A silica-encapsulated carrier mesoporous silica and its preparation method and application

Abstract

The present invention discloses a silica-encapsulated cargo mesoporous silica and its preparation method and application, belonging to the technical field of chemical materials. It includes mesoporous silica, a loaded substance, and a silica layer. Among them, the loaded substance is loaded in the pores of the mesoporous silica, and a solid silica layer with a thickness of ≥10 nm is encapsulated on the outer surface. The particle size of the mesoporous silica is greater than 150 nm. By loading organic or inorganic substances in the pores of the mesoporous silica and encapsulating a solid silica layer on the outer surface, the silicon spheres prepared in the present invention can, while exerting and promoting the functionality of the loaded substance, provide a good barrier effect, prevent the release of the loaded substance and the harmful substances generated thereby, reduce hazards, and improve the safety in use.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical materials, and more particularly relates to a silica-encapsulated loaded mesoporous silicon and a preparation method and application thereof. Background Art

[0002] Some substances that are responsive or sensitive to light, heat and external environmental stimuli are easily affected by environmental factors during the application process, resulting in decreased stability, or producing harmful substances that harm the environment and human body, limiting their application. For example, UV shielding or absorbers are often used to prepare sunscreen products for UV protection of human skin. However, organic UV absorbers such as diethylaminohydroxybenzoyl hexyl benzoate (DHHB), 3-isooctyl diphenylacrylate (OCT), 1-(4-tert-butylphenyl)-3-(4-methoxyphenyl) propane-1,3-dione (AVO), ethylhexyl triazone (UVT-150), bis-ethylhexyloxyphenol methoxyphenyl triazine ( S) and other substances can penetrate the skin, causing endocrine disorders and impairing reproductive capacity. Inorganic UV absorbers such as nano-titanium dioxide (TiO2), cerium dioxide (CeO2), and zinc oxide (ZnO) generate reactive oxygen species (ROS) under UV light. These ROS can damage cell structures or degrade organic matter into small molecules, which can then harm cells or the human body.

[0003] To provide full-spectrum UV protection, sunscreen products typically combine several organic and inorganic UV absorbers to achieve varying shielding ranges. However, interactions between different UV absorbers limit their combined use. For example, the photocatalytic effects of inorganic UV absorbers can lead to the decomposition of organic UV absorbers and other organic compounds within the system, resulting in a loss of UV protection and the production of small organic molecules that readily penetrate the skin. To improve the compatibility, safety, and sunscreen efficacy of UV absorbers, various approaches have been employed, including grafting organic absorbers onto inorganic absorbers, loading absorbers into nanoparticles, and coating absorber particles with polymers or inorganic substances. However, these approaches still present numerous challenges. For example, organic compounds are catalytically decomposed upon contact with inorganic absorbers, and polymer-encapsulated UV absorbers, forming nanoparticles, merely delay the release of organic absorbers but fail to prevent their toxic side effects from skin penetration. Mesoporous silica (MS) has been widely used to load UV absorbers due to its excellent biocompatibility, thermal and chemical stability, and controllable particle size and porous structure. However, this loading still presents safety issues, such as leakage of organic absorbers and the inability to shield the metal oxide's photocatalytic decomposition of organic components. Furthermore, organic flame retardants and dyes, which require water-proofing and leak-proofing, also require appropriate technologies to address these application challenges.

[0004] In response to the above-mentioned problems existing in the application of sunscreens, flame retardants, etc., the present invention provides a silica-encapsulated loaded mesoporous silicon and a preparation method thereof. By loading these organic or inorganic substances into the pores of the mesoporous silicon and encapsulating a solid silica layer on the outside, new and safe technologies and products are provided. Summary of the invention

[0005] In view of this, the present invention provides a silica-encapsulated loaded mesoporous silicon and a preparation method and application thereof.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A silica-encapsulated loaded mesoporous silicon comprises mesoporous silicon, a loaded substance and a silica layer, wherein the loaded substance is loaded in the pores of the mesoporous silicon and is coated on the outside with a solid silica layer having a thickness of ≥10 nm, and the particle size of the mesoporous silicon is greater than 150 nm.

[0008] Furthermore, the mesoporous silicon has active groups such as amino, silanol or dopamine.

[0009] The beneficial effect of adopting the above further technical solution is that the mesoporous silicon is surface activated, which is beneficial to the stable loading of substances.

[0010] Furthermore, the silicon dioxide layer is surface functionally modified.

[0011] The beneficial effects of adopting the above further technical solution are: improving the functionality of the silica-encapsulated mesoporous silica, such as dispersibility and compatibility with other components.

[0012] Furthermore, the above-mentioned supported substance is inorganic nanoparticles or organic or inorganic solids dried and precipitated from a solution.

[0013] Furthermore, the inorganic nanoparticles or inorganic solids are one or more of metals, metal oxides or non-metallic inorganic substances.

[0014] Furthermore, the above-mentioned metal is silver and / or gold; the above-mentioned metal oxide is one or more of titanium dioxide, zinc oxide or cerium oxide; and the above-mentioned non-metallic inorganic substance is carbon dots and / or inorganic perovskite nanocrystals.

[0015] Furthermore, the metal oxide is an inorganic sunscreen agent.

[0016] The beneficial effects of adopting the above-mentioned further technical solution are: Metal oxide nanoparticles have excellent UV shielding properties and are typical inorganic UV screens. However, their strong photocatalytic activity and the strong oxidative properties of the reactive oxygen species produced by photocatalysis can oxidatively degrade organic matter in the surrounding environment, particularly penetrating through the skin and causing cell damage. Mesoporous silica loading followed by encapsulation with a solid silicon layer can block the release of free radicals, preventing harm to the human body and the environment and improving safety.

[0017] Furthermore, the above organic matter is water-insoluble.

[0018] The beneficial effect of adopting the above further technical solution is that since the water-insoluble organic matter is more conducive to the encapsulation of the silicon layer, it will not be lost from the mesoporous silicon due to its water solubility during the silicon layer encapsulation process.

[0019] Furthermore, the water-insoluble organic matter is an organic sunscreen.

[0020] Furthermore, the organic sunscreen is diethylamino hydroxybenzoyl hexyl benzoate (DHHB), 1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)propane-1,3-dione (AVO), ethylhexyl triazone (UVT-150), 3-isooctyl diphenylacrylate (OCT), or bis-ethylhexyloxyphenol methoxyphenyl triazine ( S) or a mixture of one or more thereof.

[0021] The above-mentioned further technical solution has the beneficial effect of: These organic sunscreens are easily absorbed through the skin and released into the body and the environment, causing harm. The present invention's mesoporous silica loading and silica layer encapsulation effectively prevents the release and skin penetration of these organic sunscreens, while also improving their photostability, enhancing their UV protection and long-lasting effectiveness.

[0022] Furthermore, the particle size of the mesoporous silica is 150 nm to 5 μm.

[0023] The beneficial effects of adopting this further technical solution include: shielding UV light while preventing mesoporous silica from penetrating the skin, facilitating the formulation and application of sunscreen products such as sunscreen creams, lotions, and sprays. Excessively large particle sizes result in poor dispersibility and fluidity, hindering the formulation and application of sunscreen products. However, particles that are too small can penetrate the skin and cause damage.

[0024] Furthermore, the loading amount of the inorganic sunscreen or organic sunscreen accounts for 10 to 50% of the mass of the loaded mesoporous silica.

[0025] Furthermore, the organic sunscreen or inorganic sunscreen is loaded in the pores of the mesoporous silica, and the outer surface is sealed with a solid silicon dioxide layer with a thickness greater than 20 nm.

[0026] The beneficial effects of adopting the above further technical solution are: ensuring the mechanical stability of the silicon layer and preventing the release of the encapsulated substances and their reaction products in a long term.

[0027] The present invention also provides a method for preparing the above-mentioned silica-encapsulated loaded mesoporous silicon, comprising the following steps:

[0028] (1) The method of preparing loaded mesoporous silicon by in-situ loading includes the following steps:

[0029] Dispersing mesoporous silicon and a precursor in a solvent, or dispersing mesoporous silicon in a solvent and adding a precursor, or dispersing a precursor in a solvent and adding mesoporous silicon; stirring, centrifuging, washing, drying, and calcining at a high temperature to obtain loaded mesoporous silicon loaded with inorganic nanoparticles;

[0030] Alternatively, mesoporous silicon and a precursor are dispersed in a solvent, stirred, and then the solvent is evaporated at high temperature until it is completely evaporated, and finally calcined at high temperature to obtain loaded mesoporous silicon loaded with inorganic nanoparticles;

[0031] Alternatively, mesoporous silicon is dispersed in a solvent, a precursor is added, stirred, hydrogen peroxide is added to the reaction solution, the pH is adjusted, stirring is continued, centrifugation is performed, washing, drying, and high-temperature calcination is performed to obtain loaded mesoporous silicon loaded with inorganic nanoparticles;

[0032] Alternatively, the precursor is dispersed in a solvent, mesoporous silicon is added, heated at high temperature, then naturally cooled to room temperature, centrifuged, washed, and dried to obtain inorganic-loaded mesoporous silicon;

[0033] Alternatively, a physical loading method is used to prepare loaded mesoporous silicon, comprising the following steps:

[0034] In a sealed reaction vessel, the organic matter is dispersed in a solvent, and mesoporous silicon is added. The mixture is stirred in the dark, and then the reaction vessel is opened and stirred continuously until the solvent evaporates completely to obtain the organic matter-loaded mesoporous silicon.

[0035] Alternatively, the organic matter is dispersed in a solvent, mesoporous silicon is added, stirred, centrifuged, washed, and dried to obtain the organic matter-loaded mesoporous silicon;

[0036] Alternatively, the inorganic substance is dispersed in a solvent, mesoporous silicon is added, stirred, centrifuged, and dried to obtain the loaded inorganic substance-loaded mesoporous silicon;

[0037] (2) A method for encapsulating silica, comprising the following steps: adding a precursor component of silica to an aqueous dispersion of supported mesoporous silica, stirring, centrifuging to obtain a solid product, washing, and drying to obtain supported mesoporous silica encapsulated by silica.

[0038] Furthermore, in step (1), the loaded mesoporous silicon is prepared by an in-situ loading method, and the above-mentioned precursor is a metal inorganic salt, a metal alkoxide or a mixture of hydrated citric acid and urea.

[0039] Furthermore, the metal alkoxide is one of isopropyl titanate, methyl titanate, ethyl titanate, n-propyl titanate, isopropyl titanate or butyl titanate, or a mixture of several of them.

[0040] Furthermore, the above-mentioned metal inorganic salt is one or a mixture of zinc nitrate, zinc chloride or cerium nitrate hexahydrate.

[0041] Furthermore, in step (1), the loaded mesoporous silicon is prepared by an in-situ loading method, and the solvent is an alcohol solvent, water or an alcohol-water mixed solution.

[0042] Furthermore, in step (1), an in-situ loading method is used to prepare loaded mesoporous silicon, and the mass ratio of the above-mentioned mesoporous silicon to the metal inorganic salt or metal alkoxide is 1:0.5~2; the above-mentioned mesoporous silicon and the precursor are dispersed in a solvent, or the mesoporous silicon is dispersed in a solvent and the precursor is added, or the precursor is dispersed in a solvent and the mesoporous silicon is added, and the total concentration of the above-mentioned mesoporous silicon and the metal inorganic salt or metal alkoxide is 1.0~5.0wt%.

[0043] Furthermore, in step (1), the loaded mesoporous silica is prepared by an in-situ loading method, the stirring temperature is 20 to 70° C., and the total stirring time is 1 to 24 h.

[0044] Furthermore, in step (1), the loaded mesoporous silicon is prepared by an in-situ loading method, and the stirring is performed under a nitrogen atmosphere.

[0045] Furthermore, in step (1), the loaded mesoporous silica is prepared by an in-situ loading method, and the pH is adjusted to 10 during the stirring process.

[0046] Furthermore, in step (1), the loaded mesoporous silicon is prepared by an in-situ loading method, the temperature of the high-temperature calcination is 450-550° C., and the high-temperature calcination time is 4-6 hours.

[0047] Furthermore, in step (1), the loaded mesoporous silicon is prepared by an in-situ loading method, the high temperature heating temperature is 180° C., and the heating time is 4 hours.

[0048] Furthermore, in step (1), a physical loading method is used to prepare the loaded mesoporous silicon, and the above-mentioned solvent is one or more of water, dichloromethane, n-hexane, ethanol or isopropanol.

[0049] Furthermore, in step (1), a physical loading method is used to prepare the loaded mesoporous silicon, wherein the organic or inorganic substance is dispersed in a solvent, and the concentration of the organic or inorganic substance is 2 to 50 wt%;

[0050] Mesoporous silicon is added, the mass ratio of the mesoporous silicon to the organic matter or the inorganic matter is 1:1-20, and the concentration of the mesoporous silicon is 2-5wt%.

[0051] Furthermore, in step (1), a physical loading method is used to prepare the loaded mesoporous silica, the stirring temperature is 20 to 50° C., and the stirring time is 1 to 24 hours.

[0052] Furthermore, in step (1), a physical loading method is used to prepare loaded mesoporous silicon, wherein the organic matter is an organic sunscreen agent. In a closed reaction vessel, the organic sunscreen agent is dispersed in a solvent, and the concentration of the organic sunscreen agent is 2 to 6 wt%. Mesoporous silicon is added, and the mass ratio of mesoporous silicon to organic sunscreen agent is 1:1 to 3, and the concentration of mesoporous silicon is 2 to 5 wt%. The mixture is stirred at 30°C in a dark environment for 6 hours, and then the reaction vessel is opened and stirred continuously until the solvent is completely evaporated to obtain mesoporous silicon loaded with an organic sunscreen agent.

[0053] Furthermore, in step (2), the precursor components of the silicon dioxide include: an isopropyl alcohol solution containing or not containing 1.2% by mass of PVP, ammonia water, and a mixture of tetraethyl orthosilicate (TEOS) and isopropyl alcohol or ethanol.

[0054] Furthermore, in step (2), the mesoporous silicon is capped by dispersing the loaded mesoporous silicon in water to form an aqueous dispersion, adding an isopropanol solution and aqueous ammonia with or without PVP, and dropping a mixture of TEOS and isopropanol or ethanol, stirring and reacting at 20-60° C. for 2-24 hours, centrifuging, washing the precipitate three times with water and ethanol, respectively, and drying to obtain silica-encapsulated loaded mesoporous silicon;

[0055] Furthermore, the volume ratio of the above-mentioned mesoporous silicon aqueous dispersion, PVP isopropanol solution, ammonia water, TEOS and isopropanol mixture or TEOS and ethanol mixture is 30:0~30:2~7:30~50, and the volume content of TEOS in the TEOS and isopropanol mixture or TEOS and ethanol mixture is 9%~20%; the concentration of the loaded mesoporous silicon in the aqueous dispersion is 0.2g / 30mL, and the mass fraction of PVP in the PVP isopropanol solution is 1.2%.

[0056] Furthermore, in step (2), the sealing method of mesoporous silicon when loading organic matter dried and precipitated from the solution is as follows: the loaded mesoporous silicon is dispersed in water, stirred for 10 minutes, ammonia water is added, TEOS is slowly added dropwise, stirred at room temperature for 3 hours, centrifuged, washed three times with water and ethanol respectively, and dried to obtain mesoporous silicon loaded with organic matter and sealed with silica.

[0057] Furthermore, the mass-to-volume ratio of the cargo-loaded mesoporous silica to water is 0.2 g: 100-120 mL, and the volume ratio of water, ammonia water, and TEOS is 100-120: 0.6-1.0: 0.6-1.5.

[0058] The thickness of the above-mentioned silicon layer is controlled by the concentration of the precursor, the stirring time, and the stirring speed.

[0059] Furthermore, in the above-mentioned preparation method, surface activation of the mesoporous silica is also included to make it carry amino, silanol, or dopamine active groups.

[0060] An application of a silica-encapsulated cargo-loaded mesoporous silica in the preparation of coatings, skin care products, flame-retardant or sunscreen fabrics, and the above-mentioned silica-encapsulated cargo-loaded mesoporous silica is used to prepare emulsion, dispersion, solid, or semi-solid products.

[0061] Furthermore, when the above-mentioned load is an inorganic sunscreen or an organic sunscreen, the silica-encapsulated cargo-loaded mesoporous silica is used to prepare an anti-ultraviolet radiation product, and the above-mentioned anti-ultraviolet radiation product includes skin sunscreen products or ultraviolet protection coatings.

[0062] Furthermore, the above-mentioned anti-ultraviolet radiation product is a product with anti-ultraviolet function prepared from a mixture of the silica-encapsulated cargo-loaded mesoporous silica and one or more of plastics, fibers, or inorganic materials.

[0063] Advantages of the present invention: By loading organic or inorganic substances into the pores of mesoporous silica and encapsulating a solid silica layer on the outer surface, the prepared silica spheres can, while exerting and promoting the functionality of the loaded substances, provide a good barrier effect, prevent the release of the loaded substances and the harmful substances generated thereby, reduce hazards, and improve the safety in use. The particle size of the mesoporous silica is greater than 150 nm to avoid its skin penetration and improve the application safety. In addition, the large-particle-size mesoporous silica can have larger pores, which is beneficial to increasing the loading amount of organic and inorganic substances. Taking the loading of sunscreen agents as an example, the innovation and features are as follows: (1) Exert and effectively protect the ultraviolet resistance function of organic and inorganic sunscreen agents. At the same time, the silica layer can effectively block the release of reactive oxygen species generated by the photocatalysis of the sunscreen agent and the organic sunscreen agent, thereby preventing the contact between the reactive oxygen species and the organic sunscreen agent and the skin and preventing safety problems caused by entering the body through the skin; (2) As a platform technology, the technology of the present invention is applicable to the organic and inorganic sunscreen agents widely used at present, and the encapsulation technology also avoids the mutual influence between different sunscreen agents and the degradation effect on other organic components in sunscreen products; (3) The surface sealing layer of silica normalizes the surface properties, which has nothing to do with the physical and chemical properties of the sunscreen agent, provides convenient conditions for the combined application of various sunscreen agents, and also provides convenience for the preparation of sunscreen products, coatings, etc.; (4) The used silica and mesoporous silica are substances existing in nature, the raw materials are easily available and environmentally friendly, and no new environmental pollution is brought; (5) The process is simple, and the functionality can be further enhanced by modifying the mesoporous silica or functionalizing the surface of the silica layer. Description of the Drawings

[0064] Figure 1 : Particle morphologies of the mesoporous silica, the mesoporous silica loaded with titanium dioxide, and the mesoporous silica loaded with titanium dioxide and sealed prepared in Examples 1 and 5.

[0065] Figure 2 : Infrared spectra (FTIR) of the mesoporous silica, the mesoporous silica loaded with titanium dioxide, and the mesoporous silica loaded with titanium dioxide and sealed particles in Examples 1 and 5.

[0066] Figure 3 : Energy spectrum diagram of the mesoporous silica particles loaded with titanium dioxide and sealed prepared in Example 5.

[0067] Figure 4 : Photocatalytic shielding effect of the particles after the mesoporous silica in Examples 1 and 5 is loaded with titanium dioxide and sealed.

[0068] Figure 5: The mechanical stability of the particles of mesoporous silica loaded with inorganic sunscreen agents and sealed in Examples 1, 5, and 9 is reflected by the photocatalytic shielding effect. Among them, (1) is SiO2@MSN-4 / ZnO, (2) is SiO2@MSN-4 / ZnO treated by mechanical stirring, (3) is a mixture of MSN, ZnO, and SiO2, (4) is SiO2@MSN-1 / TiO2, (5) is SiO2@MSN-1 / TiO2 treated by mechanical stirring, and (6) is a mixture of MSN, TiO2, and SiO2.

[0069] Figure 6 : The ultraviolet shielding effects of mesoporous silica, mesoporous silica loaded with titanium dioxide, and mesoporous silica loaded with titanium dioxide and sealed in Examples 1 and 5.

[0070] Figure 7 : The particle morphologies of mesoporous silica, mesoporous silica loaded with zinc oxide, and mesoporous silica loaded with zinc oxide and sealed in Examples 1 and 9.

[0071] Figure 8 : The particle morphologies of mesoporous silica, mesoporous silica loaded with DHHB, and mesoporous silica loaded with DHHB and sealed in Examples 1 and 11.

[0072] Figure 9 : Infrared spectra (FTIR) of the particles of mesoporous silica, mesoporous silica loaded with DHHB, and mesoporous silica loaded with DHHB and sealed in Examples 1 and 11.

[0073] Figure 10 : Energy spectrum of mesoporous silica loaded with DHHB and sealed in Example 11.

[0074] Figure 11 : DHHB release rate tests of mesoporous silica loaded with DHHB and mesoporous silica loaded with DHHB and sealed in Example 11.

[0075] Figure 12 : Percutaneous penetration tests of mesoporous silica loaded with DHHB and mesoporous silica loaded with DHHB and sealed in Example 11.

[0076] Figure 13 : The ultraviolet shielding effects of mesoporous silica, mesoporous silica loaded with DHHB, and mesoporous silica loaded with DHHB and sealed in Examples 1 and 11.

[0077] Figure 14 : The particle morphologies of mesoporous silica, mesoporous silica loaded with AVO, and mesoporous silica loaded with AVO and sealed in Examples 1 and 13.

[0078] Figure 15 : Photostability tests of the ultraviolet shielding effects of mesoporous silica loaded with AVO and mesoporous silica loaded with AVO and sealed in Example 13.

[0079] Figure 16 : Ultraviolet shielding effect test of the ultraviolet intensity induction card for sunscreen. Specific implementation mode

[0080] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made. These all belong to the protection scope of the present invention.

[0081] Example 1

[0082] Preparation of mesoporous silica MSN-1:

[0083] Add 240 mL of water, 160 mL of absolute ethanol and 5 g of an aqueous solution of cetylammonium chloride (CTAC) with a mass fraction of 25% to a three-necked flask. Using a magnetic stirrer, stir at a speed of 800 rpm for 5 min, then add 4.8 g of PEG-400 and continue stirring for 20 min. Then, add 12 mL of dodecane and stir vigorously at a speed of 1200 rpm for 20 min. Then, add 15 g of Pluronic 123 (P123) and 3.2 mL of ammonia water. Finally, slowly drop 10 mL of tetraethyl orthosilicate (TEOS) into the mixture and stir and react at 60 °C at a speed of 600 rpm for 3 h. Centrifuge the solution obtained from the reaction to remove the supernatant, wash it three times with water and ethanol respectively, and evaporate and dry it at 70 °C. Calcinate the obtained powder at 550 °C for 5 h to finally obtain mesoporous silica MSN-1. The size and morphology are as Figure 1 shown in Figure A and Table 1. Figure 1 The ASEM and TEM images respectively show that the prepared mesoporous silica MSN-1 is spherical (average particle size 300 ± 10 nm) and has a pore structure.

[0084] In Examples 1 to 20 of the present invention, a magnetic stirrer (Beijing Xingde Instrument Equipment Co., Ltd., model 85-1, stirring speed 0-2600 rpm, power 20 W) was used

[0085] Example 2

[0086] Preparation of mesoporous silica MSN-2

[0087] According to the method of Example 1, add 120 mL of water, 80 mL of absolute ethanol, 10 g of P123 and 10 mL of TEOS to a three-necked flask to prepare mesoporous silica MSN-2 with a particle size of 500 ± 23 nm.

[0088] Example 3

[0089] Preparation of mesoporous silica MSN-3

[0090] According to the method in the literature (Yu-Chih Lin, et al. Colloids and Surfaces B: Biointerfaces 202(2021)111658), 8 g of P123 was dissolved in 240 mL of HCl (2 M) at 30 °C and stirred at 500 rpm for 1 h, then 9.1 mL of TEOS was added and the reaction was carried out at room temperature for 24 h and at 90 °C for 12 h. The solid obtained from the reaction was filtered, washed with water, and dried at 100 °C for 5 h. The solid was calcined at 550 °C for 5 h to obtain mesoporous silica MSN-3 with a particle size of 1 ± 0.05 μm.

[0091] Example 4

[0092] Preparation of mesoporous silica MSN-4

[0093] According to the method of Example 3, 4 g of P123 was dissolved in 160 mL of HCl (2 M) at 30 °C and stirred at 500 rpm for 1 h, then 9.1 mL of TEOS was added and the reaction was carried out at room temperature for 24 h and at 90 °C for 24 h. The solid obtained from the reaction was filtered, washed with water, and dried at 100 °C for 5 h. The solid was calcined at 550 °C for 5 h to obtain mesoporous silica MSN-4 (5.0 ± 0.5 μm).

[0094] Example 5

[0095] Preparation of mesoporous silica encapsulated with a silicon layer and loaded with titanium dioxide

[0096] (1) Preparation of mesoporous silica loaded with titanium dioxide (MSN-1 / TiO2-a)

[0097] 0.3 g of MSN-1 and 0.32 mL (0.3072 g) of titanium isopropoxide were dispersed in 25 mL of ethanol, and nitrogen was introduced to remove oxygen. The mixture was stirred at 600 rpm at room temperature (20 - 25 °C) in a nitrogen atmosphere for 24 hours. The solution was centrifuged to obtain a solid product, which was washed three times with water and ethanol respectively and then dried. The product was placed in a muffle furnace and heated to 550 °C at a heating rate of 2 °C / min and maintained for 5 h to obtain mesoporous silica MSN-1 / TiO₂ loaded with titanium dioxide.

[0098] (2) Encapsulation of mesoporous silica loaded with titanium dioxide (SiO₂@MSN-1 / TiO₂)

[0099] Disperse 0.2 g of titanium dioxide-loaded mesoporous silica in 30 mL of water and stir at 800 rpm for 5 min to form an aqueous dispersion. Then add 30 mL of an isopropanol solution of PVP with a mass fraction of 1.2%. Add 5 mL of ammonia water to provide an alkaline environment. Finally, dropwise add a mixture of 3 mL of TEOS and 30 mL of isopropanol, and stir and react at 600 rpm at room temperature for 24 hours. Centrifuge, wash the precipitate three times with water and ethanol respectively, and dry to obtain silica-encapsulated mesoporous silica-based titanium dioxide (SiO2@MSN-1 / TiO2). The structure and properties are shown in Figures 1 - 6 , 16 and Table 1.

[0100] Figure 1 Figure B shows that there are nano TiO2 particles both inside and outside the mesoporous silica. After encapsulating the silicon layer ( Figure 1 Figure C), the surface of SiO2@MSN-1 / TiO2 becomes smooth, and the presence of mesopores cannot be observed by TEM. The average thickness of the surface silicon layer of SiO2@MSN-1 / TiO2 is measured to be 15 nm through the change in particle size.

[0101] Figure 2 The comparison of infrared spectra shows the loading of TiO2 and the encapsulation of the surface silicon layer; Figure 3 The surface elemental analysis also proves the distribution of O, Si, and Ti elements on the silicon spheres; Figure 4 The experimental results of the photocatalytic shielding effect show that in the presence of MSN-1 / TiO2, after ultraviolet light irradiation, the active oxygen generated by the photocatalytic action of TiO2 causes the decomposition of methyl orange, resulting in a sharp decrease in the concentration of methyl orange in the solution with the increase of ultraviolet light irradiation time. While SiO2@MSN-1 / TiO2 with a SiO2 coating can effectively reduce the decomposition of methyl orange. Therefore, the concentration of the methyl orange solution decreases less.

[0102] Figure 5 Figure is the photocatalytic shielding effect of the particles after loading inorganic sunscreen agents on mesoporous silica and encapsulating the layer after mechanical stirring treatment. Compared with SiO2@MSN-1 / TiO2 (4) before mechanical stirring treatment, the photocatalytic shielding effect of SiO2@MSN-1 / TiO2 (5) after mechanical stirring treatment hardly changes, while the photocatalytic effect of the MSN, TiO2, SiO2 mixture (6) is very obvious, resulting in a sharp decrease in the methyl orange concentration. These results indicate that the encapsulated silicon layer has good stability and the silicon layer is not damaged under mechanical stirring. And the C 96 / C0 of SiO2@MSN-1 / TiO2 in Table 1 is 90.1%, indicating that after grinding, pressure, and mechanical stirring, the particles can ensure that 90% of the methyl orange is not decomposed after 96 hours of ultraviolet light irradiation (Table 1), further demonstrating the stability of the silicon layer.

[0103] Figure 6The UV shielding performance of mesoporous silica in Examples 1 and 5, mesoporous silica loaded with titanium dioxide, and mesoporous silica loaded with titanium dioxide and sealed with a capping layer were compared. The mesoporous silica exhibited poor UV shielding, rapidly decreasing the concentration of methyl orange under UV irradiation. However, SiO2@MSN-1 / TiO2 exhibited superior UV shielding performance, slightly lower than that of MSN-1 / TiO2 of the same mass. This is because the silicon coating reduces the TiO2 content.

[0104] Example 6

[0105] Preparation of Titanium Dioxide-Loaded Mesoporous Silica Encapsulated by Silicon Layer

[0106] Disperse 0.3g of MSN-4 in 35mL of ethanol, introduce nitrogen to deoxygenate, add 0.6mL (0.576g) of isopropyl titanate, and stir at 600rpm for 24 hours at room temperature under a nitrogen atmosphere. Centrifuge the solution to obtain a solid product, wash it three times with water and ethanol, and dry it. Place the product in a muffle furnace, heat it to 550℃ at a rate of 2℃ / min and maintain it for 5h to obtain mesoporous silica MSN-4 / TiO2 loaded with titanium dioxide;

[0107] 0.2g of MSN-4 / TiO2 was dispersed in 30mL of water and stirred at 800rpm for 5min. Then, 30mL of a 1.2% (mass fraction) PVP solution in isopropanol was added. 7mL of aqueous ammonia was added to provide an alkaline environment. Finally, a mixture of 10mL of LTEOS and 40mL of isopropanol was added dropwise, and the reaction was stirred at 600rpm at room temperature for 30 hours. After centrifugation, the precipitate was washed three times with water and ethanol, respectively, and dried to obtain silica-encapsulated mesoporous silica-based titanium dioxide (SiO2@MSN-4 / TiO2). The structure and properties are shown in Table 1.

[0108] The data in Table 1 show that the titanium dioxide loading of MSN-4 / TiO2 reaches 50% and the thickness of the SiO2@MSN-4 / TiO2 silicon layer is 50 nm, thus showing higher stability and anti-ultraviolet effect.

[0109] Example 7

[0110] Preparation of Titanium Dioxide-Loaded Mesoporous Silica Encapsulated by Silicon Layer

[0111] (1) Preparation of mesoporous silica loaded with titanium dioxide (MSN-2 / TiO2)

[0112] 0.3 g MSN-2 and 0.22 mL (0.211 g) isopropyl titanate were dispersed in 40 mL butanol, stirred at 600 rpm at 45 °C for 1 h, then butanol was evaporated at 160 °C for 2 h, and finally calcined at 450 °C for 6 h to obtain mesoporous silica MSN-2 / TiO2 loaded with titanium dioxide.

[0113] (2) Encapsulation of mesoporous silica loaded with titanium dioxide (SiO2@MSN-2 / TiO2)

[0114] Disperse 0.2 g of mesoporous silica loaded with titanium dioxide in 30 mL of water and stir at 700 rpm for 5 min. Then add 30 mL of an isopropanol solution of PVP with a mass fraction of 1.2%. Add 5 mL of ammonia water to provide an alkaline environment. Finally, dropwise add a mixture of 5 mL of TEOS and 30 mL of isopropanol, and stir and react at 700 rpm at room temperature for 24 h. Centrifuge, wash the precipitate three times with water and ethanol respectively, and dry to obtain silica-encapsulated mesoporous silica-based titanium dioxide (SiO2@MSN-2 / TiO2), and the performance is shown in Table 1.

[0115] Example 8

[0116] Preparation of mesoporous silica loaded with titanium dioxide encapsulated with a silicon layer

[0117] (1) Preparation of mesoporous silica loaded with titanium dioxide (MSN-3 / TiO2)

[0118] Disperse 0.3 g of MSN-3 into 25 mL of ethanol and 5 mL of water, add 0.316 g of tetrabutyl titanate, and stir at 600 rpm at 70 °C for 8 h. Centrifuge to collect the solid product, wash, dry, and finally calcine at 500 °C for 4 h to obtain mesoporous silica loaded with titanium dioxide MSN-3 / TiO2.

[0119] (2) Encapsulation of mesoporous silica loaded with titanium dioxide (SiO2@MSN-3 / TiO2)

[0120] Disperse 0.2 g of mesoporous silica loaded with titanium dioxide in 30 mL of water and ultrasonically disperse for 30 min. Then add 3 mL of ammonia water to provide an alkaline environment. After heating the system to 45 °C, dropwise add a mixture of 8 mL of TEOS and 35 mL of ethanol, and stir and react at 600 rpm at 45 °C for 14 h. Centrifuge, wash the precipitate three times with water and ethanol respectively, and dry to obtain silica-encapsulated mesoporous silica-based titanium dioxide (SiO2@MSN-3 / TiO2), and the performance is shown in Table 1.

[0121] Example 9

[0122] Preparation of mesoporous silica loaded with zinc oxide encapsulated with a silicon layer

[0123] (1) Preparation of mesoporous silica loaded with zinc oxide (MSN-1 / ZnO)

[0124] Disperse 1g of MSN-1 in 50mL of water, add 0.5g of zinc chloride, and stir at 600rpm for 12 hours at room temperature (22-25°C). Sodium hydroxide aqueous solution is added dropwise to the reaction solution until the pH reaches 10, and the reaction is continued for 12 hours. The reaction product is centrifuged, washed, dried, and calcined at 550°C in a muffle furnace for 4 hours to obtain zinc oxide-loaded mesoporous silica MSN-1 / ZnO.

[0125] (2) Encapsulation of mesoporous silicon loaded with zinc oxide (SiO2@MSN-1 / ZnO)

[0126] 0.2 g of mesoporous silicon loaded with zinc oxide was dispersed in 30 mL of water and stirred at 600 rpm for 5 min. Then 30 mL of an isopropanol solution of PVP with a mass fraction of 1.2% was added. 5 mL of ammonia water was added to provide an alkaline environment. Finally, a mixture of 4 mL of LTEOS and 30 mL of isopropanol was added dropwise and stirred at 600 rpm at room temperature for 24 hours. After centrifugation, the precipitate was washed three times with water and ethanol respectively, and dried to obtain silica-encapsulated mesoporous silicon-based zinc oxide (SiO2@MSN-4 / ZnO). The structure and properties are shown in Figure 5 、 7 and Table 1.

[0127] Figure 7 B shows that there are nano ZnO particles inside and outside the mesoporous silicon, and after encapsulating the silicon layer ( Figure 7 The surface of the SiO2@MSN-1 / ZnO in C) becomes smooth, and no mesopores are observed by TEM, indicating a solid silicon layer covering the surface. The average thickness of the silicon layer on the surface of the SiO2@MSN-1 / ZnO, as measured by particle size, is 17 nm.

[0128] Figure 5 After the mesoporous silica particles were loaded with inorganic sunscreen and sealed with a layer, the photocatalytic shielding effect of the particles after mechanical stirring was almost unchanged compared with SiO2@MSN-1 / ZnO(1) before mechanical stirring, while the photocatalytic shielding effect of the SiO2@MSN-1 / TiO2(2) after mechanical stirring was very obvious, and the photocatalytic effect of the mixture of MSN-1, ZnO, and SiO2(3) was very obvious, resulting in a sharp decrease in the concentration of methyl orange. These results indicate that the encapsulated silicon layer has good stability and is not damaged under mechanical stirring. The C of SiO2@MSN-1 / ZnO in Table 1 is 96 / The C0 value is 90.4%, indicating that after grinding, pressing and mechanical stirring, the particles can ensure that 90% of the methyl orange is not decomposed after 96 hours of UV irradiation (Table 1), further demonstrating the stability of the silicon layer.

[0129] Example 10

[0130] Preparation of Ceria-loaded Mesoporous Silica Encapsulated by Silicon Layer

[0131] (1) Preparation of mesoporous silica loaded with ceria (MSN-5 / CeO2)

[0132] Commercial mesoporous silica (150 nm, Hangzhou Xinqiao Biotechnology Co., Ltd., denoted as MSN-5) was used.

[0133] At room temperature, 1g of MSN-5 was dispersed in 40mL of water, and 0.96g of cerium nitrate hexahydrate was added. The mixture was stirred at 600rpm for 12 hours. A certain amount of hydrogen peroxide was added to the reaction solution, and aqueous ammonia was added dropwise until the pH reached 10. The reaction was continued for 12 hours. The reaction product was centrifuged, washed, dried, and calcined at 550°C in a muffle furnace for 4 hours to obtain ceria-loaded mesoporous silica MSN-5 / CeO2.

[0134] (2) Encapsulation of mesoporous silica loaded with ceria (SiO2@MSN-5 / CeO2)

[0135] 0.2 g of ceria-loaded mesoporous silica was dispersed in 30 mL of water and stirred for 5 min. Then, 20 mL of a 1.2% mass fraction of PVP in isopropanol was added. 5 mL of ammonia was added to provide an alkaline environment. Finally, a mixture of 3 mL of LTEOS and 27 mL of isopropanol was added dropwise, and the reaction was stirred at room temperature for 24 hours. After centrifugation, the precipitate was washed three times with water and ethanol, respectively, and dried to obtain silica-encapsulated mesoporous silica-based ceria (SiO2@MSN-5 / CeO2). The stirring speed in this example was 600 rpm. The performance is shown in Table 1.

[0136] Table 1 Structural properties of silica-encapsulated mesoporous silica prepared in Examples 5 to 10

[0137]

[0138] a The percentage of mesoporous silicon relative to the carrier; b The concentration of methyl orange solution after the particles were dispersed as photocatalysts and irradiated with ultraviolet light for 96 hours. 96 The ratio of the initial concentration C0 to the c particle as an ultraviolet absorber is placed above the methyl orange aqueous solution and irradiated with ultraviolet light for 30 hours. 30 The ratio of the initial concentration C0 to the initial concentration C0. Without any sunscreen treatment, the methyl orange aqueous solution was irradiated with a UV lamp (302nm, 8w), and C 30 / C0 is 3.6%.

[0139] Example 11

[0140] Preparation of Mesoporous Silica Encapsulated with Diethylamino Hydroxybenzoyl Hexyl Benzoate (DHHB)

[0141] (1) Preparation of DHHB-loaded mesoporous silica (MSN-1 / DHHB)

[0142] Disperse 0.4 g of DHHB in 10 mL of dichloromethane and add 0.2 g of mesoporous silica. Stir at 30°C in the dark for 6 hours to allow the mesoporous silica to fully adsorb the DHHB. Open the reaction vessel and continue stirring until the dichloromethane evaporates slowly, yielding DHHB-loaded mesoporous silica (MSN-1 / DHHB).

[0143] (2) Silicon layer encapsulation of DHHB-loaded mesoporous silica (SiO2@MSN-1 / DHHB)

[0144] Disperse 0.2g of MSN-1 / DHHB in 120mL of water, stir for 10min, and add 1.0mL of ammonia water. Then, slowly drop 1.5mL of LTEOS and stir at room temperature for 3h. Centrifuge, wash three times with water and ethanol respectively, and dry to obtain DHHB-loaded mesoporous silica with silica seal. The stirring speed in this example is 400rpm. The structure and performance are shown in Figures 8 - 13 , 16 and Table 2.

[0145] Figure 8 SEM and TEM images of MSN-1 / DHHB and SiO2@MSN-1 / DHHB are given. It can be seen that after loading DHHB, the surface of mesoporous silicon is rough and the mesopores almost disappear. After encapsulating the silicon layer, the particles become larger and the surface is smooth. The thickness of the silicon layer is about 40nm (Table 2), and it has a high UV resistance effect (Table 2).

[0146] Figure 9 Infrared spectra showed that MSN-1 / DHHB had a wavelength of 600-1200 cm -1 There is an obvious DHHB characteristic group vibration peak in the range, and the characteristic vibration peak of DHHB is weakened after encapsulating the silicon layer. Figure 10 The distribution of O, Si, and N elements in the energy spectrum shows that DHHB is uniformly distributed in mesoporous silicon.

[0147] Figure 11 This is the in vitro release curve of MSN-1 / DHHB and SiO2@MSN-1 / DHHB. DHHB is quickly released from MSN-1 / DHHB, but due to the barrier of the outer solid SiO2 layer, DHHB can hardly be released from SiO2@MSN-1 / DHHB. Therefore, the encapsulation of the silicon layer can effectively prevent the loss of DHHB. Figure 12 The results of the transdermal permeation experiment further demonstrate that due to the barrier effect of the silicon layer, almost no DHHB penetrates the skin, indicating that the SiO2@MSN-1 / DHHB particle has good safety. Furthermore, the mechanical stability results in Table 2 demonstrate that even after milling, pressure, and stirring, the DHHB content in the particles is almost completely lost.

[0148] Figure 13 The anti-ultraviolet performance shows that SiO2@MSN-1 / DHHB coated with a silicon layer exhibits similar or slightly better anti-ultraviolet ability than MSN-1 / DHHB. This indicates that the silicon layer coating does not affect the anti-ultraviolet function of the organic ultraviolet absorber.

[0149] Example 12

[0150] According to the method of Example 11, the difference is that 0.2 g of MSN-5 and 0.2 g of DHHB are used, ethanol is used as the solvent to obtain MSN-5 / DHHB-b; then 0.2 g of MSN-5 / DHHB-b is dispersed in 100 mL of water, stirred at a speed of 500 rpm for 10 min, and 0.6 mL of ammonia water is added. After that, 0.6 mL of TEOS is slowly dropped in, and stirring is continued at room temperature for 3 h. Centrifugation is carried out, and it is washed three times with water and ethanol respectively, and dried to obtain mesoporous silicon loaded with DHHB with a silica seal layer, SiO2@MSN-5 / DHHB-b. As shown in Table 2, the silicon layer thickness of SiO2@MSN-5 / DHHB-b is 20 nm, and the anti-ultraviolet effect is lower than that of SiO2@MSN-1 / DHHB.

[0151] Table 2 Structural properties of silica-encapsulated mesoporous silicon loaded with substances prepared in Examples 11 to 14

[0152]

[0153] a Percentage content relative to the mesoporous silicon loaded with substances; b The retention rate (%) of the organic load in the particles is characterized by grinding for 5 minutes, pressing at a pressure of 20 MPa for 5 minutes, and mechanically stirring at 250 rpm in ethanol for 5 minutes to characterize the stability of the silicon layer encapsulation; c The ratio of the concentration C of the methyl orange solution to the initial concentration C0 after the particles are placed above the methyl orange aqueous solution and irradiated with ultraviolet light for 30 h as an ultraviolet absorber.

[0154] Example 13

[0155] Mesoporous silicon and silicon layer loaded with 1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)propane-1,3-dione (AVO)

[0156] According to the method of Example 11, except that 0.3 g of MSN-1 and 0.6 g of AVO were used, and isopropanol was used as the solvent to obtain MSN-1 / AVO; then, 0.2 g of MSN-1 / AVO was dispersed in 110 mL of water, stirred at 500 rpm for 10 min, and 0.8 mL of ammonia water was added. Then, 1.0 mL of TEOS was slowly added dropwise, and the mixture was stirred at 400 rpm at room temperature for 3 h. Centrifuged, washed three times with water and ethanol respectively, and dried to obtain AVO-loaded mesoporous silica with a silica coating, SiO2@MSN-1 / AVO.

[0157] Figure 14 SEM and TEM images of MSN-1 / AVO and SiO2@MSN-1 / AVO were presented. It can be seen that the surface of the mesoporous silica became rough and the mesopores almost disappeared after loading AVO, and the particle size became larger and the surface became smooth after encapsulating the silica layer.

[0158] As shown in Table 2, the silica layer thickness of SiO2@MSN-1 / AVO was 35 nm, with high mechanical stability; SiO2@MSN-1 / AVO had excellent UV resistance because the AVO loading amount of MSN-1 / AVO was relatively high, reaching 50%.

[0159] Figure 15 The stability of the UV shielding performance of AVO and SiO2@MSN-1 / AVO was compared. AVO was easily decomposed under UV irradiation, and its UV resistance performance would decline. Figure 15 It can be seen that after 24 h of UV irradiation at two wavelengths, the color of the color card coated with AVO became darker, indicating that the UV shielding effect weakened; while for the color card coated with SiO2@MSN-1 / AVO, it still remained a lighter color after 24 h of UV irradiation, indicating that SiO2@MSN-1 / AVO effectively promoted the stability of the UV shielding effect of AVO.

[0160] Example 14

[0161] According to the method of Example 11, except that 0.25 g of MSN-3 and 0.5 g of ethylhexyl triazone (UVT-150) were used to prepare mesoporous silica MSN-3 / UVT-150 loaded with UVT-150 and mesoporous silica SiO2@MSN-3 / UVT-150 with a silica coating. The performance is shown in Table 2.

[0162] Example 15

[0163] According to the method of Example 11, except that 0.5 g of MSN-4 and 0.6 g of bis-ethylhexyloxyphenol methoxyphenyl triazine ( S), tetrahydrofuran was used as the solvent to prepare mesoporous silica loaded with S, MSN-4 / S and mesoporous silica SiO2@MSN-4 with a silica coating / S. The performance is shown in Table 2.

[0164] Example 16

[0165] Preparation method of sunscreen:

[0166] Component A: 51.5 g of polydimethylsiloxane (PDMS, Mn = 800), 2 g of sodium dodecylbenzenesulfonate, 1.85 g of stearic acid;

[0167] Component B: 6.5 g of glycerol, 16.5 g of 1,4-butanediol, 145 g of water;

[0168] Component C: 30 g each of the mesoporous silica particles SiO2@MSN-1 / TiO2 and SiO2@MSN-1 / DHHB with a loaded coating obtained in the previous Examples 5 and 11.

[0169] Stir Component A evenly at 60 °C at a speed of 1000 rpm, add Component B, continue to stir evenly at room temperature, and finally add Component C, and stir at a speed of 400 rpm at room temperature for 24 h.

[0170] As Figure 16 , the color change of the color card under ultraviolet irradiation is used to characterize the anti-ultraviolet effect. It can be seen that SiO2@MSN-1 / TiO2 has a good shielding effect on ultraviolet light of 304 nm, and the color of the color card is very light after ultraviolet irradiation, but the protection effect on ultraviolet light of 364 nm is poor; contrary to SiO2@MSN-1 / TiO2, SiO2@MSN-1 / DHHB has a higher protection effect on ultraviolet light of 364 nm and a weaker protection effect on ultraviolet light of 304 nm; the sunscreen prepared by compounding SiO2@MSN-1 / TiO2 and SiO2@MSN-1 / DHHB in Example 16 has a good protection effect on ultraviolet light of both wavelengths, and is similar to the function of commercial SPF50+ anti-ultraviolet products.

[0171] Example 17

[0172] Amino-functionalized mesoporous silica loaded with phytic acid:

[0173] (1) In a round-bottom flask, add 2 g of MSN-1 and 120 mL of absolute ethanol. Under nitrogen protection, dropwise add 2 mL of 3-aminopropyltrimethoxysilane, reflux at 80 °C for 16 h, then filter and wash, and dry at 80 °C to obtain amino-functionalized mesoporous silica (NH2-MSN-1).

[0174] (2) Dissolve 4 g of phytic acid (PA) powder in 10 mL of deionized water, stir evenly at room temperature. After the powder is completely dissolved, add 0.25 g of NH2-MSN-1, stir at 800 rpm at 50 °C for 12 h, then centrifuge and wash. Place the centrifuged product in a vacuum drying oven for vacuum drying to obtain mesoporous silica MSN-1 / PA loaded with phytic acid.

[0175] (3) Disperse 0.2 g of MSN-1 / PA in 30 mL of water and stir for 5 min. Then add 30 mL of an isopropanol solution of PVP with a mass fraction of 1.2%. Add 5 mL of ammonia water to provide an alkaline environment. Finally, dropwise add a mixture of 3 mL of TEOS and 30 mL of isopropanol, and stir and react at room temperature for 24 h. Centrifuge, wash the precipitate three times with water and ethanol respectively, and dry to obtain silica-encapsulated mesoporous silica loaded with phytic acid (SiO2@MSN-1 / PA). The stirring speed in this example is 400 rpm.

[0176] For the prepared SiO2@MSN-1 / PA, the mass percentage of phytic acid in MSN-1 / PA is 50%, and the thickness of the silica layer is 35 nm. At room temperature, MSN-1 / PA and SiO2@MSN-1 / PA are respectively immersed in distilled water. After 10 days, centrifuge and separate, measure the PA concentration in the distilled water, and calculate the PA loss rate, which are 85% and 1% respectively. It shows that after the silicon layer encapsulation, the dissolution of water-soluble PA can be prevented.

[0177] Example 18

[0178] Ammonium phytic acid loaded on carboxylated mesoporous silica

[0179] Suspend 0.25 g of NH2-MSN-1 prepared in Example 17 in 20 ml of dimethylformamide (DMF), add it to DMF containing 0.5 g of succinic anhydride, stir at room temperature for 24 h, centrifuge and separate, wash with absolute ethanol and deionized water, and dry in an oven to obtain carboxylated mesoporous silica COOH-MSN-1.

[0180] Dissolve 5 g of ammonium phytic acid (PAA) powder in 10 ml of deionized water, stir evenly at room temperature. After the powder is completely dissolved, add 0.5 g of COOH-MSN-1, continue to stir for 24 h, then centrifuge and wash. Place the centrifuged product in a vacuum drying oven for vacuum drying to obtain mesoporous silica spheres MSN-1 / PAA loaded with ammonium phytic acid. The stirring speed in this example is 800 rpm.

[0181] Encapsulation of the silicon layer:

[0182] 0.2g of MSN-1 / PAA was dispersed in 30mL of water and stirred for 30min. Then, 15mL of a 1.2% PVP solution in isopropanol was added, followed by 2mL of ammonia. A mixture of 5mL of LTEOS and 20mL of isopropanol was added dropwise, and the mixture was allowed to react at 60°C for 2h. The resulting solid was filtered, washed three times with water and ethanol, and dried to obtain silica-encapsulated mesoporous silica loaded with ammonium phytate (SiO2@MSN-1 / PAA). The stirring speed in this example was 400rpm.

[0183] The prepared SiO2@MSN-1 / PAA contained 20% ammonium phytate by mass and a 20nm thick silica layer. The MSN-1 / PAA and SiO2@MSN-1 / PAA were immersed in distilled water at room temperature for 10 days. The separations were centrifuged and the PAA concentrations in the distilled water were measured. The PAA loss rates were calculated to be 90% and 0.5%, respectively. This indicates that the silica layer encapsulation prevents the dissolution of water-soluble PAA.

[0184] Example 19

[0185] Mesoporous silica loaded with carbon dots: 1 g of hydrated citric acid and 2 g of urea were dissolved in 10 mL of deionized water, and then 0.25 g of amino-modified mesoporous silica (NH2-MSN-q), with a particle size of 5 μm, purchased from Xi'an Qiyue Biotechnology Co., Ltd., was added and heated in an oven at 180°C for 4 hours, followed by natural cooling to room temperature. The mesoporous silica was separated by centrifugation, washed three times with deionized water and ethanol, and then dried in an oven at 80°C to obtain mesoporous silica DMSN / CDs loaded with carbon dots.

[0186] Silica Encapsulation: Disperse 0.2g of DMSN / CDs in 30mL of water and ultrasonically disperse for 30min. Then, add 3mL of aqueous ammonia to provide an alkaline environment. After heating the system to 45°C, add a mixture of 6mL of LTEOS and 35mL of ethanol dropwise. Stir and react at 45°C for 12 hours. Centrifuge, wash the precipitate three times with water and ethanol, and dry to obtain silica-encapsulated carbon dot-loaded mesoporous silica (SiO2@DMSN / CDs). The stirring speed in this example was 400rpm.

[0187] The prepared SiO2@DMSN / CDs had a carbon dot content of 10% by mass and a silica layer thickness of 15 nm. The DMSN / CDs and SiO2@DMSN / CDs were immersed in distilled water at room temperature, stirred for 10 days, and then centrifuged. The CDs loss rates were measured and found to be 40% and 0.2%, respectively. This indicates that the silicon layer encapsulation prevents the loss of water-soluble CDs.

[0188] Example 20

[0189] 1 g of mesoporous silica MSN-4 was added to a n-hexane solution containing 2 g of inorganic perovskite nanocrystals (CsPbBr3, Xi'an Qiyue Biotechnology Co., Ltd.), stirred for 1 hour, and then centrifuged and dried to obtain mesoporous silica DMSN / CsPbBr3 loaded with CsPbBr3.

[0190] Silicon layer encapsulation: Disperse 0.2g DMSN / CsPbBr3 in 30mL water and stir for 5min. Then add 30mL of 1.2% PVP isopropanol solution. Add 5mL of ammonia water to provide an alkaline environment. Finally, add a mixture of 3mL LTEOS and 30mL isopropanol and stir at room temperature for 24 hours. Centrifuge, wash the precipitate three times with water and ethanol respectively, and dry to obtain silica-encapsulated mesoporous silica loaded with CsPbX3 (SiO2@DMSN / CsPbBr3). The stirring speed in this example is 400rpm electromagnetic stirring.

[0191] The prepared SiO2@DMSN / CsPbBr3 contained 50% CsPbBr3 by mass and a 30nm thick silica layer. The DMSN / CsPbBr3 and SiO2@DMSN / CsPbBr3 samples were immersed in water, and their fluorescence intensity was observed as a function of immersion time. The results showed that after seven days in water, the SiO2@DMSN / CsPbBr3 maintained bright green fluorescence with little decrease in intensity. However, the green fluorescence of the DMSN / CsPbBr3 completely disappeared after one hour. This indicates that in the DMSN / CsPbBr3 without the silicon layer, the CsPbBr3 adsorbed in the pores is easily decomposed by water. However, the silicon layer, which blocks the contact of ambient water with the CsPbBr3, prevents its decomposition.

[0192] Method for characterizing the structural properties of silicon spheres in the present invention:

[0193] 1. Particle surface morphology analysis and element spectrum analysis:

[0194] The morphology of the prepared particles was characterized by scanning electron microscopy (SEM, Regulus8100, Hitachi, Japan). Before SEM characterization, all samples were gold-plated for 60 seconds under argon protection to enhance the conductivity of the samples. The test was carried out at an accelerating voltage of 5 kV and a working distance of 10-15 mm, and the morphology was observed at a magnification of 5-10k. Figure 1 、 7 , 8 and 14.

[0195] The morphology of the nanoparticles was further observed by transmission electron microscopy (TEM, JEM-2100F, Hitachi, Japan) at 200 kV, and elemental mapping images were obtained on an energy dispersive X-ray spectrometer (EDX). Figure 1 、 3 , 7, 8, 10 and 14.

[0196] 2. Fourier transform infrared (FTIR) analysis:

[0197] Fourier transform infrared spectrometer (FTIR, Bio-Rad 3000, USA) was used to analyze the surface functional group composition of the samples with the scanning range set at 400–4000 cm -1 , the number of scans was set to 32. The particles were mixed with potassium bromide, ground to a fine powder and made into round tablets for testing. Figure 2 、 9 .

[0198] 3. Photocatalytic activity test of loaded inorganic absorbent particles

[0199] The photocatalytic activity of the nanoparticles was evaluated by the degradation of methyl orange aqueous solution. 0.08 g of particles were added to 80 mL of methyl orange aqueous solution with an initial concentration C0 of 20 mg / L and stirred in the dark for 30 minutes to reach adsorption equilibrium. A UVB lamp (302 nm, 8 W) was used to irradiate the methyl orange aqueous solution from above. At regular intervals, 1.5 mL of the suspension was collected from the solution and the supernatant was obtained by centrifugation. The degradation of methyl orange was monitored by the change in the absorption intensity at the maximum absorption peak of methyl orange at 465 nm. The concentration C of methyl orange was calculated using a standard calibration curve. Figure 4 、 5 .

[0200] 4. Organic absorbent release test

[0201] Disperse the particles loaded with organic absorbent in equal volumes of PBS and ethanol, place them in a dialysis bag, and place them in a container containing equal volumes of PBS and ethanol. Incubate in a shaker at 150 rpm and take samples regularly to test the release profile of the organic absorbent. Evaluate whether the particles lose the load during storage, i.e., storage stability. Figure 11 .

[0202] 5. Mechanical stability test of loaded inorganic absorbent particles

[0203] The mechanical stability of the particles was tested by retaining or not retaining the shielding effect of the silica shell on the photocatalytic effect of the particles. Grind in a mortar for 5 minutes, press at a pressure of 20 MPa for 5 minutes, disperse the particles in ethanol and mechanically stir at a rate of 250 rpm (Shanghai Lichen Instrument Technology Co., Ltd., model LC-CES-120S, stirring speed 60 - 2000 rpm, power 120 W) for 30 minutes. Add the treated particles to 80 mL of methyl orange aqueous solution with an initial concentration C0 of 20 mg / L, and stir in the dark for 30 minutes to reach adsorption equilibrium. Use a UVB lamp (302 nm, 8 w) to irradiate from above the methyl orange aqueous solution. At regular intervals, collect 1.5 mL of suspension from the solution, and centrifuge to obtain the supernatant. Monitor the degradation of methyl orange by the change in the absorption intensity at the maximum absorption peak of methyl orange at 465 nm. Calculate the concentration C of methyl orange using the standard calibration curve. See Figure 5 。

[0204] 6. Test on the Mechanical Stability of Particles Loaded with Organic Absorbents

[0205] The mechanical stability of the particles was tested by different treatments: grind in a mortar for 5 minutes, press at a pressure of 20 MPa for 5 minutes, and mechanically stir at a rate of 250 rpm after dispersing in ethanol for 5 minutes. After treatment, disperse the particles in ethanol, centrifuge, measure the concentration of the organic absorbent in ethanol with a UV spectrometer, and calculate the retention rate of the organic absorbent in the particles. See Table 2.

[0206] 7. Test on the UV Shielding Performance of Sunscreen

[0207] Add 80 mL of 20 mg / L methyl orange aqueous solution to a 100 mL beaker, then add 0.08 g of TiO2 nanoparticles as a photocatalyst and stir in the dark for 30 minutes. Cover the top of the beaker with a glass slide coated with sunscreen (2 mg / cm 2 ), and irradiate with a UV lamp (302 nm, 8 w) at a distance of 10 cm above to initiate the photocatalytic degradation of methyl orange by TiO2. At regular intervals, collect 1.5 mL of methyl orange solution from each beaker, and centrifuge to obtain the supernatant. Measure the absorbance of methyl orange at the maximum absorption peak (465 nm). Calculate the concentration of methyl orange using the standard calibration curve. At the same time, take pictures to record the color of the supernatant, and reflect the change in the concentration of the methyl orange solution through the change in shade. See Figure 6 、 13 。

[0208] Use an ultraviolet intensity sensing card to further test the ultraviolet protection performance of sunscreen and the photo-stability of sunscreen agents. Cover the glass slide coated with sunscreen agent on the ultraviolet intensity sensing card, and irradiate it with a UVB / UVA ultraviolet lamp (302 / 364 nm, 8 w) at a height of 10 cm above. Observe the color change of the card at regular intervals and take photos for record. After 24 h of irradiation, observe the ultraviolet sensitive card and take a photo. The ultraviolet intensity is reflected by the depth of the card color. See Figure 15 、 16 。

[0209] 8. Skin Permeability Test of Loaded Organic Absorbent Particles

[0210] Purchase fresh pigskin from the local market, carefully remove the subcutaneous fat with a scalpel, and cut the skin samples into circles with a diameter of 2 cm, and store them at -20 °C. Before the experiment, thaw the skin samples at room temperature and soak them in PBS for 1 hour. Prepare a PBS-ethanol solution (V / V = 1:1) as the receiving solution, and disperse the sample particles (1 mg / mL) as the diffusion solution. During the test, place the prepared pigskin between the diffusion cell and the receiving cell, and add the diffusion liquid and the receiving liquid to the diffusion cell and the receiving cell respectively. During the whole experiment, the receiving cell is stirred at a speed of 400 rpm at 35 °C. At regular intervals, collect 1 mL of the receiving liquid from the receiving cell and add 1 mL of fresh receiving liquid. Use ultraviolet-visible spectroscopy to detect the change of the organic absorbent content in the receiving liquid over time, and use the standard calibration curve to calculate the concentration of the organic absorbent. And further calculate the cumulative permeability of the organic absorbent according to formula (1).

[0211]

[0212] Where C t represents the concentration of the organic absorbent (μg / mL) measured at the t-th sampling point, C i represents the concentration of the organic absorbent (μg / mL) at the (t - 1)-th sampling point, V t and V i represent the receiving chamber and the sampling volume (mL), which are 18 mL and 1 mL in this experiment. A represents the effective skin penetration area, which is 1.13 cm 2 . See Figure 12 .

[0213] The description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A silica-encapsulated mesoporous silica, characterized in that: The invention comprises mesoporous silicon, a load and a silicon dioxide layer, wherein the load is loaded in the pores of the mesoporous silicon and the outer surface is sealed with a solid silicon dioxide layer with a thickness of ≥10nm, and the particle size of the mesoporous silicon is greater than 150nm; The load is an inorganic sunscreen agent or an organic sunscreen agent.

2. The mesoporous silica encapsulated with silica according to claim 1, characterized in that, The loading amount of the inorganic sunscreen or organic sunscreen accounts for 10-50% of the mass of the loaded mesoporous silicon.

3. A method for preparing the silica-encapsulated cargo mesoporous silica according to any one of claims 1-2, characterized in that, The following steps are involved: (1) The method of preparing loaded mesoporous silicon by in-situ loading includes the following steps: Dispersing the mesoporous silicon and the precursor in a solvent, or dispersing the mesoporous silicon in a solvent and adding the precursor, or dispersing the precursor in a solvent and adding the mesoporous silicon; stirring, centrifuging, washing, drying, and calcining at a high temperature to obtain the loaded mesoporous silicon loaded with the inorganic sunscreen; Alternatively, mesoporous silica and a precursor are dispersed in a solvent, stirred, and then the solvent is evaporated at high temperature until it is completely evaporated, and finally calcined at high temperature to obtain mesoporous silica loaded with an inorganic sunscreen agent; Alternatively, mesoporous silica is dispersed in a solvent, a precursor is added, stirred, hydrogen peroxide is added to the reaction solution, the pH is adjusted, stirring is continued, centrifugation is performed, washing, drying, and high-temperature calcination is performed to obtain mesoporous silica loaded with an inorganic sunscreen agent; Alternatively, the precursor is dispersed in a solvent, mesoporous silica is added, heated at high temperature, then naturally cooled to room temperature, centrifuged, washed, and dried to obtain the loaded mesoporous silica loaded with the inorganic sunscreen agent; The loaded mesoporous silicon is prepared by an in-situ loading method, wherein the precursor is a metal inorganic salt, a metal alkoxide or a mixture of hydrated citric acid and urea; The metal alkoxide is one or a mixture of isopropyl titanate, methyl titanate, ethyl titanate, n-propyl titanate, isopropyl titanate or butyl titanate; The metal inorganic salt is one or a mixture of zinc nitrate, zinc chloride or cerium nitrate hexahydrate; Alternatively, a physical loading method is used to prepare loaded mesoporous silicon, comprising the following steps: In a sealed reaction vessel, the organic matter is dispersed in a solvent, and mesoporous silica is added. The mixture is stirred in the dark, and then the reaction vessel is opened and stirred continuously until the solvent evaporates completely, thereby obtaining mesoporous silica loaded with an organic sunscreen agent. Alternatively, the organic matter is dispersed in a solvent, mesoporous silica is added, stirred, centrifuged, washed, and dried to obtain mesoporous silica loaded with an organic sunscreen; Alternatively, an inorganic substance is dispersed in a solvent, mesoporous silica is added, stirred, centrifuged, and dried to obtain mesoporous silica loaded with an inorganic sunscreen; (2) A method for encapsulating silica, comprising the following steps: adding a precursor component of silica to an aqueous dispersion of supported mesoporous silica, stirring, centrifuging to obtain a solid product, washing, and drying to obtain supported mesoporous silica encapsulated by silica.

4. Application of silica-encapsulated loaded mesoporous silica in the preparation of skin care products or sunscreen fabrics, characterized in that: The silica-encapsulated loaded mesoporous silica according to claim 1 is used to prepare emulsions, dispersions, solid or semi-solid products.

5. Use of the silica-encapsulated cargo mesoporous silica according to claim 4 in the preparation of skin care products or sunscreen fabrics, characterized in that, When the load is an inorganic sunscreen or an organic sunscreen, the load mesoporous silica encapsulated by silica is used to prepare an ultraviolet radiation protection product.

6. The use of a silica-encapsulated loaded mesoporous silica according to claim 5 in the preparation of skin care products or sunscreen fabrics, characterized in that: The anti-ultraviolet radiation product is an ultraviolet protective coating.

7. Use of the silica-encapsulated cargo mesoporous silica according to claim 5 in the preparation of skin care products or sunscreen fabrics, characterized in that, The anti-ultraviolet radiation product is a sunscreen product for skin.

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