A polymer-based microsphere composition, composite material and method of making the same

Abstract

The application discloses a polymer-based microsphere composition, a composite material and a preparation method thereof. The polymer-based microsphere composition comprises polymer microspheres and a high-boiling-point organic liquid, and the high-boiling-point organic liquid has a boiling point of 80 DEG C or above. The polymer-based microsphere composition is prepared by dispersing the polymer microspheres in the high-boiling-point organic liquid, and the polymer microspheres are uniformly dispersed in the high-boiling-point organic liquid and are not prone to agglomeration. The composition is used for preparing optical materials, and the prepared optical materials have good optical performance. The polymer-based microsphere composition has stable components, simple preparation process, low cost, is suitable for large-scale production and has good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of optical materials technology, specifically relating to a polymer-based microsphere composition, a composite material, and a method for preparing the same. Background Technology

[0002] Currently, various physical and chemical methods can be used to form one-dimensional, two-dimensional, or three-dimensional micro / nanostructures with certain spatial regularity within materials. When the scale of the micro / nanostructure is close to the wavelength of light, selective interference, scattering, refraction, and diffraction of incident light can occur, thus giving the material special optical properties. The specific performance of materials that generate corresponding optical properties through the interaction between the material's micro / nanostructure and incident light depends on the scale and regularity of the micro / nanostructure. Structural regularity includes various types such as short-range order with long-range order or short-range order with long-range disorder. The former is mainly represented by photonic crystal materials, and the latter by photonic glass. Regardless of whether it is photonic crystal or photonic glass, its preparation methods mainly include hard preparation and soft preparation. Hard preparation mainly involves coating inorganic materials, chemical etching, photolithography, etc., to form the desired optical structure; soft preparation refers to using colloidal particles, polymer materials, etc., through micro / nano assembly, polymer processing, etc., to form the desired optical structure. In soft fabrication technology, conventional preparation methods include using nanosphere emulsions as raw materials, coating the emulsion alone or in combination with other raw materials, heating and drying the moisture to form a coating, and then applying external force to promote the formation of the material's optical structure. The preparation methods are relatively simple. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a polymer-based microsphere composition for the preparation of optical materials, the resulting optical materials exhibiting good optical properties.

[0004] The present invention also proposes a method for preparing a polymer-based microsphere composition.

[0005] The present invention also proposes a method for preparing composite materials, which is a novel method for preparing materials containing photonic crystal structures.

[0006] The present invention also proposes a composite material.

[0007] In a first aspect, the present invention provides a polymer-based microsphere composition comprising polymer microspheres and a high-boiling-point organic liquid having a boiling point of 80°C or higher.

[0008] The polymer-based microsphere composition according to embodiments of the present invention has at least the following beneficial effects:

[0009] The polymer-based microsphere composition of this invention, through the interaction of a high-boiling-point organic liquid and the polymer microspheres, ensures that the polymer microspheres are uniformly dispersed in the high-boiling-point organic liquid and are not prone to aggregation. When used in the preparation of optical materials, this composition yields optical materials with excellent optical properties. Furthermore, the polymer-based microsphere composition exhibits stable composition, a simple preparation process, low cost, suitability for large-scale production, a wide range of applications, and promising application prospects.

[0010] High-boiling-point organic liquids, which may be referred to herein as "high-boiling-point liquids". Optionally, the high-boiling-point organic liquid is a high-boiling-point polymer molecular liquid.

[0011] In some embodiments of the present invention, the boiling point of the high-boiling-point organic liquid is above 100°C.

[0012] In some embodiments of the present invention, the high-boiling-point organic liquid is chemically stable at 50-80°C.

[0013] In some embodiments of the present invention, the boiling point of the high-boiling-point organic liquid is above 150°C.

[0014] In some embodiments of the present invention, the boiling point of the high-boiling-point organic liquid is 80-450°C. Specifically, the boiling point of the high-boiling-point organic liquid is 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, or 450°C.

[0015] In some embodiments of the present invention, the high-boiling-point organic liquid is a water-soluble solvent. The high-boiling-point organic liquid is miscible with water.

[0016] In some embodiments of the present invention, the high-boiling-point organic liquid includes, but is not limited to, monohydric alcohols, polyhydric alcohols, and alcohol polymers. Optionally, the high-boiling-point organic liquid includes at least one of monohydric alcohols or polyhydric alcohols; and / or, the high-boiling-point organic liquid includes alcohol polymers. Preferably, the polyhydric alcohol includes, but is not limited to, at least one of dihydric alcohols or trihydric alcohols.

[0017] In some embodiments of the present invention, the high-boiling-point organic liquid includes, but is not limited to, ethylene glycol, polyethylene glycol, glycerol, polyglycerol or other fatty alcohols.

[0018] In some embodiments of the present invention, the high-boiling-point organic liquid includes at least one of ethylene glycol, polyethylene glycol, glycerol, polyglycerol or other fatty alcohols.

[0019] In some embodiments of the present invention, the high-boiling-point organic liquid includes at least one of diglycerol, glycerol, polyethylene glycol, ethylene glycol, cyclohexanol, or n-butanol.

[0020] In some embodiments of the present invention, the high-boiling-point organic liquid includes at least one of diglycerol, glycerol, polyethylene glycol, ethylene glycol, or cyclohexanol.

[0021] In some embodiments of the present invention, the polyethylene glycol includes at least one of polyethylene glycol-200, polyethylene glycol-300, or polyethylene glycol-400.

[0022] The boiling points of some high-boiling-point organic liquids are shown in Table 1:

[0023] Table 1. Boiling Point Statistics of Some High-Boiling-Point Organic Liquids

[0024] High-boiling-point organic liquids Boiling point (°C) Ethylene glycol 197.3 Polyethylene glycol 200, polyethylene glycol 300, polyethylene glycol 400 240-280 glycerin 290 Diglyceride 407 n-Butanol 117 Cyclohexanol 159.6 Ethylene glycol butyl ether 171

[0025] In some embodiments of the present invention, the volume fraction of polymer microspheres in the composition is 30% or more; optionally, the volume fraction of polymer microspheres is 30%-65% or 30%-60%; and alternatively, the volume fraction of polymer microspheres is 40%-60%.

[0026] In this invention, based on the material composition of the polymer-based microsphere composition, when the volume fraction of polymer microspheres is certain (e.g., 40%-60%), the viscosity of the polymer-based microsphere composition is highly correlated with the viscosity of high-boiling-point organic liquids and / or other media components. Appropriate media materials and types and contents of high-boiling-point organic liquids can be selected according to actual production needs.

[0027] In some embodiments of the present invention, the viscosity of the polymer-based microsphere composition is 10-8000 Pa·s, and optionally, the viscosity of the polymer-based microsphere composition is 100-1000 Pa·s.

[0028] In some embodiments of the present invention, the average particle size of the polymer microspheres is 5-2000 nm. Optionally, the average particle size can be 50-2000 nm, 50-500 nm, 100-500 nm, 150-400 nm, 150-300 nm, or 150-250 nm; in some embodiments of the present invention, the average particle size of the polymer microspheres can be 50-400 nm, 50-300 nm, or 50-250 nm, etc.

[0029] In some embodiments of the present invention, the average particle size of the polymer microspheres is 5nm, 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, 1200nm, 1400nm, 1600nm, 1800nm, or 2000nm, etc.

[0030] In some embodiments of the present invention, the polymer-based microsphere composition further includes additives.

[0031] In some embodiments of the present invention, the mass fraction of the adjuvant in the composition is 5%-95%, such as 15%-80%.

[0032] In some embodiments of the present invention, the additives include at least one of wetting agents, leveling agents, or regulators.

[0033] In some embodiments of the present invention, the wetting agent includes, but is not limited to, at least one of sodium dioctyl sulfosuccinate, nonylphenol polyoxyethylene ether, sodium heavy alkylbenzene sulfonate, sodium pentane sulfonate, sodium dodecylbenzene sulfonate, sodium butylnaphthalene sulfonate, and sodium 1-butane sulfonate. Optionally, the wetting agent includes at least one of sodium dioctyl sulfosuccinate, nonylphenol polyoxyethylene ether, sodium heavy alkylbenzene sulfonate, sodium pentane sulfonate, sodium dodecylbenzene sulfonate, sodium butylnaphthalene sulfonate, or sodium 1-butane sulfonate.

[0034] In some embodiments of the present invention, the wetting agent in the additive has a mass fraction of 1%-10%, such as 1%-5%.

[0035] In some embodiments of the present invention, the leveling agent includes, but is not limited to, at least one of polydimethylsiloxane, acrylic resin, urea-formaldehyde resin, or melamine-formaldehyde resin. Optionally, the leveling agent includes at least one of polydimethylsiloxane, acrylic resin, urea-formaldehyde resin, or melamine-formaldehyde resin.

[0036] In some embodiments of the present invention, the leveling agent has a mass fraction of 0.5%-10%, such as 0.5%-2%.

[0037] In some embodiments of the present invention, the modifier includes at least one of a diluent, a curable component material, or a polymerization inhibitor. The curable component material is used to induce curing to synthesize a cured resin. In some embodiments of the present invention, the diluent is miscible with the high-boiling-point organic liquid. The diluent does not dissolve the polymer microspheres. The polymer microspheres are stably present in the diluent. Optionally, the boiling point of the diluent is above 100°C, more preferably above 120°C. In some embodiments of the present invention, the mass ratio of the diluent, the curable component material, and the polymerization inhibitor is (0-1000):(1-1000):(0-100).

[0038] In some embodiments of the present invention, the mass fraction of the regulator in the adjuvant is 10%-99%, such as 10%-80%, 80%-99%, etc.

[0039] In some embodiments of the present invention, the diluent includes, but is not limited to, at least one of ethylene glycol, polyethylene glycol, glycerol, polyglycerol, and other fatty alcohols. Optionally, the diluent includes at least one of ethylene glycol, polyethylene glycol, glycerol, and polyglycerol.

[0040] In some embodiments of the present invention, the diluent includes at least one of ethylene glycol, polyethylene glycol-200, polyethylene glycol-300, polyethylene glycol-400, glycerol, and polyglycerol.

[0041] In some embodiments of the present invention, the curable component material includes a photocurable component material. Optionally, the photocurable component material is miscible with the high-boiling-point organic liquid; the photocurable component material does not dissolve the polymer microspheres. The polymer microspheres are stably present in the photocurable component material.

[0042] In some embodiments of the present invention, the photocurable component material includes, but is not limited to, polymeric monomer I, photocurable prepolymer, or other photocurable block polymers. Optionally, the photocurable component material includes at least one of polymeric monomer I, photocurable prepolymer, or photocurable block polymer.

[0043] In some embodiments of the present invention, the polymerizing monomer I includes, but is not limited to, at least one of acrylic monomer I, acrylate monomer I, or acrylamide monomer. Optionally, the polymerizing monomer I includes at least one of acrylic monomer I, acrylate monomer I, or acrylamide monomer.

[0044] In some embodiments of the present invention, the acrylic monomer I includes, but is not limited to, at least one selected from acrylic acid, methacrylic acid, ethylacrylic acid, 2-butenoic acid, and 2-pentenoic acid. Optionally, the acrylic monomer I includes at least one selected from acrylic acid, 2-methyl-2-acrylic acid, 3,3-dimethacrylic acid, 2-ethylacrylic acid, 2-butenoic acid, 2-pentenoic acid, 2,3-dimethyl-2-pentenoic acid, or 3-methyl-2-pentenoic acid.

[0045] In some embodiments of the present invention, the acrylate monomer I includes ethylene glycol diacrylate, hydroxyethyl acrylate, 2-hydroxypropyl acrylate, hydroxybutyl acrylate, 2-hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and ethylene glycol monomethacrylate.

[0046] In some embodiments of the present invention, the acrylamide monomer includes at least one of acrylamide, N-hydroxyethylacrylamide, N-isopropylacrylamide, or N-tert-butylacrylamide.

[0047] In some embodiments of the present invention, the photocurable prepolymer includes, but is not limited to, at least one of acrylic prepolymers, acrylate prepolymers, or acrylamide prepolymers.

[0048] In some embodiments of the present invention, the photocurable component material includes, but is not limited to, one or more of ethylene glycol diacrylate, hydroxyethyl acrylate, 2-hydroxypropyl acrylate, hydroxybutyl acrylate, 2-hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and ethylene glycol monomethacrylate.

[0049] In some embodiments of the present invention, the photocurable component material further includes initiator I. Optionally, the initiator I includes, but is not limited to, at least one of benzoin and its derivatives, alkyl phenyl ketones, acyl phosphorus oxides, benzoyl groups, benzophenones, thioxanthones, etc.

[0050] In some embodiments of the present invention, the initiator I includes, but is not limited to, one or more of 2,2-dimethoxy-2-phenylacetophenone, 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-hydroxy-methylphenylpropane-1-one, 1-hydroxycyclohexylphenyl ketone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, and 2-isopropylthioxanthone. Among these, 2-hydroxy-2-methyl-1-phenyl-1-propanone is also known as α-hydroxyisobutyrylphenyl.

[0051] In some embodiments of the present invention, the mass ratio of the initiator I to the polymer monomer I, the photocurable prepolymer, and the photocurable block polymer is (0.001-10):(0.1-100):(0-100):(0-100).

[0052] In some embodiments of the present invention, the mass ratio of the initiator I to the auxiliary agent is (0.0001-10):100, such as (0.01-10):100, (1-10):100, etc.

[0053] In some embodiments of the present invention, the polymerization inhibitor includes at least one of hydroquinone, p-tert-butylcatechol, 2,6-di-tert-butyl-p-methylphenol, 4,4'-dihydroxybiphenyl, or bisphenol A.

[0054] In some embodiments of the present invention, the mass fraction of the polymerization inhibitor in the additive is less than 0.01%.

[0055] In some embodiments of the present invention, the mass ratio of the curable component material to the polymerization inhibitor is (0.001-100):(0.001-10), such as (0.1-100):(0.001-10).

[0056] Optionally, at least at room temperature, the polymer microspheres have a different refractive index than the photocurable component material or diluent. The absolute value of the difference in refractive index between the polymer microspheres and the photocurable component material is n1, and the absolute value of the difference in refractive index between the polymer microspheres and the diluent is n2. n1 and / or n2 are at least 0.001, optionally n1 and / or n2 are at least 0.01, and further optionally n1 and / or n2 are at least 0.1.

[0057] In some embodiments of the present invention, at 15-40°C, n1 and / or n2 is 0.001 or more.

[0058] In some embodiments of the present invention, at 15-40°C, n1 and / or n2 is 0.01 or more.

[0059] In some embodiments of the present invention, at 15-40°C, n1 and / or n2 is 0.1 or more.

[0060] In some embodiments of the present invention, the polymer-based microsphere composition is a polymer-based photonic coating. Optionally, in some embodiments of the present invention, the volume fraction of the polymer microspheres is 40%-60%, and the polymer-based microsphere composition is photonic glass.

[0061] In some embodiments of the invention, the polymer-based microsphere composition further includes water, wherein the water mass fraction is less than 5%, such as less than 1%.

[0062] In some embodiments of the present invention, a water-based emulsion containing microspheres can be prepared by soap-free or soap-containing emulsion polymerization; by taking steps such as stabilization, concentration, and exchange on the microsphere water-based emulsion, the water content in the emulsion is reduced, and the water is replaced with a high-boiling-point organic liquid (such as a mixture of polymer molecules), to obtain a polymer-based microsphere composition.

[0063] In some embodiments of the present invention, the raw materials for preparing the polymer microspheres include polymer monomer II and initiator II.

[0064] In some embodiments of the present invention, the polymerizing monomer II includes, but is not limited to, one or more of ethylene monomers, acrylic monomers II, or acrylate monomers II. Optionally, the polymerizing monomer II includes at least one of ethylene monomers, acrylic monomers II, or acrylate monomers II.

[0065] In some embodiments of the present invention, the ethylene monomers include styrene monomers. Optionally, the styrene monomers include, but are not limited to, at least one of styrene, methylstyrene, vinyltoluene, ethylstyrene, propylstyrene, and divinylbenzene. More optionally, the styrene monomers include at least one of styrene, α-methylstyrene, β-methylstyrene, 2-vinyltoluene, 3-vinyltoluene, 4-vinyltoluene, 1-ethyl-2-vinylbenzene, 1-ethyl-3-vinylbenzene, 1-ethyl-4-vinylbenzene, 4-isopropylstyrene, o-divinylbenzene, m-divinylbenzene, or p-divinylbenzene.

[0066] In some embodiments of the present invention, the acrylic monomer II includes, but is not limited to, at least one of acrylic acid, methacrylic acid, ethylacrylic acid, 2-butenoic acid, and 2-pentenoic acid. Optionally, the acrylic monomer II includes at least one of acrylic acid, 2-methyl-2-acrylic acid, 3,3-dimethacrylic acid, 2-ethylacrylic acid, 2-butenoic acid, 2-pentenoic acid, 2,3-dimethyl-2-pentenoic acid, or 3-methyl-2-pentenoic acid.

[0067] In some embodiments of the present invention, the acrylate monomer II includes, but is not limited to, at least one of methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, dimethyl methacrylate, dimethyl methacrylate, methyl 2-butenoate, ethyl 2-butenoate, methyl 2-pentenoate, and ethyl 2-pentenoate. Optionally, the acrylate monomer II includes at least one of methyl acrylate, ethyl acrylate, methyl 2-methacrylate, ethyl 2-methacrylate, methyl 3,3-dimethyl acrylate, ethyl 3,3-dimethyl acrylate, methyl 2-butenoate, ethyl 2-butenoate, methyl 2-pentenoate, or ethyl 2-pentenoate.

[0068] In some embodiments of the present invention, the polymeric monomer II includes at least one of acrylic acid, butyl acrylate, methyl acrylate, divinylbenzene, or styrene.

[0069] In some embodiments of the present invention, the initiator II includes at least one of persulfate, azobisisobutyronitrile, or benzoyl peroxide.

[0070] In some embodiments of the present invention, the persulfate includes, but is not limited to, potassium persulfate, ammonium persulfate, sodium persulfate, or other persulfates. Optionally, the persulfate includes at least one of potassium persulfate, ammonium persulfate, or sodium persulfate.

[0071] In some embodiments of the present invention, the mass ratio of initiator II to polymeric monomer II is (0.1-5):100. Optionally, the mass ratio of initiator II to polymeric monomer II is (0.5-2):100. Further optionally, the mass ratio of initiator II to polymeric monomer II is (0.5-1):100.

[0072] In some embodiments of the present invention, the raw materials for preparing the polymer-based microspheres also include surfactants.

[0073] In some embodiments of the present invention, the surfactant includes, but is not limited to, surfactants of the types such as nonionic surfactants and anionic surfactants. Optionally, the surfactant includes at least one of nonionic surfactants or anionic surfactants.

[0074] In some embodiments of the present invention, the nonionic surfactant includes, but is not limited to, N-vinylamide polymers or polyoxyethylene surfactants. Optionally, the polyoxyethylene surfactant includes, but is not limited to, hydrocarbon phenol polyoxyethylene ethers, fatty alcohol polyoxyethylene ethers, etc. Optionally, the nonionic surfactant includes at least one of N-vinylamide polymers or polyoxyethylene surfactants. Further optionally, the N-vinylamide polymer includes polyvinylpyrrolidone.

[0075] In some embodiments of the present invention, the anionic surfactant includes at least one of carboxylate surfactants, sulfonate surfactants, sulfate surfactants, or phosphate surfactants. Optionally, the sulfonate surfactant includes at least one of alkyl sulfonates, alkylbenzene sulfonates, alkylnaphthalene sulfonates, α-olefin sulfonates, α-sulfonyl monocarboxylates, sulfonyl esters of fatty acids, succinate sulfonates, lignin sulfonates, alkyl glycerol ether sulfonates, or alkyl diphenyl ether disulfonates. Further optionally, the alkyl sulfonate includes sodium dodecyl sulfonate.

[0076] In this invention, the higher the refractive index of the polymer microspheres, the stronger the optical effect of the prepared photonic material (such as photonic paste or composite material). The photonic material includes polymer microspheres and a matrix material (such as a substance cured including curable components). Therefore, the polymer and its raw material monomers can be adaptively selected based on the refractive index of the polymer in the polymer microspheres and the type of matrix material. The differences in refractive index of some polymers are shown in Table 2 below.

[0077] Table 2: Statistical Comparison of Refractive Index Differences Among Some Polymers

[0078]

[0079]

[0080] Note: In Table 2, the values ​​in parentheses represent the refractive index of each material.

[0081] In some embodiments of the present invention, the polymer microspheres include, but are not limited to, one or more of polyethylene materials, polyacrylic acid materials, or polyacrylate materials. In actual production, a more suitable type of polymer microsphere can be selected based on the requirements of the final optical material, and subsequently, a more suitable polymer monomer II can be chosen.

[0082] Specifically, the polymer microspheres may be made of at least one of the following materials: polystyrene, polydivinylbenzene, polymethyl methacrylate, polymethyl acrylate, polybutyl acrylate, or polyacrylic acid. Alternatively, the polymer microspheres may be made of at least one of the following materials: polystyrene, polydivinylbenzene, polymethyl methacrylate, polymethyl acrylate, polybutyl acrylate, or polyacrylic acid.

[0083] In a second aspect, the present invention provides a method for preparing a polymer-based microsphere composition, comprising the following steps: taking or preparing a mixture containing water and polymer microspheres, mixing it with a high-boiling-point organic liquid and removing the water to obtain the polymer-based microsphere composition, wherein the average particle size of the microspheres is 5-2000 nm, and the boiling point of the high-boiling-point organic liquid is above 80°C. The method for preparing the polymer-based microsphere composition of the present invention is simple, low-cost, suitable for large-scale production, and features high efficiency and wide adaptability, showing promising prospects for industrial application.

[0084] In some embodiments of the present invention, the high-boiling-point organic liquid includes, but is not limited to, the high-boiling-point organic liquid described in any of the first aspects of the present invention.

[0085] In some embodiments of the present invention, the polymer microspheres include, but are not limited to, the polymer microspheres described in any of the first aspects of the present invention.

[0086] In some embodiments of the present invention, the volume fraction of polymer microspheres in the mixture is 4%-65%.

[0087] In some embodiments of the present invention, the particle size distribution index of the polymer microspheres in the mixture is less than 15%.

[0088] Unless otherwise specified, the particle size distribution index in this article refers to the aggregation index (PDI).

[0089] In some embodiments of the present invention, the mixture containing water and polymer microspheres includes at least one of an aqueous microsphere emulsion or an aqueous microsphere composition.

[0090] Through the above embodiments, polymer-based microsphere compositions can be prepared by using aqueous microsphere emulsions or by using aqueous microsphere compositions.

[0091] In some embodiments of the present invention, the volume fraction of microspheres in the aqueous microsphere emulsion is 4%-40%, and optionally 10%-20%.

[0092] In some embodiments of the present invention, the solid content of the aqueous microsphere emulsion is 5%-40%.

[0093] In some embodiments of the present invention, the microsphere size distribution index in the aqueous microsphere emulsion is less than 15%, and the microsphere size distribution index may be less than 10%, or more preferably less than 8%.

[0094] In some embodiments of the present invention, the volume fraction of microspheres in the aqueous microsphere composition is 10%-65%, such as 20%-65%, 20%-60%, 40%-60%, etc.

[0095] In some embodiments of the present invention, the microsphere size distribution index in the aqueous microsphere composition is less than 15%.

[0096] In some embodiments of the present invention, the volume ratio of the high-boiling-point organic liquid to the emulsion is (1-5):50.

[0097] In some embodiments of the present invention, the volume ratio of the high-boiling-point organic liquid to the microsphere aqueous composition is (1-5):(30-50).

[0098] In some embodiments of the present invention, the method for preparing the polymer-based microsphere composition includes the following steps: taking the emulsion or the aqueous microsphere composition, mixing it with a high-boiling-point organic liquid, removing water, and obtaining the polymer-based microsphere composition.

[0099] In some embodiments of the present invention, a deionization purification step is included before the water removal step. In some embodiments of the present invention, the deionization purification method includes at least one of dialysis or purification by adding anion and cation exchange resins. Optionally, after deionization purification, the conductivity of the mixture is below 50 μS / cm, specifically below 30 μS / cm. Optionally, the ratio of the material to be added with the anion and cation exchange resin to the amount of the anion and cation exchange resin can be (10-10000) mL:(50-300) g.

[0100] In some embodiments of the present invention, the emulsion is deionized and purified before being mixed with the high-boiling-point organic liquid; or, the emulsion is mixed with the high-boiling-point organic liquid, deionized and purified, and then water is removed; optionally, some water in the emulsion is removed by centrifugal concentration before being mixed with the high-boiling-point organic liquid.

[0101] In some embodiments of the present invention, the method for preparing the polymer-based microsphere composition includes the following steps: removing a portion of the water from the emulsion to obtain the aqueous microsphere composition, and mixing it with a high-boiling-point organic liquid to obtain the polymer-based microsphere composition. Optionally, a dehydration step is further included after mixing with the high-boiling-point organic liquid. Optionally, a deionization purification step is further included before the partial water removal step. Optionally, a portion of the water in the emulsion is removed by centrifugal concentration. Optionally, the solid content in the aqueous microsphere composition is 5%-80%, such as 5%-60%.

[0102] In some embodiments of the present invention, the preparation method includes the following steps:

[0103] The emulsion was purified by deionization and then mixed with the high-boiling-point organic liquid to remove water, thereby obtaining the polymer-based microsphere composition.

[0104] Alternatively, the emulsion can be mixed with a high-boiling-point organic liquid and water removed to obtain the polymer-based microsphere composition.

[0105] Alternatively, the emulsion can be deionized and purified to remove some water, then mixed with the high-boiling-point organic liquid to remove water, thereby obtaining the polymer-based microsphere composition.

[0106] Alternatively, the emulsion can be partially dehydrated, purified by deionization, mixed with the high-boiling-point organic liquid, and dehydrated to obtain the polymer-based microsphere composition.

[0107] Alternatively, the emulsion is mixed with the high-boiling-point organic liquid, and after deionization purification, water is removed to obtain the polymer-based microsphere composition.

[0108] Alternatively, the aqueous microsphere composition can be mixed with the high-boiling-point organic liquid to remove water, thereby obtaining the polymer-based microsphere composition.

[0109] Alternatively, the aqueous microsphere composition can be mixed with the high-boiling-point organic liquid, and after deionization purification, water can be removed to obtain the polymer-based microsphere composition.

[0110] Alternatively, the aqueous microsphere composition can be purified by deionization and then mixed with the high-boiling-point organic liquid to remove water, thereby obtaining the polymer-based microsphere composition.

[0111] In some embodiments of the present invention, water removal is performed by heating and stirring.

[0112] In the above embodiments, a heating temperature of 30-60°C is preferred. During heating, as the volume fraction of polymer microspheres in the system continuously increases, the system viscosity also increases. Therefore, the stirring speed should not be too fast; a stirring speed of 50-100 r / min is preferred. Heating and stirring remove excess water and other aqueous solvents, and the mass / volume of the system can be continuously monitored during the process.

[0113] In some embodiments of the present invention, the heating temperature in the dehydration step is 30-60°C. Preferably, the heating temperature is 30°C, 40°C, 50°C, or 60°C.

[0114] In some embodiments of the present invention, the stirring speed in the dehydration step is 50-100 r / min. Preferably, the stirring speed is 50 r / min, 60 r / min, 70 r / min, 80 r / min, 90 r / min or 100 r / min.

[0115] In some embodiments of the present invention, the deionization purification method includes adding anion and cation exchange resins or performing deionization purification by dialysis. Optionally, the deionization purification method includes adding anion and cation exchange resins to the emulsion or the aqueous microsphere composition, or dialyzing the emulsion or the aqueous microsphere composition.

[0116] In some embodiments of the present invention, the preparation method further includes adding an auxiliary agent. Optionally, the auxiliary agent includes any of the auxiliary agents described in the first aspect of the present invention.

[0117] In some embodiments of the present invention, in the preparation method: the step of adding the auxiliary agent can be performed before, after, or simultaneously with mixing the mixture containing water and polymer microspheres with the high-boiling-point organic liquid; or / and, the step of adding the auxiliary agent can be performed before or after the water removal step; or / and, the step of adding the auxiliary agent can be performed before or after the deionization purification step. Optionally, the auxiliary agent can be added all at once, or it can be added in batches depending on the type or quantity of the auxiliary agent. It should be noted that if the step of adding the auxiliary agent is before the water removal step, it is preferable that the auxiliary agent is stable in the water removal step and does not decompose or react.

[0118] In some embodiments of the present invention, the preparation method of the polymer-based microsphere composition includes the following steps:

[0119] S (o) -1a, take the emulsion, add anion and cation exchange resins, filter, and obtain mixture I; or, dialyze the emulsion to obtain mixture I;

[0120] S (o)-2a, add a high-boiling-point organic liquid to the mixture I, remove water, and obtain the polymer-based microsphere composition; or, dehydrate the mixture I, add a high-boiling-point organic liquid, and obtain the polymer-based microsphere composition. Optionally, step S (o) -2a also includes the step of adding adjuvants.

[0121] In some embodiments of the present invention, the preparation method of the polymer-based microsphere composition includes the following steps:

[0122] S (o) -1b, The emulsion is mixed with a high-boiling-point organic liquid to obtain mixture II;

[0123] S (o) -2b, Mix the mixture II with the anion and cation exchange resins, remove water, and obtain the polymer-based microsphere composition; or, dialyze the mixture II to remove water, and obtain the polymer-based microsphere composition. Optionally, the step of adding an additive after water removal is further included.

[0124] In some embodiments of the present invention, the preparation method of the polymer-based microsphere composition includes the following steps:

[0125] S (o) -1c, take the aqueous microsphere composition, add anion and cation exchange resins, filter, and obtain mixture III; or, dialyze the aqueous microsphere composition to obtain mixture III;

[0126] S (o) -2c, a high-boiling-point organic liquid is added to the mixture III to remove water, thereby obtaining the polymer-based microsphere composition. Optionally, the process may further include adding an additive before or after water removal.

[0127] In some embodiments of the present invention, the preparation method of the polymer-based microsphere composition includes the following steps:

[0128] S (o) -1d, the microsphere aqueous composition is mixed with a high-boiling-point organic liquid to obtain mixture IV;

[0129] S (o) -2d, the mixture IV and the anion and cation exchange resins are mixed and water is removed to obtain the polymer-based microsphere composition; or, the mixture IV is dialyzed to obtain the polymer-based microsphere composition.

[0130] In some embodiments of the present invention, the preparation method of the polymer-based microsphere composition includes the following steps:

[0131] The aqueous microsphere composition is mixed with a high-boiling-point organic liquid, and water is removed to obtain the polymer-based microsphere composition.

[0132] Alternatively, the aqueous microsphere composition, a high-boiling-point organic liquid, and an additive are mixed and water is removed to obtain the polymer-based microsphere composition.

[0133] Alternatively, the aqueous microsphere composition is concentrated and then mixed with a high-boiling-point organic liquid to remove water, thereby obtaining the polymer-based microsphere composition.

[0134] Alternatively, the aqueous microsphere composition is concentrated and then mixed with a high-boiling-point organic liquid and an additive to remove water, thereby obtaining the polymer-based microsphere composition.

[0135] Alternatively, the aqueous microsphere composition is concentrated, mixed with a high-boiling-point organic liquid, water is removed, and additives are added to obtain the polymer-based microsphere composition.

[0136] Alternatively, the aqueous microsphere composition can be mixed with a high-boiling-point organic liquid, water removed, and additives added to obtain the polymer-based microsphere composition. Optionally, the concentration method includes heating.

[0137] Whether or not the photocurable component material in the additive is added can affect the composition and state of the photonic material prepared from the microsphere aqueous composition. For example, if the photocurable component material is added, a solid photonic material can be obtained after photocuring.

[0138] In some embodiments of the present invention, the volume fraction of polymer microspheres in the mixture obtained by mixing the microsphere aqueous composition or its concentrated form with a high-boiling-point organic liquid can be more than 64%, resulting in a high-viscosity slurry.

[0139] In some embodiments of the present invention, the high-boiling-point organic liquid is miscible with water, has a boiling point above 100°C, and is chemically stable at 50-80°C, thus avoiding significant self-loss during the evaporation and removal of water process.

[0140] In some embodiments of the present invention, the preparation method further includes the step of preparing the aqueous microsphere emulsion, specifically including:

[0141] S (i) -1. Take solvent I, polymerizable monomer II and surfactant, mix them to obtain mixture V;

[0142] S (i) -2, under a protective atmosphere, the mixture V is heated, initiator II is added, and the mixture is kept warm to obtain the microsphere emulsion.

[0143] The method for preparing the emulsion according to embodiments of the present invention has at least the following beneficial effects:

[0144] In this invention, solvent I, polymeric monomer II, and surfactant are first mixed and pre-emulsified, and then initiator II is added to initiate the reaction to obtain an emulsion. This invention uses polymeric monomer II (organic monomer) as raw material, and belongs to a single-step emulsion polymerization reaction with high reaction yield, and the reactivity rate can be as high as 85% or more.

[0145] This invention provides a simple method for synthesizing mononuclear microspheres. Solvent I, polymerizable monomer II, and surfactant can be added simultaneously before the reaction, requiring only one feeding (addition of initiator II) throughout the entire reaction process. The process is simple, reproducible, and suitable for large-scale production. Post-processing of the reaction product eliminates the need for demulsification and drying, resulting in low production costs. The emulsion can be used to prepare aqueous microsphere compositions, polymer-based microsphere compositions, and optical composite materials, offering a wide range of applications and promising prospects. Optionally, polymerizable monomer II comprises any one of the polymerizable monomers described in the first aspect of this invention. Optionally, initiator II comprises any one of the initiators described in the first aspect of this invention. Optionally, surfactant comprises any one of the surfactants described in the first aspect of this invention.

[0146] In some embodiments of the present invention, solvent I comprises water. Preferably, the water is deionized water.

[0147] In this invention, the higher the ratio of monomer II to solvent I, the higher the solid content of the resulting emulsion. The specific ratio of monomer II to solvent I can be selected according to actual production needs.

[0148] In some embodiments of the present invention, the ratio of the amount of polymeric monomer II to the amount of solvent I is (50-400) g: 1 L, such as (100-400) g: 1 L.

[0149] In this invention, the higher the ratio of surfactant to polymeric monomer II, the smaller the particle size of the nanospheres in the resulting emulsion.

[0150] In some embodiments of the present invention, the ratio of the amount of surfactant to solvent II is (1-100) g: 1 L.

[0151] In some embodiments of the present invention, step S (i) In step -2, the heating temperature of mixture V can be adjusted adaptively according to the type of initiator II selected. During the heat preservation stage after adding initiator II: the heat preservation temperature (i.e., polymerization reaction time) and time (i.e., reaction time) can be adjusted adaptively according to the selected initiator II, and the heat preservation temperature should be selected accordingly. Generally, the higher the polymerization reaction temperature, the shorter the reaction time.

[0152] In some embodiments of the present invention, step S(i) In step -1, mixing is performed by stirring. In some embodiments of the present invention, step S... (i) Mix in -1 at 300-400 r / min for 10-25 min.

[0153] In some embodiments of the present invention, step S (i) In step -1, solvent I, monomer II, and surfactant are added to a jacketed reactor and mixed by stirring at 350 r / min for 15 min to obtain mixture V.

[0154] In some embodiments of the present invention, step S (i) In step -2, the protective atmosphere is a nitrogen atmosphere. Specifically, optionally, step S... (i) In step -2, high-purity nitrogen gas can be bubbled through the reaction system to remove excess air.

[0155] In some embodiments of the present invention, step S (i) In step -2, the heating temperature of mixture V is 70-90℃. Optionally, the heating temperature of mixture V is approximately 85℃.

[0156] In some embodiments of the present invention, step S (i) In -2, the insulation temperature is 75-95℃, and the insulation time is 3-5h.

[0157] In some embodiments of the present invention, step S (i) In the -2, the insulation temperature is 85℃ and the insulation time is 4 hours.

[0158] In some embodiments of the present invention, step S (i) In step -2, after heating mixture V, a solution of initiator II is added. Optionally, the solution of initiator II is an aqueous solution of initiator II.

[0159] In some embodiments of the present invention, step S (i) In a mixture of -2, initiator II is added and kept warm to obtain mixture V containing reactive agglomerates. The reactive agglomerates are then removed to obtain the emulsion.

[0160] Through the above embodiments, the removal of reactive agglomerates in this invention is more conducive to the stability of the emulsion system and more conducive to the preparation of photonic materials, such as aqueous microsphere compositions, polymer-based microsphere compositions, or optical composite materials, using emulsions.

[0161] In some embodiments of the present invention, the removal of the reactive agglomerates includes sieving with a sieve.

[0162] In some embodiments of the present invention, the mesh size of the sieve is 200-300 mesh, such as 250 mesh.

[0163] In some embodiments of the present invention, step S (i) In a mixture of -2, initiator II is added, and after being kept at a certain temperature, it is cooled to room temperature to obtain mixture V containing reactive aggregates. The reactive aggregates are then removed to obtain the emulsion.

[0164] In the emulsion prepared in this invention, the polymer microspheres include polymer nanospheres. When the emulsion is used to prepare photonic materials, especially photonic crystal materials, the particle size of the polymer microspheres in the emulsion affects the reflection wavelength of the resulting photonic material. Therefore, the particle size of the polymer microspheres can be selected according to the desired reflection wavelength of the photonic material (such as composite films).

[0165] In some embodiments of the present invention, the preparation method further includes a step of preparing the microsphere aqueous composition, specifically including:

[0166] An emulsion containing polymer microspheres is purified by deionization and / or concentrated to obtain the aqueous composition of the microspheres.

[0167] In this invention, a concentration step can be selected or omitted depending on the desired viscosity of the aqueous microsphere composition or the application requirements. At different volume fractions of polymer microspheres, the polymer microspheres in the aqueous microsphere composition exhibit different crystallization characteristics, resulting in different optical properties. For example, if the volume fraction of polymer microspheres in the aqueous microsphere composition is 40%-60%, the polymer microspheres will rapidly assemble, allowing the preparation of a photonic crystal coating with iridescent colors. Optionally, the deionization purification includes at least one of dialysis or purification by adding anion and cation exchange resins. Optionally, the dialysis time is 20 hours or more. Optionally, after deionization purification, the conductivity of the emulsion is below 50 μS / cm, specifically below 30 μS / cm.

[0168] In some embodiments of the present invention, the emulsion containing polymer microspheres includes the aqueous microsphere emulsion described in any of the preceding claims.

[0169] In some embodiments of the present invention, a heating method is used for concentration, specifically a heating and stirring method.

[0170] In the above embodiments, a heating temperature of 30-80°C is preferred. During heating, as the volume fraction of polymer microspheres in the emulsion continuously increases, the emulsion viscosity also increases. Therefore, the stirring speed should not be too fast; a stirring speed of 50-100 r / min is preferred. Excess water can be removed through heating and stirring. The emulsion mass / volume is continuously monitored during the process until the desired aqueous microsphere composition is obtained. Further optionally, the heating temperature is 30-80°C. Preferably, the heating temperature is 30°C, 40°C, 50°C, 60°C, 70°C, or 80°C. Optionally, the stirring speed is 50-100 r / min. Preferably, the stirring speed is 50 r / min, 60 r / min, 70 r / min, 80 r / min, 90 r / min, or 100 r / min.

[0171] In some embodiments of the present invention, the concentration is carried out by centrifugation. For example, the solid microspheres can be concentrated at the bottom of the centrifuge tube by centrifuging the emulsion, and the concentrated microsphere aqueous composition can be obtained after removing the supernatant.

[0172] A third aspect of the present invention provides a method for preparing a composite material, comprising the following steps:

[0173] A support matrix containing a polymer-based microsphere composition is taken, and the support matrix undergoes shear strain to obtain the composite material.

[0174] The method for preparing the composite material according to embodiments of the present invention has at least the following beneficial effects:

[0175] This invention discloses a novel method for preparing composite materials containing photonic crystal structures. Using a polymer-based microsphere composition containing polymer microspheres as raw material, the supporting matrix undergoes shear strain, acting on the polymer-based microsphere composition to induce a regular arrangement of the polymer microspheres, thereby assembling the polymer microspheres and forming a photonic crystal structure. The process is simple. This invention utilizes shear-induced structural regularization, enabling the rapid assembly of large areas of polymer microspheres with high regularity structures. Since the polymer-based microsphere composition is a solid-liquid mixture, compared to conventional methods of shearing solid coatings, the shearing process of this invention is less challenging, and the assembly and regular arrangement of polymer microspheres are easier, resulting in better regularization and superior optical properties of the resulting composite material.

[0176] In some embodiments of the present invention, the particle size of the polymer microspheres in the polymer-based microsphere composition affects the reflection wavelength of the resulting composite material. Therefore, the particle size of the polymer microspheres can be selected according to the desired reflection wavelength of the composite material (such as a composite film). Preferably, the average particle size of the polymer microspheres is 5-2000 nm.

[0177] In some embodiments of the present invention, the viscosity of the polymer-based microsphere composition is 10-8000 Pa·s, 10-2000 Pa·s, 100-1000 Pa·s, or even 100-600 Pa·s.

[0178] In some embodiments of the present invention, the volume fraction of the polymer-based microsphere composition is 30% or more, specifically 40% or more, optionally 45% or more, further optionally 60% or more, and even more preferably 64% or more. Preferably, the volume fraction of the polymer-based microsphere composition is 40%-60%.

[0179] Through the above embodiments, at a volume fraction of 40%-60%, nanospheres assemble more rapidly, preparing photonic crystal coating materials with iridescent colors. Within this volume fraction range, more detailed classifications can be made based on relative viscosity, suitable for different processes. Specifically, when the volume fraction of polymer microspheres is 40%-50%, the polymer-based microsphere composition has a lower viscosity, making it more suitable for processes such as spraying and placement in a substrate. When the volume fraction of polymer microspheres is 50%-60%, the polymer-based microsphere composition has a higher viscosity, making it more suitable for processes such as scraping and brushing and placement in a substrate. In the polymer-based microsphere composition, compared to a volume fraction of no more than 60%, the viscosity of polymer-based microsphere compositions with a volume fraction greater than 60% increases sharply, increasing the processing difficulty.

[0180] In some embodiments of the present invention, the polymer-based microsphere composition includes, but is not limited to, the polymer-based microsphere composition described in any of the first aspects of the present invention or the polymer-based microsphere composition prepared by the method described in any of the second aspects of the present invention.

[0181] In some embodiments of the present invention, the method for preparing the composite material further includes the preparation of a polymer-based microsphere composition. Optionally, the method for preparing the polymer-based microsphere composition includes, but is not limited to, the method for preparing the polymer-based microsphere composition described in the second aspect of the present invention.

[0182] In some embodiments of the present invention, the polymer-based microsphere composition comprises a high-boiling-point organic liquid.

[0183] The high-boiling-point organic liquids mentioned herein include, but are not limited to, the high-boiling-point organic liquids described in any one of the first or second aspects of the present invention, specifically:

[0184] In some embodiments of the present invention, the boiling point of the high-boiling-point organic liquid is above 80°C; for example, the boiling point may be above 100°C or above 150°C.

[0185] In some embodiments of the present invention, the boiling point of the high-boiling-point organic liquid is 80-450°C, specifically 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C or 450°C.

[0186] In some embodiments of the present invention, the high-boiling-point organic liquid is a water-soluble solvent. The high-boiling-point organic liquid is miscible with water.

[0187] In some embodiments of the present invention, the high-boiling-point organic liquid includes, but is not limited to, monohydric alcohols, polyhydric alcohols, and alcohol polymers. Polyhydric alcohols include, but are not limited to, at least one of dihydric alcohols or trihydric alcohols. Optionally, the high-boiling-point organic liquid includes, but is not limited to, ethylene glycol, polyethylene glycol, glycerol, polyglycerol, or other fatty alcohols. Specifically, the high-boiling-point organic liquid may include at least one of diglycerol, glycerol, polyethylene glycol, ethylene glycol, cyclohexanol, or n-butanol.

[0188] In some embodiments of the present invention, the polymer-based microsphere composition includes an additive, which includes the additives described in any of the first aspects of the present invention.

[0189] In some embodiments of the present invention, the polymer-based microsphere composition includes a curable component material.

[0190] Whether or not the curable component is added is closely related to the final state and performance of the composite material. Optionally, after curing, the curable component yields a cured resin, which makes the composite material solid. If the curable component is not added, a paste-like fluid photonic crystal material, such as a fluid photonic crystal thin film, can be obtained.

[0191] In some embodiments of the present invention, the curing component material includes a photocurable component material. Specifically, the photocurable component material includes, but is not limited to, the photocurable component material described in any one of the first aspects of the present invention, wherein:

[0192] In some embodiments of the present invention, the photocurable component material is miscible with the high-boiling-point organic liquid. The photocurable component material does not dissolve the polymer microspheres. The polymer microspheres are stably present in both the high-boiling-point organic liquid and the photocurable component material.

[0193] In some embodiments of the present invention, the photocurable component material includes at least one of polymeric monomer I, a photocurable prepolymer, or a photocurable block polymer. The addition of polymeric monomer I, the photocurable prepolymer, or the photocurable block polymer, after curing, yields a solid composite material, such as a solid photonic crystal thin film, which can be prepared by photocuring.

[0194] In some embodiments of the present invention, the polymerizing monomer I includes, but is not limited to, at least one of the acrylic monomer I, the acrylate monomer I, or the acrylamide monomer; and / or, the photocurable prepolymer includes, but is not limited to, at least one of the acrylic prepolymer, the acrylate prepolymer, or the acrylamide prepolymer.

[0195] In some embodiments of the present invention, the photocurable component material includes, but is not limited to, ethylene glycol diacrylate, hydroxyethyl acrylate, 2-hydroxypropyl acrylate, hydroxybutyl acrylate, 2-hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, ethylene glycol monomethacrylate, etc.

[0196] In some embodiments of the present invention, the photocurable component material further includes initiator I. Optionally, the initiator I includes, but is not limited to, the initiator I described in any one of the first aspects of the present invention.

[0197] In some embodiments of the present invention, the mass ratio of the initiator I to the photocurable component material is (0.01-5):100; specifically, it can be (0.1-5):100.

[0198] In some embodiments of the present invention, the polymer-based microsphere composition includes a diluent. The diluent includes, but is not limited to, the diluent described in any of the first aspects of the present invention, specifically:

[0199] In some embodiments of the present invention, the diluent is miscible with the high-boiling-point organic liquid. The diluent does not dissolve the polymer microspheres. The polymer microspheres are stably present in the diluent.

[0200] In some embodiments of the present invention, the boiling point of the diluent is above 100°C, such as above 120°C.

[0201] In some embodiments of the present invention, the diluent includes, but is not limited to, at least one of ethylene glycol, polyethylene glycol, glycerol, polyglycerol, and other fatty alcohols. Optionally, the diluent includes at least one of ethylene glycol, polyethylene glycol, glycerol, and polyglycerol.

[0202] In some embodiments of the present invention, the polymer-based microsphere composition includes a polymerization inhibitor. The polymerization inhibitor includes, but is not limited to, the polymerization inhibitors described in any one of the first aspects of the present invention. In some embodiments of the present invention, the polymer-based microsphere composition includes a leveling agent. The leveling agent includes, but is not limited to, the leveling agent described in any one of the first aspects of the present invention. In some embodiments of the present invention, the polymer-based microsphere composition includes a wetting agent. The wetting agent includes, but is not limited to, the wetting agent described in any one of the first aspects of the present invention.

[0203] In this invention, the three-dimensional distribution of the polymer microspheres in the polymer-based microsphere composition gives them structural color under white light irradiation.

[0204] In some embodiments of the present invention, the supporting matrix includes a sandwich structure, and the method for preparing the composite material includes the following steps:

[0205] S1, a first substrate, an intermediate layer and a second substrate are sequentially stacked to form a sandwich structure, wherein the intermediate layer comprises a polymer-based microsphere composition;

[0206] S2, the sandwich structure undergoes relative movement between the first matrix and the second matrix, generating shear strain, thus obtaining the composite material.

[0207] Through the above embodiments, the first and second substrates play a role in relative shearing, support, and protection. The sandwich structure undergoes relative movement between the first and second substrates, generating shear strain that acts on the polymer-based microsphere composition. This causes the polymer microspheres in the composition to align in a regular pattern, forming a photonic crystal structure, resulting in a composite material with regularly arranged polymer microspheres. Specifically, this includes: bending the sandwich structure with external force, causing relative displacement of the opposing surfaces of the first and second substrates, generating shear strain that acts on the polymer-based microsphere composition within the sandwich structure, promoting the regular arrangement of polymer microspheres to form a photonic crystal structure; or compressing the polymer-based microsphere composition between the first and second substrates, causing flow shear between them, promoting the regular arrangement of polymer microspheres to form a photonic crystal structure. Optionally, the polymer-based microsphere composition obtained after shear strain can be retained between the first and second substrates to obtain the composite material, or the first substrate and / or the second substrate can be removed or replaced with other materials to obtain the composite material.

[0208] In some embodiments of the present invention, the polymer-based microsphere composition forms the intermediate layer.

[0209] Through the above embodiments, during the shearing process, the polymer microspheres in the intermediate layer (polymer-based microsphere composition) orderly penetrate deeper into the intermediate layer from the inner surfaces near the first and second substrates.

[0210] In some embodiments of the present invention, step S1 includes preparing the sandwich structure, the preparation of the sandwich structure including but not limited to the following methods:

[0211] The polymer-based microsphere composition is placed between a first matrix and a second matrix to form the sandwich structure;

[0212] Alternatively, the polymer-based microsphere composition can be coated onto the first or second substrate, and then the second or first substrate can be coated onto the coated polymer-based microsphere composition to obtain the sandwich structure.

[0213] Optionally, processes such as lamination, blade coating, roller coating, and precision coating can be used to control the thickness of the intermediate layer of the sandwich structure, forming a sandwich structure with three layers.

[0214] In some embodiments of the present invention, in the sandwich structure, the thickness of the intermediate layer does not exceed 0.5 mm; and / or, the thickness of the intermediate layer is not less than 0.005 mm.

[0215] In some embodiments of the present invention, the thickness of the intermediate layer in the sandwich structure is 0.005-0.5 mm, optionally 0.005-0.4 mm, and further optionally 0.005-0.3 mm.

[0216] In this invention, a thickness of no more than 0.5 mm for the intermediate layer, compared to a thickness greater than 0.5 mm, allows for better orderliness of the nanospheres penetrating deep within it. Furthermore, a thickness of 0.005-0.5 mm for the intermediate layer, compared to a thickness less than 0.005 mm, provides a more sufficient ordered structure to ensure significant structural color, resulting in smaller relative processing errors and better product uniformity. Therefore, a thickness of 0.005-0.5 mm for the intermediate layer is preferred.

[0217] In some embodiments of the present invention, in step S2, the sandwich structure and / or the polymer-based microsphere composition in the sandwich structure is heated before or during the shear strain generation of the sandwich structure.

[0218] In this invention, heating can be selected based on the viscosity of the polymer-based microsphere composition, ensuring that the polymer microspheres in the composition can achieve a regular arrangement. If heating is used, a relatively mild heating temperature is preferred. Specifically, since the polymer-based microsphere composition based on low viscosity has a relatively low viscosity at room temperature, step S2 can be carried out at room temperature. However, in some other embodiments, a mild temperature, such as 40°C, 50°C, 60°C, 70°C, or higher, can be used during the processing in step S2. For example, when processing polymer-based microsphere compositions with a high volume fraction of polymer microspheres, mild heating can moderately reduce the viscosity of the system, promoting the flow of nanospheres and faster crystallization. Optionally, the heating temperature is 10-100°C, such as 20-70°C, and further, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 80°C, 90°C, or 100°C.

[0219] In some embodiments of the present invention, in step S2, when shear strain is generated, the temperature of the polymer-based microsphere composition is 10-100°C, or optionally 20-70°C.

[0220] In some embodiments of the present invention, the first substrate is a layered structure.

[0221] In some embodiments of the present invention, the first substrate is a first base film.

[0222] In this invention, the materials of the first substrate and the second substrate can be the same or different.

[0223] In some embodiments of the present invention, the material of the first substrate includes, but is not limited to, at least one of polyester materials, polysiloxane materials, polyimide materials, polysulfone materials, or polyolefin materials. Optionally, the polyester material includes polycarbonate materials, polyphenylene ester materials, polyacrylate materials, polynaphthalene ester materials, etc. In some embodiments of the present invention, the material of the first substrate includes at least one of polysulfone, polycarbonate, polyimide, polydimethylsiloxane, polyethylene terephthalate, polymethyl methacrylate, polyethylene naphthalate, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyurethane, or other polyolefin substances.

[0224] PI: Polyimide; PDMS: Polydimethylsiloxane; PET: Polyethylene terephthalate; PEN: Polyethylene naphthalate; PMMA: Polymethyl methacrylate; PP: Polypropylene; PE: Polyethylene; Polyvinyl chloride: PVC; Polystyrene: PS; Polysulfone: PSF; Polycarbonate: PC; Polyurethane: TPU;

[0225] In some embodiments of the present invention, the first base film includes a polymer layer I.

[0226] In some embodiments of the present invention, the polymer layer I includes a polyester material layer, a polysiloxane material layer, a polyimide material layer, a polysulfone material layer, or a polyolefin material layer, etc.

[0227] In some embodiments of the present invention, the polymer layer I includes at least one of a polysulfone layer, a polycarbonate layer, a polyimide layer, a polydimethylsiloxane layer, a polyethylene terephthalate layer, a polymethyl methacrylate layer, a polyethylene naphthalate layer, a polyethylene layer, a polypropylene layer, a polyvinyl chloride layer, or a polystyrene layer.

[0228] In some embodiments of the present invention, the second substrate is a layered structure.

[0229] In some embodiments of the present invention, the second substrate is a second base film.

[0230] In some embodiments of the present invention, the material of the second matrix includes, but is not limited to, at least one of polyester materials, polysiloxane materials, polyimide materials, polysulfone materials, or polyolefin materials. Preferably, the polyester material includes polycarbonate materials, polyphenylene ester materials, polyacrylate materials, polynaphthalene ester materials, etc. Specifically, the material of the second matrix includes at least one of polysulfone, polycarbonate, polyimide, polydimethylsiloxane, polyethylene terephthalate, polymethyl methacrylate, polyethylene naphthalate, polyethylene, polypropylene, polyvinyl chloride, polystyrene, or other polyolefin substances.

[0231] In some embodiments of the present invention, the second base film includes a polymer layer II.

[0232] In some embodiments of the present invention, the polymer layer II includes a polyester material layer, a polysiloxane material layer, a polyimide material layer, a polysulfone material layer, or a polyolefin material layer, etc.

[0233] In some embodiments of the present invention, the polymer layer II includes at least one of a polysulfone layer, a polycarbonate layer, a polyimide layer, a polydimethylsiloxane layer, a polyethylene terephthalate layer, a polymethyl methacrylate layer, a polyethylene naphthalate layer, a polyethylene layer, a polypropylene layer, a polyvinyl chloride layer, or a polystyrene layer.

[0234] In some embodiments of the present invention, the ratio of the elastic modulus of the first matrix to the polymer-based microsphere composition is 2:1 or more, such as 5:1 or more, 10:1 or more, 20:1 or more, etc.

[0235] In the shearing step of this invention, such as in bending shearing, the first matrix must bend to the required radius of curvature without breaking, and have a significantly higher elastic modulus than the polymer-based microsphere composition at the processing temperature, so that the sandwich structure is less prone to permanent deformation during processing. Optionally, the ratio of the elastic modulus of the first matrix to that of the polymer-based microsphere composition is 10:1 or higher.

[0236] In some embodiments of the present invention, the elastic modulus includes Young's modulus.

[0237] In some embodiments of the present invention, the ratio of the shear modulus of the first matrix to the polymer-based microsphere composition is 100:1 or more, such as 100,000 or more.

[0238] In some embodiments of the present invention, the ratio of the elastic modulus of the second matrix to that of the polymer-based microsphere composition is 2:1 or more, such as 5:1 or more, 10:1 or more, 20:1 or more, etc.

[0239] In the shearing step of this invention, such as in bending shearing, the second matrix must bend to the required radius of curvature without breaking, and have a significantly higher elastic modulus than the polymer-based microsphere composition at the processing temperature, so that the sandwich structure is less prone to permanent deformation during processing. Optionally, the ratio of the elastic modulus of the second matrix to that of the polymer-based microsphere composition is 5:1 or higher.

[0240] In some embodiments of the present invention, the elastic modulus includes Young's modulus.

[0241] In some embodiments of the present invention, the ratio of the shear modulus of the second matrix to the polymer-based microsphere composition is 100:1 or higher, such as 100,000 or higher.

[0242] In some embodiments of the present invention, the first substrate is polymer layer I and the second substrate is polymer layer II.

[0243] In this invention, by combining the viscosity of the polymer-based microsphere composition, the volume fraction of the polymer microspheres, etc., an appropriate relative shear strain amplitude can be selected according to actual needs to better promote the efficient crystallization of polymer microspheres in the polymer-based microsphere composition and promote the formation of composite materials.

[0244] In some embodiments of the present invention, in step S2, in at least a portion of the sandwich structure, the relative shear strain amplitude of the first matrix and the second matrix is ​​not less than 5%. In some embodiments of the present invention, in step S2, in at least a portion of the sandwich structure, the relative shear strain amplitude of the first matrix and the second matrix is ​​not greater than 1000%. The relative shear strain amplitude is the ratio between the relative shear displacement of the first matrix and the second matrix during shear strain and the thickness of the interlayer. The interlayer thickness refers to the initial thickness of the interlayer during shear strain.

[0245] Optionally, the relative shear strain amplitude can be calculated based on the difference in curvature radii between polymer layer I and polymer layer II when the three-layer sandwich structure is bent. The larger the bending angle of the sandwich structure, the larger the relative shear strain amplitude, and vice versa. When the thickness of the sandwich structure is much smaller than the corresponding curvature radius, the curvature radii of polymer layer I and polymer layer II can be considered to be the same in the calculation.

[0246] In some embodiments of the present invention, in step S2, in at least a portion of the sandwich structure, the relative shear strain amplitude of the first matrix and the second matrix is ​​5%-1000%, such as 5%-300%.

[0247] Through the above embodiments, the relative shear strain amplitude of part or all of the first matrix and the second matrix is ​​5%-1000%, which can better promote the high-efficiency crystallization of polymer microspheres in the polymer-based microsphere composition and promote the formation of composite materials.

[0248] In some embodiments of the present invention, in step S2, the highest relative shear strain amplitude of the first matrix and the second matrix is ​​5%-1000%, such as 10%-400%, 10%-300%, 10%-150%, 80%-130%, etc. Unless otherwise specified, the highest relative shear strain amplitude referred to herein is the highest achievable relative shear strain amplitude of the first matrix and the second matrix in the portion where shear strain occurs.

[0249] In some embodiments of the present invention, in step S2, the maximum relative shear strain amplitude of the first matrix and the second matrix is ​​5%, 20%, 50%, 80%, 100%, 120%, 130%, 150%, 170%, 200%, 230%, 250%, 270%, 290%, or 300%.

[0250] In some embodiments of the present invention, in step S2, the shear strain step is repeated to obtain the composite material.

[0251] In some embodiments of the present invention, step S2 is repeated at least once to obtain the composite material. In some embodiments of the present invention, step S2 is repeated at least four times to obtain the composite material. Repeating the shear strain step at least four times can better promote the regular arrangement of polymer microspheres, making the composite material exhibit a more obvious structural color.

[0252] In some embodiments of the present invention, in step S2, the shear strain step is repeated more than 5 times to obtain the composite material.

[0253] In some embodiments of the present invention, in step S2, the shear strain step is repeated 50 times or less to obtain the composite material, such as repeating the shear strain step 30 times or less.

[0254] By repeating the shear strain step 30 times through the above embodiments, the regularized arrangement of polymer microspheres in the polymer-based microsphere composition in the sandwich structure can be basically saturated. Excessive repeated shearing does not bring more significant benefits. Therefore, it is preferable to repeat the shear strain step less than 30 times.

[0255] In some embodiments of the present invention, in step S2, the shear strain step is repeated 1-30 times to obtain the composite material.

[0256] In some embodiments of the present invention, in step S2, the shear strain step is repeated 4-30 times to obtain the composite material.

[0257] In some embodiments of the present invention, in step S2, the shear strain is generated by at least one of bending of the sandwich structure or shearing caused by flow of the polymer-based microsphere composition between the first matrix and the second matrix.

[0258] In some embodiments of the invention, in step S2, the shearing caused by bending is generated by at least one of bending with curved surface support or bending without curved surface support.

[0259] In some embodiments of the present invention, in the shearing caused by bending, the radius of curvature of the sandwich structure bending is 1 mm or more, such as 5 mm or more, 1-1000 mm, etc.

[0260] Through the above implementation method, compared with a curvature radius that is too small, a curvature radius of 1 mm or more will cause the stress perpendicular to the surface of the sandwich structure to produce more uniform extrusion on the polymer-based microsphere composition in the middle layer, which is more conducive to the sorting of polymer microspheres in the sandwich structure.

[0261] In some embodiments of the present invention, in the shearing caused by bending, the radius of curvature of the sandwich structure bending is 10 mm or more, such as 20 mm or more, 50 mm or more, or 100 mm or more.

[0262] In some embodiments of the present invention, in the shearing caused by bending, the radius of curvature of the sandwich structure bending is 5-100 mm, such as 10 mm, 20 mm, 30 mm, 40 mm, 50 mm or 100 mm.

[0263] In some embodiments of the present invention, the bending shearing method without surface support includes roller-supported bending shearing.

[0264] In some embodiments of the present invention, the curved shearing method with curved support includes using a cylinder, roller or support with a partially curved structure.

[0265] In some embodiments of the present invention, the curved shearing method with curved surface support includes roller-supported curved shearing.

[0266] In some embodiments of the invention, the support includes a curved surface for supporting the sandwich structure, and the sandwich structure has a contact angle with the curved surface.

[0267] The contact angle (θ) is equal to the curvature of the sandwich structure. When the curved surface has a constant radius of curvature, the contact angle is the angle formed between the center of the radius of curvature, the vertex of the angle, and the contact area between the sandwich structure and the curved surface supporting the sandwich structure.

[0268] In some embodiments of the present invention, the contact angle is 10° or more, such as 20° or more, 30° or more, 40° or more, or 50° or more.

[0269] In some embodiments of the present invention, the contact angle is 10-180°, such as 10-90°.

[0270] In some embodiments of the present invention, during bending-induced shear, the maximum relative shear strain amplitude of the first matrix and the second matrix is ​​5%-1000%, such as 5%-300%, 80%-130%, etc. The relative shear strain amplitude is the ratio between the relative shear displacement of the first matrix and the second matrix during shear strain and the thickness of the interlayer.

[0271] In some embodiments of the present invention, based on the polymer-based microsphere composition system of the present invention, when the Young's modulus of both the first matrix and the second matrix reaches 2 MPa or higher (e.g., 2 MPa-2 GPa), the highest relative shear strain amplitude can be:

[0272]

[0273] Where θ is the contact angle (its magnitude can be 0 to π), T po T1 is the initial thickness of the intermediate layer, T2 is the initial thickness of the first substrate, and T2 is the initial thickness of the second substrate.

[0274] In some embodiments of the present invention, the roller-supported bending shearing is a circular roller-supported bending shearing.

[0275] In some embodiments of the present invention, the radius of the roller is 1-1000 mm, such as 1-50 mm.

[0276] In some embodiments of the present invention, in step S2, the width of the composite material is not limited, such as being less than 10m. Width refers to the width of the composite material.

[0277] Through the above implementation method, compared with an excessively large width, a width of less than 10m will reduce the friction between the sandwich structure and the support roller, which is beneficial to the re-shearing process.

[0278] In some embodiments of the present invention, the width of the composite material is 0.05-10m, specifically such as 0.05-8m, 0.05-6m, 0.05-4m, 0.05-2m, 0.05-1m, 0.05-0.5m, etc.

[0279] In some embodiments of the invention, the flow-induced shear is generated by the extrusion of the polymer-based microsphere composition by a first matrix and a second matrix.

[0280] In some embodiments of the present invention, in the flow-induced shear, the highest relative shear strain amplitude of the first matrix and the second matrix is ​​not less than 5%, such as 5%-1000%, 5%-400%, 5%-300%, 5%-100%, 5%-90%, etc.

[0281] In some embodiments of the present invention, during the flow-induced shearing, based on the polymer-based microsphere composition system of the present invention, when the Young's modulus of both the first matrix and the second matrix reaches 2 MPa or higher (e.g., 2 MPa-2 GPa), the maximum relative shear strain amplitude can be:

[0282]

[0283] Where θ is the contact angle (its magnitude can be 0 to π), T po T1 is the initial thickness of the intermediate layer, T2 is the initial thickness of the first matrix, and T2 is the initial thickness of the second matrix. θ is the contact angle between the three-layer structure and its inscribed circle during flow-induced shear.

[0284] In some embodiments of the present invention, the flow-induced shearing includes the following operation: fixing one end of the sandwich structure to a vibration terminal and leaving the other end free, and causing shear strain in the sandwich structure by vibration of the vibration terminal.

[0285] Through the above embodiments, the vibration of the vibrating terminal causes bending of the sandwich structure, resulting in relative displacement and shear strain on the opposing surfaces of the first and second substrates, which promotes the regularization of polymer microspheres within the polymer-based microsphere composition in the intermediate layer. The amplitude and frequency of the vibrating terminal affect the radius of curvature and bending angle of the sandwich structure; therefore, appropriate amplitude and frequency of the vibrating terminal can be selected according to actual needs.

[0286] In some embodiments of the present invention, the end of the sandwich structure that is fixed to the vibration terminal is a fixed end, and the other end is a free end. The distance between the fixed end and the free end is not limited, such as 2-2000mm.

[0287] In some embodiments of the present invention, the amplitude of the vibration terminal is 0.1cm-0.5m, such as 0.1-20cm, specifically such as 0.1cm, 2cm, 5cm, 7cm, 0.1m, 0.5m, 1m, 1.5m, 2m, 2.5m, 3m, 3.5m, 4m, 4.5m or 5m.

[0288] In some embodiments of the present invention, the vibration frequency of the vibration terminal is 0.5-10Hz, such as 0.5Hz, 1Hz, 2Hz, 4Hz, 6Hz, 8Hz or 10Hz.

[0289] In this invention, due to the continuous production process of composite materials, the length of the composite material is not limited, and a suitable length of composite material can be selected according to actual production needs.

[0290] In some embodiments of the present invention, the length of the composite material is 1-1000m, such as 1m, 5m, 10m, 20m, 50m, 100m, 200m, 500m, 700m or 1000m, etc.

[0291] In some embodiments of the present invention, the polymer-based microsphere composition includes a curable component material, and step S2 further includes a curing step after shear strain occurs.

[0292] In some embodiments of the present invention, the curing step in step S2 is specifically operated as follows: after the polymer-based microsphere composition undergoes shear strain, it is cured to obtain the composite material.

[0293] The specific conditions of the curing step described in this invention can be set according to the curing component material. The specific conditions of the curing step and the curing component material include, but are not limited to, common curing component materials and their curing conditions.

[0294] In some embodiments of the present invention, the curing component material includes a photocurable component material, and the curing includes photocuring.

[0295] In some embodiments of the present invention, the photocuring includes ultraviolet light curing.

[0296] Specifically, this may include, but is not limited to, the following method: at room temperature or other temperatures, a UV curing lamp is used to irradiate the shear-strained sandwich structure, causing the photocurable component material (such as photocurable grease) in the middle layer (polymer-based microsphere composition) of the sandwich structure to crosslink and polymerize under UV excitation, thereby fixing the photonic crystal structure obtained through shear strain and forming a photonic crystal composite film with a certain mechanical strength.

[0297] In some embodiments of the present invention, the photoinitiator used in the photocuring step includes, but is not limited to, at least one of 2,2-dimethoxy-2-phenylacetophenone, 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-hydroxy-methylphenylpropane-1-one, 1-hydroxycyclohexylphenyl ketone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, α-hydroxyisobutyroylbenzene, or 2-isopropylthioxanthraphenone.

[0298] In some embodiments of the present invention, step S2 further includes the step of removing or replacing the first matrix and / or the second matrix after shear strain is generated.

[0299] In the shearing process, the first matrix and the second matrix play roles such as relative shearing, support, and protection, resulting in a composite material in which polymer microspheres are arranged in a regular pattern. The polymer-based microsphere composition obtained after shear strain can be retained between the first matrix and the second matrix to obtain the composite material, or the first matrix and / or the second matrix can be removed or replaced with other materials to obtain the composite material.

[0300] In a fourth aspect, the present invention provides a composite material prepared by the method described in any one of the third aspects of the present invention.

[0301] In some embodiments of the present invention, the composite material includes a photonic crystal structure. Optionally, the composite material contains polymer microspheres that are regularly arranged to form the photonic crystal structure within the composite material.

[0302] In some embodiments of the present invention, the composite material is a photonic thin film.

[0303] In some embodiments of the present invention, the composite material contains a cured resin.

[0304] In some embodiments of the present invention, the curing resin includes a photocurable resin.

[0305] In some embodiments of the present invention, the photocurable resin is prepared by photocuring the photocurable component material described in any one of the first to third aspects of the present invention. Attached Figure Description

[0306] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0307] Figure 1 The images shown are transmission electron microscope (TEM) images and particle size distribution diagrams of polymer nanospheres in the emulsion of Example 1 of this invention.

[0308] Figure 2 The images shown are transmission electron microscope (TEM) images and particle size distribution diagrams of polymer nanospheres in the emulsion of Example 2 of this invention.

[0309] Figure 3 The images shown are transmission electron microscope (TEM) images and particle size distribution diagrams of polymer nanospheres in the emulsion of Example 3 of this invention.

[0310] Figure 4 The graph shows the rheological properties test results of the polymer-based microsphere composition in Example 21 of this invention.

[0311] Figure 5 This is a schematic diagram of the composite material in Example 39 of the present invention;

[0312] Figure 6 This is a schematic diagram of the shearing device and bending shearing of the composite material in Example 39 of the present invention;

[0313] Figure 7 The graph shows the light reflection performance test results of the composite material in Example 39 and Comparative Example 1 of this invention.

[0314] Figure 8 The graph shows the light transmission performance test results of the composite material in Example 39 and Comparative Example 1 of this invention.

[0315] Figure 9 The figures show the test results of the light transmission performance of the composite materials in Examples 40-43 of this invention;

[0316] Figure 10 This is a schematic diagram of the shearing device for the composite material in Example 46 of the present invention;

[0317] Figure 11 This is a graph showing the light reflection stability test results of the composite material in Example 46 of this invention;

[0318] Figure 12 This is a graph showing the test results of the light reflection performance of the composite material in Example 48 of this invention. Detailed Implementation

[0319] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0320] Unless otherwise specified, the experimental methods used in the following examples, preparation examples, and comparative examples were generally performed under conventional conditions in the art or as recommended by the manufacturer. Unless otherwise specified, all raw materials and reagents used are commercially available from the general market. Some of the reagents are listed below:

[0321] Polyvinylpyrrolidone (PVP): k30: weight-average molecular weight of 40,000, but other molecular weights of PVP are also possible;

[0322] Anion-cation mixed ion exchange resin: Amberlite MB20; anion-cation mixed ion exchange resins from other manufacturers are also available.

[0323] PET film: DuPont, melinex; PET film can also be purchased from other manufacturers; Young's modulus is above 2MPa;

[0324] (I) Preparation of Emulsion

[0325] Example 1

[0326] This embodiment discloses an emulsion, abbreviated as emulsion-1, the preparation process of which includes:

[0327] At room temperature, 200g of styrene monomer, 25g of polyvinylpyrrolidone, and 1000mL of deionized water were added to a jacketed reactor and premixed by stirring at 350 rpm for 15 min. High-purity nitrogen was bubbled through the system to remove excess air, and the system was gradually heated to 85°C. Subsequently, 1g of potassium persulfate was dissolved in 10mL of distilled water and rapidly injected into the reactor. The reactor temperature was maintained at 85°C, and the reaction was continuously stirred for 4 hours. The heater was then turned off to terminate the reaction. After the system cooled to room temperature, the resulting mixture was passed through a 250-mesh sieve to remove reaction agglomerates; the filtrate was the emulsion.

[0328] Example 2

[0329] This embodiment discloses an emulsion, referred to as emulsion-2, which differs from embodiment 1 only in the amount of monomer and surfactant used. In this embodiment, the mass of styrene monomer is 100g and the mass of polyvinylpyrrolidone is 10g.

[0330] Example 3

[0331] This embodiment discloses an emulsion, referred to as emulsion-3, which differs from embodiment 1 only in the amount of surfactant used. In this embodiment, the mass of polyvinylpyrrolidone is 10g.

[0332] Example 4

[0333] This embodiment discloses an emulsion, referred to as emulsion-4, which differs from embodiment 3 only in that the type of monomer is different from that in embodiment 3. In this embodiment, 200g of methyl methacrylate is used to replace 200g of styrene monomer in embodiment 3.

[0334] Example 5

[0335] This embodiment discloses an emulsion, referred to as emulsion-5, which differs from embodiment 3 only in that the type of monomer is different from that in embodiment 3. In this embodiment, 200g of butyl acrylate is used to replace 200g of styrene monomer in embodiment 3.

[0336] Example 6

[0337] This embodiment discloses an emulsion, referred to as emulsion-6, which differs from embodiment 3 only in that the type of monomer is different from that in embodiment 3. In this embodiment, 200g of methylstyrene is used to replace the 200g of styrene monomer in embodiment 3.

[0338] Example 7

[0339] This embodiment discloses an emulsion, referred to as emulsion-7, which differs from Example 3 only in that the type of monomer is different from that in Example 3. In this embodiment, 200g of methyl acrylate is used to replace 200g of styrene monomer in Example 3.

[0340] Example 8

[0341] This embodiment discloses an emulsion, referred to as emulsion-8, which differs from embodiment 3 only in that the type of monomer is different from that in embodiment 3. In this embodiment, 200g of divinylbenzene is used to replace 200g of styrene monomer in embodiment 3.

[0342] Example 9

[0343] This embodiment discloses an emulsion, referred to as emulsion-9, which differs from Example 3 only in that the type of monomer is different from that in Example 3. In this embodiment, 200g of acrylic acid is used to replace 200g of styrene monomer in Example 3.

[0344] The differences between Examples 1-9 are statistically summarized in Table 3 below:

[0345] Table 3. Statistical table of partial information from Examples 1-9

[0346]

[0347]

[0348] The polymer microspheres in the emulsion prepared in the above examples have a particle size distribution index of less than 15% and an average particle size of 50-500 nm.

[0349] (II) Preparation of microsphere aqueous composition

[0350] Example 10

[0351] This embodiment discloses a microsphere aqueous composition, which is an aqueous photonic coating, abbreviated as: aqueous composition-1, and its preparation process includes:

[0352] Take 1000 mL of the emulsion prepared in Example 2, encapsulate it in a semi-permeable membrane with a molecular weight cutoff of 100,000, place it in 20 L of deionized water, and let it stand for 72 h. During the standing process, change the deionized water every 24 h. After dialysis, seal the composition obtained by dialysis for later use, thus obtaining the microsphere aqueous composition. The emulsion conductivity decreased to below 50 μS / cm after dialysis.

[0353] The solid content of the microsphere aqueous composition was tested as follows: 5g of the microsphere aqueous composition was placed in a beaker, placed in a 60℃ oven, and dried for 12 hours. The solid content was then measured. The content was determined based on the density of water (1g / mL) and the density of the polymer microspheres (1.05g / cm³). 3 The volume fraction of polymer microspheres in the aqueous microsphere composition was calculated to be 10%, and the mass fraction of polymer microspheres was 10% (i.e., the solid content of the emulsion).

[0354] Example 11

[0355] This embodiment discloses a microsphere aqueous composition, which is an aqueous photonic coating, abbreviated as: aqueous composition-2, and its preparation process includes:

[0356] Take 1000 mL of the emulsion prepared in Example 2, weigh 150 g of the mixed anion and cation exchange resin, and add it to the emulsion. Stir at 50 r / min at room temperature. During this process, continuously monitor the conductivity of the emulsion using a conductivity meter. When the conductivity of the emulsion decreases to 30 μS / cm, the ion exchange is complete. After removing the mixed ion exchange resin using a 250-mesh sieve, seal the resulting composition for later use, thus obtaining the microsphere aqueous composition. At this point, microsphere crystals with structural color appear on the container wall.

[0357] The solid content of the microsphere aqueous composition was tested as follows: 5g of the microsphere aqueous composition was placed in a beaker, placed in a 60℃ oven, and dried for 12 hours. The solid content was then measured. The content was determined based on the density of water (1g / mL) and the density of the polymer microspheres (1.05g / cm³). 3 The volume fraction of polymer microspheres in the aqueous microsphere composition was calculated to be 10%, and the mass fraction of polymer microspheres was 10%.

[0358] Example 12

[0359] This embodiment discloses a microsphere aqueous composition, which is an aqueous photonic coating, abbreviated as: aqueous composition-3, and its preparation process includes:

[0360] Take 100 mL of the 10% (v / v) aqueous microsphere composition from Example 10 and place it in a 500 mL open beaker. Heat at 45°C and stir at 50 r / min, continuously monitoring the solution volume. When the solution volume decreases to 16.66 mL, the concentrated aqueous microsphere composition of this example is obtained, at which point the volume fraction of polymer microspheres is 60%. In other embodiments of the present invention, concentration can also be achieved by centrifugation, specifically by centrifuging the aqueous microsphere composition from Example 10 to concentrate the solid microspheres at the bottom of the centrifuge tube, removing the supernatant to obtain the concentrated aqueous microsphere composition.

[0361] Example 13

[0362] This embodiment discloses a microsphere aqueous composition, which is an aqueous photonic coating, abbreviated as: aqueous composition-4, and its preparation process includes:

[0363] Take 100 mL of the 10% microsphere aqueous composition from Example 10 and place it in a 500 mL open beaker. Heat at 45°C and stir at 50 r / min. Monitor the solution volume continuously during this process. When the solution volume drops to 20 mL, the concentrated microsphere aqueous composition of this example is obtained. At this time, the volume fraction of polymer microspheres is 50%.

[0364] In some other embodiments of the present invention, the emulsions in Examples 1 and 3-9 may also be used to prepare the microsphere aqueous composition.

[0365] The differences between Examples 10-13 are statistically summarized in Table 4 below:

[0366] Table 4. Statistical table of partial information from Examples 10-13

[0367]

[0368] The polymer microsphere particle size distribution index in the aqueous microsphere composition prepared in the above embodiments is less than 15%.

[0369] (III) Polymer-based microsphere compositions

[0370] Example 14

[0371] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating, and its preparation process includes:

[0372] (I) Concentration: Take 500 mL of the aqueous microsphere composition (aqueous composition-2, containing 10% polymer microspheres by volume) prepared in Example 11, add 28 mL of polyethylene glycol-200, place in an open container, and stir at 45°C at a speed of 50 r / min to promote water evaporation. During this process, continuously monitor the mass of the solution, and stop heating when the mass of the solution no longer changes significantly. At this point, the volume fraction of polymer microspheres in the system is 64%.

[0373] (II) Dilution: Subsequently, 5.2 mL of ethylene glycol diacrylate and α-hydroxyisobutyroxene were added, wherein the mass of α-hydroxyisobutyroxene was 1% of the total mass of α-hydroxyisobutyroxene and ethylene glycol diacrylate. The mixture was stirred evenly at room temperature to obtain a polymer-based photonic coating with a polymer microsphere volume fraction of 60%. In some other embodiments of the present invention, the aqueous composition-1 prepared in Example 10 may be used instead of the aqueous composition-2 used in this example.

[0374] Example 15

[0375] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating, and its preparation process includes:

[0376] (I) Concentration: Same as Example 14.

[0377] (II) Dilution: Then add 12.78 mL of ethylene glycol diacrylate and α-hydroxyisobutyroxene, wherein the mass of α-hydroxyisobutyroxene is 1% of the total mass of α-hydroxyisobutyroxene and ethylene glycol diacrylate. Stir evenly at room temperature to obtain a polymer-based photonic coating with a volume fraction of 55%.

[0378] Example 16

[0379] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating. The only difference between this composition and Example 15 is that in step (I) concentration, 28 mL of diglyceride is used instead of 28 mL of polyethylene glycol-200 in Example 15.

[0380] Example 17

[0381] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating. The only difference between this composition and Example 15 is that in step (I) concentration, 28 mL of glycerol is used instead of 28 mL of polyethylene glycol-200 in Example 15.

[0382] Example 18

[0383] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating. The only difference between this composition and Example 15 is that in step (I) concentration, 28 mL of ethylene glycol butyl ether is used instead of 28 mL of polyethylene glycol-200 in Example 15.

[0384] Example 19

[0385] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating. The only difference between this composition and Example 15 is that in step (I) concentration, 28 mL of cyclohexanol is used instead of 28 mL of polyethylene glycol-200 in Example 15.

[0386] Example 20

[0387] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating. The only difference between this composition and Example 15 is that in step (I) concentration, 28 mL of n-butanol is used instead of 28 mL of polyethylene glycol-200 in Example 15.

[0388] Example 21

[0389] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating, and its preparation process includes:

[0390] Take 500 mL of the aqueous microsphere composition (containing polymer microspheres, with a volume fraction of 10%) prepared in Example 11, add 50 mL of polyethylene glycol-200, place in an open container, and stir at 45°C at a speed of 50 r / min to promote water evaporation. During this process, continuously monitor the mass of the solution, and stop heating when the mass of the solution no longer changes significantly. A polymer-based photonic coating with a volume fraction of 50% is obtained.

[0391] Example 22

[0392] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating. The only difference between this embodiment and Example 21 is that 50 mL of polyethylene glycol-300 is used instead of 50 mL of polyethylene glycol-200 in Example 21. Finally, this embodiment obtains a polymer-based photonic coating with a volume fraction of 50% polymer microspheres.

[0393] Example 23

[0394] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating. The only difference between this embodiment and Example 21 is that 50 mL of diglycerol is used instead of 50 mL of polyethylene glycol-200 in Example 21. Finally, this embodiment obtains a polymer-based photonic coating with a volume fraction of 50% polymer microspheres.

[0395] Example 24

[0396] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating. The only difference between this embodiment and Example 21 is that 50 mL of glycerol is used instead of 50 mL of polyethylene glycol-200 in Example 21. Finally, this embodiment obtains a polymer-based photonic coating with a volume fraction of 50% polymer microspheres.

[0397] Example 25

[0398] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating, and its preparation process includes:

[0399] (I) Concentration: Same as Example 14.

[0400] (II) Dilution: Then add 5.2 mL of hydroxyethyl acrylate and 1% of α-hydroxyisobutyrylbenzene, stir evenly at room temperature to obtain a polymer-based photonic coating with a polymer microsphere volume fraction of 60%.

[0401] Example 26

[0402] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating, and its preparation process includes:

[0403] (I) Concentration: Same as Example 14.

[0404] (II) Dilution: Then add 5.2 mL of hydroxybutyl acrylate and 1% of α-hydroxyisobutyrylbenzene, stir evenly at room temperature to obtain a polymer-based photonic coating with a polymer microsphere volume fraction of 60%.

[0405] Example 27

[0406] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating, and its preparation process includes:

[0407] (I) Concentration: Same as Example 14.

[0408] (II) Dilution: Then add 5.2 mL of 2-hydroxypropyl methacrylate and 1% of α-hydroxyisobutyrylbenzene, stir evenly at room temperature to obtain a polymer-based photonic coating with a polymer microsphere volume fraction of 60%.

[0409] Example 28

[0410] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating, and its preparation process includes:

[0411] (I) Concentration: Same as Example 14.

[0412] (II) Dilution: Then add 5.2 mL of hydroxypropyl acrylate and 1% of α-hydroxyisobutyrylbenzene, stir evenly at room temperature to obtain a polymer-based photonic coating with a polymer microsphere volume fraction of 60%.

[0413] Example 29

[0414] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating, and its preparation process includes:

[0415] (I) Concentration: Same as Example 14.

[0416] (II) Dilution: Then add 22 mL of ethylene glycol diacrylate and 1% α-hydroxyisobutyrylbenzene, stir evenly at room temperature to obtain a polymer-based photonic coating with a polymer microsphere volume fraction of 50%.

[0417] Example 30

[0418] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating, and its preparation process includes:

[0419] (I) Concentration: Take 500 mL of the aqueous microsphere composition (containing polymer microspheres, with a volume fraction of 10%) prepared in Example 11, add 21 mL of polyethylene glycol-200, place in an open container, and stir at 45°C at a speed of 50 r / min to promote water evaporation. During this process, continuously monitor the mass of the solution, and stop heating when the mass of the solution no longer changes significantly. At this point, the volume fraction of the polymer microspheres is 70%.

[0420] (II) Dilution: Then add 12.9 mL of ethylene glycol diacrylate and 1% α-hydroxyisobutyrylbenzene, stir evenly at room temperature to obtain a polymer-based photonic coating with a polymer microsphere volume fraction of 60%.

[0421] Example 31

[0422] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating, and its preparation process includes:

[0423] Take 500 mL of the aqueous microsphere composition (containing polymer microspheres, with a volume fraction of 10%) prepared in Example 11, add 33.4 mL of polyethylene glycol-200, place in an open container, and stir at 45°C at a speed of 50 r / min to promote water evaporation. During this process, continuously monitor the mass of the solution, and stop heating when the mass of the solution no longer changes significantly. A polymer-based photonic coating with a volume fraction of 60% polymer microspheres is obtained.

[0424] Example 32

[0425] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating, and its preparation process includes:

[0426] Take 500 mL of the aqueous microsphere composition (containing polymer microspheres, with a volume fraction of 10%) prepared in Example 11, add 41 mL of polyethylene glycol-200, place in an open container, and stir at 45°C at a speed of 50 r / min to promote water evaporation. During this process, continuously monitor the mass of the solution, and stop heating when the mass of the solution no longer changes significantly. A polymer-based photonic coating with a volume fraction of 55% polymer microspheres is obtained.

[0427] Example 33

[0428] This embodiment discloses a polymer-based microsphere composition, which differs from Example 29 in that: this embodiment uses the emulsion prepared in Example 2, replacing the "aqueous microsphere composition prepared in Example 11" used in Example 29 by an equal volume.

[0429] Example 34

[0430] This embodiment discloses a polymer-based microsphere composition, the preparation steps of which include: taking 100 mL of the aqueous microsphere composition (aqueous composition-3, containing 60% polymer microspheres by volume) obtained in Example 12, adding 20 mL of polyethylene glycol-200, adding 20 mL of ethylene glycol diacrylate and α-hydroxyisobutyroxene (wherein, the mass of α-hydroxyisobutyroxene is 1% of the total mass of α-hydroxyisobutyroxene and ethylene glycol diacrylate), and stirring evenly at room temperature to obtain a polymer-based photonic coating. Optionally, after stirring evenly at room temperature, the method further includes a step of removing water by stirring and heating. The heating temperature can be selected from 30-60℃, and the stirring speed can be selected from 40-60 r / min to promote water evaporation. Heating is stopped when the mass of the solution does not change significantly.

[0431] Example 35

[0432] This embodiment discloses a polymer-based microsphere composition, the preparation steps of which include: taking 100 mL of the aqueous microsphere composition (aqueous composition-4, containing 50% polymer microspheres by volume) obtained in Example 13, adding 28 mL of polyethylene glycol-200, adding 22 mL of ethylene glycol diacrylate and α-hydroxyisobutyroxene (wherein, the mass of α-hydroxyisobutyroxene is 1% of the total mass of α-hydroxyisobutyroxene and ethylene glycol diacrylate), and stirring evenly at room temperature to obtain a polymer-based photonic coating. Optionally, after stirring evenly at room temperature, the method further includes a step of removing water by stirring and heating. The heating temperature can be selected from 30-60℃, and the stirring speed can be selected from 40-60 r / min to promote water evaporation. Heating is stopped when the mass of the solution does not change significantly.

[0433] Example 36

[0434] This embodiment discloses a polymer-based microsphere composition, the preparation steps of which include: taking 100 mL of the aqueous microsphere composition (aqueous composition-4, containing 50% polymer microspheres by volume) obtained in Example 13, adding 18 mL of polyethylene glycol-200 and 10 mL of glycerol, adding 22 mL of ethylene glycol diacrylate and α-hydroxyisobutyroxene (wherein, the mass of α-hydroxyisobutyroxene is 1% of the total mass of α-hydroxyisobutyroxene and ethylene glycol diacrylate), and stirring evenly at room temperature to obtain a polymer-based photonic coating. Optionally, after stirring evenly at room temperature, the method further includes a step of removing water by stirring and heating. The heating temperature can be selected from 30-40℃, and the stirring speed can be selected from 40-60 r / min to promote water evaporation. Heating is stopped when the mass of the solution does not change significantly.

[0435] Example 37

[0436] This embodiment discloses a polymer-based microsphere composition, the preparation process of which also includes the addition of a wetting agent, a leveling agent, and a polymerization inhibitor. The specific preparation steps include:

[0437] Take 100 mL of the microsphere aqueous composition (containing polymer microspheres, with a volume fraction of 50%) prepared in Example 13, add 28 mL of polyethylene glycol-200 and 2 mL of glycerol, add 22 mL of ethylene glycol diacrylate and α-hydroxyisobutyroxene (wherein, the mass of α-hydroxyisobutyroxene is 1% of the total mass of α-hydroxyisobutyroxene and ethylene glycol diacrylate), add wetting agent, leveling agent and polymerization inhibitor, stir evenly at room temperature to obtain polymer-based photonic coating.

[0438] In this embodiment, the wetting agent includes at least one of sodium dioctyl sulfosuccinate, nonylphenol polyoxyethylene ether, sodium heavy alkylbenzene sulfonate, sodium pentane sulfonate, sodium dodecylbenzene sulfonate, sodium butylnaphthalene sulfonate, or sodium 1-butane sulfonate; the leveling agent includes at least one of polydimethylsiloxane, acrylic resin, urea-formaldehyde resin, or melamine-formaldehyde resin; and the polymerization inhibitor includes at least one of hydroquinone, p-tert-butylcatechol, 2,6-di-tert-butyl-p-methylphenol, 4,4'-dihydroxybiphenyl, or bisphenol A.

[0439] Specifically, based on the total mass of ethylene glycol diacrylate, α-hydroxyisobutyrophthalamide, glycerol, wetting agent, leveling agent, and polymerization inhibitor, the mass fraction of the wetting agent can be 1-5%, the mass fraction of the leveling agent can be 0.5-2%, and the mass fraction of the polymerization inhibitor can be less than 0.01%. Optionally, based on the sum of the masses of ethylene glycol diacrylate and α-hydroxyisobutyrophthalamide, the mass fraction of the polymerization inhibitor can be less than 0.1%.

[0440] Optionally, before or after adding ethylene glycol diacrylate and α-hydroxyisobutyroxene, or before or after adding wetting agent, leveling agent and polymerization inhibitor, a step of removing water by stirring and heating is also included. The heating temperature can be selected from 30-40°C, and the stirring speed can be selected from 40-60 r / min to promote the evaporation of water. Heating is stopped when the mass of the solution does not change significantly.

[0441] Example 38

[0442] This embodiment discloses a polymer-based microsphere composition, which is a polymer-based photonic coating, and its preparation process includes:

[0443] (I) Concentration: Take 500 mL of the aqueous microsphere composition (containing polymer microspheres, with a volume fraction of 10%) prepared in Example 11, add 28 mL of polyethylene glycol-200, place in an open container, and stir at 45°C at a speed of 50 r / min to promote water evaporation. During this process, continuously monitor the mass of the solution, and stop heating when the mass of the solution no longer changes significantly. At this point, the volume fraction of polymer microspheres in the system is 64%.

[0444] (II) Dilution: Subsequently, 22 mL of ethylene glycol diacrylate and α-hydroxyisobutyroxene (wherein the mass of α-hydroxyisobutyroxene is 1% of the total mass of α-hydroxyisobutyroxene and ethylene glycol diacrylate), as well as wetting agent, leveling agent, and polymerization inhibitor, are added. The mixture is stirred evenly at room temperature to obtain a polymer-based photonic coating. The types of wetting agent, leveling agent, and polymerization inhibitor are the same as in Example 37, and based on the total mass of ethylene glycol diacrylate, α-hydroxyisobutyroxene, wetting agent, leveling agent, and polymerization inhibitor, the mass fraction of the wetting agent is 1-5%, the mass fraction of the leveling agent is 0.5-2%, and the mass fraction of the polymerization inhibitor can be less than 0.01%.

[0445] In some other embodiments of the present invention, step (I) is simply taking 500 mL of the aqueous microsphere composition (containing polymer microspheres, with a volume fraction of 10%) prepared in Example 11, adding 28 mL of polyethylene glycol-200, and mixing thoroughly. Step (II) is the same as in this embodiment. Optionally, before or after adding ethylene glycol diacrylate and α-hydroxyisobutyrobenzoylbenzene, or before or after adding wetting agent, leveling agent, and polymerization inhibitor, a step of removing water by stirring and heating is also included. The heating temperature can be selected from 30-60°C, and the stirring speed can be selected from 40-60 r / min to promote water evaporation. Heating is stopped when the mass of the solution does not change significantly.

[0446] The polymer-based microsphere compositions obtained in the above embodiments have a viscosity of 100-1000 Pa·s and a water content of less than 1 wt% (Examples 34-38 are polymer-based microsphere compositions obtained by including a heating and dehydration step).

[0447] (iv) Composite materials

[0448] Example 39

[0449] This embodiment discloses a series of composite materials, which are photonic crystal composite thin films, and their preparation process includes:

[0450] (I) Take 5g of the polymer-based photonic coating (polymer-based microsphere composition) prepared in Example 29 and coat it between two PET films each 50μm thick. The ratio of the elastic modulus of the PET film to the intermediate layer is >1000:1 and the ratio of the shear modulus is 100:1 or more (e.g., 100,000:1). Use a scraping process to control the thickness of the intermediate layer to be 50μm, the scraper gap to be 150μm, and the coating speed to be 20mm / s to form a three-layer composite film I.

[0451] (II) Shear Strain (Bending Shear): At room temperature, composite film I obtained in step (I) is supported by a 2cm outer diameter roller. By controlling the height of the roller, the contact angle of composite film I is made to be 50 degrees, and the relative shear strain amplitude of the upper and lower PET films in the bent portion reaches a maximum of 87%. Composite film I is bent from one end to the other through the roller under the above conditions, which is one bending shear. The bending shear of composite film I is repeated to achieve 5, 10, 15, 20, 25, and 30 bending shears, respectively, to obtain a series of photonic crystal composite film precursors. The temperature of composite film I during the shear strain process can be 10-100℃.

[0452] (III) Curing: The photonic crystal composite film precursor obtained in step (II) is passed through the ultraviolet irradiation area at a speed of 20 m / min. The photonic crystal composite film precursor is irradiated with a 365 nm ultraviolet lamp to promote cross-linking polymerization of the acrylic resin in the middle layer of the film precursor under ultraviolet excitation (irradiation time is not limited, as long as cross-linking polymerization occurs, such as 2-20 s). The photonic crystal structure formed by bending and shearing is fixed to form a series of photonic crystal composite films with certain mechanical strength.

[0453] The relative shear strain amplitude is the ratio between the relative shear displacement of the first substrate (top PET film) and the second substrate (bottom PET film) during bending-induced shearing to the thickness of the intermediate layer; its maximum value can be calculated using equation (1) after simplification:

[0454]

[0455] For details, please refer to [the relevant information]. Figure 6 (b) is a schematic diagram of bending-induced shear, where θ is the contact angle; T1 is the initial thickness of the top PET film, T2 is the initial thickness of the bottom PET film, and T... po It is the initial thickness of the intermediate layer.

[0456] Example 40

[0457] This embodiment discloses a series of composite materials, which are photonic crystal composite films. The only difference between this embodiment and Example 39 is that 5g of the polymer-based photonic coating (polymer-based microsphere composition) prepared in Example 30 is used in step (I) of this embodiment instead of the polymer-based photonic coating prepared in Example 29 in step (I) of Example 39.

[0458] Example 41

[0459] This embodiment discloses a series of composite materials, which are photonic crystal composite films. The only difference between the preparation process and that of Example 40 is that the contact angle of composite film I in step (II) shear strain (bending shear) of this embodiment is 40 degrees and the relative shear strain amplitude of the upper and lower PET films is up to 70%.

[0460] Example 42

[0461] This embodiment discloses a series of composite materials, which are photonic crystal composite films. The only difference between the preparation process and that of Example 40 is that the contact angle of composite film I in step (II) shear strain (bending shear) of this embodiment is 70 degrees and the relative shear strain amplitude of the upper and lower PET films is up to 122%.

[0462] Example 43

[0463] This embodiment discloses a series of composite materials, which are photonic crystal composite films. The only difference between the preparation process and that of Example 40 is that the contact angle of composite film I in step (II) shear strain (bending shear) of this embodiment is 90 degrees, and the relative shear strain amplitude of the upper and lower PET films is up to 157%.

[0464] Example 44

[0465] This embodiment discloses a composite material, which is a photonic crystal composite thin film, and its preparation process includes:

[0466] (I) Take 5g of the polymer-based photonic coating (polymer-based microsphere composition) prepared in Example 31 and coat it between two PET films each 50μm thick. The ratio of the elastic modulus of the PET film to the intermediate layer is >1000:1 and the ratio of the shear modulus is 100:1 or more (e.g., 100,000:1). Use a scraping process to control the thickness of the intermediate layer to be 50μm, the scraper gap to be 150μm, and the coating speed to be 20mm / s to form a three-layer composite film I.

[0467] (II) Shear strain (bending shear): At room temperature, composite film I obtained in step (I) is supported by a 5cm outer diameter roller. Composite film I is bent by controlling the height of the roller so that the bending angle of composite film I is 50 degrees and the relative shear strain amplitude of the upper and lower PET films reaches a maximum of 87%. Composite film I is bent 30 times to obtain photonic crystal composite film.

[0468] Example 45

[0469] This embodiment discloses a series of composite materials, which are liquid photonic crystal composite films. The only difference between the preparation process and that of Example 40 is that this embodiment does not include step (Ⅲ) curing step.

[0470] Example 46

[0471] This embodiment discloses a composite material, which is a photonic crystal composite thin film. Its preparation process differs from that of Example 40 only in step (II), and it does not include a curing step. In this embodiment:

[0472] (II) Shear strain (mechanical vibration): At room temperature, one end of composite film I is fixed to a vibrating terminal (fixed end), and the other end hangs freely (free-hanging end). By controlling the amplitude of the reciprocating motion of the vibrating terminal to be 0.5-1cm and the frequency to be 5Hz, composite film I bends under the action of inertia and vibrates 50 times to obtain a photonic crystal composite film precursor. The distance between the fixed end and the free-hanging end is not limited, but can be controlled to be 2-2000mm.

[0473] Example 47

[0474] This embodiment discloses a composite material, which is a photonic crystal composite film. The difference between its preparation process and that of Embodiment 46 is that this embodiment includes a curing step, and the curing step is the same as step (Ⅲ) in Embodiment 40.

[0475] The composite material prepared in this embodiment has comparable optical properties to the composite material prepared in Example 46.

[0476] Example 48

[0477] This embodiment discloses a composite material, which is a photonic crystal composite thin film, and its preparation process includes:

[0478] (I) Take 5g of the polymer-based photonic coating (polymer-based microsphere composition) prepared in Example 32 and coat it between two PET films each 50μm thick. Use a scraping process to control the thickness of the intermediate layer to be 50μm, the scraper gap to be 150μm, and the coating speed to be 20mm / s to form a three-layer composite film I.

[0479] (II) Shear strain (mechanical vibration): At room temperature, one end of composite film I is fixed to a vibration terminal, and the other end hangs freely. By controlling the amplitude of the reciprocating motion of the vibration terminal to be 0.5-1cm and the frequency to be 3Hz, composite film I bends under the action of inertia and vibrates 50 times to obtain a liquid photonic crystal thin film.

[0480] Optionally, in step (I) of Examples 44-48, a roller can be used to control the thickness of the intermediate layer instead of the scraping process. Specifically, it may include coating the corresponding polymer-based photonic coating between two 50μm thick PET films, using a roller to control the thickness of the intermediate layer with a roller gap of 150μm, controlling the thickness of the intermediate layer at 50μm, and a speed of 20mm / s to form a three-layer composite film I.

[0481] Example 49

[0482] This embodiment discloses a composite material, which is a photonic crystal composite film. The only difference between this embodiment and Example 39 is that the polymer-based microsphere composition used in this embodiment is the polymer-based microsphere composition prepared in Example 34.

[0483] Example 50

[0484] This embodiment discloses a composite material, which is a photonic crystal composite film. The only difference between this embodiment and Example 39 is that the polymer-based microsphere composition used in this embodiment is the polymer-based microsphere composition obtained in Example 35.

[0485] Example 51

[0486] This embodiment discloses a composite material, which is a photonic crystal composite film. The only difference between this embodiment and Example 39 is that the polymer-based microsphere composition used in this embodiment is the polymer-based microsphere composition prepared in Example 36.

[0487] Example 52

[0488] This embodiment discloses a composite material, which is a photonic crystal composite film. The only difference between this embodiment and Example 39 is that the polymer-based microsphere composition used in this embodiment is the polymer-based microsphere composition prepared in Example 37.

[0489] Example 53

[0490] This embodiment discloses a composite material, a photonic crystal composite film, which differs from Example 39 only in that the polymer-based microsphere composition used in this embodiment is the same polymer-based microsphere composition obtained in Example 38. Compared with the composite material obtained in Example 39, the composite material obtained in this embodiment exhibits improved optical uniformity, reduced surface defects such as pores, comparable other optical properties, and enhanced adhesion between the intermediate layer formed by the polymer-based microsphere composition and the PET film.

[0491] Example 54

[0492] This embodiment discloses a composite material, which is a photonic crystal composite thin film. The only difference between this material and that of Example 39 is that the thickness of the intermediate layer is controlled to be 1 mm. Compared with the composite material obtained in Example 39, the composite material obtained in this embodiment exhibits stronger optical scattering, with a 5-10% increase in white light scattered intensity, but its optical performance deteriorates.

[0493] Example 55

[0494] This embodiment discloses a composite material, a photonic crystal composite thin film, which differs from Example 39 only in that the thickness of the intermediate layer is controlled to be 0.002 mm. Compared with the composite material obtained in Example 39, the composite material obtained in this embodiment has enhanced light transmittance and a 10%-20% reduction in reflection peak intensity.

[0495] Example 56

[0496] This embodiment discloses a composite material, a photonic crystal composite film, which differs from Example 39 only in that the microspheres in the polymer-based microsphere composition have a particle size of 3-8 μm. Compared with the composite material obtained in Example 39, the composite material in this embodiment exhibits significantly enhanced white light scattering, a whitish appearance, iridescent diffraction, and significantly reduced transparency.

[0497] Example 57

[0498] This embodiment discloses a composite material, which is a photonic crystal composite film. The only difference between this material and Example 39 is that the volume fraction of microspheres in the polymer-based microsphere composition is 20%. The composite material has no obvious reflective color, and the sample appears slightly whitish.

[0499] Example 58

[0500] This embodiment discloses a composite material, which is a photonic crystal composite film. The only difference between this material and Example 39 is that the volume fraction of microspheres in the polymer-based microsphere composition is 30%-38%. The composite material has structural color, but the color of the structural color varies slightly.

[0501] Example 59

[0502] This embodiment discloses a composite material, a photonic crystal composite film, which differs from Embodiment 39 only in that the relative shear strain amplitude between the first substrate and the second substrate reaches a maximum of 1%. In this embodiment, the photonic crystal composite film can be prepared by repeating bending more than 20 times.

[0503] Example 60

[0504] This embodiment discloses a composite material, which is a photonic crystal composite film. The only difference between this embodiment and embodiment 39 is that the relative shear strain amplitude of the first substrate and the second substrate is up to 400%.

[0505] Example 61

[0506] This embodiment discloses a composite material, which is a photonic crystal composite film. The only difference between this embodiment and embodiment 39 is that in step (II), the composite film I is bent back and forth a total of 50 times, while the rest is the same as in embodiment 39.

[0507] The optical properties of the composite material obtained in this embodiment are comparable to those of the composite material obtained in Example 39 after 30 reciprocating bending processes.

[0508] Example 62

[0509] This embodiment discloses a composite material, a photonic crystal composite film, which differs from Example 39 only in that the polymer-based microsphere composition used in this embodiment is the same polymer-based microsphere composition obtained in Example 33. Compared to this embodiment, the composite material microspheres in Example 39 exhibit better assembly and preparation effects.

[0510] In some other embodiments of the present invention, the polymer-based microsphere compositions of Examples 14-28 may also be used to prepare composite materials (liquid photonic crystal composite films or solid photonic crystal composite films).

[0511] In the composite material prepared in the above embodiments, the absolute value of the difference in refractive index between the microspheres and the material cured by the photocuring component is greater than 0.001 (see Table 2 for details), and the width of the composite material can be 0.05-10m.

[0512] Comparative Example 1

[0513] This comparative example discloses a composite material, which differs from Example 39 only in that the composite membrane I in this comparative example undergoes 0 bending shear cycles.

[0514] Test case

[0515] This experimental example tested the performance of the emulsions, compositions, or composite materials obtained in the examples, specifically including:

[0516] 1. The microstructure of the emulsions prepared in Examples 1-3 was tested, and the test results are as follows: Figure 1-3 As shown: Figure 1-3 The images shown are transmission electron microscopy (TEM) images (left) and particle size distribution maps (right) of the hydration radius measured by dynamic light scattering, representing the polymer nanospheres in the emulsions of Examples 1-3. Figure 1-3 The comparison shows that the size of polymer nanospheres can be controlled by adjusting the ratio and concentration of polymer monomers and surfactants. As the proportion of surfactant increases, the size of polymer nanospheres gradually decreases.

[0517] 2. The rheological properties of the polymer-based microsphere composition prepared in Example 21 were tested, and the test results are as follows: Figure 4 As shown. Figure 4 The rheological data obtained are for a photonic coating based on polyethylene glycol-200 polymer with a polymer microsphere volume fraction of 50%. The data shows that the viscosity (100-600 Pa·s) of the photonic coating prepared by the process of this invention is much lower than that of core-shell composites based on viscoelastic substrates (>10000 Pa·s) reported in related literature. Therefore, it is speculated that the reduction in viscosity and modulus directly reduces the processing difficulty of subsequent processes, eliminating the need for extrusion and rolling equipment to achieve film formation.

[0518] 3. The light reflection performance of the composite materials in Example 39 and Comparative Example 1 was tested, and the test results are as follows: Figure 7 As shown.

[0519] 4. The light transmission properties of the composite materials in Example 39 and Comparative Example 1 were tested, and the test results are as follows: Figure 8 As shown.

[0520] Depend on Figure 7-8 It can be seen that after 10 shearing cycles, the reflection spectrum has reached saturation; while the transmission spectrum basically reaches its maximum after 30 shearing cycles, indicating that the internal structure of the photonic thin film has reached its most ordered state.

[0521] 5. The light transmission performance (475nm) of the composite materials (photonic crystal composite thin films) in Examples 40-43 was tested. The test results are as follows: Figure 9 As shown. Figure 9This study examines the change in transmittance of the three-layer composite film with varying shear cycles at different bending angles. Higher transmittance at 475 nm indicates a more regular arrangement of microspheres within the composite film. The bending angle is related to the shear strain amplitude. Bending angles of 40°, 50°, 70°, and 90° correspond to the highest relative shear strain amplitudes of the upper and lower PET film layers, reaching 70%, 87%, 122%, and 157%, respectively. The data shows that the sample based on the material system of this invention exhibits the best crystallization effect under oscillatory shear cycles of up to 80%-130%.

[0522] 6. The light reflection stability of the composite material in Example 46 was tested, and the test results are as follows: Figure 11 As shown: Time stability test of reflection spectrum of liquid photonic crystal film. After 96 hours, the liquid photonic crystal film did not change significantly, indicating that the microsphere arrangement in the liquid photonic crystal film still has excellent stability at room temperature and can be used in liquid state.

[0523] 7. The light reflection performance of the composite material in Example 48 was tested, and the test results are as follows: Figure 12 As shown. The strain amplitude generated by the vibration bending of the thin film is sufficient for the crystallization of nanospheres, and because the friction caused by the contact between the guide roller and the film is eliminated, it allows for the preparation of films with larger widths, such as 5 meters or more.

[0524] In summary, this invention provides a one-step polymerization reaction to prepare mononuclear polymer nanospheres. The synthesis process is simple, requiring no demulsification, and is economical and environmentally friendly. The microsphere regularization process is simple, with low equipment requirements and low cost. Simultaneously, purification processes remove anions and cations from the polymer emulsion, enhancing the electrostatic repulsion between nanospheres and improving the regularization efficiency of the nanospheres under oscillating shear. The microsphere regularization process used in this invention is based on a liquid solvent, offering greater flexibility in substrate material selection compared to pure solid films. Microspheres move more easily in the liquid phase, leading to a wider range of applications, such as displays and sensors. The photonic crystal film preparation method can be extended from roller-supported oscillating shear to roller-free general bending shear. The photonic coating used (aqueous microsphere composition / polymer-based microsphere composition) has low viscosity and a moderate range of crystallization shear strain. The shearing process uses relatively small strain, preferably with a maximum relative shear strain of 20%-150% for two layers of PET film. A 100% strain can better balance production efficiency and material quality. The invention utilizes anhydrous or low-water-content nanosphere slurry (polymer-based microsphere composition with a water content of less than 5 wt%) to prepare photonic crystal coatings. After coating, no heating or drying is required to form the coating. The slurry formulation and preparation process are described.

[0525] It should be noted that, unless otherwise specified, the terms "room temperature" and "normal temperature" in this article refer to approximately 20-30℃; and the word "approximately" in numerical values ​​in this article means an error of ±2%.

[0526] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A method for preparing a composite material, characterized in that, Includes the following steps: S1, a first substrate, an intermediate layer and a second substrate are sequentially stacked to form a sandwich structure, wherein the intermediate layer comprises a polymer-based microsphere composition; S2, the sandwich structure undergoes relative movement between the first matrix and the second matrix, generating shear strain, to obtain the composite material; The polymer-based microsphere composition comprises polymer microspheres and a high-boiling-point organic liquid, wherein the high-boiling-point organic liquid has a boiling point of above 80°C and the water content in the polymer-based microsphere composition is less than 1 wt%.

2. The preparation method according to claim 1, characterized in that, The high-boiling-point organic liquid has a boiling point of 80-450℃; and / or, the volume fraction of polymer microspheres in the composition is 30% or more; and / or, the average particle size of the polymer microspheres is 5-2000 nm; and / or, the polymer-based microsphere composition further includes additives.

3. The preparation method according to claim 2, characterized in that, The high-boiling-point organic liquid includes at least one of a monohydric alcohol or a polyhydric alcohol; and / or, the high-boiling-point organic liquid includes an alcohol polymer.

4. The preparation method according to claim 3, characterized in that, The high-boiling-point organic liquid includes at least one of diglycerol, glycerol, polyethylene glycol, ethylene glycol, cyclohexanol, or n-butanol.

5. The preparation method according to claim 2, characterized in that, The additives include at least one of wetting agents, leveling agents, or conditioning agents.

6. The preparation method according to claim 5, characterized in that, The modifier includes at least one of a diluent, a curable component material, or a polymerization inhibitor.

7. The preparation method according to claim 1, characterized in that, The preparation method of the polymer-based microsphere composition includes the following steps: taking or preparing a mixture containing water and polymer microspheres, mixing it with a high-boiling-point organic liquid and removing the water to obtain the polymer-based microsphere composition.

8. The preparation method according to claim 7, characterized in that, The particle size distribution index of the polymer microspheres in the mixture is less than 15%.

9. The preparation method according to claim 7, characterized in that, The process includes a deionization purification step before the water removal step.

10. The preparation method according to claim 9, characterized in that, The deionization purification method includes at least one of dialysis or purification by adding anion and cation exchange resins.

11. The preparation method according to claim 7, characterized in that, The mixture containing water and polymer microspheres includes at least one of an aqueous microsphere emulsion or an aqueous microsphere composition.

12. The preparation method according to claim 11, characterized in that, The aqueous microsphere emulsion contains 4%-40% microspheres by volume; or / and the microsphere size distribution index in the aqueous microsphere emulsion is less than 15%.

13. The preparation method according to claim 11, characterized in that, The microsphere volume fraction in the aqueous microsphere composition is 10%-65%; or / and the microsphere size distribution index in the aqueous microsphere composition is less than 15%.

14. The preparation method according to claim 11, characterized in that, The preparation method of the polymer-based microsphere composition includes the following steps: taking the aqueous microsphere emulsion or the aqueous microsphere composition, mixing it with a high-boiling-point organic liquid, removing water, and obtaining the polymer-based microsphere composition.

15. The preparation method according to claim 14, characterized in that, The emulsion is partially dehydrated to obtain the aqueous microsphere composition, which is then mixed with a high-boiling-point organic liquid to obtain the polymer-based microsphere composition.

16. The preparation method according to claim 15, characterized in that, The emulsion is concentrated by centrifugation to remove some of the water.

17. The preparation method according to claim 15, characterized in that, The process also includes a dehydration step after mixing with high-boiling-point organic liquids.

18. The preparation method according to claim 14, characterized in that, The emulsion is purified by deionization before being mixed with the high-boiling-point organic liquid; or, the emulsion is mixed with the high-boiling-point organic liquid, purified by deionization, and then dehydrated.

19. The preparation method according to claim 18, characterized in that, The emulsion is concentrated by centrifugation to remove some of the water, and then mixed with the high-boiling-point organic liquid.

20. The preparation method according to claim 11, characterized in that, The preparation method also includes adding auxiliary agents.

21. The method for preparing the composite material according to claim 1, characterized in that, In step S2, the shear strain step is repeated to obtain the composite material.

22. The method for preparing the composite material according to claim 1, characterized in that, The polymer-based microsphere composition forms the intermediate layer.

23. The method for preparing the composite material according to claim 22, characterized in that, In a sandwich structure, the thickness of the intermediate layer does not exceed 0.5 mm; and / or the thickness of the intermediate layer is not less than 0.005 mm.

24. The method for preparing the composite material according to claim 22, characterized in that, In step S2, in at least a portion of the sandwich structure, the relative shear strain amplitude of the first matrix and the second matrix is ​​not less than 5%; and / or, in step S2, in at least a portion of the sandwich structure, the relative shear strain amplitude of the first matrix and the second matrix is ​​not greater than 1000%; The relative shear strain amplitude is the ratio between the relative shear displacement of the first matrix and the second matrix and the thickness of the intermediate layer during shear strain.

25. The method for preparing the composite material according to claim 1, characterized in that, In step S2, the shear strain is generated by at least one of the following methods: shear caused by bending of the sandwich structure or shear caused by flow of the polymer-based microsphere composition between the first matrix and the second matrix.

26. The method for preparing the composite material according to claim 25, characterized in that, In the shearing caused by bending, the radius of curvature of the sandwich structure bending is greater than 1 mm.

27. The method for preparing the composite material according to claim 25, characterized in that, The shear caused by the bending is generated by at least one of bending with or without surface support.

28. The method for preparing the composite material according to claim 27, characterized in that, The bending shearing method with curved surface support includes using a cylinder, roller, or support with a partially curved surface structure.

29. The method for preparing the composite material according to claim 28, characterized in that, The support includes a curved surface for supporting the sandwich structure, and the sandwich structure has a contact angle with the curved surface.

30. The method for preparing the composite material according to claim 29, characterized in that, The contact angle is 10° or higher.

31. The method for preparing the composite material according to claim 25, characterized in that, In bending-induced shear, the highest relative shear strain amplitude between the first and second matrices is 5%-1000%.

32. The method for preparing the composite material according to claim 25, characterized in that, When the Young's modulus of both the first and second matrices reaches 2 MPa or higher, the maximum relative shear strain amplitude is: ； where θ is the contact angle, θ is 0~π, T po T0 is the initial thickness of the intermediate layer, T1 is the initial thickness of the first substrate, and T2 is the initial thickness of the second substrate.

33. The method for preparing the composite material according to claim 25, characterized in that, The flow-induced shearing is generated by the extrusion of the polymer-based microsphere composition by the first and second matrices.

34. The method for preparing the composite material according to claim 25, characterized in that, The shearing caused by the flow includes the following operation: fixing one end of the sandwich structure to the vibration terminal, leaving the other end free, and causing shear strain in the sandwich structure by the vibration of the vibration terminal.

35. The method for preparing the composite material according to claim 34, characterized in that, The amplitude of the vibration terminal is 0.1cm-0.5m; and / or the vibration frequency of the vibration terminal is 0.5-10Hz.

36. The method for preparing the composite material according to claim 25, characterized in that, In the shear caused by the flow, the highest relative shear strain amplitude of the first matrix and the second matrix is ​​not less than 5%.

37. The method for preparing the composite material according to claim 1, characterized in that, The polymer-based microsphere composition includes a curable component material, and step S2 further includes a curing step after shear strain occurs.

38. The method for preparing the composite material according to claim 37, characterized in that, Step S2 also includes the step of removing or replacing the first matrix and / or the second matrix after shear strain is generated.

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