Sols, uses thereof and water-free products prepared therefrom

Abstract

The present application relates to sols, uses thereof, and water-impermeable products prepared therefrom, in particular, the sols are formed from a solvent, an alkoxide, a biopolymer, and a catalyst, and can be used to prepare water-impermeable products, including water-impermeable fiber-based products.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 202080060808.2, filed on July 24, 2020, entitled "Soluble, Multifunctional Applications of Soluble and Related Products". Technical Field

[0002] This invention relates to colloidal solutions (referred to as sols), the use of sols to impart desired properties to products, products manufactured using sols, and methods of using such sols. Specifically, this invention relates to sols formed from solvents, alkoxides, biopolymers, and catalysts, their use in preparing waterproof products, and waterproof fiber-based products prepared therefrom. Background Technology

[0003] The properties of materials used in commercial products are often important for the intended function or use of a given product. For example, paper, paperboard, and other materials are commonly used as packaging for commercial products. Material properties of packaged products, such as the permeability of the packaging material to water, oil, and other fluids, can be controlled by using functionalized coatings that utilize impermeable plastic materials or composites. In many industries, such as the food and beverage industry, plastics can be applied to other permeable media to promote the retention of liquid products within specific packaged articles. Similar methods can be used to prevent fluids from entering articles that may be damaged by exposure to water, air, or other fluids. In one instance, some paper or paperboard products undergo a process called internal sizing or surface sizing, where hydrocarbon-derived materials (such as microplastics) are used to modify the porosity, absorbency, abrasion resistance, or other properties of the material. In another instance, the growth of microorganisms (such as bacteria, fungi, viruses, and parasites) in commercial products is often controlled using disinfectants; however, the use of disinfectants can lead to environmental hazards and is associated with the formation of drug-resistant strains of microorganisms. Antimicrobial coatings provide an alternative method for controlling microbial growth. Traditional antimicrobial coating compositions rely on the biocidal effects of copper, silver, zinc, or organic additives such as phenolic biocides, quaternary ammonium compounds, and fungicides. These materials interfere with the spread of microorganisms through various mechanisms, such as binding to microorganisms and interfering with their respiration or disrupting microbial proteins and / or cell walls. The raw materials used to produce existing functionalized coatings are often derived from feedstocks with associated environmental costs. For example, metallic coatings may be derived from mining activities, while plastic materials are often derived from hydrocarbon feedstocks. The materials or chemicals used to manufacture such materials and related byproducts may also be toxic. Some materials may also degrade over time to produce particulates, such as microplastics. Furthermore, many such materials may release potentially hazardous substances during use. Therefore, there are ongoing health and environmental concerns associated with many common materials found in consumer products and industrial environments. Summary of the Invention

[0004] The inventors of this invention have discovered a novel, innovative, and non-toxic alternative to conventional functional coating compositions in the form of a sol. Hereinafter, the term "sol" refers to a dispersion of colloidal particles in a liquid solvent. Sols may also be referred to as sol mixtures. Many sols formed from small colloidal particles are substantially transparent and colorless. For example, sols formed from silicon-based functional materials are typically transparent and colorless because the particles forming the sol are small enough that they do not scatter light. Some sols formed from larger particles may be colored and / or at least partially opaque. For example, sols formed from titanium-based functional materials may be distinctly white. When applied to a range of materials, sols can form impermeable and / or antimicrobial and / or alternative functional coating compositions. Thus, sols can be used as barrier and / or antimicrobial coating compositions and can provide other functionalities such as hydrophobicity, oleophobicity, antifouling, biofouling resistance, stain resistance, optical transparency, optical opacity, antireflectivity, and adhesion promotion. Sols used as barriers can provide a barrier against liquids, vapors, and / or gases (such as oxygen). Sols can contain readily available natural materials that ensure the resulting sol is inexpensive. Furthermore, sols can be applied directly to surfaces without special surface preparation, ensuring ease of use. In addition, some sols have been shown to provide durable and heat-resistant coatings, demonstrating that sols can form resilient and long-lasting functional coatings.

[0005] According to the present invention, a sol comprising a solvent, an alkoxide, and a catalyst is provided for use in the preparation of waterproof products. The present invention further provides a waterproof fiber-based product prepared using a sol. According to another aspect of the present invention, a sol comprising a solvent, an alkoxide, a biopolymer, and a catalyst is provided. A method for preparing a sol comprising a solvent, an alkoxide, a biopolymer, and a catalyst is also provided. The method comprises: a) dispersing a biopolymer in a solution comprising a catalyst, and then adding an alkoxide; b) dispersing an alkoxide in a solvent, adding a catalyst, and then adding a biopolymer; or c) dispersing an alkoxide in a solution comprising a catalyst, and then adding a biopolymer. Yet another aspect of the present invention provides a coated product wherein the product has been coated with a sol comprising a solvent, an alkoxide, a biopolymer, and a catalyst. Powders derived from the sol as described herein form yet another aspect of the present invention. These and other aspects will be apparent to those skilled in the art from this disclosure. For the avoidance of doubt, the scope of the invention is defined by the appended claims. Attached Figure Description

[0006] Figure 1 These are scanning electron microscope (SEM) images of the surface of a product to which the sol according to the invention has been applied.

[0007] Figure 2This is a schematic cross-sectional view of the surface of a product after the sol according to the invention has been applied.

[0008] Figure 3A These are photographs of the surface of phosphor bronze after the application of the sol according to the present invention. Figure 3B The image shows the contact angle of a water droplet on an uncoated area of ​​phosphor bronze, and Figure 3C The image shows the contact angle of a water droplet on a phosphor bronze coated area. Detailed Implementation

[0009] Sols can be formed by dispersing one or more materials having a suitable small particle size in a solution. Some sols may further contain additional components, such as catalysts or functional components. Sols suitable for use in this invention can be any sol that can be applied, coated, or incorporated into a product to impart beneficial properties or characteristics to the resulting product. Sols suitable for use in this invention typically contain functional materials and solvents. In one embodiment, the invention can be used with sols containing solvents, functional metal alkoxides, and optionally present biopolymers and / or optionally present catalysts. The term "metal alkoxide" includes alkoxides containing metals, organically modified alkoxides containing metals, alkoxides containing metalloids, and organically modified alkoxides containing metalloids. The solvent used to form the sol can contain water, one or more alcohols, any other suitable solvent, or any combination thereof. When present, the one or more alcohols can include methanol, ethanol, butanol, ethylene glycol, isopropanol, any other suitable alcohol, and any combination thereof. Biosolvents, such as bioethanol, can also be used. Biopolymers, if present, may include starch-based polymers, hemicellulose-based polymers, cellulose-based polymers, lignin-based polymers, chitosan-based polymers, any other suitable biopolymers or modified biopolymers, and any combination thereof. The sol may additionally or alternatively contain one or more flours derived from natural materials. Suitable flours may include oat flour, barley flour, rye flour, wheat flour, rice flour, bamboo flour, lentil flour, chickpea flour, pea flour, corn flour, or any combination thereof. Where the sol contains a functional metal alkoxide, the alkoxide generally conforms to the general formula M(OR). x or R C -M(OR) x Where “M” represents any metal that forms a metal alkoxide that can be hydrolyzed in the presence of a suitable solvent. “R” and “R” C "" indicates an alkyl group typically having 1 to 30 carbon atoms, which can take any suitable form, such as straight-chain, branched, aromatic, or complex. "x" is generally equivalent to the valence of the corresponding metal ion "M". In one embodiment, R can be methyl, ethyl, propyl, or butyl. When the metal ion "M" has a valence greater than 1, each R group can be identical. CThis refers to any suitable organic group that will form and maintain a covalent bond with the metal "M" after the hydrolysis of the alkoxide. In some embodiments, R and R C They can be the same. In other implementations, R and R C They can be different. Any suitable metal alkoxide can be used. Examples of suitable metal alkoxides include Si(OR)4, Ti(OR)4, Al(OR)3, Zr(OR)3, and Sn(OR)4, as well as R C -Si(OR)3、R C -Ti(OR)3、R C -Al(OR)2、R C -Zr(OR)2 and R C -Sn(OR)3. In specific embodiments, R can be methyl, ethyl, propyl, or butyl. In some specific embodiments, R C It can be phenyl, cyclopentyl, or any other suitable organic group capable of maintaining a covalent bond with a metal. The metal of the metal alkoxide can include silicon, titanium, aluminum, zirconium, tin, or any other suitable metal. In certain embodiments, the metal alkoxide may be selected from the group consisting of: Ti(isopropoxy)4, Al(isopropoxy)3, Al(sec-butoxy)3, Zr(n-butoxy)4, Zr(n-propoxy)4, n-propyltriethoxysilane, tetrapropyl orthosilicate, titanium tert-butoxide (IV), titanium isopropoxide (IV), triethoxysilane, methyltriethoxysilane, triethoxy(octyl)silane, phenyl-triethoxysilane, titanium ethoxide (iv), triethoxy-methylcyclopentane, (3-glycidoxypropyl)trimethoxysilane, cyclopentyltriethoxysilane, 3-amino-propyltriethoxysilane, triethoxy-3-(2-imidazolin-1-yl)propylsilane, and any combination thereof. In selected embodiments, the metal alkoxide may be selected from the group consisting of tetraethoxysilane, phenyltriethoxysilane, methyltriethoxysilane, and any combination thereof. In further selected embodiments, the metal alkoxide may be selected from the group consisting of tetrapropyl orthosilicate, titanium tert-butoxide (IV), titanium isopropoxide (IV), triethoxysilane, methyltriethoxysilane, triethoxy(octyl)silane, phenyl-triethoxysilane, titanium ethoxide (iv), triethoxy-methoxyalkylcyclopentane, (3-glycidoxypropyl)trimethoxysilane, cyclopentyltriethoxysilane, and any combination thereof. In still selected embodiments, the metal alkoxide may be selected from the group consisting of Ti(isopropoxy)4, Al(isopropoxy)3, Al(sec-butoxy)3, Zr(n-butoxy)4, Zr(n-propoxy)4, and alkoxides based on n-propyltriethoxysilane, and any combination thereof. Catalysts suitable for the sol include at least one of an acid or a base. Examples of acid catalysts include hydrochloric acid, citric acid, nitric acid, and acetic acid. Examples of basic catalysts include sodium hydroxide, potassium hydroxide, and ammonia.

[0010] Sols can be formed by dispersing a functional material with a suitable small particle size in a solvent and optionally adding a catalyst. The functional material can be particles having at least one size in the range of about 1 nm to 1 μm. Alternative methods for preparing a sol include dispersing the functional material in a solution optionally containing a catalyst, followed by the addition of a biopolymer and / or one or more other functional additives. In the presence of a biopolymer and / or one or more other functional additives, the sol containing the functional material can typically be stored for a period of time prior to the addition of the biopolymer and / or one or more other functional additives. Additional functional additives can be added at any stage of the method for preparing the sol. For example, in a sol containing a biopolymer, the additional functional additive can be added before or after dispersing the biopolymer in the solution but before the addition of the alkoxide, or alternatively, after the biopolymer and alkoxide are added to the solution. One or more functional additives can be added at different stages of the sol preparation process. The functional additives can be used to adjust the properties of the sol, such as controlling its viscosity, density, or rheology; making the sol suitable for UV, visible, or IR curing; and / or to add additional functionality to coatings prepared using the sol, such as color, pH sensitivity, conductivity, or fluorescence. The functional additives used will vary depending on the intended use of the sol. Suitable functional additives include photoinitiators, resins, oils, dyes (including pH-sensitive dyes and fluorescent dyes), salts, surfactants, composite particles, mineral or other inorganic particles (including carbonates, carbides, oxides, hydroxides, nitrates, bromides, etc.), and metal particles (including alloys and particles containing one or more metals and one or more additional non-metallic components). Sols can also be formed in the absence of any additives, biopolymers, or catalysts. More specifically, sols may be completely or substantially free of additives and / or biopolymers and / or catalysts during formation and / or use.

[0011] The sol used in this invention can be used without prior modification. Therefore, products prepared using the sol according to the invention can be prepared from the product and the sol without modification of the sol prior to use. For example, a waterproof product can be prepared from the product and a sol that is substantially free of additives, i.e., the waterproof product is prepared by applying the sol to the product in the absence of any functional additives. Alternatively, the sol used in this invention can be modified prior to use. For example, the sol used in this invention can be modified by diluting the sol with a solvent, combining the sol with a functional additive, or both diluting the sol with a solvent and combining the sol with a functional additive. Suitable solvents for diluting the sol include solvents used to disperse alkoxides during sol formation (sometimes referred to as sol solvents), other solvents miscible with the sol solvent, or combinations thereof. Functional additives can be used to adjust the properties of the sol, such as its rheology, density, or viscosity, and / or to add additional functionality to coatings prepared using the sol. The functional additives used will vary depending on the intended use of the sol, and suitable functional additives include photoinitiators, resins, salts, and fluorescent dyes.

[0012] By definition, sols are generally stable. Therefore, a sol can form at some point before its use. For example, a sol can form and be stored for up to 1 hour, 1 day, 1 week, 1 year, 10 years, or longer before use. However, a sol can also form immediately, in less than 2 seconds, less than 15 seconds, less than 30 seconds, less than 1 minute, or less than 1 hour before use. Using a sol in such embodiments can include coating one or more products with the sol or including the sol as part of a material formulation.

[0013] The sol can be formed geographically close to the location where it will be used. Alternatively, the sol can be formed at a location far from where it will be used and then transported to that location. In one embodiment, the sol can be formed online at the manufacturing site a few seconds before being applied to one or more products. In another embodiment, the sol can be formed in a separate manufacturing facility and then transported by road, rail, air, sea, pipeline, or equivalent to a geographically different location where the sol will be applied to one or more products. More generally, where appropriate, the sol can be formed separately from the product to which it will ultimately be applied. In such embodiments, the sol and the product to which it will be applied will be placed together after the sol has been formed. Alternatively, the sol can be formed around the product to which it will be applied, such that the formed sol coats the product immediately, substantially immediately, or shortly after its formation.

[0014] As used herein, the term "product" is intended to include intermediate products, unfinished works, and unfinished products, as well as their components, plus articles and articles finished in other ways. For example, applying a sol mixture to a product may involve adding the mixture to pulp, wet pulp, air-laid pulp, or dry pulp prior to its formation into paper or a three-dimensional molded shape. In this embodiment, the sol is contained within the material matrix forming the product and can therefore be considered a component additive. Applying the mixture to a product may also involve coating all or part of the outer surface of the otherwise finished product with a sol dispersion or suspension. Generally, the mixture can be applied to a product by any suitable method, including brushing, spraying, spray drying, roller coating, dripping, injection, transfer, immersion, dipping, mixing, spreading, scraping, padding, etc. Depending on the nature of the product and the desired properties and characteristics, the mixture may be applied to a single product or article using one or more application methods. For example, a sol intended to form an impermeable coating will typically be applied to the product by brushing, spraying, padding, dipping, scraping, or roller coating. In one embodiment, antimicrobial activity for lumpy material intended for further processing can be achieved by incorporating the mixture into an intermediate material. One embodiment of the lumpy material suitable for further processing is intermediate pulp prior to papermaking using intermediate pulp. The sol can be applied to a product previously coated with the same sol or another sol to impart a thicker functional layer of the same sol or to impart a range of functional benefits, for example, when the sol used to form the first coating and the sol used to form the second coating are different. In this way, the sol can be used to form a primer coating on a product before being applied to one or more coatings that may contain or not contain sol. For example, a sol primer can be used on paper or paperboard products. Any desired number of different sol coatings can be formed. In the case of using multilayer sol coatings, all coatings may contain one or more sols. Alternatively, one or more layers spaced between or around different sol coatings may be sol-free or substantially sol-free. Products coated with the sol of the present invention can be formed from any suitable material. More specifically, the product may include wood products, textile products, leather products, metal (including alloy) products, concrete products or building materials, cardboard products, paper or pulp products, plastic products, glass products, ceramic products, composite materials, electronic circuits, sand, bricks, marble, soil, paints, coating products, food and beverage products, medical devices, pharmaceuticals, and combinations thereof.

[0015] To avoid ambiguity, the term "component additive" as used herein refers to the addition of the sol itself as an additive to one or more materials, unfinished works, bulk intermediates, solutions, substances, etc. Therefore, the term "component additive" is used differently from the term "functional additive," which herein refers to one or more other functional substances added to the sol before, during, or after its formation to impart one or more properties to the sol. To further avoid ambiguity, functional additives may be added to the sol before it is used as a component additive, and a sol that does not contain any functional additives may be used as a component additive.

[0016] Unbound by theory, the functional properties imparted to products used with sols may arise from the formation of a widely cross-linked coating between the reactive functional groups of the components forming the sol. Furthermore, in some cases, during or after application to a product, in addition to forming a cross-linked coating, the sol may at least partially form transient nanodispersions, microdispersions, or suspensions. Cross-linked coatings and / or transient nanodispersions, microdispersions, or suspensions can perform a filling function by partially or completely blocking or impermeable channels on the surface of the product. Therefore, coating a product with a sol may result in a combination of functional sol coatings comprising discrete functional or reactive particles. Thus, sol mixtures can simultaneously serve as coatings, fillers, and binders for materials with porous and / or permeable properties. When the mixture is applied to a product, the sol will cover the surface of the product and flow into any pores, serrated notches, orifices, or similar features on the surface and inner layers of the product. Liquids can carry any nano- or micro-dispersed suspended material in the sol into the porous and / or permeable material. Therefore, sol coatings can be used to fill or partially fill the pore volume on the surface of a product. In one implementation, the sol can be used as part of the paper sizing process. When applied to a product, any sol remaining in the liquid phase will cover the exterior of the product, but may also penetrate further into the product than the solid material. Once the liquid sol component has penetrated the surface of the product, the sol may continue to form nano-dispersions, micro-dispersions, or suspensions due to mechanisms such as the interaction between the sol and substances such as water present in the internal structure of the product. The sol can thus form a solid material within the internal matrix of the product surface and fill or partially fill the void volumes within the product structure. Parts of the product surface morphology and internal structure that may not be achievable through additional solid surface treatments can be achieved with the liquid sol upon application. Once settled, the liquid sol coating surface can thus form a continuous coating with discrete particles formed before or during application, as the surface-accessible pores may have been filled by the liquid sol. Internal void spaces can be filled by further development of the post-sol coating or by forming an internal coating within the internal void spaces of the product during the drying of the liquid sol. In this way, sols can coat the surface of a product, fill or partially fill pore volumes with material, and bind the material together by forming a solid within the internal structure of the surface it has penetrated. This bonding, filling, and coating is not always feasible for sols, as some sols either form a surface coating and / or penetrate into the product structure. Some sols are used only to coat the surface of the product, thereby forming the aforementioned cross-linked coating. Other sols may penetrate the product surface to form both surface and internal coatings without forming transient nanodispersions, microdispersions, or suspensions.

[0017] Figure 1Scanning electron microscope (SEM) images of fiber products coated using the method described herein are shown. The SEM images show areas where a continuous cross-linked coating 1 has formed, where the sol has dried. Surface-accessible pores 2 are filled with a combination of the cross-linked coating and particles 3 formed during the formation of transient nano-dispersions, micro-dispersions, or suspensions. Figure 2 A schematic diagram of the coated material is shown. Figure 2 In this process, product 4 has been coated with a sol, thereby forming a coating 5 on the outer surface of product 4 and its exposed surface pores 6a. A solid material formed from transient nano-dispersions, micro-dispersions, or suspensions 7 further fills the accessible pore spaces on the product surface. With the sol having penetrated the internal product structure, additional particles 9 are formed in the internal coating 8 and the internal pore spaces 6b. Therefore, in Figure 2 In a specific embodiment, the sol functions as coating 5, filler 7, and adhesives 8 and 9.

[0018] The sol of the present invention may optionally contain one or more biopolymers. If present, the one or more biopolymers may include one or more polysaccharides. For example, biopolymers may include starch-based polymers, hemicellulose-based polymers, cellulose-based polymers, lignin-based polymers, chitosan-based polymers, any other suitable biopolymers or modified biopolymers, and any combination thereof. The sol may additionally or alternatively contain one or more flours derived from natural materials. Suitable flours may include oat flour, barley flour, rye flour, wheat flour, rice flour, bamboo flour, lentil flour, chickpea flour, pea flour, corn flour, or any combination thereof. The use of biopolymers in the sol of the present invention can act as natural surfactants, forming a network with negatively charged substances such as alkoxides (if present).

[0019] The starches suitable for use in this invention include positively charged plant-derived starches or their synthetic and derived equivalents, such as cationic starches. Depending on the desired properties of the sol, other starches, such as anionic or neutral starches, may also be used. In some embodiments, starch and other polysaccharides may be combined in a single sol, which can help optimize the sol's function. The cationic starches suitable for use in this invention include primary, secondary, tertiary, and quaternary cationic starches. Quaternary ammonium starches are cationic in both high and low pH solutions, while primary, secondary, and tertiary ammonium starches are cationic only in low pH solutions. Therefore, different types of cationic starches may be suitable for different applications. Sols containing one or more starches or cationic starches may be water-impermeable and / or oil-impermeable and / or vapor-impermeable and / or gas-impermeable and / or antimicrobial and / or hydrophobic and / or oleophobic and / or antifouling and / or biofouling-resistant and / or anticontamination and / or antireflective. Specifically, quaternary ammonium starches have been found to be particularly effective in imparting antimicrobial properties to sols. Generally, antimicrobial sols can be antibacterial and / or antifungal and / or antiviral and / or antialgal and / or antiparasitic. Starch-containing sols have also been shown to effectively prevent the growth of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus hirae.

[0020] The flour suitable for use in this invention includes plant-derived flours with positive or negative charges, or their synthetic and derived equivalents. Depending on the desired properties of the sol, other flours, such as neutral flours, may also be used. Different flours can be combined in a single sol, which can help optimize the function of the sol. Additionally or alternatively, depending on the desired properties and functions of the sol, the flour may be combined with one or more additional polysaccharides. Generally, plant-derived flour is in powder form of plant material (e.g., wheat). Flour contains a range of components including proteins, fats, sugars, starches, amino acids, vitamins, and trace elements. The composition of flour depends on the composition of the material from which it is derived. For example, oat flour may contain a larger proportion of cellulose than wheat flour. Exemplary compositions of various plant powders that can be used in the sols of this invention are provided in Table 1. The flour used in this invention may be selected from oat flour, barley flour, rye flour, wheat flour, buckwheat flour, rice flour, bamboo flour, lentil flour, chickpea flour, green pea flour, corn flour, and combinations thereof. Other plant-derived flours, including starch, hemicellulose, cellulose, lignin, or other polysaccharides, may also be used.

[0021] Table 1: Exemplary Composition of Flour Derived from Various Plant Materials

[0022]

[0023] Typically, plant-derived flour used in the sol of this invention may contain 5 to 85% by weight starch, optionally with 0 to 30% by weight hemicellulose, 0 to 50% by weight cellulose, 0 to 25% by weight lignin, 0 to 35% by weight protein, and 0 to 25% by weight ash. Other suitable flours may contain 20 to 80% by weight starch, optionally with 5 to 30% by weight hemicellulose, 0 to 50% by weight cellulose, 0 to 25% by weight lignin, 0 to 35% by weight protein, and 0 to 25% by weight ash. Still other suitable flours may contain 45 to 80% by weight starch, optionally with 5 to 30% by weight hemicellulose, 0 to 50% by weight cellulose, 0 to 25% by weight lignin, 0 to 35% by weight protein, and 0 to 25% by weight ash. Another type of flour suitable for the sol of the present invention may contain 45 to 70% by weight of starch, optionally with 5 to 15% by weight of hemicellulose, 0 to 10% by weight of cellulose, 0 to 7% by weight of lignin, 10 to 15% by weight of protein, and 0 to 5% by weight of ash. In other embodiments, suitable flour may contain 20 to 70% by weight of starch, optionally with 0 to 15% by weight of hemicellulose, 0 to 10% by weight of cellulose, 0 to 10% by weight of lignin, 5 to 35% by weight of protein, and 0 to 25% by weight of ash. Alternatively or additionally, suitable flour may contain 45 to 70% by weight of starch, optionally with 5 to 15% by weight of hemicellulose, 0 to 10% by weight of cellulose, 0 to 10% by weight of lignin, 5 to 15% by weight of protein, and 0 to 10% by weight of ash. Furthermore, the flour for the sol that may be suitable for use in this invention may contain 45 to 85% by weight of starch, optionally with 0 to 15% by weight of hemicellulose, 0 to 10% by weight of cellulose, 0 to 10% by weight of lignin, 0 to 15% by weight of protein and 0 to 10% by weight of ash.

[0024] Sols containing one or more flours can be water-impermeable, oil-impermeable, and / or vapor-impermeable, and / or air-impermeable, and / or hydrophobic, and / or thermoelastic, and / or optically transparent, and / or oleophobic, and / or stain-resistant, and / or anti-fouling, and / or anti-reflective. Specifically, coatings formed from sols containing one or more flours have been found to exhibit flexibility and durability in use. For example, coatings formed from sols containing one or more flours maintain impermeability and / or other functional barriers even when the surface on which the coating is formed is deformed, bent, or subjected to mechanical or thermal stress. Coatings formed from sols containing one or more flours also exhibit heat resistance. For example, heating a coating formed from a sol containing flours to above 200°C provides no significant degradation in terms of impermeability. Furthermore, coatings formed from sols containing one or more flours can impart mechanical and / or thermoelasticity to other coatings placed thereon. In embodiments where multiple sol coatings are applied to a single product, flour-based sols can be used as functional primers. In such embodiments, applying flour-based sol to the product has been shown to improve resistance to cracking or stress failure of sol coatings placed on top of a flour-based sol coating. Other sol coatings placed on flour-based sol have shown improved resistance to high temperatures or deformation of the coated surface.

[0025] Functional or multifunctional powders may be derived from the sols described herein. Suitable methods for obtaining powders include drying the sol at room temperature and then grinding the dried product to form a powder; heating the sol to form a dried product and then grinding the dried product to obtain a powder; centrifuging the sol to obtain a powder by sedimentation; other methods that combine mixing, shaking and separating, sonicating, and other methods to obtain powder particles of uniform size.

[0026] Powders can possess one or more functional characteristics of coatings formed by sols in other ways. Therefore, powders can be antimicrobial and / or hydrophobic and / or oleophobic and / or antifouling and / or biofouling and / or stain-resistant and / or adhesion-promoting and / or antireflective, and / or any other properties provided by the sol from which the powder is formed. Generally, antimicrobial powders can be antibacterial, antifungal, antiviral, antialgae-resistant, and / or antiparasitic.

[0027] By adding a suitable solvent, the powder can be reconstituted into a sol. The reconstituted sol can then be used with respect to the sol of the present invention in the manner described herein. The powder can be stored for more than 2 years, more than 18 months, more than 12 months, more than 6 months, more than 1 month, more than 2 weeks, and more than 1 week without loss of function, without significant degradation or loss of function. Providing a dry, powdered sol can offer various benefits to the end user, including reduced transportation costs, reduced storage volume, and improved long-term stability.

[0028] This powder can be used as a multifunctional component additive in the manufacture of products including wood, textiles, leather, metals (including alloys), concrete, cardboard, paper, plastics, bioplastics, glass, ceramics, sand, bricks, electronic circuits, fillers, marble, coatings, pigments, adhesives, pastes, and combinations thereof, wherein combinations thereof include composite products and biocomposite products. Such products can be in the form of molecules (e.g., small molecules encapsulated in sol-gels for drug delivery), films, particles, fibers, sheets, pastes, liquids, and combinations thereof. Furthermore, the powder can be used to form nanoparticles that can be suspended in a solvent to provide a multifunctional nanoparticle coating suspension. For the avoidance of doubt, the sol of the present invention, when in liquid form, can also be used as a component additive where appropriate. In one embodiment, a liquid or powdered sol, optionally containing one or more functional additives, can be added as a component additive to a material or process raw material that is subsequently used to form a film or biofilm on one or more products. In this embodiment, the sol or powdered sol can impart impermeability or other properties typically achieved by including synthetic polymers, such as plastics, microplastics, or natural polymers modified with synthetic chemical functional groups, in the material or process feedstock. Therefore, the sol can be used to form impermeable membranes or biofilms that are substantially free of plastics or microplastics. In other embodiments, the liquid or powdered sol can be used as a component additive in plastics or bioplastics to impart the desired functionality to the plastic or bioplastic matrix while reducing the amount of hydrocarbon-containing material required to form a given volume of plastic or bioplastic.

[0029] The sols of the present invention and the powders formed from the sols of the present invention can be used in a variety of applications to provide one or more functions in said applications. The sols can be used to manufacture products used in a range of industries such as automotive, engineering, construction, aerospace, marine, defense, electronics (including optoelectronic devices and sensors), energy (including batteries, energy storage devices, and renewable energy), photonics, food, medical, household goods, paper, adhesives, interior or exterior decoration, home décor, additive manufacturing, oil and gas, separation and purification, fashion, and cosmetics. The sols can be used to prepare products comprising, for example, materials such as: wood, textiles, leather, metals (including alloys), concrete, cardboard, paper, plastics, bioplastics, glass, ceramics, sand, brick, electronic circuits, marble, clay, painted surfaces, and combinations thereof, wherein combinations thereof include composite products and biocomposite products. The sols of the present invention can be added to existing compositions, allowing the existing compositions to benefit from the functions of the sols. For example, the sol of the present invention can be added to existing compositions to provide antimicrobial compositions and / or hydrophobic compositions and / or oleophobic compositions and / or antifouling compositions and / or antistaining compositions and / or adhesion promoting and / or antireflective compositions. Therefore, the sol of the present invention can be used as a component additive in coating formulations. For example, a sol or a powder formed from a sol can be added to one or more coating formulations to impart one or more properties to a coating formed from a coating composition to which a sol or sol powder has been added. The sol or the powder formed from a sol can thus alter the coating's impermeability to water, oil, and / or vapor and / or air, and / or hydrophobicity and / or thermoelasticity and / or optical transparency and / or oleophobicity and / or antifouling and / or antistaining and / or antireflective and / or abrasion resistance and / or adhesion. A coating with added sol or a powder formed from a sol can be used to coat an already coated product. In one embodiment, the product can be coated with a sol prior to being coated with an additional coating comprising one or more sols or powders formed from sols as component additives.

[0030] When a sol is used to form a coated product, the product can be one or more particles, fibers, molded products (including molded products of regular and irregular shapes), sheets, molecules (e.g., small molecules encapsulated in sol-gel for drug delivery), and combinations thereof. A product coated with a sol can be permeable or porous prior to sol coating. Alternatively, a product coated with a sol can be impermeable or non-porous prior to sol coating. Examples of non-porous and impermeable products can be metal or glass plates. The coated product can form part of or be used to manufacture a secondary product, i.e., the secondary product can include the coated product according to the invention, such that the secondary product benefits from the functionality of the sol. For example, the coated product can include particles or fibers for manufacturing a composite product that can be antimicrobial and / or hydrophobic and / or oleophobic and / or antifouling and / or biofouling and / or stain-resistant and / or antireflective. The coated product can also help promote adhesion and / or increase the strength of the composite product or biocomposite product. Specific examples of coated products or secondary products containing coated products include packaging (such as food and beverage packaging, medical packaging, cosmetic packaging, battery packaging, and electronic device packaging), medical devices, fluid containers, cooking utensils and accessories, fiber-based products, or any product that may benefit from an impermeable, antimicrobial, or other functional coating.

[0031] The invention will now be described in more detail with reference to some specific embodiments, wherein the sol described herein is used to impart one or more properties to fibrous products. Fiber products are products composed of fibers, strands, threads, strips, or any other similar structures. For example, fibrous products prepared using one or more of the sols described herein may include pulp (pulp stock, wet pulp, air-laid pulp, dry pulp), paper, paperboard, board, textiles, clothing, woven materials, or combinations thereof, including composite fiber-based products and bio-composite fiber-based products. Specifically, fibrous products comprising or coated with the sols of the present invention can be used as primary, secondary, or tertiary packaging for the food and beverage, electronic devices (including optoelectronic devices and sensors), engineering, electrical appliances, cosmetics, medical devices, pharmaceuticals, fashion, cosmetics, personal care products, household goods (e.g., hangers or cartons), interior or exterior décor, home furnishings, automotive, aerospace, maritime, defense, or construction industries. Such packaging is ideally suited for use in the food and beverage industry in the form of containers because the hydrophobic and / or oleophobic and / or anti-fouling properties imparted by the sol make it possible to form robust containers capable of holding liquids without leakage.

[0032] The sol used with the fiber-based product can be formed simultaneously with the fiber-based product. For example, the sol is applied to the fiber-based product during its formation, thereby providing the fiber-based product with the sol's functionality, such as impermeability, in a single step during preparation. In such an embodiment, the sol is applied to the fiber-based product when both the fiber-based product and the sol are formed. Alternatively, the sol used in this invention can be formed separately from the fiber-based product and then applied to the fiber-based product after sol formation to prepare a sol-treated product. In such an embodiment, the sol is applied to the fiber-based product after sol formation. A pre-formed sol can be applied during the formation of the fiber-based product, such that the impermeable fiber-based product is prepared in two steps (sol formation step, followed by a combined fiber-based product formation and sol application step), or it can be prepared after the formation of the fiber-based product, such that the impermeable fiber-based product is prepared in three steps (sol formation step, followed by a fiber-based product formation step, and then a sol application step). Pre-prepared sol can be applied during the formation of pulp, air-laid pulp, dry pulp, paper, paperboard, board, composite fiber-based products, biocomposite fiber-based products, or combinations thereof. Pre-prepared sol can also be applied after the formation of pulp, air-laid pulp, wet pulp, dry pulp, paper, paperboard, board, composite fiber-based products, biocomposite fiber-based products, or combinations thereof. It should be understood that when using sol to impart water impermeability to fiber products, water-impermeable paper, paperboard, board, composite products, or biocomposite products can be formed from water-impermeable pulp, air-laid pulp, or dry pulp in a single step, two steps, or three steps. Furthermore, the sol according to the invention enables the preparation of water-impermeable paper, paperboard, board, composite products, or biocomposite products, which typically require the use of an adhesive in combination with another material for formation. Therefore, water-impermeable fiber-based products can be formed in the absence of an adhesive typically required in their formation. For example, using the sol with pulp, air-laid pulp or dry pulp according to the invention can allow the formation of waterproof paperboard or paper without additional adhesives.

[0033] The sol used according to the present invention can be applied to a product by: spraying the sol onto the product, immersing the product in the sol, wetting the product in the sol, rolling the sol onto the product, brushing the sol onto the product, wiping the sol onto the product, impregnating the product with the sol by padding, discharging the sol onto the product, flowing the sol onto the product, using slot coating technology, mixing the sol or powder obtained from the sol into a fiber mixture, or any combination thereof. When the sol is applied to the surface of a fiber-based product, the sol can be applied to the entire surface of the fiber-based product or only a portion of the surface of the fiber-based product.

[0034] The sol of the present invention can be applied to a product, such as a fiber-based product, to form a base coating on which other coatings can be applied. Alternatively, the sol can be applied to a product to form a coating on an existing coating. For example, the sol can be applied to a fiber-based product to form a top coating on an existing base coating. The coating or top coating formed by applying the sol can be optically transparent and / or impermeable and / or hydrophobic and / or oleophobic and / or stain-resistant and / or antireflective.

[0035] In some other embodiments, the sol can be used to coat electronic circuits such as printed circuit boards (PCBs) to form an impermeable barrier against water or other fluids that could damage the PCB. The sol can also impart other benefits to the PCB, such as protection against harmful chemicals, abrasion resistance, or improved properties such as dielectric properties. The sol can be applied to the PCB using the methods described herein. In another embodiment, the sol can be used to coat metal surfaces to protect them from corrosion or to prevent light from reflecting off the coated metal surface.

[0036] Example

[0037] The invention can be further understood by considering the following examples. All chemicals were used as is, without further purification.

[0038] Examples 1 to 18 provide various methods by which sols can be formed.

[0039] Example 1: Formation of Sol

[0040] Tetraethoxysilane (100%, 5.5 ml) was added dropwise to a mixture of ethanol (7 ml) and HCl aqueous solution (0.1 M, 1.7 ml). The solution was stirred for about 40 hours until a sol was formed.

[0041] Example 2: Formation of Sol

[0042] Titanium ethoxide (IV) (100%, 5.5 ml) was added dropwise to a mixture of ethanol (7 ml) and HCl aqueous solution (0.1 M, 1.7 ml). The solution was stirred for about 2 hours until a sol was formed.

[0043] Example 3: Formation of Sol

[0044] Add 100% methyltriethoxysilane (7.5 ml) dropwise to a mixture of ethanol (15 ml) and 0.1 M HCl aqueous solution (2 ml). Stir the solution for about 1 hour until a sol is formed.

[0045] Example 4: Formation of Sol

[0046] Add titanium isopropoxide (9 g) to a mixture of ethanol (6.5 ml) and HCl aqueous solution (0.1 M, 1.8 ml). Stir the mixture for about 30 hours until a sol is formed.

[0047] Example 5: Formation of Sol

[0048] Add zirconium isopropoxide (8.5 g) to a mixture of ethanol (6.3 ml) and HCl aqueous solution (0.1 M, 1.6 ml). Stir the mixture for about 1 hour until a sol is formed.

[0049] Example 6: Formation of Sol

[0050] Add 100% methyltriethoxysilane (5.8 ml) dropwise to a mixture of ethanol (6.2 ml) and NaOH aqueous solution (0.1 M, 1.5 ml). Stir the solution for about 30 hours until a sol is formed.

[0051] Example 7: Formation of Sol

[0052] Add aluminum isopropoxide (9.2 g) to a mixture of ethanol (6.5 ml) and HCl aqueous solution (0.1 M, 1.6 ml). Stir the mixture for about 1 hour until a sol is formed.

[0053] Example 8: Formation of Sol

[0054] A mixture (5 ml) of silanolate precursors consisting of 50% tetraethoxysilane and 50% methyltriethoxysilane was added dropwise to a mixture of ethanol (10 ml) and NaOH aqueous solution (0.1 M, 2 ml). The solution was stirred for about 30 hours until a sol was formed.

[0055] Example 9: Formation of Sol

[0056] Solution A – Titanium ethoxide (IV) (5 ml) is added dropwise to ethanol (10 ml). Solution B – 5 ml of solution A is added to a mixture of 50% tetraethoxysilane and 50% phenyltriethoxysilane silane precursors (5.2 ml). The mixture is then added dropwise to a mixture of ethanol (8.2 ml) and HCl aqueous solution (0.1 M, 1.8 ml). The solution is stirred at room temperature for approximately 1 hour until a sol is formed.

[0057] Example 10: Formation of Sol

[0058] A mixture of 50% tetraethoxysilane and 50% phenyltriethoxysilane siloxane precursors (5.2 ml) was added dropwise to a mixture of ethanol (10 ml) and HCl aqueous solution (0.1 M, 2 ml). The solution was stirred at room temperature for about 6 hours until a sol was formed.

[0059] Example 11: Formation of Sol

[0060] Cationic starch (CS; 7 mg) was dispersed in a mixture of ethanol (10 ml) and HCl aqueous solution (0.1 M, 1.6 ml) to produce a solution with a pH of 2. A silanolate precursor consisting of 100% tetraethoxysilane (5.2 ml) was added dropwise to this stirred solution, and stirring was continued for another 8 hours.

[0061] Example 12: Formation of Sol

[0062] Cationic starch (CS; 7 mg) was dispersed in a mixture of ethanol (10 ml) and HCl aqueous solution (0.1 M, 1.6 ml) to produce a solution with a pH of 2. A silanolate precursor consisting of 100% methyltriethoxysilane (5.2 ml) was added dropwise to this stirred solution, and stirring was continued for another 2 hours.

[0063] Example 13: Formation of Sol

[0064] Chitosan (6 mg) was dispersed in a mixture of ethanol (12 ml) and HCl aqueous solution (0.1 M, 2 ml) to produce a solution with a pH of 2. A mixture of 6 ml of silanolate precursors consisting of 50% tetraethoxysilane and 50% phenyltriethoxysilane was added dropwise to this stirred solution, and stirring was continued for another 1.5 hours.

[0065] Example 14: Formation of Sol

[0066] Wheat flour (7 mg) was dispersed in a mixture of ethanol (8 ml) and NaOH aqueous solution (0.1 M, 2 ml) to produce a solution with a pH of 13. A mixture of 5.2 ml of silanolate precursors consisting of 50% tetraethoxysilane and 50% methyltriethoxysilane was added dropwise to this stirred solution, and stirring was continued for another 30 minutes.

[0067] Example 15: Formation of Sol

[0068] Cationic starch (CS; 5 mg) was dispersed in a mixture of ethanol (10 ml) and NaOH aqueous solution (0.1 M, 1.5 ml) to produce a solution with a pH of 13. Methyltriethoxysilane (5.2 ml) was added dropwise to this stirred solution, and stirring was continued for another 20 minutes.

[0069] Example 16: Formation of Sol

[0070] Wheat flour (5 mg) was dispersed in a mixture of ethanol (6 ml), NaOH aqueous solution (0.1 M, 1 ml), and methyltriethoxysilane (1 ml) to produce a solution with a pH of 13. A mixture of silanolates (1 ml) consisting of 50% tetraethoxysilane and 50% phenyltriethoxysilane was added dropwise to this stirred solution, and stirring was continued for another 30 minutes.

[0071] Example 17: Formation of Sol

[0072] Cationic starch (CS; 5 mg) was dispersed in a mixture of ethanol (7.6 ml) and HCl aqueous solution (0.1 M, 1.6 ml) to produce a solution with a pH of 2. A mixture of 50% tetraethoxysilane and 50% phenyltriethoxysilane silanol precursors (5.2 ml) was added dropwise to this stirred solution, and stirring was continued for another hour.

[0073] Example 18: Formation of Sol

[0074] Wheat flour (5 mg) was dispersed in a mixture of ethanol (6 ml), NaOH aqueous solution (0.1 M, 1 ml), and methyltriethoxysilane (1 ml) to produce a solution with a pH of 13. Triethoxysilane (1 ml) was added dropwise to this stirred solution, and stirring was continued for another hour.

[0075] Example 19: Formation of Sol

[0076] Wheat flour (5 mg) was dispersed in a mixture of ethanol (6 ml), NaOH aqueous solution (0.1 M, 1 ml), and methyltriethoxysilane (1 ml) to produce a solution with a pH of 13. A mixture of silanols consisting of 50% tetraethoxysilane and 50% phenyltriethoxysilane (1 ml) was added dropwise to this stirred solution, and stirring was continued for another hour.

[0077] Examples 20 and 21 demonstrate methods for forming powders from sols.

[0078] Example 20: Powder Formation

[0079] Cationic starch (CS; 5 mg) was dispersed in a mixture of ethanol (7.2 ml) and NaOH aqueous solution (0.1 M, 1.6 ml) to produce a solution with a pH of 13. A mixture of 50% tetraethoxysilane and 50% methyltriethoxysilane silanol precursors (5.2 ml) was added dropwise to this stirred solution, and stirring was continued for another hour. The solution was then centrifuged for 5 minutes and dried at room temperature to obtain a white powder.

[0080] Example 21: Powder Formation

[0081] Cationic starch (CS; 5 mg) was dispersed in a mixture of ethanol (7.2 ml) and NaOH aqueous solution (0.1 M, 1.6 ml) to produce a solution with a pH of 13. Methyltriethoxysilane (5.2 ml) was added dropwise to this stirred solution, and stirring was continued for another hour. The solution was then centrifuged for 5 minutes and dried at room temperature to obtain a white powder.

[0082] Examples 22 to 43 provide examples of how to apply sol to various products or to impart one or more functional properties to various materials.

[0083] Example 22: Coated Particleboard

[0084] The particleboard was coated with the sol prepared in Example 17 by manually immersing it in the sol for 2 minutes and then drying it at 40°C for 1 hour. The coated sample was left at room temperature for three weeks. Then, during winter, the coated sample was left outdoors with an uncoated particleboard for one month. Before visually comparing the two samples, both samples were moved indoors and dried at room temperature for 3 weeks. Due to its absorbency, the uncoated particleboard swelled to a larger size than the coated one, which also led to increased porosity. Fungi also developed on the uncoated particleboard but not on the coated particleboard.

[0085] Example 23: Coated Paper

[0086] The sol was sprayed onto paper and dried at 40°C for 30 minutes, thus coating an A4 sheet of paper with the sol prepared in Example 17. The coated paper was stored at room temperature for 3 weeks, and then its water impermeability was tested with hot water (recently boiled, estimated temperature 90°C) and cold water (estimated temperature 20°C). The coated paper was impermeable to both hot and cold water, and no water passed through the coated paper.

[0087] Example 24: Coated Aluminum

[0088] Prior to coating with the sol prepared in Example 17, a piece of aluminum was coated with a primer. Antimicrobial activity against Staphylococcus aureus and Escherichia coli was tested on the coated aluminum and an uncoated reference aluminum strip according to ISO 22196:2011. The antimicrobial tests were performed by Eurofins. The tests were conducted in a commercial laboratory. The results showed that when comparing experimental data from coated and uncoated aluminum samples, the logarithm of E. coli decreased by 1.31, and the logarithm of Staphylococcus aureus decreased by 1.12.

[0089] Example 25: Coated Cup

[0090] A permeable paper cup was coated with the sol prepared in Example 15. Dairy ice cream was placed in the coated container and allowed to partially melt at room temperature. The exterior of the coated container was inspected for signs of permeation or leakage, but no signs were observed. The coated container and ice cream were then placed in a freezer at approximately -18°C for 3 days, subsequently removed and left at room temperature overnight to allow the ice cream to melt. The exterior of the coated container was again inspected for signs of permeation or leakage, but no signs were observed. The coated paper cup and ice cream were returned to the freezer and removed again as described. Once complete, the ice cream was discarded and the coated paper cup was inspected for signs of liquid seeping into the paper base. No liquid seepage into the paper was observed.

[0091] Example 26: Coated Bowl

[0092] A bowl formed from pulp fibers was coated with the sol prepared in Example 12. Instant noodles were placed in the coated bowl, and 300 ml of boiling water (estimated temperature 90°C) was added. The noodles and water were stirred, and the bowl was microwaved in an 850W microwave oven for 2 minutes. The bowl and contents were removed from the microwave, and the contents were stirred again. After the bowl and contents had cooled to room temperature, the bowl was examined for signs of liquid seeping into the pulp fibers. No seepage or leakage was observed.

[0093] Example 27: Coated Bowl

[0094] A bowl formed from pulp fibers was coated with the sol prepared in Example 12. The coated bowl was placed in an oven at 220°C for 30 minutes, then removed and cooled to room temperature. 2.5g of instant coffee mixture was added to the bowl, followed by 250ml of boiling water (estimated temperature 90°C). The coffee was allowed to stand in the bowl for 30 minutes, after which it was discarded, and the bowl was examined for signs of coffee seeping into the pulp or other leakage. No seepage or leakage was detected.

[0095] 2.5g of instant coffee and 250ml of boiling water (estimated temperature 90℃) were placed in a disposable coffee cup and left to stand for 30 minutes. The coffee was then discarded, and the degree of contamination was assessed separately for the inside of the disposable coffee cup and the coated pulp bowl. Compared to the disposable coffee cup, the coated pulp bowl showed approximately a 50% reduction in contamination severity.

[0096] Example 28: Adhesive

[0097] The sol prepared in Example 17 was then added to and mixed with 5% by weight of polyvinyl acetate adhesive as an additive. The tack and adhesive strength of the resulting adhesive were measured relative to the adhesive without the sol. The adhesive containing the sol additive exhibited enhanced adhesive strength compared to the adhesive without the sol.

[0098] Further evaluation of the above adhesives was conducted to determine their solubility in water. The adhesives without sol dissolved in water, while the adhesives with sol additives did not dissolve in water after immersion for 30 minutes.

[0099] Example 29: Coated Bronze

[0100] A piece of phosphor bronze was manually immersed in the sol prepared in Example 18 for 1 minute and allowed to dry at room temperature for 5 minutes, then dried at 60°C for 20 minutes, thereby coating the phosphor bronze. A functional coating was then applied to the sol coating and dried at 60°C. The coated sample was then allowed to stand for three weeks. The coated bronze block was then heated to 200°C and held for 1 hour. After the bronze block cooled, it was bent to check for cracks in the coating as shown in Figure 3, and the cracks were visually inspected by dripping water onto the coated and uncoated areas of the bronze block. Figure 3B and 3C The formed droplets are used to test hydrophobicity. Figure 3B The water droplets on the uncoated area of ​​the bronze shown have a low contact angle, indicating good wettability / poor hydrophobicity, while Figure 3C The water droplets on the bronze-coated area shown have a high contact angle, indicating incomplete wetting / good hydrophobicity.

[0101] Another phosphor bronze block was coated with only the functional coating and dried at 60°C. This other bronze block was then heated to 200°C for 1 hour. After cooling, it was bent to check for cracking of the coating. The coating on the other bronze block (without the sol prepared in Example 18) showed cracking across the entire surface.

[0102] Example 30: Coated Paper

[0103] The sol was sprayed onto paper and dried at 40°C for 30 minutes, thus coating an A4 sheet of paper with the sol prepared in Example 18. The coated paper was stored at room temperature for one week, and then its water impermeability was tested with hot water (recently boiled, estimated temperature 90°C) and cold water (estimated temperature 20°C). The coated paper was impermeable to both hot and cold water, and no water passed through the coated paper.

[0104] Example 31: Coated Aluminum

[0105] A flat piece of aluminum was coated with the sol prepared in Example 18. The sol-coated aluminum was dried at room temperature for 5 minutes, then at 60°C for 20 minutes. A functional coating was then applied to both the sol-coated aluminum and an uncoated aluminum reference sample, and both samples were allowed to settle at room temperature for three weeks. The aluminum samples were bent and the coating was examined for cracking or damage. Neither sample showed any visible defects. Both samples were then heated in an oven to 250°C for 30 minutes. After removal from the oven, both samples were bent again and the coating cracking was evaluated again. No cracking or damage was observed on the sample containing the sol coating. Cracking and functional loss were observed on the reference coating without the sol coating, covering essentially the entire surface.

[0106] Example 32: Coated Cup

[0107] A permeable paper cup was coated with the sol from Example 14. Dairy ice cream was placed in the coated container and allowed to partially melt at room temperature. The exterior of the coated container was inspected for signs of permeation or leakage, but none were observed. The coated container and ice cream were then placed in a freezer at approximately -18°C for 3 days, subsequently removed and left at room temperature overnight to allow the ice cream to melt. The exterior of the coated container was again inspected for signs of permeation or leakage, but none were observed. The coated paper cup and ice cream were returned to the freezer and removed again as described. Once complete, the ice cream was discarded and the coated paper cup was inspected for signs of liquid seeping into the paper base. No liquid seepage into the paper was observed.

[0108] Example 33: Coated pulp fibers

[0109] Two basins made of permeable coarse pulp fibers were coated with the sol of Example 16. 300 ml of boiling water (estimated temperature 90°C) was added to the first basin, followed by 300 ml of cold water (estimated temperature 7°C) to the second basin. The water was allowed to stand in the coated basins for 2 hours. The basins and water were examined for signs of liquid penetration into the pulp fibers. No penetration or leakage was observed.

[0110] Example 34: Coated fabric

[0111] Household fabric blackout curtains were coated with the sol-gel method of Example 19. A cup of hot coffee (estimated temperature 75°C) was poured onto the coated blackout curtain and left to stand for 5 minutes. Some coffee flowed across the surface of the blackout curtain and out. Small drops of coffee remaining on the surface of the blackout curtain were visually observed in the pits within the curtain's surface. The surface of the blackout curtain was then washed with water to remove all remaining coffee. The surface of the blackout curtain was examined for signs of staining or contamination. No staining or contamination of the blackout curtain material occurred. Furthermore, no flow of coffee or water through the blackout curtain material was observed during the experiment.

[0112] The experiment was repeated using the same but uncoated fabric blackout curtain. The blackout curtain absorbed some of the coffee, and coffee was observed flowing through the uncoated curtain. After washing with water, significant staining of the fabric was observed when the coffee residue on the surface of the blackout curtain was removed.

[0113] Example 35: Coated Cup

[0114] The sol from Example 10 was brushed onto the inner surface of a cardboard cup. The mixture was then allowed to dry on the surface of the cardboard cup.

[0115] Add 25 ml of water to each of the coated cardboard cup and the uncoated control cardboard cup. Observe the water immediately soak through the uncoated cardboard cup and leak into the surrounding area. If the 25 ml of water in the coated cardboard cup is retained and no leakage is observed for more than 1 hour, then stop observing.

[0116] Example 36: Coated flowerpot

[0117] Dilute the sol from Example 12 with 75 ml of water. Then, within 10 minutes of dilution with water, spray the mixture onto the exposed surface of the permeable pulp flowerpot. Allow the mixture to dry on the flowerpot surface.

[0118] Add 50 ml of dairy ice cream to each of the coated flowerpot and the uncoated control pot, and allow it to melt over 2 hours. Liquid seepage was observed through the uncoated pot after approximately 30 minutes, becoming increasingly noticeable over the next hour. No seepage or leakage was observed in the coated pot during this period, at which point observation was stopped.

[0119] Example 37: Coated wood

[0120] The sol from Example 13 was rolled onto the exposed surface of the wooden floor tiles. The mixture was then allowed to dry on the surface of the wooden floor tiles.

[0121] Nine drops of water, each approximately 0.75 ml, were placed in a 3x3 square grid on the surface of the coated wooden tile. The process was repeated on the same uncoated wooden tile. Over the next 5 to 10 minutes, the water droplets from the uncoated wooden tile were visibly absorbed into the surface, leaving wet, circular stains. The water droplets placed on the coated wooden tile remained on the surface for 5 hours, at which point observation was stopped.

[0122] Example 38: Coated wood

[0123] The coated wooden floor tile from the previous embodiment was cut in half to create two tiles half the thickness of the original tile. The surface of each half-thick tile, previously located inside the thicker original tile, was subjected to the water droplet experiment described in Example 37. Water droplets were left on the surface of each half-thick tile for 5 hours, at which point observation was stopped.

[0124] Example 39: Coated Painted Wood

[0125] The experiment of Example 37 was repeated using the sol from Example 4 and pre-coated wooden floor tiles. Water droplets placed on uncoated painted wooden floor tiles were observed to be slowly absorbed into the tile surface within 15-30 minutes. Water droplets placed on the surface of coated wooden floor tiles remained on the coated painted wooden floor tile surface for 5 hours, at which point observation was stopped.

[0126] Example 40: Coated Paper

[0127] The sol was brushed onto a sheet of paper and dried at 60°C for 90 minutes, thereby coating four sheets of A4 paper with each of the sols in Examples 1, 2, and 9. The coated paper was stored at room temperature for 4 weeks, and then its water impermeability was tested. The coated paper was water-impermeable; no water permeated through the coated paper.

[0128] Example 41: Coated Electronic Circuit

[0129] The circuit was printed onto a pre-washed fabric and coated with the sol-gel of Example 8. Under standard conditions, the printed circuit on the fabric was washed 15 times in a standard household washing machine. No functional loss was observed in the circuit after 15 washes. The printed fabric was weighed before and after the 15 wash cycles. Negligible weight loss was recorded during the repeated washing process.

[0130] Example 42: Coated Sand

[0131] Sand was coated with the sol from Example 3 and allowed to dry. The dried coated sand was arranged in a ring shape at the bottom of a container, and water was poured into the inside of the ring. After three hours, no damage to the sand ring was observed from the water, at which point the experiment was stopped. A second uncoated sand sample of equal mass was arranged in a ring shape at the bottom of the same container, and water was poured into the inside of the ring. After 5 minutes, damage to the uncoated sand ring was observed from the water.

[0132] Example 43: Sol as an additive

[0133] Dissolve gum arabic in warm water and allow it to cool. Add the sol from Example 1 to the gum arabic solution and mix for 30 seconds, then apply the mixture to uncoated paper. Repeat the experiment using gum arabic without any sol additives. Paper coated with the solution containing the sol additive becomes impermeable and has a clear and transparent coating. Paper not coated with the sol additive has an uneven texture and color coating that remains permeable to water.

[0134] Examples 44 to 67 shown in Table 2 demonstrate the coating performance of sols containing various solvents, biopolymers, and alkoxides on a variety of substrates at different dilution levels. All sols provide a coating that enhances the hydrophobicity, impermeability, and / or strength of the material. Coatings marked "Best" indicate better quality than those marked "Better," and coatings marked "Better" in turn indicate better quality than those marked "Good."

[0135] Table 2: Matrix of other sol examples

[0136]

[0137]

[0138] Table 3 shows Examples 68 to 93, demonstrating the coating performance of sols containing various flours and different catalysts at different dilution levels on various substrates. All sols provide a coating that enhances the hydrophobicity, impermeability, and / or strength of the material. Coatings marked "Best" indicate better quality than those marked "Better," and coatings marked "Better" in turn indicate better quality than those marked "Good." The sols of Examples 68 to 93 were formed using ethanol as a solvent and tetraethyl orthosilane and / or methyltriethoxysilane as alkoxides.

[0139] Table 3: Matrix of flour sol examples

[0140]

[0141]

[0142] The following aspects also form part of the disclosure of this invention:

[0143] Aspect 1: Sol containing solvents, alkoxides and catalysts is used for the preparation of waterproof products.

[0144] Aspect 2: The use of the sol according to aspect 1, wherein the sol forms a coating on one or more surfaces of the product.

[0145] Aspect 3: The use of the sol according to aspect 1 or 2, wherein the sol fills or partially fills one or more pore volumes or void volumes of the product.

[0146] Aspect 4: The use of the sol according to aspects 1, 2 or 3, wherein the sol acts as a binder to promote the cohesion of the product.

[0147] Aspect 5: Use of the sol according to any one of the preceding aspects, wherein the product is a fiber-based product.

[0148] Aspect 6: Use of the sol according to any one of the preceding aspects, wherein the alkoxide is selected from silanolates, metal alkoxides, phosphoalkoxides, organically modified alkoxides, and any combination thereof.

[0149] Aspect 7: Use of the sol according to any one of the preceding aspects, wherein the alkoxide is selected from n-propyltriethoxysilane, tetrapropyl orthosilicate, titanium tert-butoxide (IV), titanium isopropoxide (IV), triethoxysilane, methyltriethoxysilane, triethoxy(octyl)silane, phenyl-triethoxysilane, titanium ethoxide (IV), triethoxy-methylcyclopentane, (3-glycidoxypropyl)trimethoxysilane, cyclopentyltriethoxysilane, 3-amino-propyltriethoxysilane, triethoxy-3-(2-imidazolin-1-yl)propylsilane, and any combination thereof.

[0150] Aspect 8: Use of the sol according to any one of the preceding aspects, wherein the catalyst is at least one of an acid and / or a base.

[0151] Aspect 9: The use of the sol according to aspect 8, wherein the catalyst is selected from hydrochloric acid, citric acid, nitric acid, acetic acid, sodium hydroxide, potassium hydroxide, ammonia, and any combination thereof.

[0152] Aspect 10: Use of the sol according to any one of the preceding aspects, wherein the solvent comprises water, one or more alcohols, and any combination thereof.

[0153] Aspect 11: Use of the sol according to aspect 10, wherein the solvent comprises methanol, ethanol, isopropanol, butanol, ethylene glycol or any combination thereof.

[0154] Aspect 12: Use of the sol according to any one of the preceding aspects, wherein the sol is substantially composed of a solvent, an alkoxide and a catalyst.

[0155] Aspect 13: Use of the sol according to any one of the preceding aspects, wherein the impermeable product is prepared by applying the sol to the product in the absence of any functional additives.

[0156] Aspect 14: Use of the sol according to any one of Aspects 1 to 11, wherein the sol comprises one or more functional additives.

[0157] Aspect 15: Use of the sol according to aspect 14, wherein the one or more functional additives include photoinitiators, resins, oils, dyes, salts, minerals or other inorganic particles, surfactants, composite particles and / or metal particles.

[0158] Aspect 16: Use of the sol according to any one of the preceding aspects, wherein the sol is added as a component additive to the material of the product and / or to one or more coatings applied to the product.

[0159] Aspect 17: Use of the sol according to any one of the preceding aspects, wherein the product is a fiber-based product, and the impermeable fiber-based product includes pulp, paper, paperboard, board or combinations thereof, including composite fiber-based products and biocomposite fiber-based products.

[0160] Aspect 18: Use of the sol according to any one of Aspects 1 to 16, wherein the product is a plastic or a bioplastic.

[0161] Aspect 19: Use of the sol according to any one of Aspects 1 to 16, wherein the product is an adhesive or coating.

[0162] Aspect 20: Use of the sol according to any one of the preceding aspects, wherein the sol is applied during the formation of the product to prepare a water-impermeable product.

[0163] Aspect 21: Use of the sol according to aspect 20, wherein the product is a fiber-based product, and the sol is applied during the formation of pulp, wet pulp, air-laid pulp, or dry pulp.

[0164] Aspect 22: Use of the sol according to any one of the preceding aspects, wherein the sol is applied after the product is formed to prepare a water-impermeable product.

[0165] Aspect 23: The use of the sol according to aspect 22, wherein the product is a fiber-based product, and the sol is applied to the pulp, wet pulp, air-laid pulp or dry pulp after forming the pulp stock, wet pulp, air-laid pulp or dry pulp.

[0166] Aspect 24: The use of the sol according to aspect 21 or 23, wherein the impermeable paper, paperboard, board, composite fiber-based product or biocomposite fiber-based product is formed from the pulp, air-laid pulp or dry pulp.

[0167] Aspect 25: Use of the sol according to any one of the preceding aspects, wherein the sol is applied to the product by: spraying the sol onto the product, immersing the product in the sol, wetting the product in the sol, rolling the sol onto the product, brushing the sol onto the product, wiping the sol onto the product, impregnating the product with the sol by padding, discharging the sol onto the product, flowing the sol onto the product, using a slot coating technique, using a doctor blade application technique, or any combination thereof.

[0168] Aspect 26: Use of the sol according to any one of the preceding aspects, wherein the sol is applied to the entire surface of the product or only to a portion of the product surface.

[0169] Aspect 27: Use of the sol according to any one of the preceding aspects, wherein the sol is applied to a product to form an undercoat on which other coatings can be applied, or wherein the sol is applied to a product to form a coating over an existing coating.

[0170] Aspect 28: Use of the sol according to aspect 27, wherein the undercoat or topcoat formed by applying the sol according to the invention is optically transparent and / or impermeable and / or hydrophobic and / or oleophobic and / or antistaining and / or antireflective.

[0171] Aspect 29: Use of the sol according to any one of the preceding aspects, wherein the impermeable product is used as primary, secondary or tertiary packaging.

[0172] Aspect 30: Use of the sol according to aspect 29, wherein the packaging is for use in the food and beverage, electronic devices, engineering, electrical appliances, cosmetics, medical devices, pharmaceuticals, fashion, personal care products, household goods, interior or exterior decoration, home furnishings, automotive, aviation, maritime, defense or construction industries.

[0173] Aspect 31: The use of the sol according to aspect 30, wherein the packaging is in the form of a container used in the food and beverage industry.

[0174] Aspect 32: Use of the sol according to any one of aspects 1 to 11 or 14 to 31, wherein the sol further comprises one or more biopolymers.

[0175] Aspect 33: The use of the sol according to aspect 32, wherein the biopolymer is selected from starch, cationic starch, modified starch, flour, wheat flour, barley flour, lentil flour, bamboo flour, corn flour, oat flour, rye flour, buckwheat flour, rice flour, chickpea flour, green pea flour, chitin, cellulose, hemicellulose, or any combination thereof.

[0176] Aspect 34: A waterproof fiber-based product prepared using a sol according to any one of aspects 1 to 33.

[0177] Aspect 35: A sol comprising a solvent, an alkoxide, a biopolymer, and a catalyst.

[0178] Aspect 36: The sol according to aspect 35, wherein the biopolymer comprises starch.

[0179] Aspect 37: The sol according to aspect 36, wherein the starch comprises cationic starch.

[0180] Aspect 38: The sol according to aspect 37, wherein the cationic starch is selected from quaternary ammonium cationic starch, tertiary ammonium cationic starch, and any combination thereof.

[0181] Aspect 39: The sol according to aspect 35, wherein the biopolymer comprises flour.

[0182] Aspect 40: The sol according to aspect 39, wherein the flour comprises 5 to 85% starch, 0 to 30% hemicellulose, 0 to 50% cellulose, 0 to 25% lignin, 0 to 35% protein and 0 to 25% ash.

[0183] Aspect 41: The sol according to aspect 39 or 40, wherein the flour comprises 45 to 85% starch, 0 to 15% hemicellulose, 0 to 10% cellulose, 0 to 7% lignin, 10 to 15% protein and 0 to 5% ash.

[0184] Aspect 42: The sol according to any one of Aspects 38 to 40, wherein the flour is selected from wheat flour, barley flour, lentil flour, bamboo flour, corn flour, oat flour, rye flour, buckwheat flour, rice flour, chickpea flour, green pea flour, or any combination thereof.

[0185] Aspect 43: The sol according to any one of aspects 35 to 42, wherein the catalyst is at least one of an acid and a base.

[0186] Aspect 44: The sol according to aspect 43, wherein the catalyst is selected from hydrochloric acid, citric acid, nitric acid, acetic acid, sodium hydroxide, potassium hydroxide, ammonia, and any combination thereof.

[0187] Aspect 45: The sol according to any one of aspects 35 to 44, wherein the alkoxide is selected from silicon alkoxides, metal alkoxides, phosphoalkoxides, and any combination thereof.

[0188] Aspect 46: The sol according to any one of Aspects 35 to 45, wherein the alkoxide is selected from n-propyltriethoxysilane, tetrapropyl orthosilicate, titanium tert-butoxide (IV), titanium isopropoxide (IV), triethoxysilane, methyltriethoxysilane, triethoxy(octyl)silane, phenyl-triethoxysilane, titanium ethoxide (IV), triethoxy-methoxycyclopentane, (3-glycidoxypropyl)trimethoxysilane, cyclopentyltriethoxysilane, 3-amino-propyltriethoxysilane, triethoxy-3-(2-imidazolin-1-yl)propylsilane, and any combination thereof.

[0189] Aspect 47: A sol according to any one of aspects 35 to 46, wherein the solvent comprises water, one or more alcohols, and any combination thereof.

[0190] Aspect 48: The sol according to aspect 47, wherein the solvent comprises methanol, ethanol, isopropanol, butanol, ethylene glycol or any combination thereof.

[0191] Aspect 49: The sol according to any one of aspects 35 to 48, wherein the sol comprises one or more functional additives.

[0192] Aspect 50: The sol according to aspect 49, wherein the one or more functional additives include photoinitiators, resins, oils, dyes, salts, mineral or other inorganic particles, surfactants, composite particles and / or metal particles.

[0193] Aspect 51: A method for preparing a sol according to any one of aspects 35 to 50, the method comprising:

[0194] a) Disperse the biopolymer in a solution containing the catalyst, then add an alkoxide; or

[0195] b) Disperse the alkoxide in a solvent, add a catalyst, and then add the biopolymer; or

[0196] c) Disperse the alkoxide in a solution containing the catalyst, and then add the biopolymer.

[0197] Aspect 52: The method according to aspect 51, wherein the catalyst is at least one of an acid or a base.

[0198] Aspect 53: The method according to aspect 51 or 52, wherein the method further comprises adding one or more functional additives and / or one or more substrates.

[0199] Aspect 54: The method according to aspect 53, wherein the one or more functional additives and / or one or more substrates are added prior to the formation of the sol.

[0200] Aspect 55: The method according to aspect 53, wherein one or more functional additives and / or one or more substrates are added during the formation of the sol.

[0201] Aspect 56: The method according to aspect 53, wherein the one or more functional additives and / or one or more substrates are added after the sol is formed.

[0202] Aspect 57: The method according to any one of aspects 51 to 56 further comprises centrifuging the sol and / or drying the sol to form a solid.

[0203] Aspect 58: The method according to aspect 57 further includes grinding the solid to a desired particle size.

[0204] Aspect 59: A coated product, wherein the product has been coated with a sol according to any one of aspects 35 to 50.

[0205] Aspect 60: The coated product according to aspect 59, wherein the coating is impermeable and / or optically transparent and / or airtight and / or antimicrobial and / or hydrophobic and / or oleophobic and / or antifouling and / or anticontamination and / or adhesion-promoting and / or antireflective.

[0206] Aspect 61: Coated products according to aspect 59 or 60, wherein said products include wood, textiles, leather, metals (including alloys), concrete, cardboard, paper, plastics, bioplastics, glass, ceramics, sand, electronic circuits, bricks, marble, soil, painted surfaces, and combinations thereof, wherein the combinations thereof include composite products and biocomposite products.

[0207] Aspect 62: A coated product according to any one of Aspects 59 to 61, wherein the product is in the form of molecules, particles, fibers, molded products, sheets, and combinations thereof.

[0208] Aspect 63: A powder derived from a sol according to any one of aspects 35 to 50.

[0209] Aspect 64: The powder according to aspect 63 further comprises one or more functional additives.

[0210] Aspect 65: The powder according to aspect 64, wherein the functional additive includes photoinitiators, resins, oils, dyes, salts, minerals or other inorganic particles, surfactants, composite particles and / or metal particles.

[0211] Aspect 66: Use of the powder according to any one of aspects 63 to 65 as a component additive in the formation of one or more products or in a coating of one or more products.

[0212] Although specific embodiments have been illustrated and described herein, various alternatives and / or equivalent implementations may be used instead of the specific embodiments shown and described without departing from the scope of this disclosure. This application is intended to cover any modifications or variations of the specific embodiments discussed herein. Therefore, this disclosure is intended to be limited only by the claims and their equivalents.

Claims

1. A sol formed from a solvent, an alkoxide, a biopolymer, and a catalyst, wherein... The solvent includes one or more alcohols, water, or any combination thereof; The alkoxides include Ti(isopropoxy)4, Al(isopropoxy)3, Al(sec-butoxy)3, Zr(n-butoxy)4, Zr(n-propoxy)4, n-propyltriethoxysilane, tetrapropyl orthosilicate, titanium tert-butoxide (IV), titanium isopropoxide (IV), triethoxysilane, methyltriethoxysilane, tetraethoxysilane, triethoxy(octyl)silane, phenyl-triethoxysilane, titanium ethoxide (iv), triethoxy-methylcyclopentane, (3-glycidoxypropyl)trimethoxysilane, cyclopentyltriethoxysilane, 3-amino-propyltriethoxysilane, triethoxy-3-(2-imidazolin-1-yl)propylsilane, and any combination thereof; The biopolymers include starch-based polymers, hemicellulose-based polymers, cellulose-based polymers, lignin-based polymers, and chitosan-based polymers; and The catalyst is at least one of an acid and / or a base.

2. The sol according to claim 1, wherein the biopolymer comprises starch.

3. The sol according to claim 2, wherein the starch comprises cationic starch.

4. The sol according to claim 3, wherein the cationic starch is selected from quaternary ammonium cationic starch, tertiary ammonium cationic starch, and any combination thereof.

5. The sol according to claim 1, wherein the biopolymer comprises flour.

6. The sol of claim 5, wherein the flour comprises 5 to 85% starch, 0 to 30% hemicellulose, 0 to 50% cellulose, 0 to 25% lignin, 0 to 35% protein and 0 to 25% ash.

7. The sol according to claim 6, wherein the flour comprises 45 to 85% starch, 0 to 15% hemicellulose, 0 to 10% cellulose, 0 to 7% lignin, 10 to 15% protein and 0 to 5% ash.

8. The sol according to any one of claims 5 to 7, wherein the flour is selected from wheat flour, barley flour, lentil flour, bamboo flour, corn flour, oat flour, rye flour, buckwheat flour, rice flour, chickpea flour, green pea flour, or any combination thereof.

9. The sol according to any one of claims 1 to 7, wherein the catalyst is selected from hydrochloric acid, citric acid, nitric acid, acetic acid, sodium hydroxide, potassium hydroxide, ammonia, and any combination thereof.

10. The sol according to any one of claims 1 to 7, wherein the solvent comprises methanol, ethanol, isopropanol, butanol, ethylene glycol, water, or any combination thereof.

11. The sol according to any one of claims 1 to 7, wherein the sol comprises one or more functional additives.

12. The sol according to claim 11, wherein the one or more functional additives include photoinitiators, resins, oils, dyes, salts, minerals or other inorganic particles, surfactants, composite particles and / or metal particles.

13. The sol according to any one of claims 1 to 7, wherein the sol is substantially composed of a solvent, an alkoxide, a biopolymer, and a catalyst.

14. Use of the sol according to any one of claims 1 to 13 in the preparation of waterproof products.

15. Use of the sol according to claim 14, wherein the sol forms a coating on one or more surfaces of the waterproof product.

16. Use of the sol according to claim 14, wherein the sol fills or partially fills one or more pore volumes or void volumes of the impermeable product.

17. Use of the sol according to claim 14, wherein the sol acts as a binder to promote cohesion in the waterproof product.

18. Use of the sol according to any one of claims 14 to 17, wherein the impermeable product is a fiber-based product.

19. Use of the sol according to any one of claims 14 to 17, wherein the sol is added as a component additive to the material of the impermeable product and / or to one or more coatings applied to the impermeable product.

20. Use of the sol according to any one of claims 14 to 17, wherein the impermeable product is a fiber-based product, and the impermeable fiber-based product comprises pulp, paper, paperboard, board, or combinations thereof, including composite fiber-based products and biocomposite fiber-based products.

21. Use of the sol according to any one of claims 14 to 17, wherein the product is a plastic or a bioplastic.

22. Use of the sol according to any one of claims 14 to 17, wherein the product is an adhesive or coating.

23. Use of the sol according to any one of claims 14 to 17, wherein the sol is applied during the formation of the product to prepare the waterproof product.

24. Use of the sol according to claim 23, wherein the product is a fiber-based product, and the sol is applied during the formation of pulp stock, wet pulp, air-laid pulp, or dry pulp.

25. Use of the sol according to any one of claims 14 to 17, wherein the sol is applied after the product is formed to prepare the waterproof product.

26. Use of the sol according to claim 25, wherein the product is a fiber-based product, and the sol is applied to the pulp, wet pulp, air-laid pulp, or dry pulp after the pulp stock, wet pulp, air-laid pulp, or dry pulp has been formed.

27. Use of the sol according to claim 24 or 26, wherein the impermeable paper, paperboard, board, composite fiber-based product or biocomposite fiber-based product is formed from said pulp, air-laid pulp or dry pulp.

28. Use of the sol according to any one of claims 14 to 17, wherein the sol is applied to the product by: spraying the sol onto the product, immersing the product in the sol, wetting the product in the sol, rolling the sol onto the product, brushing the sol onto the product, wiping the sol onto the product, impregnating the product with the sol by padding, discharging the sol onto the product, flowing the sol onto the product, using a slot coating technique, using a doctor blade application technique, or any combination thereof.

29. Use of the sol according to any one of claims 14 to 17, wherein the sol is applied to the entire surface of the product or only to a portion of the surface of the product.

30. Use of the sol according to any one of claims 14 to 17, wherein the sol is applied to the product to form an undercoat on which other coatings can be applied, or wherein the sol is applied to the product to form a coating over an existing coating.

31. Use of the sol according to claim 30, wherein the undercoat or topcoat formed by applying the sol is optically transparent and / or impermeable and / or hydrophobic and / or oleophobic and / or antistaining and / or antireflective.

32. Use of the sol according to any one of claims 14 to 17, wherein the waterproof product is used as primary, secondary or tertiary packaging.

33. Use of the sol according to claim 32, wherein the packaging is for use in the food and beverage, electronic devices, engineering, electrical appliances, cosmetics, medical devices, pharmaceuticals, fashion, personal care products, household goods, interior or exterior decoration, home furnishings, automotive, aviation, maritime, defense or construction industries.

34. Use of the sol according to claim 33, wherein the packaging is a container form used in the food and beverage industry.

35. A waterproof fiber-based product prepared by using a sol according to any one of claims 1 to 13.

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