Super-hydrophobic coating

Abstract

A composition is provided that includes an emulsion containing a plurality of particles. An article is provided that includes a substrate and a plurality of particles having a hollow core and a shell, wherein the plurality of particles are in the form of a coating layer on the substrate. Further, a method for coating a substrate is provided.

Description

Technical Field

[0001] Cross - reference to related applications This application claims the benefit of priority based on U.S. Provisional Patent Application No. 63 / 352,055, filed on June 14, 2022. The above - mentioned content is hereby incorporated by reference into this specification as if fully set forth herein in its entirety.

[0002] The present invention belongs to the fields of pickering emulsions and their uses such as superhydrophobic coatings.

Background Art

[0003] According to the latest United Nations estimates compiled by Worldometer, the current world population is 7.9 billion as of November 2021. This value is expected to reach 9 billion by 2037. In Europe, a total of 5,146 cases of food - borne and water - borne diseases, including 48,365 illnesses and 40 deaths, were reported to the European Food Safety Authority (EFSA) in 2018. From these facts, humanity will face serious food insecurity and an increase in the number of diseases related to food poisoning in the coming decades. To solve this ongoing problem, it is necessary to prevent food contamination by pathogens. Such measures contribute to maintaining the productivity of the food industry and people who are constantly facing the disposal of products made unusable by the activities of microorganisms and the formation of biofilms.

[0004] Pickering emulsions are generally known as any type of emulsion, such as oil - in - water or water - in - oil, stabilized by solid particles instead of surfactants. Pickering emulsions are usually stabilized by nanoparticles (NPs), which self - organize at the oil - water interface and act as a physical barrier.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Currently, pickering emulsions are mainly based on aromatic solvents such as toluene and xylene as the oil phase. However, aromatic solvents are known to be highly toxic and thus have limitations in practical use in large-scale industrial processes. Therefore, there is an unaddressed need to develop new anti-biofilm coatings based on low-toxic organic solvents suitable for industrial applications.

Means for Solving the Problems

[0006] In one aspect, there is a composition comprising core-shell particles dispersed in a hydrophobic solvent, wherein the core of the core-shell particles contains an aqueous solution, the shell of the core-shell particles contains hydrophobic metal oxide nanoparticles and polymer particles, the w / w ratio of the hydrophobic solvent to the aqueous solution in the composition is from 6:4 to 10:1, the w / w concentration of the hydrophobic metal oxide nanoparticles in the composition is from 0.5% to 5%, the average cross-section of the core-shell particles is from 1 μm to 100 μm, the ratio of the hydrophobic metal oxide nanoparticles to the polymer particles is from 30:1 to 1:1, and the hydrophobic solvent is dimethyl carbonate (DMC) or contains the same.

[0007] In one embodiment, the w / w concentration of the hydrophobic metal oxide nanoparticles in the composition is from 1.5% to 3%.

[0008] In one embodiment, the w / w concentration of the polymer particles in the composition is from 0.5% to 3%.

[0009] In one embodiment, the average cross-section of the polymer particles is from 1 nm to 10 μm.

[0010] In one embodiment, the hydrophobic metal oxide nanoparticles have a chemical modification covalently bonded to the metal oxide particles, and the metal oxide particles are or contain SiO2 particles.

[0011] In one embodiment, the chemical modification is polysiloxane, polysilane, (C1-C 20 ) alkylsilyl group, (C1-C 20)It contains any one of alkoxysilane groups, any copolymers thereof or any combination thereof.

[0012] In one embodiment, the polysiloxane contains PDMS.

[0013] In one embodiment, the polymer particles are configured to coalesce at a temperature of 20 to 90 °C, and the polymer particles are latex nanoparticles containing a thermoplastic polymer characterized by a glass transition temperature of 10 to 90 °C.

[0014] In one embodiment, the thermoplastic polymer contains polyacrylate, polyester, polyurethane, any derivatives thereof or any copolymers.

[0015] In another aspect, there is provided a coated substrate in which at least one surface is in contact with a coating, the coating containing a plurality of hollow microparticles, the shell of the hollow microparticles containing hydrophobic metal oxide nanoparticles and a thermoplastic polymer, and the ratio of the hydrophobic metal oxide nanoparticles to the thermoplastic polymer in the shell being from 30:1 to 1:1. In one embodiment, the coated substrate is characterized by a water contact angle of at least 120°.

[0016] In one embodiment, the coated substrate has a roll-off angle of 0 to 10°.

[0017] In one embodiment, the substrate contains a plastic substrate, a cellulose-based substrate (such as wood, paper, etc.), a glass substrate, a ceramic substrate, a metal substrate (such as aluminum), a textile substrate, and a wood substrate, or any combination thereof.

[0018] In one embodiment, the hydrophobic metal oxide nanoparticles have a chemical modification covalently bonded to the metal oxide particles, and the metal oxide particles are selected from nanoclay, SiO2, TiO2, Al2O3, Fe2O3, ZnO, and ZrO, or any combination thereof.

[0019] In one embodiment, the chemical modification includes any one of polysiloxane, polysilane, (C1-C 20 ) alkylsilyl group, (C1-C 20 ) alkoxysilane group, any copolymer thereof or any combination thereof.

[0020] In one embodiment, the polysiloxane includes PDMS.

[0021] In one embodiment, the coating is in the form of a continuous layer characterized by a thickness of 0.5 to 50 μm.

[0022] In one embodiment, the outer surface of the coated substrate is characterized in that the root mean square (RMS) of the surface height is 20 to 100 nm.

[0023] In one embodiment, the coated substrate is characterized by wear stability measured by a tape test or a sandpaper test.

[0024] In one embodiment, the hydrophobic metal oxide nanoparticles are incorporated into the matrix of the thermoplastic polymer, and the ratio of the hydrophobic metal oxide nanoparticles to the thermoplastic polymer in the coating is 25:1 to 5:1.

[0025] In another aspect, there is provided a method for manufacturing a coated substrate of the present invention, including applying the composition of the present invention onto a substrate and exposing the substrate in contact with the composition to a temperature exceeding the glass transition point of the polymer particles, thereby obtaining a coated substrate.

[0026] In one embodiment, the temperature is 25 to 200 °C.

[0027] Unless otherwise defined, all technical and / or scientific terms used herein shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, exemplary methods and / or materials are described below. In case of conflict, this patent specification, including definitions, will control. Furthermore, the materials, methods, and examples are illustrative only and not intended to be limiting necessarily.

[0028] Further embodiments and the entire scope of application of the present invention will become apparent from the detailed description provided below. However, it should be understood that various changes and modifications within the spirit and scope of the present invention will be apparent to those skilled in the art from this detailed description, and thus the detailed description and specific examples, while indicating preferred embodiments of the present invention, are provided for illustrative purposes only.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0030] According to some embodiments, the present invention provides a coating composition comprising a plurality of core-shell particles, wherein the core of the particles contains a liquid and the shell of the particles contains hydrophobic metal oxide nanoparticles in contact with polymer particles. In some embodiments, the composition comprises a water-in-oil (W / O) Pickering emulsion. In some embodiments, the composition comprises an oil-in-water (O / W) Pickering emulsion. The emulsion according to the present invention comprises microparticles comprising a shell of hydrophobic metal oxide (e.g., silica) nanoparticles in contact with polymer particles and a core comprising an aqueous solution. In some embodiments, the emulsion is used as an active coating. In some embodiments, the polymer particles are polymer nanoparticles.

[0031] According to some embodiments, the present invention provides a composition comprising core-shell particles dispersed in a hydrophobic solvent, wherein the core of the core-shell particles contains an aqueous solution, the shell of the core-shell particles contains hydrophobic metal oxide nanoparticles, the hydrophobic metal oxide nanoparticles are in contact with polymer particles, the hydrophobic metal oxide nanoparticles are surface-modified hydrophobic metal oxide nanoparticles (e.g., surface-modified silica nanoparticles), the w / w concentration of the hydrophobic metal oxide nanoparticles in the composition is 0.5 to 5%, and the ratio of the hydrophobic metal oxide nanoparticles to the polymer particles is 30:1 to 1:1.

[0032] In some embodiments, the shell is a single-layer shell. In some embodiments, the single-layer shell comprises or consists essentially of hydrophobic metal oxide nanoparticles. In some embodiments, the shell comprises a plurality of distinct layers, each layer comprising hydrophobic metal oxide nanoparticles or polymer particles. In some embodiments, the hydrophobic metal oxide nanoparticles are at the interface between the main phase and the secondary phase. In some embodiments, the hydrophobic metal oxide nanoparticles are at the interface, form an inner layer of the core-shell particles, the inner layer faces the core and surrounds the core, and further contacts an outer layer (e.g., a coaxial or non-coaxial outer layer that is only bonded to a part of the inner layer). In some embodiments, the hydrophobic metal oxide nanoparticles and the polymer particles stabilize a composition (e.g., an emulsion or dispersion). In some embodiments, the polymer particles are dispersed in the main phase. In some embodiments, the polymer particles are in contact with one or more core-shell particles. In some embodiments, the polymer particles bridge / connect between two or more core-shell particles. In some embodiments, the polymer particles in contact with the core-shell particles are in the form of a matrix composed of a network of bridges that connect or contact two or more core-shell particles. In some embodiments, each bridge is an agglomerate of polymer particles.

[0033] In some embodiments, the hydrophobic metal oxide nanoparticles comprise silica nanoparticles modified with polysiloxane. In some embodiments, the w / w concentration of the polymer particles in the composition is 0.5 - 3%. In some embodiments, the particles comprise a shell encapsulating an aqueous core.

[0034] According to some embodiments, the present invention provides an article comprising a substrate coated with the coating composition of the present invention. In some embodiments, the article comprises a coated substrate comprising a coating layer in contact with the substrate on top of the substrate, the coating layer comprising a polymer matrix and hydrophobic metal oxide nanoparticles incorporated on or in the polymer matrix, and the polymer matrix of the coating composition and the polymer particles are composed of the same polymer.

[0035] In some embodiments, the coating layer is an active coating (e.g., characterized by reducing microbial load and / or preventing microbial adhesion). In some embodiments, the coating layer is formed by applying the coating composition of the present invention to a surface and drying it. In some embodiments, an article comprising the coating layer (i.e., the outer surface of the coating) is characterized by antibacterial properties, anti-fogging properties, water repellency, oil repellency, etc. In some embodiments, the outer surface of the article (i.e., the coated surface) is printable.

[0036] In some embodiments, the coating is stable against mechanical wear (e.g., maintaining at least 90% of its surface roughness, shape, dimensions, and / or chemical composition).

[0037] Composition In one aspect of the present invention, there is a composition comprising an emulsion or a dispersion. In some embodiments, the emulsion is an O / O Pickering emulsion. In some embodiments, the emulsion is a W / O Pickering emulsion. In some embodiments, the emulsion is an O / W Pickering emulsion.

[0038] In some embodiments, the composition of the present invention comprises an emulsion or a dispersion containing a plurality of core-shell particles with a diameter of 1 μm to 100 μm. The core-shell particles comprise a shell containing hydrophobic metal oxide nanoparticles in contact with polymer particles. The w / w ratio of the hydrophobic solvent to the aqueous solution in the composition is 6:4 to 10:1. The w / w concentration of the hydrophobic metal oxide nanoparticles in the composition is 0.5% to 5%. The average cross-section of the core-shell particles is 1 μm to 100 μm. The ratio of the hydrophobic metal oxide nanoparticles to the polymer particles is 30:1 to 1:1. In some embodiments, the composition of the present invention is as described above, and the hydrophobic solvent is dimethyl carbonate (DMC) or includes it.

[0039] In some embodiments, the composition of the present invention comprises core-shell particles dispersed in a hydrophobic solvent. Each core-shell particle comprises a core surrounded by a shell. The core comprises an aqueous solution, and the shell comprises hydrophobic metal oxide nanoparticles. At least a portion of the hydrophobic metal oxide nanoparticles is in contact with polymer particles. The w / w ratio of the hydrophobic solvent to the aqueous solution in the composition is from 6:4 to 10:1. The average cross-section of the core-shell particles is from 1 μm to 100 μm. The ratio of the hydrophobic metal oxide nanoparticles to the polymer particles in the composition is from 30:1 to 5:1. In some embodiments, the w / w concentration of the hydrophobic metal oxide nanoparticles in the composition is from 0.1% to 10%.

[0040] In some embodiments, the composition of the present invention is an emulsion or dispersion comprising a plurality of core-shell particles (e.g., droplets), and the core-shell particles are essentially composed of an aqueous core and hydrophobic metal oxide nanoparticles in contact with polymer particles that form or define the shell.

[0041] In some embodiments, the composition of the present invention comprises an emulsion or dispersion comprising a plurality of particles, and the particles are in the form of droplets. In some embodiments, the particles are in the form of core-shell particles (e.g., each particle comprises a shell and a core).

[0042] In some embodiments, the composition of the present invention is fluid at a temperature in the range of -30 to 90 °C, -30 to 40 °C, -30 to 50 °C, -30 to 70 °C, or any range therebetween. In some embodiments, the composition of the present invention is liquid at a temperature in the range of -30 to 90 °C, -30 to 40 °C, -30 to 50 °C, -30 to 70 °C, or any range therebetween.

[0043] As used herein, the term "pickering emulsion" refers to an emulsion that uses solid particles as a stabilizer to stabilize droplets of a substance in a dispersed phase in the form of droplets dispersed throughout a continuous phase.

[0044] As used herein, the term "emulsion" refers to a combination of at least two fluids in which one of the fluids is present in the form of droplets in the other fluid. The term "emulsion" includes microemulsions.

[0045] As used herein, the term "fluid" refers to a substance that flows and tends to conform to the outline of its container, i.e., a liquid, a gas, a viscoelastic fluid, etc. Generally, a fluid is a substance that cannot withstand a static shear stress, and when a shear stress is applied, the fluid produces a continuous and permanent distortion. A fluid can have any suitable viscosity that allows for flow. When two or more fluids are present, each fluid can be selected essentially independently from any fluid (liquid, gas, etc.) by one of ordinary skill in the art, taking into account the relationship between the fluids. In some cases, the droplets can be contained within a carrier fluid, such as a liquid.

[0046] In some embodiments, the composition comprises a hydrophobic solvent selected from an aliphatic organic solvent, an aromatic organic solvent, a ketone solvent, an ether solvent, an ester solvent, a halogenated solvent, or any combination thereof. In some embodiments, the hydrophobic solvent is substantially free of halogenated solvents.

[0047] In some embodiments, the hydrophobic solvent is immiscible with water. In some embodiments, the hydrophobic solvent is characterized by a water solubility of less than 1 g / 1L, less than 0.1 g / 1L, less than 0.01 g / 1L, less than 0.001 g / 1L, or any range therebetween at a temperature of 20 - 27°C.

[0048] In some embodiments, the hydrophobic solvent is characterized by a water solubility of 0.1% - 15%, 1% - 15%, 5% - 15%, 10% - 15%, 12% - 14%, 5% - 14% (w / w), or any range therebetween.

[0049] In some embodiments, the hydrophobic solvent is characterized by a dipole moment of less than 1.8, less than 1.5, less than 1.3, less than 1.0, less than 0.8, less than 0.6, less than 0.4, less than 0.2, less than 0.1, or any range therebetween.

[0050] In some embodiments, the hydrophobic solvent is characterized by a dipole moment in the range of 0 to 0.5, 0.5 to 1, 1 to 1.5, or any range therebetween.

[0051] In some embodiments, the hydrophobic solvent is characterized by the dipole moment and water solubility as described above.

[0052] In some embodiments, the hydrophobic solvent does not contain other non-hydrophobic solvents. In some embodiments, the fluid consists essentially of a hydrophobic solvent. In some embodiments, the hydrophobic solvent refers to any known hydrophobic solvent used in the chemical industry and / or pharmaceutical industry. In some embodiments, the hydrophobic solvent does not substantially contain other liquids. In some embodiments, the hydrophobic solvent includes a plurality of hydrophobic solvents (e.g., a mixture of solvents).

[0053] Non-limiting examples of hydrophobic solvents (e.g., aliphatic hydrocarbons) include, but are not limited to, pentane, hexane, cyclohexane, octane, heptane, or any combination thereof. Other aliphatic hydrocarbon solvents such as ethyl ether, methyl ethyl ketone (MEK), methyl isobutyl ketone, dichloromethane, chloroform, aliphatic esters (such as ethyl acetate), etc. are well known in the art.

[0054] Non-limiting examples of hydrophobic solvents (e.g., aromatic hydrocarbons) include, but are not limited to, toluene, ethylbenzene, xylene, chlorobenzene, styrene, dichlorobenzene, nitrobenzene, trimethylbenzene, trichlorobenzene, or any combination thereof. In some embodiments, the compositions of the present invention are substantially free of chlorinated solvents, fluorinated solvents, or both. In some embodiments, the hydrophobic solvent is or includes dimethyl carbonate (DMC).

[0055] In some embodiments, the composition further comprises an effective amount of an active agent. In some embodiments, the effective amount is an antibacterial effective amount (i.e., an amount sufficient to reduce, prevent, or eradicate the microbial load on the surface of a substrate coated with the composition / dry coating of the present invention). In some embodiments, the effective amount is an amount sufficient to protect plants (i.e., an amount sufficient to reduce, prevent, or eradicate plant pests on or in a cultivation area proximate to an article of the present invention, a greenhouse having at least one wall in contact with the composition / dry coating of the present invention, etc.). In some embodiments, the effective amount includes a concentration of the active agent in the composition in the range of 0.1% - 20%, 0.1% - 5%, 5% - 10%, 10% - 20%, 0.1% - 15%, 0.1% - 10%, 1% - 5%, 1% - 10% (w / w), or any range therebetween).

[0056] In some embodiments, the effective amount refers to the concentration of the active agent in the composition sufficient to impart antibacterial activity to the composition. In some embodiments, the active agent is an antibacterial agent. In some embodiments, the active agent is dissolved or dispersed in the main phase (i.e., the hydrophobic solvent of the composition). In some embodiments, the active agent is dissolved in DMC. In some embodiments, the antibacterial agent is selected from waxes (e.g., natural waxes such as propolis), aliphatic aldehydes (such as the compounds listed in Table 3), and / or essential oils.

[0057] Examples of essential oils that are not limiting include, but are not limited to, tea tree oil, eucalyptus oil, lemongrass oil, thymol, or carvacrol, or any combination thereof.

[0058] In some embodiments, the core-shell particles of the present invention comprise an aqueous core and an amphiphilic shell. In some embodiments, the core-shell particles are in the form of colloidosomes.

[0059] In some embodiments, the core-shell particles have a spherical geometric shape or shape. In some embodiments, the core-shell particles have an expanded or contracted shape. In some embodiments, the plurality of core-shell particles do not have a characteristic geometric shape or shape. In some embodiments, the core-shell particles have a spherical, quasi-spherical, quasi-elliptical, contracted, concave, irregular shape, or any combination thereof.

[0060] In some embodiments, the plurality of core-shell particles are shaped substantially spherically, substantially as described herein. In some embodiments, the plurality of core-shell particles are shaped substantially elliptically, substantially as described herein. One of ordinary skill in the art will appreciate that the exact shape of each of the plurality of core-shell particles can vary from particle to particle. Further, the exact shape of the core-shell particles is derived from any of the above geometric shapes, and thus the shape of the particles does not perfectly fit a particular geometric shape. One of ordinary skill in the art will appreciate that the exact shape of the core-shell particles can have a substantial deviation (such as at least 5%, at least 10%, at least 20% deviation) from a particular geometric shape (such as a sphere or an ellipse).

[0061] In some embodiments, the core-shell particles have a cross-section in the range of 1 μm to 500 μm, 1 μm to 100 μm, 5 μm to 100 μm, 10 μm to 100 μm, 20 μm to 50 μm, 20 μm to 100 μm, 20 μm to 70 μm, 10 μm to 80 μm, 10 μm to 70 μm, 10 μm to 40 μm, 20 μm to 40 μm, 50 μm to 100 μm, 1 μm to 80 μm, 10 μm to 80 μm, 50 μm to 80 μm, 10 μm to 50 μm, 80 μm to 100 μm, 100 μm to 200 μm, 200 μm to 300 μm, 300 μm to 400 μm, 400 μm to 500 μm, 1 μm to 10 μm, 5 μm to 10 μm, 1 μm to 50 μm, 10 μm to 50 μm, 5 μm to 50 μm, or 1 μm to 5 μm, or any range or value therebetween.

[0062] In some embodiments, the cross-section of the core-shell particles described herein represents an average cross-section. In some embodiments, the cross-section of the core-shell particles described herein represents the average or median size of a plurality of particles. In some embodiments, for example, the average or median size of at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95% of the particles is in the range of 1 μm to 100 μm, 5 μm to 50 μm, 1 μm to 50 μm, 5 μm to 10 μm, 10 μm to 50 μm, or any range therebetween. In some embodiments, the diameter of the core-shell particles described herein is a dry diameter (i.e., the diameter of the isolated dry particles). In some embodiments, a plurality of core-shell particles have a uniform size. By "uniform" or "homogeneous" is intended, for example, a size distribution that varies within a range of ±60%, ±50%, ±40%, ±30%, ±20%, or ±10% or less, or any value therebetween.

[0063] In some embodiments, the core-shell particles are in the form of droplets.

[0064] In some embodiments, the diameter of the droplet is in the range of 1 μm to 100 μm, 5 μm to 100 μm, 10 μm to 100 μm, 50 μm to 100 μm, 1 μm to 80 μm, 10 μm to 80 μm, 50 μm to 80 μm, 1 μm to 10 μm, 5 μm to 10 μm, 1 μm to 50 μm, 10 μm to 50 μm, 5 μm to 50 μm, or 1 μm to 5 μm, or any range therebetween.

[0065] As used herein, the term "droplet" refers to an isolated portion of a first fluid surrounded by a second fluid. It should be noted that the droplet is not necessarily spherical and can take other shapes depending on, for example, the external environment. In some embodiments, the droplet has a minimum cross-sectional dimension that is substantially equal to the maximum dimension of the channel perpendicular to the flow of the fluid in which the droplet is present. In some cases, the droplet can be a vesicle such as a liposome, a colloidosome, or a polymersome. The fluid droplet can have any shape and / or size. Usually, monodisperse droplets are substantially of the same size. The shape and / or size of the fluid droplet can be determined, for example, by measuring the average diameter or other characteristic dimension of the droplet. The "average diameter" of a plurality of or a series of droplets is the arithmetic mean of the average diameters of each droplet. A person skilled in the art would be able to determine the average diameter (or other characteristic dimension) of a plurality of or a series of droplets using, for example, laser light scattering, microscopy, or other known techniques. The average diameter of a single droplet in a non-spherical droplet is the diameter of a perfect sphere having the same volume as the non-spherical droplet.

[0066] In some embodiments, the average diameter of the droplet (and / or a plurality of or a series of droplets) is in the range of 5 μm to 100 μm, 5 μm to 50 μm, 1 μm to 50 μm, or any range therebetween. In some embodiments, the average diameter of the droplet is the wet diameter (i.e., the diameter of the particles in the solution).

[0067] In some embodiments, the core-shell particles of the present invention are droplets. In some embodiments, the core-shell particles of the present invention are colloidosomes.

[0068] In some embodiments, the core-shell particles comprise hydrophobic metal oxide nanoparticles in an amount of 1% to 10%, 1% to 15%, 1% to 13%, 1% to 10%, 2% to 10%, 2% to 3%, 2% to 5%, 5% to 10%, 3% to 10%, 2% to 7%, 2% to 6% (w / w), or any range therebetween, and the core-shell particles are droplets (e.g., having an aqueous core).

[0069] In some embodiments, the core-shell particles comprise polymer particles in an amount of 1% to 10%, 1% to 15%, 1% to 13%, 1% to 10%, 2% to 10%, 2% to 3%, 2% to 5%, 5% to 10%, 3% to 10%, 2% to 7%, 2% to 6% (w / w), or any range therebetween, and the core-shell particles are droplets (e.g., having an aqueous core).

[0070] In some embodiments, the ratio of hydrophobic metal oxide nanoparticles to polymer particles in the core-shell particles and / or compositions of the present invention is 30:1 to 1:1, 30:1 to 1.5:1, 30:1 to 2:1, 30:1 to 3:1, 30:1 to 4:1, 30:1 to 5:1, 20:1 to 5:1, 20:1 to 10:1, 30:1 to 10:1, 25:1 to 5:1, 25:1 to 10:1, 5:1 to 4:1, 5:1 to 3:1, 5:1 to 5:2, 3:1 to 1.5:1, 5:1 to 2:1, or any range therebetween.

[0071] In some embodiments, the stable compositions of the present invention comprise substantially hollow spherical core-shell particles. In some embodiments, the stable compositions of the present invention comprise core-shell particles in an amount of 30 to 70%, 30 to 50%, 40 to 70%, 40 to 60%, 30 to 60%, 50 to 70%, 50 to 60%, by weight, or any range therebetween.

[0072] In some embodiments, the hydrophobic metal oxide nanoparticles are bound to or in proximity to the polymer particles within the shell. In some embodiments, the hydrophobic metal oxide nanoparticles are mixed with the polymer particles within the shell. In some embodiments, the binding is via non-covalent bonds or interactions. In some embodiments, the binding is adsorption (physical adsorption). In some embodiments, the binding is via non-ionic physical bonds or interactions. In some embodiments, the shell is composed of a single layer. In some embodiments, the shell is composed of multiple distinct layers. In some embodiments, the shell comprises a first layer essentially composed of metal oxide nanoparticles and a second layer essentially composed of polymer particles.

[0073] In some embodiments, the shell is in the form of a layer. In some embodiments, the shell is in the form of a uniform layer. In some embodiments, the shell is in the form of a homogeneous layer. In some embodiments, the hydrophobic metal oxide nanoparticles and the polymer particles are homogeneously dispersed throughout the total volume of the shell. In some embodiments, at least a portion of the hydrophobic metal oxide nanoparticles and / or the polymer particles are in contact with or present within the core. In some embodiments, 50 - 99.9%, 60 - 99.9%, 70 - 90%, 80 - 95% of the total weight of the hydrophobic metal oxide nanoparticles and the polymer particles are present within the interphase of the composition (or within the shell of the core-shell particles).

[0074] In some embodiments, the hydrophobic metal oxide nanoparticles and the polymer particles constitute up to 80%, up to 85%, up to 90%, up to 92%, up to 95%, up to 97%, up to 99%, up to 98%, up to 96% w / w of the shell of the core-shell particles. In some embodiments, the hydrophobic metal oxide nanoparticles and the polymer particles constitute up to 80%, up to 85%, up to 90%, up to 92%, up to 95%, up to 97%, up to 99%, up to 98%, up to 96% of the total dry weight of the core-shell particles.

[0075] In some embodiments, the shell consists essentially of hydrophobic metal oxide nanoparticles. In some embodiments, the hydrophobic metal oxide nanoparticles constitute up to 80%, up to 85%, up to 90%, up to 92%, up to 95%, up to 97%, up to 99%, up to 98%, up to 96%, or 70 - 99%, 80 - 95%, 70 - 95% of the total surface area of the shell. In some embodiments, the shell consists essentially of hydrophobic metal oxide nanoparticles and the polymer particles are dispersed or distributed within the continuous phase (i.e., the hydrophobic solvent). In some embodiments, the polymer particles are in the form of particle agglomerates that bridge between adjacent core - shell particles (and contact the shell).

[0076] In some embodiments, the shell comprises an inner portion facing the core of the core - shell particle (e.g., an aqueous core) and an outer portion facing the continuous phase (e.g., a hydrophobic solvent). In some embodiments, the shell forms an interfacial layer between the core of the core - shell particle (e.g., an aqueous core) and the continuous phase (e.g., a hydrophobic solvent). In some embodiments, the composition is a w / o emulsion, where the aqueous discontinuous phase forms the core of the core - shell particles of the invention and the intermediate phase forms the shell of the core - shell particles that encapsulates and / or stabilizes the aqueous core.

[0077] In some embodiments, the inner portion is in contact with the core. In some embodiments, the inner portion is bonded to the core. In some embodiments, the shell stabilizes the core. In some embodiments, the shell encapsulates the core.

[0078] In some embodiments, the shell is a layered shell. In some embodiments, the inner portion forms a first layer and the outer portion forms a further layer. In some embodiments, the inner portion of the shell is mainly composed of polymer particles and the outer portion is mainly composed of hydrophobic metal oxide nanoparticles, or vice versa.

[0079] In some embodiments, the shell is single-layered or includes the same, in which hydrophobic metal oxide nanoparticles and polymer particles are mixed. In some embodiments, the shell defines an intermediate layer (or interphase) containing hydrophobic metal oxide nanoparticles in contact or bonded with the polymer particles, and the intermediate layer is substantially homogeneous. In some embodiments, the polymer particles enhance the stability of the shell and thus extend the shelf life (or stability) of the composition of the present invention. In some embodiments, the stable composition of the present invention substantially retains the initial particle size of the core-shell particles over the period described herein when stored under standard storage conditions (e.g., under ambient conditions of a temperature of 10 to 30 °C).

[0080] In some embodiments, the shell has a thickness in the range of 5 nm to 50 nm, 15 nm to 50 nm, 30 nm to 50 nm, 1 nm to 50 nm, 2 nm to 50 nm, 5 μm to 10 nm, 10 nm to 50 nm, 5 nm to 30 nm, 15 nm to 30 nm, 1 nm to 20 nm, 2 nm to 20 nm, 5 nm to 20 nm, or 10 nm to 20 nm, 20 nm to 30 nm, 30 nm to 40 nm, 40 nm to 80 nm, 80 nm to 100 nm, 100 nm to 200 nm, 200 nm to 300 nm, 300 nm to 500 nm, or any range therebetween. In some embodiments, the thickness of the shell is quantified using scanning electron microscopy (SEM).

[0081] In some embodiments, the hydrophobic metal oxide nanoparticles include inorganic metal oxide-based particles having a chemical modification (e.g., having an attached hydrophobic group). In some embodiments, the inorganic metal oxide-based particles include semimetal oxide particles and metal oxide particles (e.g., titanium oxide, zirconium oxide, zinc oxide, aluminum oxide, etc.). In some embodiments, the semimetal oxide includes silica. In some embodiments, the hydrophobic metal oxide nanoparticles are surface-modified particles. In some embodiments, the chemical modification covalently bonds to at least a portion of the outer surface of the metal oxide nanoparticles. In some embodiments, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 90%, at least 95%, at least 99%, or any range therebetween of the hydroxy groups and / or oxy groups of the metal oxide nanoparticles are replaced by the chemical modification (e.g., covalently bond to a chemical modification such as a hydrophobic group). In some embodiments, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 90%, at least 95%, at least 99% of the -OH and / or -O- groups on the terminal surface of the metal oxide nanoparticles are replaced by the chemical modification.

[0082] In some embodiments, the hydrophobic metal oxide nanoparticles include SiO2 nanoparticles covalently bonded to a chemical modification. In some embodiments, the hydrophobic metal oxide nanoparticles include chemically modified SiO2 nanoparticles. In some embodiments, the chemical modification covalently bonds to at least a portion of the outer surface of the SiO2 nanoparticles as described above.

[0083] The hydrophobic metal oxide nanoparticles disclosed herein refer to chemically modified particles, and the chemical modification includes silylation, halogenation, halogenation and alkylation particles (such as by halo-dimethylsilane), or haloalkylated particles, which will be understood by those skilled in the art. In some embodiments, the chemical modification substantially does not contain fluorine atoms. In some embodiments, the chemical modification contains fluorine atoms. In some embodiments, the hydrophobic metal oxide nanoparticles disclosed herein are non-fluorinated particles. In some embodiments, the hydrophobic metal oxide nanoparticles disclosed herein include, inter alia, silyl, siloxane, polysiloxane, polysilane, (C1-C 20 ) alkylsilyl, (C1-C 20 ) alkoxysilane, (C1-C 20 ) halosilyl, and / or (C1-C 20 ) alkylhalosilyl modified metal oxide particles (such as silica nanoparticles). In some embodiments, the halosilyl, halo, and alkylhalosilyl contain a halogen selected from Cl, Br, and I.

[0084] In some embodiments, the hydrophobic metal oxide nanoparticles include metal oxide nanoparticles with polysiloxane functionalization, polysilane functionalization, alkyl functionalization, silane functionalization, alkoxysilane functionalization, alkylsilane functionalization, or any combination thereof.

[0085] In some embodiments, the chemical modification includes any of polysiloxane, (C1-C 20 ) alkyl, (C1-C 20 ) alkylsilane group, vinyl, epoxy, cycloalkane, alkene, alkyne, ether, silyl group, and siloxane group, or any combination thereof. In some embodiments, the polysiloxane has the formula 1: [-SiR1R2-O-] n , or the formula 1A: R3-[-SiR1R2-O-] n-R3, where R1 and R2 are each independently selected from the group consisting of hydrogen, an alkyl group, an alkoxy group, a thioalkoxy group, an aryl group, a condensed ring, an alkaryl group, a heteroaryl group, a cycloalkyl group, an aryloxy group, a thioaryloxy group, an ether group, and a halo group, or any combination thereof, each R3 is independently selected from the group consisting of hydrogen, a halo group, an alkoxy group, a hydroxy group, and a bond, and n is an integer in the range of 10 to 150000. In some embodiments, at least one of R1 and R2 is not hydrogen. In some embodiments, the polysiloxane comprises a single polysiloxane species or a plurality (e.g., 2, 3, 4, or 5) of chemically distinct polysiloxanes.

[0086] In some embodiments, n is an integer in the range of 10 to 50, 50 to 100, 100 to 120000, 100 to 100000, 100 to 90000, 100 to 70000, 100 to 50000, 100 to 40000, 100 to 30000, 100 to 30000, 100 to 10000, 100 to 9000, 100 to 8000, 100 to 5000, 100 to 4000, 100 to 3000, 100 to 2000, 100 to 200, 200 to 500, 500 to 1000, 200 to 150000, 500 to 150000, 100 to 150000, 1000 to 150000, 2000 to 150000, 5000 to 150000, 10000 to 150000, 500 to 100000, 500 to 90000, 500 to 70000, 500 to 50000, 500 to 40000, 500 to 30000, 500 to 30000, 500 to 10000, 500 to 9000, 500 to 8000, or 500 to 5000, or any range therebetween.

[0087] In some embodiments, R1, R2, or both are each independently selected from hydrogen and a C1-C 20 alkyl group. In some embodiments, R1 and R2 are each independently C1-C 20 alkyl. In some embodiments, C1-C 20Alkyl contains from 1 to 20, 1 to 3, 3 to 5, 5 to 10, 10 to 15, 15 to 20 carbon atoms (or methylene groups), or any range therebetween. In some embodiments, C1-C 20 Alkyl includes alkanes, alkenes, alkynes, or combinations thereof. In some embodiments, C1-C 20 Alkyl is a straight-chain alkyl. In some embodiments, C1-C 20 Alkyl is a straight-chain alkane.

[0088] In some embodiments, R1, R2, or both are selected from the group consisting of hydrogen and lower alkyl groups, or both.

[0001] As used herein, the term "alkyl" alone or in combination refers to a straight-chain, branched-chain, or cyclic chain containing at least one carbon atom and having no double or triple bonds between carbon atoms. As used herein, the term "lower alkyl" refers to C1-C6 alkyl. "Lower alkyl" may be represented by "C1-C4 alkyl" or similar designations. By way of example only, "C1-C4 alkyl" indicates an alkyl having 1, 2, 3, or 4 carbon atoms, i.e., alkyl is selected from methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and t-butyl. Thus, C1-C4 includes C1-C2 and C1-C3 alkyl. Alkyl can be substituted or unsubstituted. Alkyl includes methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl, hexyl, ethenyl, propenyl, butenyl, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl, each optionally substituted but not limited thereto.

[0089] In some embodiments, C1-C 20 Alkyl and / or lower alkyl is substituted by a substituent selected from halo, hydroxy, amino, cyano, nitro, alkylamide, acyl, or combinations thereof.

[0090] In some embodiments, R1, R2, or both are selected from hydrogen, methyl, ethyl, butyl, isobutyl, or combinations thereof.

[0091] In some embodiments, the hydrophobic metal oxide nanoparticles comprise polysiloxane-functionalized silica nanoparticles. In some embodiments, the polysiloxane is or comprises an alkylated siloxane polymer, any mixture thereof, or any copolymer. In some embodiments, the silicone-based polymer comprises poly(dimethylsiloxane) (PDMS), any mixture thereof, or any copolymer. In some embodiments, the polysiloxane comprises a PDMS elastomer. In some embodiments, the polysiloxane consists essentially of PDMS.

[0092] In some embodiments, the polysiloxane has an average molecular weight in the range of 500 g / mol to 150,000 g / mol. In some embodiments, the silicone-based polymer has an average molecular weight in the range of 500 g / mol to 150,000 g / mol, 500 g / mol to 10,000 g / mol, 500 g / mol to 20,000 g / mol, 500 g / mol to 50,000 g / mol, 500 g / mol to 5,000 g / mol, 1,700 g / mol to 150,000 g / mol, 1,900 g / mol to 150,000 g / mol, 2,000 g / mol to 150,000 g / mol, 2,500 g / mol to 150,000 g / mol, 4,000 g / mol to 150,000 g / mol, 5,000 g / mol to 150,000 g / mol, 7,000 g / mol to 150,000 g / mol, 10,000 g / mol to 150,000 g / mol, 20,000 g / mol to 150,000 g / mol, 50,000 g / mol to 150,000 g / mol, 70,000 g / mol to 150,000 g / mol, 100,000 g / mol to 150,000 g / mol, 1,500 g / mol to 100,000 g / mol, 1,500 g / mol to 80,000 g / mol, 1,500 g / mol to 50,000 g / mol, 1,500 g / mol to 20,000 g / mol, 1,500 g / mol to 10,000 g / mol, 2,000 g / mol to 100,000 g / mol, 2,000 g / mol to 80,000 g / mol, 2,000 g / mol to 50,000 g / mol, 2,000 g / mol to 20,000 g / mol, 2,000 g / mol to 10,000 g / mol, 5,000 g / mol to 100,000 g / mol, 5,000 g / mol to 80,000 g / mol, 5,000 g / mol to 50,000 g / mol, 5,000 g / mol to 20,000 g / mol, or 5,000 g / mol to 10,000 g / mol, or any range therebetween.

[0093] As used throughout this specification, the term "polymer" refers to an organic substance composed of a plurality of repeating structural units (backbone units) covalently bonded to each other.

[0094] In some embodiments, the hydrophobic metal oxide nanoparticles are characterized by an average particle size of 1 nm to 900 nm. In some embodiments, the hydrophobic metal oxide nanoparticles are 2 nm to 600 nm, 2 nm to 100 nm, 2 nm to 50 nm, 2 nm to 30 nm, 2 nm to 20 nm, 2 nm to 70 nm, 2 nm to 550 nm, 2 nm to 520 nm, 2 nm to 500 nm, 2 nm to 480 nm, 2 nm to 450 nm, 2 nm to 400 nm, 2 nm to 350 nm, 2 nm to 300 nm, 2 nm to 250 nm, 2 nm to 200 nm, 2 nm to 150 nm, 2 nm to 100 nm, 5 nm to 600 nm, 10 nm to 600 nm, 15 nm to 600 nm, 20 nm to 600 nm, 40 nm to 600 nm, 50 nm to 600 nm, 100 nm to 600 nm, 5 nm to 500 nm, 10 nm to 500 nm, 15 nm to 500 nm, 20 nm to 500 nm, 40 nm to 600 nm, 50 nm to 500 nm, 100 nm to 500 nm, 5 nm to 400 nm, 10 nm to 400 nm, 15 nm to 400 nm, 20 nm to 400 nm, 40 nm to 400 nm, 50 nm to 400 nm, 100 nm to 400 nm, 5 nm to 50 nm, 5 nm to 40 nm, 2 nm to 50 nm, or 2 nm to 40 nm, or characterized by an average particle size in any range therebetween. In some embodiments, at least 90% of the size of the nanoparticles varies within ±25%, ±20%, ±15%, ±19%, less than ±5%, or any value range therebetween of the sizes disclosed above.

[0095] As used herein, the term “average” or “median” size refers to the diameter or cross-section of the particle. The average size of the particles can be evaluated using any technique known in the art, such as dynamic light scattering (DLS).

[0096] Non-limiting examples of the hydrophobic particles of the present invention are chemically modified hydrophobic fumed silica such as AEROSIL® R202.

[0097] Hydrophobic metal oxide nanoparticles can generally be shaped into spheres, incomplete spheres, especially of a size that adheres to a substrate, rods, cylinders, ribbons, sponges, and any other shape, or in the form of clusters of any of these shapes, or as a mixture of one or more shapes. In some embodiments, the hydrophobic particles have a spherical, quasi-spherical, quasi-ellipsoidal, irregular shape, or any combination thereof.

[0098] In some embodiments, the hydrophobic metal oxide nanoparticles are compatible with polymer particles. In some embodiments, the hydrophobic metal oxide nanoparticles are dispersible in the hydrophobic solvents described herein. In some embodiments, the hydrophobic metal oxide nanoparticles are configured to stabilize an aqueous core dispersed in a main phase. In some embodiments, chemical modifications (e.g., polysiloxanes such as PDMS) have an affinity for polymer particles. In some embodiments, the hydrophobic metal oxide nanoparticles can bind (e.g., via non-covalent interaction-mediated) or adhere to the hydrophobic metal oxide nanoparticles, and optionally, the binding or adhesion refers to the ability of the hydrophobic metal oxide nanoparticles to form a homogeneous complex with coalesced polymer particles or polymer particles in a molten state. In some embodiments, the binding or adhesion refers to the ability of the hydrophobic metal oxide nanoparticles to non-covalently bond or associate with the polymer particles in the composition of the present invention, and the hydrophobic metal oxide nanoparticles and the polymer particles are in a solid state (e.g., below the glass transition points of the hydrophobic metal oxide nanoparticles and the polymer particles). In some embodiments, the non-covalent bond or association is sufficient to stabilize the liquid core of the core-shell particles of the present invention.

[0099] In some embodiments, the average particle size (or average cross-section) of the polymer particles is from 1 nm to 10 μm. In some embodiments, the average particle size (or average cross-section) of the polymer particles is from 1 nm to 500 nm, from 1 nm to 100 nm, from 10 nm to 500 nm, from 10 nm to 100 nm, from 100 nm to 500 nm, from 10 nm to 200 nm, from 200 nm to 500 nm, from 50 nm to 500 nm, from 50 nm to 200 nm, or any range therebetween. In some embodiments, the polymer particles are polymer nanoparticles. In some embodiments, the polymer particles are characterized by a narrow size distribution. In some embodiments, the polymer particles are characterized by a polydispersity index (PDI) in the range of 0.01 to 0.3, 0.1 to 0.3, 0.01 to 0.2, 0.01 to 0.1, 0.1 to 0.2, or less than 0.3, less than 0.2, less than 0.1, or any range therebetween.

[0100] In some embodiments, the polymer particles comprise a thermoplastic polymer or are essentially composed of a thermoplastic polymer. In some embodiments, the thermoplastic polymer is characterized by a glass transition temperature in the range of 10 to 90 °C, 20 to 90 °C, 20 to 80 °C, 30 to 90 °C, 30 to 80 °C, 30 to 60 °C, or any range therebetween.

[0101] In some embodiments, the polymer particles are latex nanoparticles. In some embodiments, the polymer particles are configured to coalesce at a temperature in the range of 20 to 90 °C, 10 to 200 °C, 20 to 200 °C, 20 to 150 °C, 20 to 100 °C, 20 to 90 °C, 30 to 90 °C, 25 to 90 °C, 20 to 80 °C, 20 to 70 °C, 20 to 60 °C, 30 to 80 °C, 30 to 70 °C, 30 to 60 °C, or any range therebetween. In some embodiments, the polymer particles are configured to coalesce at a temperature greater than 20 °C, greater than 30 °C, greater than 25 °C, greater than 35 °C, greater than 40 °C, and / or lower than 90 °C, or any range therebetween.

[0102] The term "coalescence" is well understood by those skilled in the art and refers, inter alia, to the aggregation and / or melting or disintegration of polymer particles above their coalescence temperature to form a polymer matrix. Thus, during coalescence, the polymer particles fuse or aggregate to form a continuous structure.

[0103] In some embodiments, the thermoplastic polymer is or comprises a polyacrylate, polyester, polyurethane, polystyrene, any derivative thereof or any copolymer. An exemplary polyacrylate is PRIMER 1853 (obtained from Michemflex, Belgium).

[0104] In some embodiments, the thermoplastic polymer is or comprises a polyacrylate. In some embodiments, the thermoplastic polymer is or comprises a polyacrylate and polystyrene.

[0105] In some embodiments, the polymer particles stabilize the core-shell particles. In some embodiments, the polymer particles are in contact with one or more core-shell particles. In some embodiments, the contact is by bridging. In some embodiments, the polymer particles bridge / connect between two or more core-shell particles. Exemplary bridging is shown in FIG. 13E. In some embodiments, the polymer particles in contact with the core-shell particles are in the form of a matrix composed of a network of bridges connecting or in contact with two or more core-shell particles. In some embodiments, each bridge is an agglomerate of polymer particles.

[0106] In some embodiments, the core (e.g., droplet) of the core-shell particles of the present invention is essentially composed of an aqueous solution.

[0107] In some embodiments, the core of the core-shell particles further comprises an active agent in an amount of 0.1% to 50%, 0.1% to 5%, 5% to 10%, 10% to 20%, 20% to 30%, 30% to 50% (w / w), or any range therebetween. In some embodiments, the core of the particles comprises an active agent in an amount of 0.1% to 50%, 0.1% to 5%, 5% to 10%, 10% to 20%, 20% to 30%, 30% to 50% (v / v), or any range therebetween.

[0108] In some embodiments, the active agent includes a water-soluble molecule, a lipid-affinity molecule, and a water-insoluble molecule. In some embodiments, the water-soluble molecule has a solubility greater than 10 g / L in an aqueous solvent. In some embodiments, the active agent is a bioactive compound. In some embodiments, the active agent includes an essential oil, a herbicide, a pesticide, a fungicide, or any combination thereof.

[0109] As used herein, the term "active agent" refers to any type of substance that, when included (solubilized) in the composition of the present invention, can impart additional properties (such as antimicrobial activity, plant protection activity, etc.) to the composition that would not otherwise be present if the active agent were not present. In some embodiments, the active agent has antifungal, antibacterial, anti-insect, antiviral, anti-mold, or plant protection properties. In some embodiments, the active agent functions as a pesticide. In some embodiments, the active agent includes a pesticide, a herbicide, a fragrance, a fungicide, or any combination thereof. In some embodiments, the active agent includes a plurality of active agents, and the active agents are as described herein. In some embodiments, the active agent is soluble in a hydrophobic solvent.

[0110] In some embodiments, the composition of the present invention is a liquid composition in which a plurality of core-shell particles of the present invention are dispersed. In some embodiments, the composition of the present invention is in the form of an emulsion (W / O or O / W emulsion), dispersion, suspension, and microemulsion or any combination thereof. In some embodiments, the composition is in the form of the Pickering emulsion described herein. In some embodiments, the composition comprises a water-in-oil (W / O) Pickering emulsion. In some embodiments, the composition comprises an oil-in-water (O / W) Pickering emulsion.

[0111] In some embodiments, the composition of the present invention is in the form of an emulsion comprising a hydrophobic solvent (e.g., as the main phase) and a plurality of core-shell particles of the present invention dispersed in the hydrophobic solvent. In some embodiments, the composition of the present invention is substantially homogeneous. In some embodiments, the composition of the present invention is in the form of a water-in-oil emulsion and an oil-in-water Pickering emulsion in which an activator is dissolved in an aqueous solution. In some embodiments, the composition of the present invention is in the form of a water-in-oil emulsion and an oil-in-water Pickering emulsion in which an activator is dissolved in a hydrophobic solvent.

[0112] In some embodiments, the w / w ratio of the hydrophobic solvent to the aqueous solution in the composition is 6:4 to 10:1, 6:4 to 8:4, 2:1 to 3:1, 3:1 to 5:1, 5:1 to 10:1, 2:1 to 10:1, 2:1 to 5:1, 6:4 to 3:1, 3:1 to 10:1, 3:1 to 8:1, 6:1 to 10:1, or any range therebetween.

[0113] In some embodiments, the w / w ratio of the aqueous solution to the hydrophobic solvent in the composition of the present invention is about 1:1 (w / w). In some embodiments, the w / w ratio of the aqueous solution to the hydrophobic solvent in the composition of the present invention is from 1:1 to 1:3 (w / w), 1:1 to 1:2 (w / w), 1:1.5 to 1:3 (w / w), 1:1.5 to 1:4 (w / w), 1:1.5 to 1:5 (w / w), or any range therebetween. In some embodiments, the w / w ratio of the aqueous solution to the hydrophobic solvent in the composition of the present invention is about 1:4 (w / w).

[0114] In some embodiments, the composition of the present invention (e.g., an emulsion) comprises from 30% to 90% (w / w), 30% to 40% (w / w), 40% to 50% (w / w), 50% to 55% (w / w), 55% to 60% (w / w), 60% to 70% (w / w), 70% to 80% (w / w), 80% to 90% (w / w), or any range therebetween of the core-shell particles of the present invention.

[0115] In some embodiments, the w / w concentration of the polymer particles of the present invention in the composition of the present invention is from 0.5% to 5%, 1.5% to 5%, 1.5% to 3%, 1% to 2%, 2% to 3%, 3% to 5%, 1% to 5%, 1% to 3%, or any range therebetween.

[0116] In some embodiments, the w / w concentration of the hydrophobic metal oxide nanoparticles of the present invention in the composition of the present invention is from 0.1% to 10%, 0.1% to 5%, 0.5% to 5%, 0.5% to 1%, 0.5% to 3%, 1% to 2%, 2% to 3%, 3% to 5%, 1% to 5%, 1% to 3%, 1.5% to 5%, 1.5% to 3%, 1.5% to 4%, or any range therebetween.

[0117] In some embodiments, the composition is stable over at least 6 hours (h), at least 12 h, at least 24 h, at least 48 h, at least 72 h, at least 96 h, at least 10 days (d), at least 1 month (m), at least 3 m, at least 6 m, at least 9 m, at least 12 m, at least 24 m, up to 3 m, up to 6 m, up to 9 m, up to 24 m, or any range therebetween.

[0118] As used herein, the term "stable" refers to the ability of a liquid composition to substantially maintain its integrity, such as being substantially free of aggregation, precipitation, and / or phase separation. In some embodiments, a stable composition (e.g., a composition of the present invention or a liquid composition) is substantially free of aggregates. In some embodiments, an aggregate comprises a plurality of core-shell particles attached or bonded to one another.

[0119] In some embodiments, the composition of the present invention is stable under normal storage conditions, including, inter alia, (i) a temperature up to 50 °C, up to 40 °C, up to 30 °C, up to 25 °C, or any range therebetween, (ii) an ambient atmosphere including exposure to ambient gas and optionally humidity, (iii) a pressure near standard atmospheric pressure, (iv) exposure to UV, or any combination of (i) to (iv).

[0120] In some embodiments, the liquid composition of the present invention has adhesion to the surface of a substrate. In some embodiments, the substrate is as described below. In some embodiments, the composition is used as a superhydrophobic coating, an oil-repellent coating, a water-repellent coating, an antifungal coating, an antibacterial coating, an insect-resistant coating, an antiviral coating, an anti-mold coating, an anti-freezing coating, an anti-fogging coating, a plant protection coating, a food packaging coating, or a pesticide coating.

[0121] Article According to some embodiments, the present invention provides an article comprising (i) a substrate and (ii) a coating in contact with the substrate, wherein the coating comprises the hydrophobic metal oxide nanoparticles disclosed herein and a thermoplastic polymer (e.g., polyacrylate, polyester, polyurethane, any derivative thereof or any copolymer) disclosed herein. In some embodiments, the ratio of the hydrophobic metal oxide nanoparticles to the thermoplastic polymer in the coating is from 30:1 to 1:1, from 20:1 to 5:1, from 25:1 to 5:1, from 30:1 to 10:1, from 20:1 to 10:1, from 30:1 to 5:1, from 4:1 to 1.5:1, from 3:1 to 1.5:1, from 2:1 to 1.5:1, or any range therebetween.

[0122] In some embodiments, the coating is as described herein and further characterized by (i) a water contact angle of at least 120°, at least 130°, at least 150°, at least 160°, at least 180°, or any range therebetween, and / or (ii) a roll-off angle of from 0 to 10°, from 0 to 5°, from 2 to 10°, from 5 to 10°, from 0 to 7°, from 0 to 9°, from 1 to 10°, from 1 to 5°, or any range therebetween.

[0123] In some embodiments, the coating is as described herein and the coating is composed of a plurality of hollow microparticles, the shell of the hollow microparticles comprises hydrophobic metal oxide nanoparticles and a thermoplastic polymer, and the core of the hollow microparticles is substantially a cavity. In some embodiments, the hollow microparticles are obtained from the core-shell particles of the present invention. In some embodiments, the hollow microparticles are essentially composed of coalesced polymer particles and hydrophobic metal oxide nanoparticles, and the polymer particles and the hydrophobic metal oxide nanoparticles are as disclosed herein. In some embodiments, the shell of the hollow microparticles is chemically similar or identical to the shell of the core-shell particles described above. In some embodiments, the hollow microparticles substantially do not contain the polymer particles disclosed herein.

[0124] In some embodiments, the coalesced polymer particles define a polymer matrix composed of a thermoplastic polymer, as disclosed herein. In some embodiments, the polymer matrix is an intertwined matrix composed of randomly distributed polymer chains of the thermoplastic polymer. In some embodiments, the polymer chains are randomly distributed within the matrix. In some embodiments, the matrix is substantially free of aligned or oriented polymer chains. In some embodiments, the matrix is substantially free of polymer chains aligned or oriented in a particular direction. In some embodiments, the matrix comprises or consists essentially of polymer chains aligned or oriented in a particular direction.

[0125] In some embodiments, the hydrophobic metal oxide nanoparticles are incorporated within the polymer matrix. In some embodiments, the hydrophobic metal oxide nanoparticles are homogeneously dispersed within the polymer matrix. In some embodiments, the hydrophobic metal oxide nanoparticles are surrounded by the polymer matrix. In some embodiments, the hydrophobic metal oxide nanoparticles are physically and / or chemically adsorbed onto or within the polymer matrix.

[0126] In some embodiments, the hollow microparticles are obtained by drying the composition of the present invention applied onto a substrate, the drying including exposing the composition to a temperature suitable for inducing coalescence of the polymer particles. In some embodiments, the hollow microparticles are obtained by exposing the core-shell particles of the present invention to a temperature suitable for inducing coalescence of the polymer particles (e.g., 20-90 °C).

[0127] In some embodiments, a plurality of hollow microparticles are bonded to a substrate. In some embodiments, the plurality of hollow microparticles are in the form of a coating layer bonded to at least one surface of the substrate. In some embodiments, a plurality of hollow microparticles are impregnated into the substrate. In some embodiments, a plurality of hollow microparticles are incorporated into the substrate.

[0128] In some embodiments, the coating is in the form of a polymeric matrix consisting essentially of or including a thermoplastic polymer, and further includes hydrophobic metal oxide nanoparticles incorporated or homogeneously dispersed within the polymeric matrix. In some embodiments, the hydrophobic metal oxide nanoparticles are surrounded by the polymeric matrix. In some embodiments, the hydrophobic metal oxide nanoparticles are physically and / or chemically adsorbed onto or within the polymeric matrix.

[0129] In some embodiments, the coating is in the form of hollow microparticles, with adjacent microparticles being close to or in contact with each other, and the shell of the hollow microparticles being composed essentially of or consisting of hydrophobic metal oxide nanoparticles and polymer particles. In some embodiments, the hydrophobic metal oxide nanoparticles and polymer particles are mixed within the shell. In some embodiments, the hydrophobic metal oxide nanoparticles and polymer particles are homogeneously dispersed within the coating.

[0130] In some embodiments, each hollow microparticle is in the form of a hollow sphere. In some embodiments, 30% - 99.9%, 30% - 50%, 50% - 60%, 60% - 70%, 70% - 80%, 80% - 90%, 90% - 99.9%, or any range therebetween of the total weight of the hollow microparticles is composed of hydrophobic metal oxide nanoparticles and polymer particles, and the core of the hollow microparticle is a cavity (e.g., substantially free of liquid). In some embodiments, the core of the hollow microparticle is substantially free of hydrophobic metal oxide nanoparticles and / or polymer particles and / or thermoplastic polymer.

[0131] In some embodiments, the core of the hollow microparticle contains 50 - 99.9%, 50 - 60%, 60 - 70%, 70 - 80%, 80 - 90%, 90 - 95%, 95 - 99.9% v / v, or any range therebetween of a gaseous substance (such as air).

[0132] In some embodiments, the particle size of the hollow microparticles is equivalent to the particle size or diameter of the corresponding core-shell particles described herein. In some embodiments, the average particle size of the hollow microparticles is 0.1% to 10%, 0.2% to 10%, 0.3% to 10%, 0.4% to 10%, 0.5% to 10%, 0.1% to 8%, 0.1% to 5%, or 0.1% to 1% of the average diameter of the corresponding core-shell particles, or any range therebetween. In some embodiments, the average particle size of the hollow microparticles is 0.5 μm to 100 μm, 0.9 μm to 100 μm, 1 μm to 20 μm, 1 μm to 50 μm, 10 μm to 50 μm, 1 μm to 100 μm, 2 μm to 15 μm, 2.5 μm to 15 μm, 0.5 μm to 10 μm, 0.9 μm to 10 μm, 1 μm to 10 μm, 2 μm to 10 μm, 2.5 μm to 10 μm, 10 μm to 20 μm, 30 μm to 40 μm, 40 μm to 50 μm, 50 μm to 60 μm, 60 μm to 70 μm, 70 μm to 80 μm, 80 μm to 100 μm, or any range therebetween.

[0133] In some embodiments, a plurality of hollow microparticles are stably bonded to at least one surface of a substrate. In some embodiments, the coating layer is stably adhered to at least one surface of the substrate. In some embodiments, the article and / or the coating layer are stable during long-term storage for at least 1 month (m), at least 6 m, at least 12 m, at least 1 year, at least 2 years, or any range therebetween (e.g., substantially maintaining the bond to the substrate, substantially free of physical defects, substantially maintaining its shape, substantially maintaining its dimensions, physical and mechanical properties, etc.). In some embodiments, the article and / or the coating layer are stable when exposed to ambient conditions (especially including abrasion, climatic conditions, UV radiation, water, water vapor, temperatures from -30 to 40 °C).

[0134] In some embodiments, the article further comprises an antibacterial substance. In some embodiments, the antibacterial substance comprises wax (e.g., propolis) and / or essential oil components (e.g., carvacrol).

[0135] According to some embodiments, the present invention provides an article comprising a substrate in contact with a coating comprising the hollow microparticles of the present invention, and the ratio of the hydrophobic metal oxide nanoparticles to the thermoplastic polymer in the coating is from 30:1 to 1.5:1, from 20:1 to 5:1, from 20:1 to 2:1, from 20:1 to 3:1, from 20:1 to 4:1, from 4:1 to 1.5:1, from 3:1 to 1.5:1, from 2:1 to 1.5:1, or any range therebetween.

[0136] According to some embodiments, the present invention provides an article comprising a substrate in contact with a coating comprising hydrophobic metal oxide nanoparticles incorporated or homogeneously dispersed within a polymer matrix defined by a thermoplastic polymer, and the ratio of the hydrophobic metal oxide nanoparticles to the thermoplastic polymer in the coating is from 30:1 to 1.5:1, from 20:1 to 5:1, from 20:1 to 2:1, from 20:1 to 3:1, from 20:1 to 4:1, from 5:1 to 1.5:1, from 4:1 to 1.5:1, from 3:1 to 1.5:1, from 2:1 to 1.5:1, or any range therebetween.

[0137] In some embodiments, the substrate is selected from a polymer substrate, a glass substrate, a stone substrate, a ceramic substrate, a mineral substrate, a composite substrate comprising stone particles and a polymer, a metal substrate (including metals such as aluminum, steel, precious metals, transition metals, etc.), a paper substrate, a cardboard substrate, a polystyrene substrate, a tissue-based substrate, a cellulose-based substrate (e.g., wood, paper, etc.), a brick wall, a sponge, a textile, a non-woven fabric, or a wood substrate, or any combination thereof.

[0138] In some embodiments, the substrate is a polymer substrate comprising a thermoplastic polymer such as a polyolefin (e.g., PE, PP), a rubber, a polycarbonate, a polyester, a polyamide, etc. In some embodiments, the substrate is a paper substrate, a metal substrate, and / or a polymer substrate. In some embodiments, the substrate is a multilayer substrate (e.g., a laminate, a coextruded polymer substrate), etc.

[0139] In some embodiments, the coating is in the form of a coating layer. In some embodiments, the coating is in the form of a substantially uniform continuous layer. In some embodiments, the coating layer contains a hydrophobic solvent in the remaining amount (e.g., 10 ppm to 0.3% of the weight of the coating).

[0140] In some embodiments, the coating or the coating layer is characterized by an average thickness in the range of 100 nm to 500 μm, 500 nm to 10 μm, 500 nm to 50 μm, 1 to 50 μm, 500 nm to 5 μm, 800 nm to 10 μm, 800 nm to 5 μm, 100 nm to 400 μm, 100 nm to 300 nm, 300 nm to 500 nm, 500 nm to 1000 nm, 250 nm to 400 μm, 500 nm to 400 μm, 900 nm to 400 μm, 1 μm to 400 μm, 10 μm to 400 μm, 50 μm to 400 μm, 100 μm to 400 μm, 250 μm to 400 μm, 10 nm to 100 μm, 25 nm to 100 μm, 50 nm to 100 μm, 100 nm to 100 μm, 250 nm to 100 μm, 500 nm to 100 μm, 900 nm to 100 μm, 1 μm to 100 μm, 10 μm to 100 μm, 50 μm to 100 μm, 10 nm to 10 μm, 25 nm to 10 μm, 50 nm to 10 μm, 100 nm to 10 μm, 250 nm to 10 μm, 500 nm to 10 μm, 900 nm to 10 μm, or 1 μm to 10 μm, or any range therebetween.

[0141] In some embodiments, the coating layer has an outer surface facing the surroundings and an inner surface facing the substrate. In some embodiments, the outer surface of the coating layer is characterized by a water contact angle (WCA) in the range of 120° to 180°, 130° to 165°, 130° to 160°, 130° to 150°, or 135° to 165°, or any range therebetween.

[0142] In some embodiments, the outer surface of the article is characterized by a water contact angle of at least 130°. In some embodiments, the outer surface of the article is characterized by a water contact angle in the range of 100° to 180°, 110° to 180°, 120° to 180°, 130° to 180°, 130° to 168°, 130° to 165°, 130° to 160°, 130° to 150°, or 135° to 165°, or any range therebetween.

[0143] In some embodiments, the outer surface of the coating layer is characterized by a roll-off (RA) angle of less than 30°, less than 25°, less than 20°, less than 15°, less than 10°, less than 9°, less than 8°, less than 7°, less than 6°, or less than 5°, less than 3°, or any value therebetween. In some embodiments, the outer surface of the coating layer is characterized by an RA angle in the range of 10° to 0°, 10° to 3°, 10° to 5°, 9° to 0°, 9° to 3°, 9° to 5°, 8° to 1°, 8° to 3°, 8° to 5°, 5° to 3°, 3° to 0°, 1° to 0°, or any range therebetween. In some embodiments, the outer surface of the article is characterized by an RA angle of less than 10°, less than 9°, less than 8°, less than 7°, less than 6°, or less than 5°, or any value therebetween.

[0144] In some embodiments, the outer surface of the coating layer is characterized by a static contact angle in the range of 130° to 170°, 140° to 160°, 135° to 165°, 145° to 155°, 145° to 160°, 150° to 160°, or any range therebetween.

[0145] In some embodiments, the surface roughness of the outer surface of the coating layer is 20 to 100 nm, 1 to 10 nm, 10 to 100 nm, 10 to 20 nm, 10 to 50 nm, 20 to 50 nm, 50 to 100 nm, 10 to 200 nm, 100 to 200 nm, or any range or value therebetween.

[0146] In some embodiments, the outer surface of the coating layer is characterized by a root mean square (RMS) surface height of 20 to 100 nm, 10 to 20 nm, 10 to 50 nm, 20 to 50 nm, 50 to 100 nm, 10 to 200 nm, or any range or value therebetween.

[0147] In some embodiments, the outer surface of the coating layer is characterized by a peak roughness (based on AFM analysis) of 100 to 800 nm, 200 to 800 nm, 200 to 600 nm, 300 to 800 nm, 300 to 600 nm, or any range or value therebetween.

[0148] In some embodiments, the coating layer and / or the article is stable at a temperature in the range of -100°C to 200°C, -50°C to 200°C, -10°C to 200°C, 0°C to 200°C, 10°C to 200°C, 50°C to 1500°C, 100°C to 200°C, -100°C to 200°C, -50°C to 200°C, -10°C to 200°C, 0°C to 200°C, 10°C to 100°C, 100°C to 200°C, or any range therebetween.

[0149] In some embodiments, the coating layer and / or the article is characterized by wear stability as measured by the wear test described below.

[0150] In some embodiments, the coating layer is characterized by a transparency of 30% to 100%, 40% to 100%, 50% to 100%, 60% to 100%, 70% to 100%, 80% to 100%, 30% to 99.9%, 40% to 99.9%, 50% to 99.9%, 60% to 99.9%, 70% to 99.9%, 80% to 99.9%, 30% to 99%, 40% to 99%, 50% to 99%, 60% to 99%, 70% to 99%, 80% to 99%, 30% to 98%, 40% to 98%, 50% to 98%, 60% to 98%, 70% to 98%, 80% to 98%, 30% to 95%, 40% to 95%, 50% to 95%, 60% to 95%, 70% to 95%, 80% to 95%, 30% to 90%, 40% to 90%, 50% to 90%, 60% to 90%, 70% to 90%, or 80% to 90%, or any range therebetween.

[0151] In some embodiments, the article is or includes a coated cellulose-based substrate, and the coated cellulose-based substrate is characterized by a tensile stress in the range of 50 to 70 MPa, 50 to 65 MPa, 55 to 65 MPa, 55 to 70 MPa, or any range therebetween.

[0152] In some embodiments, the coating layer is water-repellent. In some embodiments, the coating layer does not allow water to pass through. In some embodiments, the coating layer substantially reduces the absorption of water by the substrate.

[0153] In some embodiments, the article is characterized by a tensile stress that is at least 2 times, at least 3 times, or at least 4 times stronger compared to a similar article without the coating layer (e.g., uncoated paper).

[0154] In some embodiments, the article is or comprises a coated cellulose-based substrate, and the cellulose-based substrate and / or the article is characterized by a water absorption rate of up to 40%, up to 30%, up to 25%, or about 20% relative to the dry weight of the article, or any range therebetween. In some embodiments, the article is characterized by a water absorption rate that is at least one-half, at least one-two point five, at least one-third, at least one-fourth, or at least one-fifth less compared to a similar article without a coating layer (or compared to an article comprising the same substrate coated with a latex coating).

[0155] In some embodiments, the substrate is a cellulose-based wet substrate, and the article is characterized by an average maximum tensile stress that is at least two times, at least two point five times, at least three times, at least four times, or at least five times greater compared to a similar article without a coating layer (or compared to an article comprising the same substrate coated with a latex coating).

[0156] In some embodiments, the coating layer is a substantially uniform coating layer characterized by a substantially uniform density and / or surface pattern. In some embodiments, the coating layer is characterized by a pattern that includes a microstructure and a nanostructure, and the nanostructure is formed on top of the microstructure. In some embodiments, the coating layer is characterized by a pattern consisting essentially of a microstructure. In some embodiments, the microstructures are in proximity to each other. In some embodiments, adjacent microstructures are adjacent to each other. In some embodiments, adjacent microstructures are in contact with each other (e.g., having at least a point of contact). In some embodiments, the microstructures are shaped spherically. In some embodiments, the microstructures are shaped elliptically. In some embodiments, the microstructures have a rectangular, rhomboidal, prismatic, trapezoidal, pyramidal, hexagonal, honeycomb shape, or have substantially no uniform structure and / or defined structure. In some embodiments, the microstructure is in the form of a three-dimensional honeycomb-like structure.

[0157] In some embodiments, each microstructure is a hollow-shaped particle comprising a hollow (void) core and a shell containing the hydrophobic metal oxide particles and polymer particles disclosed herein. In some embodiments, the hydrophobic metal oxide particles and polymer particles are uniformly dispersed within the shell. In some embodiments, the hydrophobic metal oxide particles and polymer particles are in the form of separate layers within the shell (e.g., an inner layer facing the core and containing the metal oxide particles is in contact with an outer layer containing the polymer particles). In some embodiments, the polymer particles are in the form of composite particles (e.g., composite latex particles). In some embodiments, the shell of the microstructure consists essentially of hydrophobic metal oxide nanoparticles and latex particles, and the ratio of hydrophobic metal oxide nanoparticles to latex particles is as disclosed above.

[0158] In some embodiments, the nanostructure is in the form of aggregated nanoparticles, and the nanoparticles are characterized by an average particle size in the range of 10 - 100 nm, 10 - 80 nm, 10 - 70 nm, 10 - 60 nm, 10 - 50 nm, or any range therebetween.

[0159] In some embodiments, the coating layer is an antibacterial coating.

[0160] In some embodiments, the coating layer has at least one characteristic selected from antifungal coatings, antibacterial coatings, anti-insect coatings, antiviral coatings, anti-mold coatings, plant protection coatings, and pesticide coatings.

[0161] In some embodiments, the coating of the present invention is an antibacterial and anti-biofilm coating. In some embodiments, the coating of the present invention can reduce or prevent at least one of (i) biofilm formation and (ii) microbial load. In some embodiments, the reduction is at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 70%, at least 100%, or any range therebetween, compared to a control. In some embodiments, the control is the same substrate without the coating layer of the present invention. In some embodiments, the antibacterial coating can reduce the microbial load to a range of 1 / 2 to 1 / 20, 1 / 2 to 1 / 5, 1 / 5 to 1 / 7, 1 / 7 to 1 / 10, 1 / 10 to 1 / 12, 1 / 12 to 1 / 15, 1 / 15 to 1 / 20, or any range therebetween. In some embodiments, the antibacterial coating can reduce the microbial load to a range of 1 / 20 to 1 / 100,000, 1 / 20 to 1 / 100, 1 / 100 to 1 / 1000, 1 / 1000 to 1 / 10,000, 1 / 10,000 to 1 / 100,000, 1 / 100,000 to 1 / 1,000,000, or any range therebetween, compared to a control (e.g., a similar article without the coating disclosed herein).

[0162] In some embodiments, the coating of the present invention is an anti-biofilm coating that can prevent biofilm formation on the coated surface.

[0163] As used herein, the term "biofilm" refers to a three-dimensional microbial community encapsulated in a matrix exhibiting multicellular characteristics. Thus, as used herein, the term "biofilm" includes not only surface-associated biofilms, but also biofilms in suspensions such as flocs and granules. A biofilm may contain a single microbial species, a mixed-species complex, and may contain bacteria or other microorganisms.

[0164] As used herein, the term "reduction" in any grammatical form relates to a reduction of any type of biofilm (e.g., pellicle, bundle) on or within an article as compared to a similar article without the coating described herein. In some embodiments, the formation of biofilm on the anti-biofilm coating is essentially invalidated (e.g., prevented), or at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least one tenth, at least one hundredth, at least one thousandth, at least one ten-thousandth, or any value therebetween, as compared to an uncoated substrate.

[0165] In some embodiments, the article of the present invention comprises a coating layer characterized by a reduction in microbial load and / or a reduction in biofilm formation, the reduction being in the range of 1 / 2 to 1 / 20, 1 / 20 to 1 / 100,000, 1 / 20 to 1 / 100, 1 / 100 to 1 / 1000, 1 / 1000 to 1 / 10,000, 1 / 10,000 to 1 / 100,000, 1 / 100,000 to 1 / 1,000,000, or any range therebetween, as compared to a control. In some embodiments, the reduced microbial load refers to the number of CFUs of microorganisms on or within the coating layer as compared to a control (e.g., a similar article without the coating disclosed herein). In some embodiments, the reduction in the microbial load and / or biofilm formation of the control and the article of the present invention is evaluated by exposing to microorganisms at a similar concentration (e.g., CFU).

[0166] In some embodiments, the coating layer is 1 - 10 4 CFU / cm 2 、1 - 10 CFU / cm 2 、10 - 100 CFU / cm 2 、100 - 10 3 CFU / cm 2 、10 3 ~10 4 CFU / cm 2 、10 3 ~105 CFU / cm 2 or characterized by a microbial load in any range therebetween.

[0167] In some embodiments, the biofilm contains bacteria. In some embodiments, the microorganisms include bacteria and / or fungi. In some embodiments, the bacteria are selected from Gram-positive bacteria and / or Gram-negative bacteria. In some embodiments, the bacteria are spore-forming bacteria. In some embodiments, the bacteria are thermophilic bacteria. In some embodiments, the term "microorganism" refers to any prokaryote belonging to all phyla in the Kingdom Prokaryota. The term "bacteria" is intended to encompass all microorganisms considered to be bacteria, including Escherichia coli, Mycoplasma, Chlamydia, Actinomyces, Streptomyces, and Rickettsia. This definition includes all forms of bacteria, including cocci, bacilli, spirochetes, spheroplasts, protoplasts, etc.

[0168] In some embodiments, the bacteria belong to the genus Escherichia. In some embodiments, the bacteria are or include Escherichia coli.

[0169] In some embodiments, the coating layer according to the present invention is stable against climate change. In some embodiments, the coating layer is stable against temperature changes, heating, cooling, UV radiation, and corrosive elements in the atmosphere. In some embodiments, the properties of the coating layer are not affected or changed by climate change as described herein. In some embodiments, the article according to the present invention is stable against climate change. In some embodiments, the article is stable against temperature changes, heating, cooling, UV radiation, and corrosive elements in the atmosphere. In some embodiments, the properties of the article are not affected or changed by climate change as described herein.

[0170] Method According to some embodiments, the present invention provides a method for coating a substrate. In some embodiments, the method includes: i) providing a substrate; and ii) contacting at least a portion of the substrate with the composition described herein, thereby forming a coating layer on the substrate. In some embodiments, the method of the present invention further includes preparing the coating layer under conditions suitable for drying the liquid coating layer, thereby obtaining a dried coating layer on the substrate. In some embodiments, the method of the present invention is for obtaining a substrate coated as described herein. In some embodiments, the substrate is as described herein.

[0171] In some embodiments, the conditions suitable for drying include exposing the coating layer to a temperature above the glass transition point of the polymer particles (and / or the thermoplastic polymer) as described herein. In some embodiments, the conditions suitable for drying include exposing the coating layer to a temperature above the coalescence point of the latex polymer particles. In some embodiments, the conditions suitable for drying include exposing the coating layer to a temperature in the range of 10 - 200°C, 20 - 200°C, 40 - 200°C, 50 - 200°C, 40 - 100°C, 40 - 150°C, 20 - 80°C, 25 - 80°C, 30 - 90°C, 30 - 80°C, 30 - 60°C, or any range therebetween. In some embodiments, the temperature is lower than the melting point or the disintegration temperature of the substrate.

[0172] In some embodiments, drying includes exposing the coating layer to any one of vacuum, thermal radiation, microwave radiation, infrared radiation, and UV-visible light radiation, or any combination thereof.

[0173] In some embodiments, the contacting is selected from the group consisting of spin coating, roll coating, spray coating, and kiss coating, air knife coating, anilox coater, flexo coater, gap coating, dip coating, rod coating, and immersion.

[0174] In some embodiments, drying is performed by placing the coated substrate in a hot air furnace, whereby a dried coated substrate is obtained, and the hot air furnace is at a temperature in the range of 20°C to 180°C, 25°C to 180°C, 30°C to 180°C, 30°C to 150°C, 30°C to 90°C, 30°C to 80°C, 30°C to 70°C, 30°C to 60°C, 40°C to 180°C, 40°C to 150°C, 40°C to 90°C, 40°C to 80°C, 40°C to 70°C, 40°C to 60°C, 50°C to 180°C, 50°C to 150°C, 50°C to 90°C, 50°C to 80°C, 50°C to 70°C, or 50°C to 60°C, or any range therebetween.

[0175] In some embodiments, drying is performed for a time in the range of 1 hour to 24 hours, 2 hours to 24 hours, 3 hours to 24 hours, 5 hours to 24 hours, 6 hours to 24 hours, 1 hour to 12 hours, 2 hours to 12 hours, 3 hours to 12 hours, 5 hours to 12 hours, 6 hours to 12 hours, 1 hour to 8 hours, 2 hours to 8 hours, 3 hours to 8 hours, or 5 hours to 8 hours, or any range therebetween.

[0176] In some embodiments, drying includes air drying.

[0177] In some embodiments, the coating adheres to the substrate. In some embodiments, the article is stable. In some embodiments, the article remains stable when exposed to UV radiation, IR radiation, visible light radiation, thermal radiation, microwave radiation, or any combination thereof.

[0178] As used herein, the term "stable" refers to the ability of an article (e.g., a coated substrate) to maintain its structural and / or mechanical integrity, such as without cracks and / or deformations. In some embodiments, an article is said to be stable when it substantially maintains its structural and / or mechanical integrity under outdoor conditions such as temperatures from -25 to 75 °C, UV and / or visible light radiation. In some embodiments, a stable article is rigid under outdoor conditions. In some embodiments, a stable article maintains its tensile strength and / or elasticity. In some embodiments, "substantially" is as described below. In some embodiments, a stable article can maintain its superhydrophobic properties (e.g., substantially maintain its initial water contact angle) in continuous wear cycles, as disclosed herein.

[0179] In some embodiments, the article is in the form of a film. In some embodiments, the article is in the form of a continuous layer. In some embodiments, the article is in the form of tableware. In some embodiments, the article is in the form of a packaging material. In some embodiments, the article is in the form of a packaged article. In some embodiments, the article is in the form of a food packaging article. In some embodiments, the packaging material is for packaging edible items.

[0180] In some embodiments, the coated substrate has at least one feature selected from an antifungal coating, an antibacterial coating, an insect-resistant coating, an antiviral coating, an anti-mold coating, a plant protection coating, a pesticide coating.

[0181] General As used herein, the term "about" refers to ± 10%.

[0182] The terms "comprise", "include", "have" and their conjugations mean "including but not limited to".

[0183] The term "consisting of" means "including and limited to those".

[0184] The term "consisting essentially of" means that a composition, method, or structure (e.g., a coating) may include additional ingredients, steps, and / or parts only if the additional ingredients, steps, and / or parts do not substantially change the basic novel features of the claimed composition, method, or structure. Thus, as used herein, the term "consisting essentially of" means that a composition, method, or structure (e.g., a coating) does not substantially include any active ingredients other than the ingredients of the compositions disclosed herein.

[0185] As used herein, the word "exemplary" is used to mean "serving as an example, instance, or illustration". Embodiments described as "exemplary" should not necessarily be construed as preferred or advantageous over other embodiments and / or as excluding the incorporation of features from other embodiments.

[0186] As used herein, the word "optionally" is used to mean "provided in some embodiments and not provided in other embodiments". Any particular embodiment of the invention may include a plurality of "optional" features as long as such features are not inconsistent.

[0187] As used herein, the singular forms "a", "an", and "the" include plural references unless the context clearly dictates otherwise. For example, the term "compound" or "at least one compound" may include a plurality of compounds including mixtures thereof.

[0188] Throughout this application, various embodiments of the invention may be presented in a range format. It should be understood that the description in range format is for convenience and brevity only and should not be construed as rigidly limiting the scope of the invention. Thus, the description of a range should be considered to specifically disclose all possible sub-ranges within the range, as well as the individual numerical values that are considered to be within the range. For example, a description of a range such as "1 to 6" should be considered to specifically disclose sub-ranges such as "1 to 3", "1 to 4", "1 to 5", "2 to 4", "2 to 6", "3 to 6", etc., as well as the individual numerical values within the range, such as 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0189] Whenever a numerical range is indicated in this specification, it is intended to include any number (fractional or integer) recited within the indicated range. The phrases "from the first recited number to the second recited number" and "from the first recited number through the second recited number" are used interchangeably herein and are intended to include the first and second recited numbers and all fractional and integer numbers therebetween.

[0190] As used herein, the term "substantially" refers to at least 85%, at least 90%, at least 92%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or any range or value therebetween.

[0191] As used herein, the term "method" refers to a manner, means, technique, and procedure for accomplishing a given task, including, but not limited to, manners, means, techniques, and procedures known to or readily developed from known manners, means, techniques, and procedures by physicians in the fields of chemistry, pharmacology, biology, biochemistry, and medicine.

[0192] As used herein, the term "treating" includes halting, substantially suppressing, delaying, or reversing the progression of a symptom, substantially alleviating the clinical or aesthetic state of a symptom, or substantially preventing the manifestation of the clinical or aesthetic state of a symptom.

[0193] It will be appreciated that certain features of the invention described in connection with individual embodiments may also be provided in combination in a single embodiment. Conversely, various features of the invention described in connection with a single embodiment may also be provided separately or in any suitable partial combination or in any other suitable embodiment of the invention. Specific features described in connection with various embodiments should not be considered essential features of those embodiments unless the embodiments are inoperative without those elements.

[0194] The various embodiments and aspects of the invention described above and claimed in the following claims are experimentally supported in the following examples.

[0195] Examples Materials and Methods Preparation of Silica-Stabilized Pickering Emulsions Pickering emulsions were prepared based on an aqueous solution (1 wt%) of Latex PRIMER1853.E (obtained from Michemflex, Belgium) in double-distilled water (DDW) and hydrophobic silica (Aerosil R202, estimated primary particle size 14 nm, obtained from Evonik, Germany) in a solvent (toluene, dimethyl carbonate, or cyclohexane) (analytical grade, obtained from Fisher Scientific, UK). The hydrophobic silica NPs were dispersed in various v / v% ratios of the latex solution in v / v% ml of toluene or dimethyl carbonate by applying ultrasound (Sonics Vibra-Cell 750W, amplitude 25%) for 10 minutes at different wt% silica contents.

[0196] Preparation of Pickering Emulsion in DMC Stabilized by Latex Pickering emulsions of DMC and an aqueous latex dispersion (Latex PRIMER1853) (1 wt%) were prepared at various oil - to - water ratios. The miscibility of DMC in water is 13.9%, and thus the volume of the solvent was calculated based on the following formula: oil ml×1.139 = solvent ml (for example, when the oil - to - water ratio is 8:2, the required solvent is 8 ml×1.139 = 9.112 ml). The overall method is as follows: The organic solvent and the latex aqueous dispersion (1 wt%) were sonicated for 10 minutes to obtain a final emulsion volume of 10 ml.

[0197] Preparation of Pickering Emulsion in DMC Stabilized by Silica and Latex Pickering emulsions were prepared using hydrophobic silica (Aerosil R202, estimated primary particle size 14 nm, obtained from Evonik, Germany) with different mass fractions wt%, a latex aqueous dispersion (1 wt%), and DMC. As disclosed above, the volume of the solvent was calculated using the formula: oil ml×1.139 = solvent ml. This Pickering emulsion was prepared by dispersing various v / v% of hydrophobic silica NPs together with the aqueous latex dispersion in dimethyl carbonate. Briefly, all components were mixed together and sonicated in a 10 - ml glass vial for 10 minutes.

[0198] Coating Application The prepared emulsions were applied onto various surfaces by the roll - coating method (wire length 45 cm, wire diameter 1 mm). To enable rapid evaporation of the emulsion, these surfaces were placed in a hot - air oven maintained at 60 - 80 °C for 1 hour.

[0199] Instability Analysis The instability analysis of the emulsion was performed using a multi - sampling analytical centrifuge LUMiSizer® (L.U.M. GmbH, Berlin, Germany), which enables the measurement of the intensity of transmitted light as a function of time and position over the entire length of the sample simultaneously.

[0200] Microscopy and image analysis Confocal microscopy Samples were analyzed by laser scanning confocal microscopy (Leica, Wetzlar, Germany) using 552 nm excitation light. Fluorescence emission of Nile red was recorded at 565 - 660 nm. The average droplet diameter was measured for each sample using the Fiji software particle analysis tool based on confocal microscopy images.

[0201] Pickering emulsions in DMC stabilized by silica and / or latex were investigated by labeling oil, silica, and latex with Nile red, 5,6-carboxyfluorescein, and Nile blue, respectively. Imaging was performed by confocal fluorescence microscopy using solid-state lasers at 552, 493, and 631 nm to excite Nile red, 5,6-carboxyfluorescein, and Nile blue, respectively. Fluorescence emission of each dye was detected at wavelengths specific to the dye, 635, 517, and 660 nm, respectively. For analysis, 2 μl was taken and placed on a slide glass and covered with a cover glass. The size distribution of the droplets was analyzed using Fiji software by measuring the diameter of the droplets (more than 100 droplets in two images).

[0202] Cryogenic scanning electron microscopy (cry-SEM) Low-temperature scanning electron microscope analysis was performed using a JSM-7800F Schottky field emission SEM microscope (JEOL Ltd., Tokyo / Japan) equipped with a low-temperature system (Quorum PP3010, Quorum Technologies Ltd., Loughton / UK). Liquid nitrogen was used in all heat exchange units of the low-temperature system. Small droplets of the emulsion were placed between two rivets on the sample holder, rapidly frozen with liquid nitrogen for several seconds, transferred to the preparation chamber, and sectioned there (at -140 °C). The exposed cross-section was sublimated (-85 °C for 20 minutes) to eliminate the presence of condensed ice and then coated with platinum (at 10 mA for 50 seconds). The temperature of the sample was maintained at -140 °C. Images were acquired with a low-energy electron detector (LED) at an acceleration voltage of 5.0 kV and a working distance of 4 mm.

[0203] Wear resistance analysis The wear resistance of the coating was tested using standard nitrile gloves. The coated samples were placed on a scale and pressed with a finger. While maintaining a pressure of 1 kg, the finger was moved in one direction over each sample. Each tracing of the entire sample with the finger was counted as one wear cycle.

[0204] Water absorption test In the test, five paper samples of each group (i.e., control, latex, and superhydrophobic coating SHC) were cut to 3×1 inches. Each sample was then immersed completely for 10 seconds, dried on dry paper (Kimwipe) for 2 seconds, and its weight was measured with an analytical balance. For confocal characterization evaluation, 6-amino fluorescein (1 mg / L) was added to the water in which the samples were immersed.

[0205] Mechanical analysis The mechanical properties of the uncoated paper and coated paper samples were measured using an extensometer (Instron 3345). The measurements were carried out according to the standard measurement method (ASTM D828) using a 5,000 N test head, and clamp pressures of 9 bar and 4 bar while testing the dry samples and wet samples respectively. During the measurement of the wet samples, the samples were immersed in DDW for 5 seconds, then hung for 45 seconds to dry before measurement.

[0206] Solvent residue The detection of DMC residues in the dry samples was carried out using GC / MS. This test was performed on paper samples cut into small squares (samples of approximately a few mm in size), and then the weight was measured. The residual DMC content of the samples was normalized against the weight of each sample. The DMC concentration was determined according to a pre-prepared calibration curve of 0.5 - 20 ppm.

[0207] Biofilm assay Bacteria were inoculated into Mueller - Hinton (MH) growth medium and diluted until the suspension reached OD595 (3×10 8 CFU). Then, the diluted medium was dispensed into 24 - well plates (SPL Life Sciences). To evaluate the antibacterial / biofilm activity of the coating, 1×1 cm or 2×2 cm cut - outs of the coated PP were placed surface - down in the pre - prepared Mueller - Hinton (MH) growth medium. Then, the samples were cultured at 37 °C for 20 hours and washed three times to remove floating cells. Multicellular cells were collected from the surface using a cell scraper (Greiner Bio - one) with 250 μl of MH 1%. Then, each sample was diluted using MH 1% to a final volume of 2 ml. After dilution, the samples were sonicated (20 minutes, 37 KHz) and further mixed using a vortex for 30 minutes. After mixing, serial dilutions were made using 180 μl of each sample until the final dilution was reached. Then, the bacteria were spread on lysogenic medium (LB) agar plates and cultured at 37 °C for 20 hours. The growth of the bacteria was determined by counting the live cells.

[0208] Surface wettability analysis To examine the surface wettability, the static water contact angle (CA) and the roll-off angle (RA) were measured at ambient temperature using a Drop Shape Analyzer (DSA 100 Kruss). A 5 μl water droplet (AR grade) was dispersed on the coating surface and a side view image was captured. To measure the RA of water, the stage was tilted and a 5 μl water droplet was dropped onto the surface. The RA was recorded as the stage tilt angle at which all the water droplets began to roll off the coating surface. To confirm the reproducibility of the results, 18 measurements were checked on two replicate samples prepared under the same conditions.

[0209] The surface wettability and the static water contact angle (CA) value of the Pickering emulsion in DMC stabilized by silica and latex were measured with a Drop Shape Analyzer. Briefly, 200 ml of water (AR grade) was heated using a hot plate or cooled using an ice bath, then 5 μl droplets of the Pickering emulsion were pipetted and manually dropped onto the surface. Similarly, for the dynamic contact angle measurement, 5 μl of water (AR grade) was dropped onto the surface in a drop and suction loop operation, then an image was captured and analyzed using "Advance" software. To confirm the reproducibility of the results, 9 measurements were performed on two replicate samples.

[0210] Morphological study The microstructure of the prepared polymer particles was examined using a Transmission Electron Microscope (TEM). To perform cryo-TEM analysis, the latex was diluted with double-distilled water. Droplets of the diluted latex were placed on a carbon-coated grid and dried in a dissector.

[0211] Scanning Electron Microscope (SEM) The model MIRA3 from TESCAN was used at 5 kV, and scanning electron microscope (SEM) images of the prepared coating were obtained using a secondary electron detector. To prepare samples for SEM analysis, the PP surface coated with a pickering emulsion was placed on an aluminum sample holder covered with carbon tape. To reduce the charging effect, the samples were sputter-coated with gold palladium. Atomic force microscope (AFM) analysis was performed by operating a commercially available AFM (JPK Nanowizard III) in tapping mode. A silicon cantilever coated with aluminum was used with a spring constant of approximately 40 N / m and driven at a frequency of 250 kHz in air. All AFM experiments were conducted at room temperature.

[0212] Atomic Force Microscope (AFM) Atomic force microscope (AFM) analysis was performed by operating a commercially available AFM (JPK Nanowizard III) in tapping mode. A silicon cantilever coated with aluminum was used with a spring constant of approximately 40 N / m and driven at a frequency of 250 kHz in air. All AFM experiments were conducted at room temperature.

[0213] Example 1 Preparation of Latex-Based Emulsion The inventors conducted various tests using DMC as a hydrophobic solvent and an aqueous latex dispersion to test the emulsion-forming ability at various solvent ratios with or without hydrophobic silica nanoparticles. The oil-water ratio was appropriately varied (to obtain a final volume of 10 mL). The overall methodology was as follows: A mixture of DMC and an aqueous latex dispersion (1 wt% latex particles) was sonicated for 10 minutes. The results are summarized in Table 1. [Table 1]

[0214] High standard deviation values at ratios of 2:8, 4:6, 5:5, 7:3, and 8:2 indicate a polydisperse system where droplets of various diameters are observed in the same emulsion.

[0215] DMC-based emulsions were prepared at a total polymer concentration of 1% wt and the oil / water ratio was varied to 2:8, 3:7, 4:6, 5:5, 7:3, and 8:2 at a constant total polymer concentration of 1% wt, and the droplet size distribution was evaluated using confocal microscopy. The size distribution and average diameter of the oil droplets in these emulsions are shown in Table 1. As can be seen from Table 1, the change in the oil phase concentration affected the size distribution profile of the oil droplets, and the average droplet diameter was in the range of 8.88 - 39.97 μm. The average diameter plotted as a function of the oil / water ratio suggests that an increase in the proportion of the solvent (and the accompanying decrease in the proportion of water) led to an increase in the average diameter of the droplets (Table 1).

[0216] To understand the microstructure, the emulsion samples were cryo-sectioned, water was sublimated in a low-temperature preparation chamber, and then the samples were imaged under a low-temperature electron microscope.

[0217] By sublimating the water in the sectioned samples, the presence of a polymer pore-like network and a continuous aqueous phase in the internal space became visible, confirming that the emulsion samples had a complex microstructure.

[0218] Looking closely at the cryo-SEM images of an oil-in-water emulsion based on toluene and water (8:2) with 1 wt% latex polymer, the inventors confirmed individual spheres with one thin separate layer. When the latex particles completely cover the droplet surface, a polymer shell is formed by sintering the latex particles into one homogeneous monolayer. This was achieved by heating the emulsion above the Tg (or coalescence point) of the acrylic latex particles (-25 °C) to induce particle coalescence.

[0219] Emulsions prepared using DMC and latex copolymers in the aqueous phase were O / W type at time zero and immediately showed soft aggregation and creaming. Cryo-SEM images of cryo-fractured samples of the cream layer suggest that oil droplets are surrounded by the mesh of the polymer network to form a barrier and prevent internal contact between oil droplets. On the 5th day, the inventors observed a change in the behavior of the emulsion. By confocal microscopy, complete phase separation and the absence of droplets, so-called phase inversion transition steps, were shown at ratios of 2:8, 4:6, and 6:4. Phase inversion to a water-in-oil emulsion occurred at ratios of 6:4, 7:3, and 8:2 (Table 2). Therefore, it became clear that a stable emulsion could not be formed based only on latex as an emulsion stabilizer.

[0220] In a Pickering emulsion, the type of emulsion is controlled by the wettability of silica nanoparticles. Therefore, phase inversion can be triggered by changing the hydrophobicity of the emulsifier or other physical or chemical parameters such as pH, electrolyte, temperature, surfactant concentration, etc. In this case, due to the competition between silica nanoparticles dispersed in the oil part and the surfactant in the aqueous part of the 1 wt% latex solution, a transition phase inversion from an O / W emulsion to a W / O emulsion occurred. The transition phase inversion can be achieved by changing the hydrophilic-lipophilic balance (HLB) of any emulsion system at a constant volume fraction of the dispersed phase. The inversion from an o / w emulsion to a w / o emulsion can be achieved by decreasing and reversing the HLB of the system. Therefore, the inventors considered that it was necessary to incorporate hydrophobic silica nanoparticles into the emulsion to obtain a stable emulsion.

[0221] Preparation of latex-hydrophobic silica-based Pickering emulsions The prototypes and tests conducted in the experiment of DMC: latex dispersed in water with hydrophobic silica were summarized in Table 2 for time zero, day 5, and day 32. At this stage, the emulsion-forming ability with various components and the ratio of solvent to silica nanoparticles were tested. The oil-water ratio was appropriately varied at a silica concentration of 1 wt.% (to obtain a final volume of 10 mL). DMC solvent, R202 silica, and an acrylic latex copolymer dispersed in water were used. The overall methodology was as follows: The organic solvent DMC and silica particles dispersed in water based on the latex were sonicated for 10 minutes to obtain a 10 mL mixture.

[0222]

Table 2

[0223] After heating the treated polypropylene surface at 60 °C for 1 hour, it was suggested that the inventors could distinguish individual droplets by cryo-SEM and that the heating did not induce the fusion of adjacent droplets (Figure 4A).

[0224]

Table 3

[0225] In further experiments, the inventors observed that stable compositions (emulsions) of the present invention could be formed using 2% wt of hydrophobic silica NPs (Aerosil R202, PDMS-functionalized silica NPs) at various DMC: water (1 wt% latex NPs) ratios in the range of 9:1 to 2:8, respectively. The inventors currently consider that the most preferred v / v range of DMC: water is at least 1:1, or 6:4 to 9:1, for example, about 8:2 to 9:1.

[0226] The coating (also referred to herein as the "superhydrophobic coating") obtained by depositing an exemplary composition of the present invention containing DMC: water in a volume ratio of 8:2, 1 wt% latex, and 2 wt% hydrophobic silica was characterized by cryo-SEM and confocal microscopy. Carboxyfluorescein was covalently bonded to the hydrophobic silica. The addition of hydrophobic silica formed a water-in-oil (DMC) inverse emulsion. Micrographs of single droplets (Figures 13A, 13B) show aggregates of small latex adhering to a continuous interfacial shell layer (mainly composed of hydrophobic silica). Examination of several droplets in the same way revealed a similar structure (Figure 13D).

[0227] To understand the spatial arrangement of the studied system, confocal images were collected and stacked (Z-stack) to generate a single 3D image of approximately 15 μm. The stacked images (Figure 13F) show that the silica particles are the main stabilizers and remain at the interface. The acrylic latex particles assist in the stabilization of the water droplets and occupy the interface as co-stabilizers, but more predominantly, they form a stable particle network between the water droplets in the main phase. Without being bound by a particular theory, each particle type is thought to play a different role in the formation and stabilization of the emulsion, and thus the terms "α particles" and "β particles" were assigned to the silica and acrylic latex particles, respectively (Figure 13C). Interestingly, the addition of silica particles changed the position and arrangement of the latex particles from a state of being dispersed in water to a state of forming a bridge structure in the main phase. The schematic diagram in Figure 13E shows the positions of each particle type.

[0228] Example 2 The inventors further succeeded in coating the above-mentioned Pickering emulsion onto substrate samples (e.g., glass, paper, aluminum, and polypropylene). The surface morphology, water repellency, and mechanical properties of the resulting coated substrates were extensively investigated.

[0229] Analysis of the Coated Surfaces This study presents AFM measurements performed on four different interfaces. First, the untreated polypropylene surface was used as a comparative blank. Also, as a comparative analysis, polypropylene surfaces coated with 1% latex emulsion and emulsions without stabilizing nanoparticles were investigated. The surface of the blank sample (Figure 6A) was relatively flat, and the average roughness (R a ) was between 5.22 ± 0.44 and 6.68 ± 0.57. On the other hand, the R a of the proper coating was 51.46 ± 1.58. The surface wettability was examined by CA. The measurement results of these coatings are shown in Figure 7.

[0230] The untreated polypropylene surface and the composite coating covered with non-silica emulsion showed similar CA values, less than 90° (Figure 7). The silica content affected the wettability of the coating. As the concentration of nanoparticles increased, the contact angle increased to 150°. The low standard deviation values indicate the homogeneity and uniformity of the coating.

[0231] From these measurements and observations, the inventors concluded that an excellent superhydrophobic coating can be produced based on an emulsion with a silica content of 2 wt%, a ratio of DMC of 8:2, and 1 wt% latex.

[0232] It was found that the average static contact angle of the coated polypropylene surface was 149.67 ± 1.27°, and the average static contact angle of the untreated surface was 80.89 ± 6.37. Figure 8 shows representative images corresponding to the water contact angle of the coating (Figure 8A - 8B). Regarding the static water contact angle, the coating shown in Figure 8B was significantly increased compared to the coating shown in Figure 8A.

[0233] To determine the durability of the coating, a 4×4 cm polypropylene surface treated with an 8:2 ratio of DMC and latex-based emulsion containing 2 wt% silica nanoparticles was immersed in water for two weeks under the same physical and chemical conditions. The change in the hydrophobic properties of the coating was studied using the contact angle based on the average value of 15 measurements (Figure 9).

[0234] The contact angle on the first day was 151.61, and on the 15th day, this value became 151.07. However, it was noted that the standard deviation from the average value became slightly higher, which may indicate that the hydrophobic strength varies at different measurement points on the polypropylene surface.

[0235] Furthermore, the inventors successfully coated a paper substrate with the exemplary emulsion of the present invention to obtain a superhydrophobic surface. Test pieces of Whatman paper were coated with a one-layer emulsion preparation of DMC and water in a ratio of 9:1 to 8:2 stabilized with 1 wt% to 2 wt% silica NPs. When the ratio was 9:1 and the silica NPs were 1 wt%, the contact angle value was 126.48°, and when it was 2 wt%, the contact angle was 141.45°. When the ratio was 8:2 and the silica NPs were 1 wt%, the contact angle was 143.00°, and when it was 2 wt%, it was 149.72°.

[0236] Images of the wettability of the superhydrophobic paper substrate treated with the exemplary emulsion of the present invention are shown in Figures 10A1 to 10A5 and Figure 10B in comparison with the control.

[0237] Example 3 To evaluate the antibacterial properties of the coated films (including polypropylene or paper substrates) of the present invention, the inventors studied the formation of Escherichia coli biofilms on the coated films of the present invention in comparison with untreated controls. The toluene-based composition of the present invention reduced biofilm formation by 90%, and the dimethyl carbonate-based composition reduced biofilm formation by 91% on the PP substrate and by 96% on paper without additional activators (see Figure 12). Therefore, it is considered that only the coatings described herein (without activators such as antibacterial agents) are involved in the antibacterial activity of the coated films of the present invention.

[0238] Example 4 Mechanical and Physical Properties of the Superhydrophobic Coating Furthermore, the inventors examined the template pattern of the superhydrophobic coating (SHC) on the glass surface. 5 μl of the exemplary composition of the present invention labeled with a fluorescent dye (referenced above) was applied onto a slide glass. Confocal microscope images were taken at different time intervals (i.e., immediately after application, 30 seconds later, and 60 seconds later). Figures 14A1 - 14A5, Figures 14B1 - 14B5, and Figures 14C1 - 14C5 show a newly dropped droplet, 30 seconds after dropping, and 60 seconds after dropping, respectively, and a scheme showing each step of the formation of the coating layer is also attached. The first 30 seconds (Figures 14A, 14B) are characterized mainly by the evaporation of the solvent, followed by the evaporation of both the solvent and water (Figure 14C). By maintaining their volume during the first 30 seconds, adjacent droplets gather and are connected by latex particles. The formation of the particle bridge is essential to prevent the collapse of the side surface, thereby maintaining the hexagonal pattern even when water has almost completely evaporated.

[0239] The inventors tested the exemplary coatings of the present invention for water repellency and mechanical properties, as well as the durability of the coatings after a number of abrasion cycles (Figure 15A). The values obtained were compared with uncoated paper and latex-coated paper as a control group (Figure 15A).

[0240] First, three sample groups were evaluated for water absorption after coating each side with a single layer (approximately 3 μm) (Figure 15A). The samples were immersed five times for 10 seconds each (total 50 seconds), and the weight was measured. No significant difference was observed in the absorption rate after 50 seconds of immersion between 71% ± 6.16 in the control group and 67% ± 6.24 in the latex group. Furthermore, the addition of hydrophobic silica contributed to the water repellency of the coating, and the increase in weight after immersion was slight (about 21%). These results were visually demonstrated in confocal images (Figures 15C1 - 15C3), and after immersion in water / fluorescent dye for 50 seconds, SHC (Figure 15C3) showed very low fluorescence compared to both the uncoated control group (Figure 15C1) and the latex group (Figure 15B1).

[0241] Figures 15B1 - 15B3 include SEM micrographs showing that the latex layer completely covers the paper surface (Figure 15B2) and that silica particles are mainly present at the top of the coating (Figure 15B3).

[0242] Furthermore, the measured static contact angle (CA) was not necessarily related to the water absorption ability, as the CA of the control, latex, and the coating of the present invention was 0°, 84 ± 5°, and 154 ± 3° respectively. Depending on the application, for coating on an industrial scale, it is important to have a certain degree of abrasion resistance while maintaining functionality. Figure 15D shows the water absorption rate and CA for wear cycles with a 60 gr load applied 20 times on sandpaper (No. 36). The wear test showed that superhydrophobicity was maintained (>150°) after all 20 wear cycles. Furthermore, the increase in the average weight after 50 seconds of immersion reached 24 ± 5.5 and 21 ± 3.3 for the scraped sample and the sample not in contact with the scraper respectively. The robustness of the coating would be due to an acrylic latex designed to act as an industrial sealer and an adhesive with self - crosslinking properties.

[0243] To establish the correlation between the mechanical properties and water absorption rate shown in Fig. 15A, mechanical analysis was performed on wet paper (red columns in Figs. 15E - 15F) and dry paper (blue columns in Figs. 15E - 15F) for three sample groups. As shown in Fig. 15D, for the dry latex coating, the highest average maximum tensile stress (59.5 ± 1.4 MPa) was recorded. However, when testing the average maximum tensile stress of the wet samples, the glass substrate coated according to the present invention showed an approximately 4.5 - fold increase compared to both the control group and the latex group (the measured values were 15.7 ± 1.5 for the coated substrate according to the present invention, 3.5 ± 0.4 and 3.2 ± 0.9 MPa for the control group and the latex group, respectively). Without being bound by a particular theory, it is considered that when water penetrates the paper substrate, the hydrogen bonds between the fibers weaken, the fibers swell, and ultimately break. The difference in strength can be seen in the Young's modulus of the samples (Fig. 15E), which reflects the stress applied per unit surface area.

[0244] The SHC paper showed a significantly improved ability to withstand higher stress loads after wetting. Interestingly, the inventors were able to minimize the curing and reduction in mechanical properties commonly seen in solvent - based coatings of paper substrates.

[0245] The wetting properties of SHC were further evaluated, such as its behavior towards various water temperatures, acidic and alkaline water droplets, and other interactions that provide a more definitive assessment of the coating.

[0246] Fig. 16A shows that there is a negative correlation between the static contact angle (CA) of the droplets dropped on the surface and the temperature. The average CA value of the water droplets decreased to approximately 145° when the temperature exceeded 40°C.

[0247] This correlation is explained by the fact that the vapor trapped in the air pockets between the surface and water reduces the CA of the coated surface. Fig. 16B shows the measurement of the advancing contact angle (ACA) and the receding contact angle (RCA) by increasing and decreasing the volume of the droplets at an angle of 0°, respectively.

[0248] Example 5 Evaluation of Superhydrophobic Antibacterial Agents In addition to the anti-biofilm properties (by preventing bacterial attachment to the coated surface) that essentially characterize the superhydrophobic coating of the present invention, the inventors incorporated propolis (an exemplary active agent) into the composition of the present invention to obtain antibacterial properties. The inventors used a propolis extract in DMC to substantially remove hydrophilic colloids and other hydrophilic particles that might affect the superhydrophobic properties of the resulting coating.

[0249] The inventors extracted propolis by mixing propolis with DMC and then centrifuging the mixture to obtain a clear supernatant. The resulting propolis solution in DMC was then used to prepare the coating composition of the present invention.

[0250] Before evaluating the newly formed preparation for its antibacterial ability, it was subjected to GCMS to identify the compounds in the coating. Table 4 shows the compounds identified based on the calculation of peak areas and their relative concentrations (%). Interestingly, the propolis extract was mainly composed of aliphatic aldehydes. [Table 4]

[0251] Furthermore, the residual amount of DMC in the dry coating was measured by GCMS, and the results are summarized in Table 5. Table 5: Identification of Residual DMC (%) and ppm / 100 mg as a Function of the Composition and Drying Method of the Coatings Studied Using GCMS [Table 5]

[0252] Although the present invention has been described in conjunction with its specific embodiments, it is obvious that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims.

[0253] All publications, patents, and patent applications mentioned in this specification are hereby incorporated by reference in their entirety as if each individual publication, patent, or patent application were specifically and individually indicated to be incorporated by reference. Further, any citation or identification of a reference in this application should not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not necessarily be construed as limiting.

Claims

1. A composition comprising a plurality of core-shell particles dispersed in a hydrophobic solvent, a. The core of the core-shell particles contains an aqueous solution, b. The shell of the core-shell particles contains hydrophobic metal oxide nanoparticles, and the shell is in contact with polymer particles, c. The w / w ratio of the hydrophobic solvent to the aqueous solution in the composition is 1:1 to 10:1, d. The w / w concentration of the hydrophobic metal oxide nanoparticles in the composition is 0.5 to 5%, e. The average cross-section of the core-shell particles is 1 μm to 100 μm, f. The hydrophobic solvent is dimethyl carbonate (DMC) or contains the same, Composition.

2. The composition according to claim 1, wherein the w / w concentration of the hydrophobic metal oxide nanoparticles in the composition is 1.5 to 3%.

3. The composition according to claim 1 or 2, wherein the ratio of the hydrophobic metal oxide nanoparticles to the polymer particles is 30:1 to 1:

1.

4. The composition according to any one of claims 1 to 3, wherein the w / w concentration of the polymer particles in the composition is 0.05 to 2%.

5. The composition according to any one of claims 1 to 4, wherein the average cross-section of the polymer particles is 1 nm to 10 μm.

6. The hydrophobic metal oxide nanoparticles have a chemical modification covalently bonded to the metal oxide particles, and the metal oxide particles are SiO ２ particles or contain the same, and the composition according to any one of claims 1 to 5.

7. The chemical modification is polysiloxane, polysilane, (C １ -C ２０ ) alkylsilyl group, (C １ -C ２０ ) alkoxysilane group, any copolymer thereof, or any combination thereof, the composition according to claim 6.

8. The composition according to claim 7, wherein the polysiloxane is PDMS.

9. The composition according to any one of claims 1 to 8, wherein the polymer particles are latex nanoparticles containing a thermoplastic polymer characterized by a glass transition temperature of 10 to 90 °C.

10. The composition according to claim 9, wherein the thermoplastic polymer includes polyacrylate, polyester, polyurethane, polystyrene, any combination thereof, or any copolymer.

11. The composition according to any one of claims 1 to 10, further comprising 0.1 to 20% by weight of a bioactive agent.

12. The composition according to claim 11, wherein the active agent is selected from essential oils, waxes, or both, antibacterial agents, preservatives, and pesticides, or any combination thereof.

13. A coated substrate, at least one surface of which is in contact with a coating, a. The coating contains a plurality of hollow microparticles, b. The shell of the hollow microparticles contains hydrophobic metal oxide nanoparticles and a thermoplastic polymer, c. The ratio of the hydrophobic metal oxide nanoparticles to the thermoplastic polymer in the shell is from 30:1 to 1:

1. Coated substrate. **Claim 14** The coated substrate according to claim 13, wherein the thermoplastic polymer is in the form of latex particles. **Claim 15** The coated substrate according to claim 13 or 14, wherein the thermoplastic polymer comprises polyacrylate, polyester, polyurethane, polystyrene, any combination thereof, or any copolymer. **Claim 16** The coated substrate according to any one of claims 14 to 15, wherein the coated substrate is characterized by either a roll-off angle of 0 to 10° or a water contact angle of at least 120°. **Claim 17** The coated substrate according to any one of claims 13 to 16, wherein the substrate comprises a plastic substrate, a cellulose-based substrate, a glass substrate, a ceramic substrate, a metal substrate, a textile substrate, and a wood substrate, or any combination thereof. **Claim 18** The hydrophobic metal oxide nanoparticles are chemically modified SiO ２ The coated substrate according to any one of claims 13 to 17, comprising particles. **Claim 19** The chemically modified SiO ２ The coated substrate according to claim 18, wherein the particles are PDMS-modified silica particles. **Claim 20** The coated substrate according to any one of claims 13 to 19, wherein the coating is in the form of a continuous layer characterized by a thickness of 0.5 to 50 μm. **Claim 21** The coated substrate according to any one of claims 13 to 20, wherein the outer surface of the coated substrate is characterized by a root mean square (RMS) surface height of 20 to 100 nm. **Claim 22** The coated substrate according to any one of claims 14 to 21, wherein the hydrophobic metal oxide nanoparticles are in contact with the latex particles, and the weight ratio of the hydrophobic metal oxide nanoparticles to the latex particles in the coating is from 25:1 to 5:

1. **Claim 23** The coated substrate according to claim 22, wherein the latex particles are acrylate latex particles and are characterized by an average particle diameter of 1 to 100 nm. **Claim 24** The coated substrate according to any one of claims 13 to 23, wherein the coating is a water-repellent coating. **Claim 25** The coated substrate according to claim 24, wherein the substrate is a cellulose-based substrate, and the coated substrate is characterized by a water absorption rate of at most 30% of the weight of the substrate. **Claim 26** The coated substrate according to any one of claims 13 to 25, wherein the coating is any one of an anti-biofilm coating, an antibacterial coating, or both of them.

27. A method for producing a coated substrate according to any one of claims 13 to 26, comprising applying the composition according to any one of claims 1 to 11 onto a substrate, and exposing the substrate in contact with the composition to conditions suitable for drying, thereby obtaining a coated substrate.

28. The method according to claim 27, wherein the conditions suitable for drying include a temperature of 10 to 200 °C.

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