ± 13 degrees, silica with BST Midori RP averaged 24 ± 3 degrees, and silica with HDTMS performed the best, with an average around 20 ± 2.2degrees. As before, the introduction of silica NPs prior to the functional coatings improved the coatings’ hydrophobicity, particularly in the case of HDTMS. As with the static contact angle, the sliding angle for untreated fabrics and fabrics treated with silica alone could not be measured, as the water droplet was rapidly absorbed.Scale-up testing:

[0147] FIG. 6A shows the results of scale-up testing according to some embodiments. Production was scaled up to increase fabric area by 40 times to produce 400 cm2 samples for robust water repellency, breathability, and washing durability testing. Energy dispersive X- ray spectroscopy was conducted on a sample, according to some embodiments, that was coated with silica and HDTMS from the small-scale testing, and a sample from the scale-up, according to some embodiments.

[0148] According to some embodiments, as shown in FIG. 6A, shown therein is energy dispersive x-ray spectroscopy of silicon content on a small lab scale sample and two scaled- up samples (one unwashed and one washed). N = 3, spectrum was averaged over 16 square millimeters per sample.

[0149] FIGs. 6B and 6C show the results of testing static contact and sliding angle of water droplets on the scaled-up samples, according to some embodiments, largely match those of the small samples. Five sample locations were taken on three samples of each condition. HDTMS alone was not tested as its hydrophobic performance was considerably worse than HDTMS applied to fabric coated with silica NPs. Representative images of the water static contact angles are displayed in FIGs. 5B, 5C. The static contact angles of samples coated in BST Midori RP without silica NPs averaged 159 ± 5.9 degrees. This increase from the contact angle measured on the 9 cm2samples was likely due to the difference in coating process at a lab scale versus industrial sample testing scale, where rubber rollers squeeze the water-based liquid into the fabric, according to some embodiments.This could not be replicated on the smaller samples, which were squeezed dry by hand and weighed before and after application to determine their wet pickup of polymer (defined as the gain in mass divided by the initial mass), according to some embodiments. The shortcoming of this method, which yielded a wet pickup of 0.15%, was that it did not adequately replicate the rolling pressure of industry standard equipment, which yielded a wet pickup absorption of 88% on the 400 cm2samples. Thus, it was likely that there was more polymer on the 400 cm2samples, which may account for the increase in static contact angle. The 400 cm2samples coated with silica NPs and BST Midori RP averaged 160 ± 4 degrees and were comparable to their smaller counterparts, as were silica-and-HDTMS-coated samples, which averaged 169 ± 2.7 degrees. The sliding angle results are more aligned with the results from the small samples: the BST Midori RP on polyester alone had an average sliding angle of 32 ± 3.8 degrees, silica with BST Midori RP had an average of 22 ± 5 degrees, and silica with HDTMS had an average of 17 ± 2.9 degrees.Breathability testing:

[0150] In some embodiments, breathability was measured by an adapted version of the ASTM E96-E water vapor transmission test. Samples were stretched and adhered to a plastic ring, which was then sealed to an aluminum cup filled with 150 mL water. Tire sealed cups were initially weighed, and again weighed twice a day for seven days along with measurements of temperature, humidity, and air pressure. The water vapor transmission rate (WVTR [kg m'2s'1]) is defined according to Equation (1):IFF 771 — -1Xf where m / [kg] is the final mass of water in the cup, m [kg] is the initial mass of water in the cup, A [m2] is the area of the cup mouth, and t [h] is the time elapsed. This quantity was used to calculate the permeance (P [kg m'2s'1Pa'1]) according to Equation (2):FFF TR p = _S(Rt — Ri) where S' [Pa] is the saturation vapor pressure at the test temperature (21.5 °C). Ri is the relative humidity at the source inside the cup expressed as a fraction, and R2 is the relative humidity at the vapor sink at the time of weighing expressed as a fraction.

[0151] FIGs. 7A and 7B show the mass change of the sample cups over the duration of a week, according to some embodiments. Plain untreated polyester was compared to polyester coated with silica NPs, silica NPs and BST’s Midori RP, silica NPs and HDTMS, and BST Midori RP (without silica NPs). Overall, all samples performed similarly to the untreated control, indicating that breathability is not impacted by the presence of the silica NPs, the addition of the HDTMS coating, nor the coating of the BST Midori RP polymer. The samples coated in BST Midori RP were conducted at a different date with different ambient humidity.

[0152] According to some embodiments, the 400 cm2 samples were also subjected to further textile industry standard water repellency testing including the American Association of Textile Chemists and Colorists AATCC 22-2001 Spray Test and ISO 9865:1991 Bundesmann Rain-Shower Test. The results of testing these embodiments are shown in FIGs. 70, 7D, 7E, and 7F. For FIGs 7D-7F, for each cycle shown on the x-axis of the figure, the bar on the left represents the unwashed results, while the bar on the right represents washed results. Unwashed and washed 400 cm2 polyester samples were prepared of silica alone, Midori RP alone, silica with BST Midori RP, and silica with HDTMS. A second set of the same conditions was prepared and washed at Beyond Surface Technology’s lab facility, at 40°C (EN ISO 6330 (5A program)) with accompanying ballast fabric. The 5A program is described as a “non-fast cotton” cycle. All samples and accompanying ballast added up to approximately 1 kg and washed for 1 hour with 20g Oecoplan Color washing powder in eachcycle. After washing, samples were tumbled on an extra dry setting for one hour, with additional tumbling for 30 minutes. The samples were laid out in a drying rack overnight. In the AATCC 22-2001 Spray Test, 250 ml water is applied for 25-30 seconds on each sample (N = 1) that has been pre-stretched in a 155 ± 5 mm hoop and placed at a 45° angle 250 mm below the spray nozzle. At the end of the test droplet spray patterns on the sample were matched to a visual rating chart. A rating of 100 is the highest, indicating “no sticking or wetting of upper surface,” while 0 indicates the “complete wetting of whole upper and lower surfaces.”

[0153] According to some embodiments, as shown in FIG. 7C, AATCC 22-2001 spray test results give a rating from 0-100 (least repellent to most repellent) based on an optical assessment to samples sprayed for 30 seconds with 250 mL water. Unwashed samples (left, solid) are compared to washed samples (right, diagonal stripe pattern). N = 1 per condition.

[0154] According to some embodiments, samples coated with silica combined with hydrophobic functional finishes remained water-repellent over the course of repeated Bundesmann testing and demonstrated spray test ratings from 80-100.

[0155] According to some embodiments, as shown in FIGs. 7D-7F, shown therein are Bundesmann test results expressed in three different metrics to compare the hydrophobic performance of washed and unwashed PET fabrics retested over the course of 3 repeated test cycles (N = 3). Samples were polyester coated with or without silica, without silica and with BST’s Midori RP, silica with BST’s Midori RP, and silica with HDTMS. In FIG. 7D, the water repellency rating is a visual observation rating given by the technician at the end of the ten-minute test. Scores between 1-5 indicate least to most repellent, where a score of 1 represents a fully wetted sample and a score of 5 expresses a highly hydrophobic sample.Bars without error bars indicate all three samples received the same rating. In FIG. 7E, average water flow through is the amount of water collected in the cups that flowed throughthe samples at the end of the test. Here it is expressed as a percent of the maximum amount of water that can flow into the cup when no sample is present, 780 mL. In FIG. 7F, average water absorption is determined by weighing the dry weight of the sample before the test, centrifuging the sample after removing it from the cup at the end of the test, and weighing again.

[0156] FIGs. 8A, 8B and 8C show the results of stiffness testing, according to some embodiments. For FIGs 8B-8C, for each instance of “weft” or “warp” shown on the x-axis of the figure, the bar on the left represents the unwashed results, while the bar on the right represents washed results. To determine the impact of the composites on the polyester’s hand feel and tactile quality, ASTM D1388 Stiffness Testing was conducted using the cantilever test, in which the bending length was observed and the flexural ri gidi ty was calculated. The flexibility of samples coated with silica or silica and HDTMS remained the same as the untreated polyester, while the flexural rigidity of samples treated with Midori RP or silica and Midori RP was greatly increased by between 700% and 1,850% in the weft and warp directions.

[0157] According to some embodiments, as shown in FIGs. 8A-8C, shown therein are flexibility of the surface functionalization from the 400 cm2 samples. In FIG. 8 A, photographs of 20 cm by 5 cm pieces cut from the 400 cm2 samples were draped over a 5x5x0.5 inch concrete block. Silica with BST Midori RP is represented in the top row and silica with HDTMS is represented in the bottom row. The silica with HDTMS sample conforms more closely to the edges of the concrete block. As shown in FIGs. 8B and 8C, the Bending Length (B) and Flexural Rigidity (C) as measured by ASTM DI 388. N = 4 sample locations on 3 samples of each condition in both the warp and weft directions. Lower bending length and flexural rigidity numbers represent greater flexibility of the fabric, indicating more drape and a softer tactile hand feel.

[0158] According to some embodiments, ASTM D1388 - Standard Test Method for Stiffness of Fabrics was conducted on the polyester fabric samples of untreated fabric, silica alone, BST Midori RP alone, silica with BST Midori RP, and silica with HDTMS. Samples were previously washed at the North Carolina State Zeis Textiles Extension. Three specimens cut to 25 by 200 mm, in both the warp and the weft directions, either washed or unwashed, was tested for four locations on the face and back of each end of the specimen. Using the cantilever method on an SDL Atlas M003B manual fabric stiffness tester, the specimens were loaded onto the apparatus’ stationary table, weighted with a moveable linear scale and slid forward until the overhung sample touched the indicator, inclined at 41 .5 ± 0.5 degrees. When the sample touched the indicator, the reference point at the top of the apparatus was used to determine the length of overhang (O [mm]). The measurements were conducted in a room with a standard textile atmosphere of 21 ± 1 °C and 65 ± 2% relative humidity.Wash testing results:

[0159] According to some embodiments, to reflect realistic garment laundering, three 400 cm2 APTES-functionalized polyester samples with silica and HDTMS coatings were repeatedly machine-washed to investigate the durability of their water-repellent finish and the robustness of the particle-to-substrate bond. They w'cre compared to three 400 cm2 samples that had not been previously APTES-functionalized but were coated with silica and HDTMS. As a further comparison, three similarly sized samples of a cotton broadcloth were also prepared with silica and HDTMS in the same fashion, though this was done without APTES, as APTES was not expected to form bonds with cellulosic fibers. All samples were washed in a washing machine engineered to meet the standards of the American Association of Textile Chemists and Colorists (AATCC) LP1 wash test and several tests were conducted to compare the washed samples against the unwashed samples, including SEM imaging (asshown in FIG. 9A) and the measurement of contact and sliding angle of washed samples after one and 65 washes.

[0160] According to some embodiments, as shown in FIG. 9A, shown therein is SEM imaging of unwashed PET fabric coated with silica with and without HDTMS, with and without a linker (APTES) to bind the silica to the PET, as well as a cotton sample coated in silica and with and without HDTMS and without a linker (left). The same samples were washed 65 times and imaged after washing (right). The top section shows the untreated PET and cotton at two scales, 200 and 10 pm.

[0161] According to some embodiments, after an initial wash, EDS measurements of a 400 cm2 sample showed no change to the silica content of a sample coated in silica NPs and HDTMS, indicating that one wash does not remove the silica NPs, as shown in FIG. 6A.

[0162] According to some embodiments, further EDS and silica NP particle counting was conducted on all samples before and after the 65 wash cycles. FIGs. 9B and 9C show the result of this washing, according to some embodiments.

[0163] According to some embodiments, as shown in FIGs. 9B and 9C, shown therein are the results of quantifying silicon content before and after 65 wash cycles. According to some embodiments, FIG. 9B shows energy dispersive x-ray spectroscopy of silicon content on unwashed and after 65 wash cycles on pieces cut from the 400 cm2 samples. Spectrum was averaged over 16 square millimeters per sample, N = 1. According to some embodiments, FIG. 9C shows silica nanoparticle counts on unwashed and after 65 wash cycles from SEM (image area 5.5 pm2) images of the 400 cm2 samples. N = 3.

[0164] According to some embodiments, EDS was taken after 65 wash cycles, well over a year’s worth of garment washing if a coated garment was washed once a week, representing a heavy amount of wash and use (FIG. 4B). Note that EDS only counts atoms in the top few microns of the samples, so the measurements may not have accounted for silicon atomswithin the fabric or covered by thick coatings. Silica NP quantities were also counted from SEM images where the image area was 5.5 gm2, taken from the 400 cm2samples before and after washing, as shown in FIG. 9C.

[0165] Prior to washing, samples pretreated with APTES appeared to display the highest silicon concentration, although this was reduced after coating them with HDTMS. However, on samples with polyester untreated with APTES, there appeared to be higher silicon content after the HDTMS coating. Handling the fabric between functionalization and measurement may possibly have led to a loss of silicon, particularly in APTES-free samples. It may be that APTES pretreatment on polyester provides ample binding sites throughout and within the fiber surface - this was also observed via SEM imaging (FIGs. 8A, 8B, 8C), where APTES- pretreated polyester appeared to have more even coatings of SiNPS than polyester without pretreatment. Similar trends were reflected in the NP count results (FIGs. 9B, 9C).

[0166] According to some embodiments, on all samples, including both polyester and cotton, there was a decrease in silicon content after 65 wash cycles in both the EDS and particle counts. When considering the water-repellent performance of the washed polyester samples (as described for FIGs. 10A, 10B, 10C, 10D), APTES pretreatment on the polyester gave the silica-and-HDTMS-coated polyester an edge in long-term water-repellent performance over the non-pretreated polyester. The greater silicon loading of all washed HDTMS-coated polyester and cotton samples suggested that both the hydrophobicity and the polymerization layer of the HDTMS coating may help retain the SiNPs, as reported elsewhere. As HDTMS also contains silicon atoms, the polymerized layer will have some degree of silicon content. The cotton with HDTMS represented some of the highest silicon content after washing, which contradicted the water repellency results and the NP count results, in which water repellency was lost after the 20th wash cycle (as shown in FIG. 10A). It may be that the shape of cotton yams, which are composed of relatively short staple fibers(as opposed to polyester yarns, which are made of long filaments), may have allowed the degradation of hydrophobicity by mechanisms other than particle loss.

[0167] Accordingly, in some embodiments, particle counts and EDS after 65 washes indicated a decreased Si NP particle count on all samples, but less so on those samples coated with HDTMS. It may be possible that the HDTMS forms a polymer matrix over the silica NPs and traps them, preventing them from washing off the fabric in addition to the bond provided by the pretreatment of the polyester with the APTES linker.

[0168] According to some embodiments, as shown in FIGs. 10A-I0D, samples were subjected to 65 wash cycles to compare the longevity of hydrophobic performance of PET fabric coated with silica and HDTMS with and without an APTES linker to bind the silica to the PET. A cotton sample coated in silica and HDTMS without a linker was also wash tested. N = 5 sample locations on 3 samples of each condition. According to some embodiments, FIG. 10A shows water static contact angles. By the twentieth wash cycle, the silica-and- HDTMS-coated PET with APTES began to differ in performance in both static contact and sliding angles from the silica-and-HDTMS-coated PET without APTES. According to some embodiments, FIG. 10B shows water sliding angles of the same surface treatments on polyester fabric. After fifteen wash cycles the difference between PET with and without APTES was significant. The cotton fabric was pinned at 90 degrees after washes 5, 10, and 15, and absorbed water after the fifteenth wash cycle and could not be measured. According to some embodiments, FIGs 10C and 10D show the samples appeared to interact with surfactant residue after each wash cycle, leading to fluctuating contact and sliding angles. FIGs. 10C and 10D compare the unwashed samples against samples after the 65th wash cycle, and after an additional copious rinse in deionized water. According to some embodiments, FIG. 10C depicts water static contact angles differed between the washed samples of silica-and-HDTMS-coated PET (with an additional deionized water rinse) withand without APTES. According to some embodiments, FIG. 10D shows water sliding angles between the washed samples (with an additional deionized water rinse) of silica-and- HDTMS -coated PET with and without APTES.

[0169] According to some embodiments, SEM analysis, particle counts, and EDS of the samples before washing revealed that silica NPs of both sizes were deposited on all samples (as shown in FIGs. 3, 9A-9C). On the samples without a linker such as APTES, the silica tended to organize around cracks and surface features or to self-assemble in between the fibers of the cotton and PET, while on the PET pretreated with APTES the silica appeared to evenly decorate the fibers in a monolayer. Monolayer formation may be facilitated by the creation of multiple binding sites across the fiber by APTES. It is hypothesized that a monolayer would create a more effective platform for durable hydrophobicity over many wash cycles, minimizing the chances for excess particles in clumps to be removed in the wash and expose areas of non-functionalized particles or fabric below. The HDTMS coating appeared to encase silica NPs on all samples prior to washing, with particularly large clusters of HDTMS and silica NPs noted on the cotton and PET without APTES. The PET pretreated with APTES appeared to have regular patterns of HDTMS-coated silica across the surface of the fibers. After 65 wash cycles, silica could not be found on the cotton samples with or without HDTMS. The occasional lone silica particle could still be found on both the PET samples without HDTMS. Silica NPs did appear present within the HDTMS coatings on both the washed PET samples with and without APTES, although they appeared in greater numbers in both sizes on the PET pretreated with APTES.

[0170] According to some embodiments, soap bubbles were found in the washing machine at the end of each full wash and rinse cycle. After the first five washes, it was observed that the samples could not be measured for contact and sliding angles the same day as the wash testing as water wicked into the samples, but when tested after 24 hours allsamples demonstrated some degree of water repellency, and further renewed repellency after an oven dry at 85 degrees C for 20 min. This was consistent with studies that report the decrease in water repellency after laundering for all categories of water-repellent finishes, including fluorocarbon-based repellent finishes and silanes. This may have been due to the presence of lingering surfactant residues from the laundry cycle, which could break the surface tension of the droplet under test when solvated and absorb the water into the fabric. The potential for surfactant residues to create a polar affinity to water has been reported after analyzing the performance impacts of washing several commercially available textiles coated in both PF As or PFA-free durable water-repellent finishes when washed in different textile detergents. The use of an AATCC machine simulated real-world wash cycles, which may also leave soap left over on the fabric depending upon relative water softness in a region.

[0171] According to some embodiments, an alternate explanation involves the heat- enabled reorientation of alkyl chains after disruption by washing. When first applied to fabric, the hydrophobic moieties of allcyl- chains can be closely packed in a crystal packing structure, orienting the outermost atomic layer tips of this structure to interact with and repel water. When comparing washed durable water-repellent coatings of fluorocarbon, hydrocarbon, and silicone-based durable water-repellent fabric coatings, it has been proposed that washing disrupts the packing structure of these moieties, exposing less hydrophobic areas of the garment and increasing wettability. ¥ et when these same coatings are reheated, they can find a return to high levels of water repellency, which can be attributed to the flexible carrier polymers or the spacer segments linking the hydrophobic moieties, causing a reorientation and return to a tight packing structure. Further, the polymer surfaces of water- repellent coatings can trap and bind water molecules during washing, also creating a polar affinity to water, which are released upon reheating. To reduce the impact of this phenomenon on our measurements, all samples were measured for contact and sliding anglesafter heating for 20 minutes at 85 degrees C the day after their wash to allow them to fully dry and drive off any water that might solvate the residual surfactant. Additional research to test across an array of washing machines, wash cycles and dryer cycles could more accurately reflect how implementing HDTMS at scale might impact a consumer’s washing behavior, or whether other silanes could improve ease of use while maintaining hydrophobicity, in some embodiments.

[0172] According to some embodiments, for the PET samples that had been pretreated with the APTES linker and coated with silica and HDTMS, water static contact angles remained within the superhydrophobic realm across the 65 wash tests (with ~ 160 ± 4.5 degrees after the final wash test; as shown in FIGs. 10A- 10D), while the average water static contact angle of silica-and-HDTMS-coated PET without the APTES linker gradually declined to 147.9 ± 8 degrees (FIGs. 5A-5C, 10A). However, the sliding angles for both gradually increased, suggesting incremental decreases in water repellency (FIG. 10B). On both samples, excess or unattached silica may have washed off over the course of the wash cycles. The divergence in performance between PET with and without a linker is more obvious in the sliding angles than the contact angle measurements, with APTES-pretreated samples expressing superior durability. After the 15th wash cycle, droplets slid off at an average of 21.5 ± 5 degrees on the APTES-pretreated samples, compared to 28.7 ± 7 degrees without APTES. After the 25th wash cycle, the sliding angles for both pretreated and nonpretreated samples begin to appear to fluctuate while gradually increasing. After 65 wash cycles, thoroughly rinsing the samples in deionized water substantially restored the sliding angle, suggesting that some of the washing-induced degradation in functionality is reversible and can possibly be attributed to the aggregation of detergent residue on the samples (FIGs. 10A-10D). The alkyl chains presented by the HDTMS could be attractive to the lipophilic portion of the amphiphilic detergent molecules, which are removed by the rinse. FIGs. 10Cand 10D summarize the differences in contact and sliding angles before and after 65 washes, with and without a deionized water rinse, according to some embodiments. After repeated washing and a deionized water rinse, the static contact angle of silica-and-HDTMS-coated PET without APTES was ~12 ± 4.5 degrees lower than the unwashed sample, while the sliding angle had risen by 12 ± 4.1 degrees. The static contact angle of silica-and-HDTMS- coated PET with APTES after 65 wash cycles and a rinse with deionized water had been reduced by only 4 ± 2.9 degrees, while the sliding angle rose by 9 ± 4.3 degrees. The PET pretreated with APTES and coated with silica and HDTMS apparently retained more silica NPs and remains more hydrophobic and resilient over the course of robust wash testing than PET without a pretreatment to establish a particle-to-substrate bond.

[0173] According to some embodiments, the coating was also more hydrophobic than available data in a literature review of commercially available C8, C < 6, silicone, and hydrocarbon durable water-repellent coatings and other solutions that enhance these compounds with surface roughness (as shown in FIG. 11 A, i IB, 11C). As shown in FIGs. i 1A-11C, results of composites, according to some embodiments, are shown as “PET- APTES-Si-HDTMS.” For FIG 11C, for each group of results shown on the x-axis of the figure, the bar on the left represents the unwashed results, while the bar on the right represents washed results. Other results are for commercially available PFAS, silicon or hydrocarbon products.

[0174] According to some embodiments, as shown in FIGs. 11 A-11C, shown there in is a comparative analysis of PET fabric with a linker (APTES) coated with silica and HDTMS against commercially available long- and short-chain PFAs, silicone compound and hydrocarbon durable water repellent coatings, as well as solutions proposing surface roughening to enhance those compounds. Values for surface treatments other than silica and HDTMS are average of published values. According to some embodiments, FIG. 11 A showswater static contact angles over several wash cycles. According to some embodiments, FIG. 1 IB shows water sliding angles over several wash cycles. According to some embodiments, FIG. 11C shows AATCC 22-2001 Spray Test before and after one wash cycle.

[0175] According to some embodiments, over the first five and 10 washes, the water static contact angle of the silica-and-HDTMS-coated cotton (initially about 114 ± 9 degrees, hydrophobic but not superhydrophobic by industry standard definitions) began to decrease, and by the 20th wash cycle all water droplets wicked into the fabric. The same cotton was also dipped in HDTMS without silica NPs, but without providing a silica surface for the silane to bond to, the cotton did not become water-repellent and no contact angles could be measured. The initial water repellency on the silica-coated samples is an indication that silica was present and HDTMS bonded to the silica, while the decline in contact angle and eventual breakdown of water repellency by the 15th wash cycle indicates that the silica NPs likely detached during the wash cycle. It can be inferred that dipping cotton directly in silica sols does not produce a stable coating of silica NPs without the presence of a covalent linker.Testing the reusability of the solution:

[0176] According to some embodiments, after the initial application of silica nanoparticles, excess nanoparticles were observed in the Sol A and Sol B solutions. An additional experiment on scaled-up 400 cm2 polyester samples was prepared to determine the reusability of the APTES, Sol and HDTMS solutions. The static contact and sliding angles of water droplets on the four subsequent batches of scaled-up samples largely match those of the first batch (as shown in FIG. 12). Over subsequent batches, the sliding angle gradually decreased, perhaps due to particle agglomeration or larger particles due to continued deposition of the sol-gels over time, leading to different deposition upon the substrate. Theresults indicate the solution is reusable for at least five treatments without impacting the water-repellent performance, which allows for a reusable, water-free closed loop system.

[0177] According to some embodiments, FIG. 12 depicts hydrophobic performance metrics of polyester fabrics coated with HDTMS water-repellent coatings for five test batches repeatedly reusing the sample solutions of SiNPs and HDTMS. N = 5 sample locations on 6 samples of each batch. Measurements were taken in different locations from the same sample.Fourier transform infrared (FTIR) spectroscopy

[0178] According to some embodiments, to further verify the presence of chemical bonds in each step of the process, samples were analyzed by Fourier Transform Infrared (FTIR) spectroscopy (FIG. 4B). When pretreated with APTES, the polyester shows a broad increase around 3400 cm-1, corresponding to a primary amine NH2 stretching mode. The reduction of this peak after the addition of silica suggests the silica reacted the carbonyl with the amines on the APTES. Further, when the PET substrate spectrum is subtracted from the PET- APTES-Silica NPs spectrum (FIG. 4B, middle row inset), increases in the band from 900- 1200 cm-1 are clearly visible, indicating Si-O-Si bonds and the presence of a silica coating. The addition of HDTMS or Midori RP both show clear additional peaks in the 2800-3000 cm-1 region, corresponding to alkyl groups (most prominently CH2 stretching modes).Textile Industry Standard Water Repellency Testing on 400 cm2 samples

[0179] According to some embodiments, to accurately reflect the textile industry’s water repellency testing requirements, the 400 cm2 polyester samples underwent a series of water repellency tests common in the textile industry, including the American Association of Textile Chemists and Colorists' AATCC 22-2001 Spray Test, and the ISO 9865: 1991(E)Bundesmann Rain Shower test.

[0180] According to some embodiments, spray tests were conducted at Beyond Surface Technology’s laboratory on one sample each of unwashed or washed untreated fabric, silica alone, BST’s Midori RP alone, silica and Midori RP and silica and HDTMS. Samples were pre-stretched in a hoop and placed beneath a funnel with a spray nozzle as 250 mL of water is sprayed for 25 - 30 seconds. At the end of the test, the samples were given a score from 0-100 based on a visual comparison to a rating chart, where 0 indicates complete wetting and 100 represents no wetting on the sample (FIG. 7C). The silica alone and untreated samples were not repellent and received a score of 0. The unwashed BST Midori RP alone was scored higher than the unwashed Midori RP with added silica, although the washed versions both received a score of 100. This may depend on the amount of stretch applied to the sample when placed in the hoop, or the position in which the pores between the warp and weft were exposed to the spray. Both the unwashed and washed versions of the silica and HDTMS were the most consistently hydrophobic and received a score of 100.

[0181] According to some embodiments, the Bundesmann test simulates the body walking in the rain. Samples were mounted to four rotating cups at an angle and receive artificial rainwater while the back of each sample is subjected to rubbing to mimic the pressure of a user’s body moving beneath a garment. At the end of the ten-minute test, three observations were recorded. First, a repellency rating from 1-5 was given by the technician based on observation and comparison to a visual chart, with one indicating the sample is fully wetted and 5 displaying the most repellency. Second, the amount of water that flowed through the sample into the cup was measured in mL. Finally, the samples were weighed before and after the test, first while dry, and then after removal from the cups and a spin in a centrifuge to calculate water absorption percent. A modified version of the ISO 9865: 1991 (E) Bundesmann Rain Shower test was conducted in which samples were run through the test cycle three times each and allowed to dry overnight in between test cycles. This cadence wTaschosen to better reflect typical user use, where an item like a raincoat might be worn on multiple occasions before washing (FIGs. 7D-7F). Tests were conducted for 3 cycles each at North Carolina State Zeis Textiles Extension on each condition (N = 3): unwashed or washed untreated fabric, silica alone, BST’s Midori RP alone, silica with Midori RP and silica with HDTMS.

[0182] According to some embodiments, the water flow through Bundesmann results indicated wide ranges of standard deviation, particularly on the untreated fabric and the fabric coated with silica alone, both whose water flow through appears to reduce after each cycle and after washing as if they gain water repellency over washing and time (FIG. 7E).However, when compared to the water absorption percent for the same samples, it appeared water does absorb fairly consistently into the samples, unlike the samples coated with water- repellent finishes (FIG. 7F). These non-functionalized samples both absorbed more water than the water-repellent samples, and in particular the sample coated in silica alone displayed the highest absorption rates, indicating the increased hydrophilicity gained from the silica NPs. From the contact and sliding angle testing, both of these non-functionalized samples were hydrophilic as they absorbed water every time (FIGs. 5A, 5D). It was possible that the sample preparation by stretching the samples on the Bundesmann cup mouths impacted the pore sizes between the warp and weft. When combined with the placement of the warp and weft in relation to the shower head, this may impact the water flow through rate on all samples, resulting in the highly variable water flow through rates over time and washing. Unsurprisingly, both of these non-functionalized samples were consistently given a visual water repellency rating of 1 , indicating full wetting at the end of every test (FIG. 7D).

[0183] According to some embodiments, of the samples functionalized for water repellency, the Bundesmann water flow through and water absorption measurements appeared to suggest that BST Midori RP alone performs better than the silica with Midori RPor silica with HDTMS (FIGs. 7E-7F). The visual water repellency rating for the unwashed functionalized samples were all rated within the 4 - 5 range and no one treatment appears to provide any particular advantage over another (FIG. 70). However, the contact and sliding angles taken from the same samples (FIGs. 6B-6C) contradict this by revealing better water repellency on the silica and Midori RP with its observed higher static contact and lower sliding angles than the Midori alone, and the best water repellency observed on the silica with HDTMS reporting the highest and lowest static contact and sliding angles. As with the nonfunctionalized samples, the water flow through of the functionalized samples may be impacted by the sample stretching method prior to mounting on the cups, or the orientation of the warp and weft in relation to the shower head. Further, it may be related to the relative thickness of the coatings. The Midori RP polymer had a wet pickup application of 88% on the untreated polyester and 75% on the sample pretreated with silica, which may suggest the presence of a thicker coating on the fabric without silica than the fabric with silica. To take the Bundesmann water absorption measurement, the standard test method includes spinning the sample in a centrifuge prior to weighing the sample after the test, which may be enough to pin and spin the water into the fabric rather than off the fabric. From the test method, it was unclear how much water is on the sample before it was spun out or how much water is spun into the sample. Water absorption for silica and HDTMS appeared to go up to an average 11% after wash while the water flow through also increased by ~ 15%, while its visual repellency rating was also lower than its unwashed counterpart, indicating its performance was significantly worse after washing. However, as seen from the contact and sliding angle results from wash testing over 65 wash cycles and the impact of a deionized water rinse after the 65th cycle, it was likely that surfactant residue existed on the samples and impacts its performance when solvated by the water from the Bundesmann shower head.Fabric Stiffness Testing on 400 cm2 samples

[0184] According to some embodiments, to quantify the flexibility of the untreated fabrics and subsequent coatings, the ASTM DI 388 test method for stiffness of fabrics was conducted using the cantilever test option to determine bending length and flexural rigidity. Swatches in both the warp and the weft direction 25 by 200 mm were cut from the unwashed and washed polyester 400 cm2 samples without coating, with the addition of silica NPs alone, silica NPs coated with HDTMS or Midori RP, and Midori RP alone (N=3). An overhang length O [mm] was determined (see Supplementary Experimental section below); from this, the bending length (c [nun]) was calculated according to: c = O / 2.

[0185] According to some embodiments, to determine the flexural rigidity (G [pjoule / m]) using the bending length (c [mm]), the weight of the fabric was established using ASTM D3776, the standard test method for determining mass per unit of fabric. Each of the circles cut for the Bundesmann samples (N=3) were measured and weighed together. First, the total area of all three samples was established by calculating: A = n «3. 14(d / 2)A2, where A [mm2] is the area of the specimen, n is the number of specimens, and d [mm] is the diameter of the specimens.

[0186] According to some embodiments, next, the mass of the specimens (W [g / m2]) evaluated as: W = 10A6*M / A, where M [g] is the total mass of the specimens and A [mm2] is the total area of the specimens.

[0187] According to some embodiments, this quantity is used to calculate the flexural rigidity (G [pjoule / m]) according to: G= (1.421 *( 10A(-5)) m s-2)*W*cA3, where W [g / m2] is the mass of the specimens and c [mm] is the bending length.

[0188] According to some embodiments, the bending length and flexural rigidity were calculated for each test location (N=4 testing locations on 3 samples each in both the warp and weft directions) and averaged together, shown in FIGs. 8A-8C. The untreated fabric was quite flexible in both the warp and weft directions, with a bending length just below 1 mm.The addition of the silica coating only slightly increases this rigidity in both warp and weft directions, and after the first wash it returned to comparable values to the bending and flexural rigidity of the untreated fabric. The additional treatment of HDTMS on the silica NPs did not appear to impact the bending length or flexural rigidity of the original fabric. However, the Midori RP alone and the Midori RP atop silica NPs both increased the bending length of the original polyester by approximately 110% in the weft direction and 180% in the warp direction. The flexural rigidity of the Midori RP and Midori RP on silica NP samples was greatly increased, with a 750% and 700% increase in weft and 1700% and 1850% increase in warp flexural rigidity respectively. This was reduced after an initial wash, but the wash does not return the samples to the stiffness levels of the untreated fabric. This marked difference in drape and stiffness can be visually observed in the photographs in FIGs. 8A-8C, where a silica-and-HDTMS-coated sample draped over a concrete block conforms more closely to the edges of the block than a silica-and-Midori RP -coated swatch. This suggested that neither the addition of silica NPs nor the addition of HDTMS to the NPs impacts the drape and hand feel of the fabric, which maintains the comfort and wearability of the original fabric.Comparative analysis

[0189] According to some embodiments, the comparative results in FIGs. 11A-11C suggest that the PET-APTES-Si NP-HDTMS substrate produced in this study offered a static contact angle (FIG. 11 A) higher than commercially available water repellent solutions and other solutions that seek to introduce surface roughness; this superior performance was maintained over the course of 65 wash cycles. When it comes to sliding angles (FIG. 1 IB), the same unwashed specimen did not have a sliding angle as low as that of long- or shortchain PFAs or that of surface roughening combined with silicone or hydrocarbon compounds, although it performed better than commercially available silicone and hydrocarboncompounds. After several wash cycles, there was less available data for sliding angle, which was the least reported test method. The most available data was for several wash cycles of surface roughening with silicone compounds; after 65 wash cycles and a DI water rinse, the PET-APTES-Si NP-HDTMS reported in this study were lower by ~5°. When comparing via the AATCC 22-2001 Spray test, the PET-APTES-Si NP-HDTMS reported in this study is comparable before and after one wash with commercially available C8 PF As (FIG. 11C).Demonstration of technology on a variety' of materials, and application of commercially available nanoparticles:

[0190] According to some embodiments, to determine whether the system is applicable to additional substrates, the existing method was applied to a variety of textile materials commonly used in the outdoor and protective apparel industries. Substrates included an untreated meta-aramid fiber textile often incorporated into firefighting turnout gear and tightly woven textiles used for rain gear including polyester, polyamide and polyamide / elastane blends. The samples represented a diverse range of weaves including a plain weave, a satin weave, and a crepe weave.

[0191] Further, according to some embodiments, commercially available nanoparticles were applied to the previously tested polyester fabric as well as to the new substrates to test the viability of the system as a drop-in replacement to Stober method nanoparticles.

[0192] According to some embodiments, to verify the presence of silica nanoparticles, scanning electron microscopy (as shown in FIGs. 13A-13C) was conducted on the samples. These characterization methods confirmed the presence of silica nanoparticles and the transferability of the method to a variety of substrates. Contact and sliding angle measurements (as shown in FIGs. 14A-14B) confirm the transferability of this method.

[0193] According to some embodiments, as shown in FIGs. 13A-13C, shown therein are SEM of new substrates (A, Untreated) with the application of either Stober method silica NPs (B) or with commercially available silica NPs (C, nanoComposix). Substrates included:originally tested polyester fabric, Nomex (meta-aramid), a 94% polyamide 6% elastane blend, a new polyester fabric with a different weave, and a polyamide (PA) fabric.

[0194] According to some embodiments, as shown in FIGs. 14A-14B, shown therein are hydrophobic performance metrics of new substrates with HDTMS water-repellent coatings compared against the performance of fabrics prepared either with Stober method silica NPs or with commercially available silica NPs (nanoComposix). Substrates include: originally tested polyester fabric, Nomex (meta-aramid), a 94% polyamide 6% elastane blend, a new polyester fabric with a different weave, and a polyamide (PA) fabric. For each graph, N = 3. Measurements were taken in different locations from the same sample. A. Static contact angles of water. High water contact angles indicate higher repellency. B. Sliding angles of water on fabrics. Polyester that was untreated or treated with silica alone absorbed the water and could not be measured. The water droplets on polyamide samples were pinned and could not be measured. Lower sliding angle indicates higher water repellency. In FIGs. 14A-14B, for each material, the bar on the left shows the results for the Stober method nanoparticles, while the bar on the right shows the results for the commercially available NPs.

[0195] According to some embodiments, as shown in FIG. 15, the nanoparticles can have diameters in two different ranges. According to some embodiments, the smaller nanoparticles in solution A (Sol A) average 144 ± 45.6 nm and the larger nanoparticles in solution B (Sol B) average 590 ± 104.5 nm (N = 3).Fabric cleaning and preparation:

[0196] According to some embodiments, for solution reusability tests, large samples measuring 20 cm2 were cut from white tightly woven 100% polyester fabric (Joann Fabric and Craft). For testing on new substrates, small square samples measuring 9 cm2 were cut from all materials. An untreated plain weave meta-aramid (100%, Nomex, Dupont) textile used for firefighting turnout gear was provided by the Textile Protection and Comfort Center,Wilson College of Textiles North Carolina State. Beyond Surface Technologies, Switzerland provided the following materials sampled from outdoor industry' standard textiles: a plain weave blue polyamide (94%) elastane (6%) blend, a white satin weave polyester (100%), and a cream polyamide ( 100%) crepe weave. All samples were washed in a 1 % v / v solution of Jacquard Synthrapol textile detergent (Blick Art) in deionized (DI) water. Samples were rinsed in DI water and dried with compressed air.Fabric surface functionalization:

[0197] According to some embodiments, to activate the surface and add active functional groups to PET via a transamidation process without degrading the polyester, a 1% v / v solution of 3-aminopropyltriethoxysilane (Sigma Aldrich) in a 70:30 (by volume) DI waterethanol mixture was prepared and stirred at 400 RPM at room temperature for 30 minutes. Samples were added to the prepared solution and stirred for 1 hour, removed and rinsed with DI water, followed by dipping in a 1% v / v aqueous acetic acid solution in DI water (pH 4) to drive the condensation reaction for the subsequent silica attachment.Silica particle fabrication following Stober method:

[0198] According to some embodiments, hierarchical silica NPs were produced. Two distributions of silica particle sizes were produced, one with an average of 144 ± 45.6 nm (Sol A) and the other with an average of 590 ± 104.5 nm (Sol B). For Sol A, 8.6% v / v tetraethylorthosilicate (TEOS, Sigma Aldrich) was slowly added to ethanol (VWR) and stirred at 300 RPM at room temperature for 5 minutes. 5% v / v ammonium hydroxide (Sigma Aldrich) was added dropwise and stirred at 25°C for a minimum of 12 hours. To prepare Sol B, 14.3% v / v TEOS was added to Ethanol and stirred 300 RPM at room temperature for 5 minutes. A solution of 49% DI water, 33% ethanol, and 18% ammonium hydroxide was added slowly and stirred for a further 2 hours. Samples were first immersed in the larger particles (Sol B) for 5 minutes, removed and immersed in an ethanol rinse, followed bydrying at 80°C for 5 minutes and curing at 120°C for 2 minutes. Samples were then immersed in the smaller particles (Sol A) for 5 minutes, removed and immersed in an ethanol rinse, followed by drying at 80°C for 5 minutes and curing at 120°C for 2 minutes.Commercial silica particle application:

[0199] According to some embodiments, silica nanoparticles of two sizes, 500 nm and 120 nm, with a concentration of 10 mg / mL in deionized water were procured from nanoComposix (VWR International). The prepared solution was sonicated for 10 minutes prior to use. One suspension of each size of nanoparticle was prepared with 2% v / v nanosphere solution added to ethanol and stirred 300 RPM at room temperature for 5 minutes. Samples were first immersed in the larger particle suspension (500 nm) for 5 minutes, removed and immersed in an ethanol bath to rinse, followed by drying at 80°C for 5 minutes and curing at 120°C for 2 minutes. Samples were then immersed in the smaller particle suspension (120 nm) for 5 minutes, removed and immersed in an ethanol bath to rinse, followed by drying at 80°C for 5 minutes and curing at 120°C for 2 minutes.Silane surface functionalization:

[0200] According to some embodiments, 3% v / v hexadecyltrimethoxysilane (HDTMS, Sigma Aldrich) in ethanol was stirred at 400 RPM for 5 min. Samples were stirred in the solution for 24 hours at room temperature, rinsed in ethanol and air dried, then cured for 1 hour at 120°C.Solution reusability testing:

[0201] According to some embodiments, five batches of six 20 cm2 tightly woven 100% polyester fabric (Joann Fabric and Craft) were prepared and treated in batches step-wise in the above-prepared solutions of APTES, Sol A, Sol B, and HDTMS.Water static contact and sliding angles:

[0202] According to some embodiments, 10 ml droplets were deposited in five positions per sample using a Kruss DSA 100 Drop Shape Analyzer. Static water contact angles were measured using the Young-Laplace fitting method. Sliding angles were measured at the angle at which the droplet fully detached from the surface, tested on both the warp and weft directions.

[0203] According to some embodiments, polyester fabric with a hierarchically structured layer of two sizes of silica NPs functionalized with a fluorine-free silane or a fluorine-free acrylic polymer can produce robust PFA-free superhydrophobic finishes.

[0204] In some embodiments, a textile composite can provide a design platform where the combination of a surface activation layer on a flexible substrate with an application of discrete silica NPs provides a durable, flexible, breathable, and transparent scaffold for a range of surface functionalizations. In some embodiments, HDTMS can provide excellent superhydrophobic performance when patterned onto a coating consisting of silica NPs in two sizes, approximately 100-200 nm and 500-600 nm. In some embodiments, the finished fabric can maintain contact angles between 170 ± 2.8 degrees and 166 ± 2.9 degrees and sliding angles between 19 ± 4 degrees and 28 ± 4.3 degrees over the course of 65 wash cycles.

[0205] In some embodiments, comparing a textile composite to a polyester coated with silica and HDTMS without pretreatment with APTES to bind the particles to the fabric can show that the presence of an APTES linker improved performance over the 65 wash cycles.

[0206] In some embodiments, improvements in hydrophobicity and omniphobicity in this system are possible with the introduction of different surface chemistries.

[0207] In some embodiments, the layered surface coating system also offers the potential for further functionalization of the silica NPs beyond hydrophobicity by attaching different surface-modifying molecules. In some embodiments, other functional coatings include photoswitchable color, antimicrobial colloidal silver, pH- or thermal responsivity, andselective patterning to create surfaces with multiple functionalities in segregated domains, for example, having areas of hydrophilicity and areas of hydrophobicity. In some embodiments, the composite’s even coating of discrete, non-shearing, covalently bound silica nanoparticles have potential for future applications on diverse substrates such as non-wovens and elastic fabrics including knits and soft polymers, allowing for a high degree of stretch and return afforded by the particles and their attachment pattern.

[0208] Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present disclosure. For example, while the embodiments described above refer to particular features, the scope of this disclosure also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present disclosure is intended to embrace all such alternatives, modifications, and variations as falling within the scope of the claims, together with all equivalents thereof.

Claims

CLAIMSWhat is claimed is:

1. A textile composite comprising: a textile material; a plurality of linkers covalently bonded to the textile material; a layer of nanostructures covalently bonded to the plurality of linkers; and a coating covalently bonded to the layer of nanostructures; wherein the layer of nanostructures is disposed between the textile material and the coating.

2. The textile composite of claim 1 , wherein the textile material comprises a woven material, a knit material, a nonwoven material, or a combination thereof.

3. The textile composite of claim 1, wherein the textile material comprises a woven polyester material.

4. The textile composite of claim 1 , wherein the linkers comprise a ligand.

5. The textile composite of claim 1, wherein the textile material comprises a synthetic fiber, synthetic film, natural fiber, bio-based material, bioderived material, or combinations thereof.

6. The textile composite of claim 1 , wherein the linkers comprise a silane or a thiol.

7. The textile composite of claim 1, wherein the linkers comprise a silane.

8. The textile composite of claim 1, wherein the linkers comprise 3- aminopropyltriethoxysilane (APTES) or 3-aminopropyltrimethoxysilane (APTMS).

9. The textile composite of claim 1, wherein the nanostructures comprise silica, copper oxide, titania, silver oxide, zirconia, nanocellulose, diatoms, structurally colored particles, pigments, copper, titanium, silver, gold, polymer nanoparticles, semiconductor nanoparticles, or a combination thereof.

10. The textile composite of claim 1, wherein the nanostructures comprise silica.11 . The textile composite of claim 1 , wherein the nanostructures comprise a metal oxide, metal, or a combination thereof.

12. The textile composite of claim 1, wherein the nanostructures comprise nanoparticles of different sizes.

13. The textile composite of claim 11, wherein the nanostructures comprise large nanoparticles having a diameter of about 500 to 1 ,000 nanometers and small nanoparticles having a diameter of about 10 to 300 nanometers.

14. The textile composite of claim 1, wherein the coating is hydrophobic, oleophobic, UV-resistant, antibacterial, antimicrobial, hydrophilic, thermoregulating, moisture wicking, photo switching, vapor permeable, gas permeable, color switching, antiabrasive, anticorrosive, or a combination thereof.

15. The textile composite of claim 1, wherein the coating is hydrophobic.

16. The textile composite of claim 1, wherein the coating is oleophobic.

17. The textile composite of claim 1, wherein the plurality of linkers are covalently bonded to the textile material by one or more of silicon-oxy gen bond, ester bond, metal-sulfur bond, metal-oxygen bond, and amide bond.

18. The textile composite of claim 1, wherein the layer of nanostructures is covalently bonded to the plurality of linkers by one or more of silicon-oxygen bond, ester bond, metal-sulfur bond, metal-oxygen bond, and amide bond.

19. The textile composite of claim 1, wherein the coating is covalently bonded to the layer of nanostructures by one or more of silicon-oxygen bond, ester bond, metal-sulfur bond, metal-oxygen bond, and amide bond.

20. The textile composite of claim 1, wherein the textile composite is perfluoroalkyl and polyfluoroalkyl (PFA)-free.21 . A method of making a textile composite, the method comprising the following sequential steps: providing a textile material; covalently bonding a plurality of linkers to the textile material; covalently bonding a layer of nanostructures to the plurality of linkers; covalently bonding a coating to the layer of nanostructures to produce the textile composite; wherein the layer of nanostructures is disposed between the textile material and the coating.

22. The method of claim 21 , wherein covalently bonding the plurality of linkers to the textile material comprises immersing the texting in a solution containing the plurality of linkers.

23. The method of claim 21, wherein the textile material comprises a woven material, a knit material, a nonwoven material, or a combination thereof.

24. The method of claim 21, wherein the layer of nanostructures comprises a group of large nanostructures and a group of small nanostructures, wherein the group of large nanostructures are covalently bonded to the plurality of linkers first.

25. The method of claim 21, wherein the nanostructures are dried and cured after being covalently bonded to the plurality of linkers.

26. The method of claim 21, wherein the textile material comprises synthetic fibers, synthetic films, natural fibers, bio-based materials, bioderived materials, or combinations thereof.

27. The method of claim 21, wherein the linkers comprise 3- aminopropyltriethoxysilane (APTES) or 3-aminopropyltrimethoxysilane (APTMS).

28. The method of claim 21, wherein the nanostructures comprise silica, copper oxide, titania, silver oxide, zirconia, nanocellulose, diatoms, structurally colored particles, pigments, copper, titanium, silver, gold, polymer nanoparticles, semiconductor nanoparticles, or a combination thereof.

29. The method of claim 21, wherein the nanostructures comprise large nanoparticles having a diameter of about 500 to 1,000 nanometers and small nanoparticles having a diameter of about 10 to 300 nanometers.

30. The method of claim 21, wherein the plurality of linkers is covalently bonded to the textile material by one or more of silicon-oxygen bond, ester bond, metal-sulfur bond, metal-oxygen bond, and amide bond.

31. The method of claim 21 , wherein the layer of nanostructures is covalently bonded to the plurality of linkers by one or more of silicon-oxygen bond, ester bond, metal-sulfur bond, metal-oxygen bond, and amide bond.

32. The method of claim 21, wherein the coating is covalently bonded to the layer of nanostructures by one or more of silicon-oxygen bond, ester bond, metal- sulfur bond, metal-oxygen bond, and amide bond.

33. The method of claim 21, wherein the textile composite is perfluoroalkyl and polyfluoroalkyl (PFA)-free.

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