A kind of silicon dioxide microsphere, moisturizing type ROS-scavenging gold-loaded silicon dioxide micropowder and preparation method thereof

Abstract

The invention discloses a silicon dioxide microsphere, a moisture-retaining gold-loaded silicon dioxide micropowder capable of removing ROS, and a preparation method thereof. The silicon dioxide microsphere SNS with a positive charge is prepared by adding sodium dihydrogen phosphate and calcium lactate to raw materials such as sodium silicate, hydrochloric acid, and polyethyleneimine (PEI), and adjusting the pH of the reaction system. Then, sodium alginate and gold are loaded on the surface of the silicon dioxide microsphere to obtain a moisture-retaining gold-loaded silicon dioxide micropowder capable of removing ROS. The invention significantly improves the ability and moisture retention of silicon oxide powder to remove ROS, and has high sweat-resistant strength, stable properties, and good biocompatibility.

Description

Technical Field

[0001] The present invention relates to the technical field of cosmetics, and in particular to a silicon dioxide microsphere, a moisturizing gold-loaded silicon dioxide micropowder capable of removing ROS, and a preparation method thereof. Background Art

[0002] Silica (SiO2) microspheres are commonly used as cosmetic fillers. First, due to their spherical microstructure, the contact area and friction resistance between particles are extremely small, which makes them have good fluidity and are usually used in cosmetics to increase their smoothness. Second, they have huge pore volume and specific surface area, which enables them to be used as an adsorbent or a carrier of chemical substances. Third, they are rich in pores and have a certain oil absorption capacity, which can play a role in skin oil control. Silica microspheres also have the advantages of high resistance to sweat erosion and stable properties.

[0003] Although silica microspheres are mostly used in cosmetics, they are usually only carriers and do not have other skin care functions. The most important skin care effects of cosmetics are moisturizing and delaying skin aging, but silica microspheres themselves do not have moisturizing and antioxidant functions. Summary of the invention

[0004] The purpose of the present invention is to provide a silica microsphere, a moisture-retaining gold-loaded silica micropowder capable of scavenging ROS and a preparation method thereof in view of the above-mentioned deficiencies in the prior art, and to combine the obtained positively charged silica microspheres with sodium alginate and gold particles. The obtained moisture-retaining gold-loaded silica micropowder capable of scavenging ROS has good biocompatibility, strong antioxidant properties, high moisture retention, good dispersibility and the like.

[0005] The technical solution adopted by the present invention to achieve the above-mentioned purpose is:

[0006] In a first aspect, the present invention provides a method for preparing silica microspheres, comprising the following steps:

[0007] Mixing sodium silicate with pure water, stirring to fully dissolve, to obtain a sodium silicate aqueous solution A;

[0008] Mix concentrated hydrochloric acid and pure water, stir and fully dissolve to obtain hydrochloric acid aqueous solution B;

[0009] Mixing polyethyleneimine with pure water, stirring to fully dissolve, to obtain polyethyleneimine aqueous solution D;

[0010] Mix sodium dihydrogen phosphate and hydrochloric acid aqueous solution B and stir thoroughly to obtain solution C;

[0011] Calcium lactate and polyethyleneimine aqueous solution D are mixed and stirred sufficiently to obtain solution E, and then mixed and stirred sufficiently with hydrochloric acid aqueous solution B to obtain solution F;

[0012] Sodium silicate aqueous solution A and solution C are added dropwise to solution F at the same time, the pH of the reaction system is adjusted, and the reaction system is stirred sufficiently. When solution C is added dropwise, solution B is added until solution A is added dropwise. After obtaining suspension G, it is aged, filtered, and washed to obtain positively charged silica microspheres SNS.

[0013] Preferably, the mass volume ratio of the raw materials used in the preparation is 16g:0.75g:135-255mL:0.30g:0.07g-0.28g, wherein the concentration of the hydrochloric acid aqueous solution B is 0.6mol·L -1 .

[0014] Preferably, the pH of the reaction system is regulated by simultaneously adding the sodium silicate aqueous solution A and solution C, and when solution C is completely added, solution B is added until solution A is completely added, and the pH value of the reaction system is regulated to be 3-5.

[0015] Preferably, the preparation method specifically comprises:

[0016] Aging the suspension G for 3 hours; or,

[0017] The suspension G was filtered and washed with pure water and anhydrous ethanol in sequence, washed twice with 100 mL of pure water and once with 100 mL of anhydrous ethanol.

[0018] The second aspect of the present invention provides a silica microsphere, which is a positively charged silica microsphere prepared by the above-mentioned preparation method of silica microsphere.

[0019] The third aspect of the present invention provides a method for preparing a moisture-retaining gold-loaded silica micropowder capable of removing ROS, using the silica microspheres as raw materials, comprising the following steps:

[0020] Mixing the sodium alginate solution with pure water, stirring and mixing thoroughly to obtain a sodium alginate SA aqueous solution I;

[0021] The reducing agent solution is mixed with pure water, and stirred to mix thoroughly to obtain a reducing aqueous solution L;

[0022] Disperse silica microspheres SNS in anhydrous ethanol, stir and fully disperse to obtain suspension H;

[0023] The sodium alginate SA aqueous solution I is added dropwise to the suspension H, and the mixture is stirred sufficiently for reaction t1 to obtain a suspension J; the chloroauric acid solution is added dropwise to the suspension J, and the mixture is stirred sufficiently for reaction t2 to obtain a suspension K;

[0024] Then, the reducing aqueous solution L is added dropwise into the suspension K and stirred sufficiently for reaction t3 to obtain a suspension M, which is then filtered, washed, and dried to obtain a moisturizing gold-loaded silica micropowder SNS@S-Au that can remove ROS.

[0025] Preferably, the mass volume ratio of the raw material dosage of the silica microspheres: sodium alginate SA: chloroauric acid: reducing agent solution is 4g: 0.02g-0.04g: 0.001g-0.003g: 0.24mL; wherein the concentration of the sodium alginate solution is 0.2wt%; the reducing agent solution is at least one of sodium ascorbate solution, sodium citrate solution and hydrazine hydrate solution, and the concentrations of the sodium ascorbate solution and the sodium citrate solution are both 0.07mol·L -1 , the concentration of the hydrazine hydrate solution is 80v / v; the concentration of the chloroauric acid solution is 1.0wt%.

[0026] Preferably, the preparation method specifically comprises:

[0027] The sufficient stirring reaction t1 is a reaction time of 0.5h;

[0028] The sufficient stirring reaction t2 is a reaction time of 15min;

[0029] The sufficient stirring reaction t3 is a reaction time of 30 minutes.

[0030] Preferably, the preparation method specifically comprises:

[0031] The suspension M was filtered, washed with pure water and anhydrous ethanol in sequence, and then dried. It was washed twice with 100 mL of pure water, washed once with 100 mL of anhydrous ethanol, and dried at 55°C.

[0032] The fourth aspect of the present invention provides a moisture-retaining gold-loaded silica micropowder capable of scavenging ROS, which is prepared by the aforementioned method for preparing moisture-retaining gold-loaded silica micropowder capable of scavenging ROS. The moisture-retaining gold-loaded silica micropowder capable of scavenging ROS is formed by combining sodium alginate SA and gold particles loaded on the surface of positively charged silica microspheres.

[0033] The present invention uses sodium silicate (Na2O·nSiO2), hydrochloric acid, and polyethyleneimine (PEI) as raw materials, adds sodium dihydrogen phosphate and calcium lactate to form calcium phosphate as a co-precipitation agent, and successfully prepares silica microspheres (SNS) at room temperature by magnetic stirring, and has good monodispersity (such as PDI can be 0.270); in the process of synthesis, the pH of the reaction system is controlled to make the particle size of the silica microspheres controllable, sodium dihydrogen phosphate and calcium lactate are added to introduce calcium ions and phosphate ions to promote the reaction and form calcium phosphate as a co-precipitation agent, and polyethyleneimine provides amino groups to make the surface of the silica microspheres positively charged. The method has the advantages of low raw material cost, simple process, energy-saving production and low environmental pollution, and the amino groups are simply and successfully introduced to make the surface of the silica microspheres positively charged.

[0034] Then, the positively charged active group amino group introduced on the surface of the silica microspheres is used to form a specific interaction force (including electrostatic interaction and complexation) with the negatively charged carboxyl group in the subsequently added sodium alginate. The calcium ions doped in the prepared silica microspheres interact with the carboxyl groups in the sodium alginate molecules to form chemical crosslinks. The introduced carboxyl groups are combined with the subsequently added gold ions through coordination bonds, and then a reducing agent aqueous solution is added to reduce the gold ions. Sodium alginate and gold particles are successfully loaded on the surface of the silica microspheres, which correspondingly exhibits better antioxidant properties. A moisturizing, ROS-scavenging gold-loaded silica micropowder material, namely, gold-loaded silica micropowder SNS@S-Au, is prepared.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention utilizes the obtained silica microspheres with positive charges on their surfaces to combine with sodium alginate SA and gold particles. The obtained moisturizing gold-loaded silica micropowder capable of scavenging ROS has good biocompatibility, strong antioxidant properties, high moisturizing properties, good dispersibility and the like. The structures of the silica microspheres and the moisturizing gold-loaded silica micropowder capable of scavenging ROS (SNS@S-Au) are effectively controlled, and the preparation method has the advantages of simple operation, low cost, and green environmental protection.

[0037] The above is an overview of the technical solution of the invention. The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 SEM images of silica microspheres SNS (left) and gold-loaded silica powder SNS@S-Au (right);

[0039] Figure 2 FT-IR spectra of silica microspheres SNS and gold-loaded silica powder SNS@S-Au;

[0040] Figure 3 The XRD patterns of silica microspheres SNS and gold-loaded silica powder SNS@S-Au;

[0041] Figure 4 The scavenging rate spectrum of ROS scavenging by silica microspheres SNS and gold-loaded silica micropowder SNS@S-Au;

[0042] Figure 5 This is the water loss rate spectrum of silica microspheres SNS and gold-loaded silica powder SNS@S-Au. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the following is a detailed description in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0044] First, sodium orthosilicate (Na2O·nSiO2), hydrochloric acid, and polyethyleneimine (PEI) were used as raw materials, sodium dihydrogen phosphate and calcium lactate were added to introduce ions to promote the reaction and form a calcium phosphate co-precipitation agent, the speed of adding raw materials was controlled to adjust the pH of the reaction system, and positively charged silica (SiO2) microspheres were prepared by magnetic stirring; then, the SiO2 silica microsphere powder was dispersed in anhydrous ethanol to load sodium alginate and gold on the surface of the silica microspheres. By loading sodium alginate and gold particles on the surface of silica microspheres, the ability of silica powder to remove ROS and its moisturizing properties were significantly improved. This new material not only has the advantages of good fluidity, high sweat resistance, and stable properties, but also significantly improves the ability to remove ROS and its moisturizing properties.

[0045] The specific implementation steps of the present invention mainly include:

[0046] The first step is to prepare positively charged silica microspheres (SNS) using sodium orthosilicate (Na2O·nSiO2) as the silicon source and 0.6 mol·L -1Hydrochloric acid provides an acidic environment, polyethyleneimine (PEI) is used as a template, sodium dihydrogen phosphate and calcium lactate are added to form a calcium phosphate co-precipitation agent, and in the preparation process, the speed of adding raw materials is controlled to adjust the pH of the reaction system so that the particle size of the silica microspheres can be controlled (this is because sodium silicate is first neutralized with acid to generate silicic acid, and the further reaction mechanism is the dehydration condensation of silicic acid and the negative ions generated by its dissociation. The acidity of silicic acid is very weak, and the concentration of negative ions in the system is low. Therefore, the concentration of negative silicate ions is the controlling factor of the polycondensation reaction rate. When the pH value rises from 3 to 5, the degree of ionization of the original silica hydroxyl group increases, and the reaction rate will gradually accelerate. Increasing the reaction rate will promote a large number of nucleations in the early stage of the reaction, thereby reducing the particle size of the final product. This is similar to the mechanism of the effect of temperature on particle size. The pH value is essentially to adjust the reaction rate, thereby controlling the number of nucleations in the system at the early stage of the reaction, and ultimately achieving the purpose of controlling the particle size of the product); sodium dihydrogen phosphate and calcium lactate are added to introduce calcium ions and phosphate ions to promote the reaction and form calcium phosphate as a co-precipitation agent (as H + With continuous addition, a large number of primary particles are generated instantly, and the nuclei do not have time to collide and form precipitation, and a mixture of sol and precipitation is generated. The surface of the silica sol particles is covered with hydroxyl groups, and the colloid particles contact each other to polymerize. Through the dehydration between the hydroxyl groups, Si(OH)4 continuously forms a siloxane structure -Si-O-Si-, and the viscosity of the system increases rapidly until a gel is formed. The gel will agglomerate hard during the drying process, resulting in a large particle size of the product and no fixed morphology. Hydrochloric acid, as a raw material, can slowly release H + , controlling the rate of nucleation. Silicon dioxide is negatively charged during the nucleation process and reacts with Ca in calcium lactate. 2+ The zeta potential formed is greater than H + , the double electron layer is diffused and the hydration film covering the surface of the particles is thickened, preventing direct contact between particles during the collision process and avoiding continuous dehydration condensation between particles to form gel). Polyethyleneimine provides amino groups to make the surface of the silica microspheres positively charged, thus obtaining silica microspheres SNS.

[0047] The second step is to prepare gold-loaded silica micropowder SNS@S-Au, and introduce positively charged amino groups into the surface of the synthesized silica microspheres, that is, sodium alginate containing negatively charged carboxyl groups can be attached to the surface of silica microspheres (SNS). The carboxyl groups in sodium alginate SA are bound to gold ions through coordination bonds, and then hydrazine hydrate is added to reduce the gold ions. Therefore, gold particles are loaded on the silica surface, that is, a composite material of silica microspheres loaded with sodium alginate SA and gold particles, namely gold-loaded silica micropowder SNS@S-Au, is prepared; the gold-loaded silica micropowder SNS@S-Au is also configured into a suspension of appropriate concentration, and the ability to scavenge ROS is measured by ultraviolet spectrophotometer.

[0048] Example 1

[0049] This embodiment provides a method for preparing silica microspheres SNS and silica microspheres SNS, and the specific steps include:

[0050] Dissolve 16 g of sodium silicate in 125 mL of pure water to obtain solution A;

[0051] 2) Dissolve concentrated hydrochloric acid in pure water to obtain 0.6 mol·L -1 The hydrochloric acid aqueous solution is solution B;

[0052] 3) Dissolve 0.75 g of sodium dihydrogen phosphate in 75 mL of solution B to obtain solution C;

[0053] 4) Dissolve 0.30 g of polyethyleneimine PEI (weight average molecular weight 600 Da) in 100 mL of pure water to obtain solution D;

[0054] 5) Dissolve 0.14 g of calcium lactate in 100 mL of solution D to obtain solution E;

[0055] 6) Add 50 mL of solution B to 100 mL of solution E to obtain solution F;

[0056] 7) Add solution A and solution C dropwise to solution F at the same time, adjust the dropping speed so that the pH of the reaction system is about 3, and when solution C is added dropwise, continue to add solution B until solution A is added dropwise (the total amount of hydrochloric acid solution, i.e., solution B, used in this example is 255 mL), to obtain suspension G;

[0057] 8) Suspension G is aged for 3 hours;

[0058] 9) Filter the suspension G, wash it twice with 100 mL of pure water and once with 100 mL of anhydrous ethanol, and save it for later use.

[0059] Example 2

[0060] This embodiment provides a method for preparing silica microspheres SNS and silica microspheres SNS, which are basically the same as those in Example 1, except that the pH of the reaction system is changed. The specific steps include:

[0061] 7) Solution A and solution C were added dropwise to solution F at the same time, and the dropping speed was adjusted to make the pH of the reaction system 4. When solution C was added dropwise, solution B was added until solution A was added dropwise (the total amount of hydrochloric acid solution used in this example was 195 mL), to obtain suspension G.

[0062] Example 3

[0063] This embodiment provides a method for preparing silica microspheres SNS and silica microspheres SNS, which are basically the same as those in Example 1, except that the pH of the reaction system is changed. The specific steps include:

[0064] 7) Solution A and solution C were added dropwise to solution F at the same time, and the dropping speed was adjusted to make the pH of the reaction system 5. When solution C was added dropwise, solution B was added until solution A was added dropwise (the total amount of hydrochloric acid solution used in this example was 135 mL), to obtain suspension G.

[0065] Example 4

[0066] This embodiment provides a preparation method of silica microspheres SNS and silica microspheres SNS, which are basically the same as those in Example 2, except that the amount of calcium lactate is changed. The specific steps include:

[0067] Solution E was obtained by dissolving 0.28 g of calcium lactate in 100 mL of solution D.

[0068] 7) Solution A and solution C were added dropwise to solution F at the same time, and the dropping speed was adjusted to make the pH of the reaction system 4. When solution C was added dropwise, solution B was added until solution A was added dropwise (the total amount of hydrochloric acid solution used in this example was 205 mL), to obtain suspension G.

[0069] Example 5

[0070] This embodiment provides a preparation method of silica microspheres SNS and silica microspheres SNS, which are basically the same as those in Example 2, except that the amount of calcium lactate is changed. The specific steps include:

[0071] 5) 0.07 g of calcium lactate was dissolved in 100 mL of solution D to obtain solution E.

[0072] 7) Solution A and solution C were added dropwise to solution F at the same time, and the dropping speed was adjusted to make the pH of the reaction system 4. When solution C was added dropwise, solution B was added until solution A was added dropwise (the total amount of hydrochloric acid solution used in this example was 190 mL), to obtain suspension G.

[0073] The above Examples 1-5 obtain different silica microspheres SNS by adjusting the pH of the reaction system and the amount of calcium lactate. Examples 1-5 are all suitable silica microspheres SNS suitable for preparing SNS@S-Au. For this reason, the applicant exemplarily selects the silica microspheres SNS prepared in Example 5 as the raw materials required for the preparation of gold-loaded silica micropowder SNS@S-Au. This is mainly because when the pH of the reaction system in Example 5 is 4 and the amount of calcium lactate is 0.07g, the positive charge on the surface of the obtained SNS microspheres is moderate, and the amount of calcium lactate is appropriate. The coprecipitation reaction also realizes that the doped calcium element is partially located on the surface of the microspheres, which facilitates the subsequent anchoring of alginate molecules on the surface of the microspheres, and the particle size of the prepared SNS microspheres is also suitable. When preparing the gold-loaded silica micropowder SNS@S-Au, the positively charged surface of the silica microspheres is used to allow the sodium alginate containing negatively charged carboxyl groups to adhere to the surface of the silica microspheres (SNS). In Example 5, the surface of the silica microspheres SNS is positively charged and has a high potential, which can well attach the sodium alginate to the surface of the silica microspheres (SNS). The monodispersity of the silica microspheres SNS obtained in Example 5 is also good, which is also conducive to the prepared moisturizing gold-loaded silica micropowder that can remove ROS having the advantages of high moisture retention and good dispersibility. The test data results of the silica microspheres SNS of Examples 1-5 are shown in Table 1 below:

[0074] Table 1 Test results of silica microspheres SNS of Examples 1-5

[0075]

[0076] Example 6

[0077] This embodiment provides a preparation method of gold-loaded silica micropowder SNS@S-Au and gold-loaded silica micropowder SNS@S-Au, and the specific steps include:

[0078] 1) Dispersing 4 g of the silica microspheres SNS of Example 5 in 40 mL of anhydrous ethanol to obtain a suspension H;

[0079] 2) Dissolve 10 mL of 0.2 wt% sodium alginate solution in 20 mL of pure water to obtain solution I.

[0080] 3) Add all the solution I dropwise to the obtained suspension H, and react for 30 minutes under sufficient stirring to obtain suspension J;

[0081] 4) 0.2 mL of 1 wt% chloroauric acid solution was added dropwise to suspension J, and the mixture was reacted for 15 min under sufficient stirring to obtain suspension K;

[0082] 5) Dissolve 0.24 mL of reducing agent solution in 12 mL of pure water (the reducing agent solution in this example is sodium ascorbate solution with a concentration of 0.07 mol·L -1 ), to obtain solution L;

[0083] 6) Add all the solution L dropwise into the suspension K, react for 30 min with sufficient stirring to obtain the suspension M. Filter and wash twice with 100 mL of pure water and once with 100 mL of anhydrous ethanol, and dry at 55°C for later use.

[0084] Example 7

[0085] This embodiment provides a preparation method of gold-loaded silica micropowder SNS@S-Au and gold-loaded silica micropowder SNS@S-Au, which is basically the same as Example 6, except that the amount of sodium alginate is changed. The specific steps include:

[0086] 2) Dissolve 20 mL of 0.2 wt% sodium alginate solution in 40 mL of pure water to obtain solution I.

[0087] Example 8

[0088] This embodiment provides a preparation method of gold-loaded silica micropowder SNS@S-Au and gold-loaded silica micropowder SNS@S-Au, which is basically the same as Example 6, except that the amount of sodium alginate is changed. The specific steps include:

[0089] 2) Dissolve 15 mL of 0.2 wt% sodium alginate solution in 30 mL of pure water to obtain solution I.

[0090] Example 9

[0091] This embodiment provides a preparation method of gold-loaded silica micropowder SNS@S-Au and gold-loaded silica micropowder SNS@S-Au, which is basically the same as Example 8, except that the amount of chloroauric acid is changed. The specific steps include:

[0092] 4) Add 0.1 mL of 1 wt% chloroauric acid solution dropwise to suspension J and react for 15 min with sufficient stirring to obtain suspension K.

[0093] Example 10

[0094] This embodiment provides a preparation method of gold-loaded silica micropowder SNS@S-Au and gold-loaded silica micropowder SNS@S-Au, which is basically the same as Example 8, except that the amount of chloroauric acid and the type of reducing agent are changed. The specific steps include:

[0095] 0.3 mL of 1 wt% chloroauric acid solution was added dropwise to suspension J, and the mixture was reacted for 15 min under sufficient stirring to obtain suspension K.

[0096] 5) Dissolve 0.24 mL of the reducing agent solution in 12 mL of pure water (the reducing agent solution in this embodiment is a mixed solution, i.e., a sodium ascorbate solution and a hydrazine hydrate solution are mixed in a volume ratio of 1:1, and the concentration of the sodium ascorbate solution is 0.07 mol·L -1 , the concentration of hydrazine hydrate solution is 80v / v%), and solution L is obtained;

[0097] Tests and test results:

[0098] Depend on Figure 1 It can be seen that SNS and SNS@S-Au are spherical under the microscopic view, with a diameter of about 348nm for SNS and about 484nm for SNS@S-Au. Compared with SNS, the morphology of SNS@S-Au has not changed significantly, only the diameter has become relatively larger, indicating that sodium alginate and gold particles may be successfully loaded on the surface of silica microspheres to increase the diameter.

[0099] Depend on Figure 2 It can be seen that 1642cm -1 、1659cm -1 The absorption peak at is caused by the stretching vibration of the carboxyl group, indicating that sodium alginate is successfully loaded on the surface of SNS and SNS@S-Au is successfully prepared.

[0100] Depend on Figure 3 It can be seen that the XRD spectra of SNS and SNS@S-Au are displayed, with black representing SNS@S-Au and red representing SNS. In the XRD spectrum of SNS@S-Au, specific lattice peaks corresponding to gold particles can be found, indicating that gold particles are successfully loaded on the surface of SNS, that is, SNS@S-Au is prepared.

[0101] Depend on Figure 4 It can be seen that it is generally believed that ascorbic acid VC has strong antioxidant ability. As a control, the ROS clearance rate of ascorbic acid VC is as high as 95%, the ROS clearance rate of silica microspheres SNS is less than 20%, and the ROS clearance rate of SNS@S-Au, i.e., silica microspheres loaded with gold particles, is higher than 80%, which is close to the ROS clearance rate of ascorbic acid VC, and its ROS clearance rate is significantly higher than that of SNS, indicating that SNS@S-Au has good antioxidant properties.

[0102] Figure 5Corresponding experimental method: Preparation of sample solution: Weigh 1.2g and 0.6g of silica microspheres SNS of Example 5 and disperse them in 10mL of water to obtain 1.2wt% and 0.6wt% solutions; Weigh 1.2g and 0.6g of gold-loaded silica micropowder SNS@S-Au of Example 10 and disperse them in 10mL of water to obtain 1.2wt% and 0.6wt% solutions. Positive control: 10mL 1.2wt% SA solution and 10mL 0.6wt% SA solution. Blank control: 10mL deionized water.

[0103] Experimental steps: (1) Mark the weighing bottle and place it in a drying oven to dry to constant weight. Place a piece of filter paper of appropriate size in the weighing bottle and weigh its mass, which is recorded as m0 (weighing bottle + dry filter paper).

[0104] (2) Soak the corresponding filter paper in the corresponding solution for 5 minutes and then dry it for 1 minute.

[0105] (3) Place the corresponding filter paper in the corresponding weighing bottle and weigh its mass, recorded as M.

[0106] (4) Place the weighing bottle in the moisturizing cylinder and weigh the mass every 0.5 h, recorded as m x .

[0107] Calculate the water loss rate of the sample, water loss rate: (Mm x ) / (M-m0)x100%.

[0108] In the cosmetics industry, it is generally believed that sodium alginate has a good moisturizing effect. Figure 5 It can be seen that pure water has the fastest water loss rate, and the water loss rates of 0.6wt% SNS@S-Au dispersion and 1.2wt% SNS@S-Au dispersion are slower than those of 0.6wt% SNS dispersion and 1.2wt% SNS dispersion, and their water loss rates are close to those of 0.6wt% sodium alginate solution and 1.2wt% sodium alginate solution, indicating that sodium alginate loaded on the surface of silica microspheres still has good moisture retention, which gives the new material SNS@S-Au moisture retention, indicating that SNS@S-Au has good moisture retention.

[0109] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs may also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the invention should also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a moisture-retaining gold-loaded silica micropowder capable of removing ROS, characterized in that: The steps include: Mixing the sodium alginate solution with pure water, stirring and mixing thoroughly to obtain a sodium alginate SA aqueous solution I; The reducing agent solution is mixed with pure water, and stirred to mix thoroughly to obtain a reducing aqueous solution L; Disperse silica microspheres SNS in anhydrous ethanol, stir and fully disperse to obtain suspension H; The sodium alginate SA aqueous solution I is added dropwise to the suspension H, and the mixture is stirred sufficiently for reaction t1 to obtain a suspension J; the chloroauric acid solution is added dropwise to the suspension J, and the mixture is stirred sufficiently for reaction t2 to obtain a suspension K; Then, the reducing aqueous solution L is added dropwise to the suspension K and stirred for reaction t3 to obtain a suspension M, which is then filtered, washed, and dried to obtain a moisturizing gold-loaded silica micropowder SNS@S-Au capable of removing ROS; the silica microspheres SNS are prepared by the following steps: Mixing sodium silicate with pure water, stirring to fully dissolve, to obtain a sodium silicate aqueous solution A; Mix concentrated hydrochloric acid and pure water, stir and fully dissolve to obtain hydrochloric acid aqueous solution B; Mixing polyethyleneimine with pure water, stirring to fully dissolve, to obtain polyethyleneimine aqueous solution D; Mix sodium dihydrogen phosphate and hydrochloric acid aqueous solution B and stir thoroughly to obtain solution C; Calcium lactate and polyethyleneimine aqueous solution D are mixed and stirred sufficiently to obtain solution E, and then mixed and stirred sufficiently with hydrochloric acid aqueous solution B to obtain solution F; Sodium silicate aqueous solution A and solution C are added dropwise to solution F at the same time, the pH of the reaction system is adjusted, and the mixture is stirred thoroughly. When solution C is added dropwise, solution B is added until solution A is added dropwise, and the suspension G is obtained, which is then aged, filtered, and washed to obtain positively charged silica microspheres SNS. The raw materials used in the preparation of the silica microspheres SNS include the sodium silicate: sodium dihydrogen phosphate: hydrochloric acid aqueous solution B: polyethylene imine: calcium lactate in a mass volume ratio of 16g: 0.75g: 135-255mL: 0.30g: 0.07g-0.28g, wherein the concentration of the hydrochloric acid aqueous solution B is 0.6mol·L -1 ; The pH of the reaction system is regulated by simultaneously adding the sodium silicate aqueous solution A and solution C, and when the solution C is completely added, the solution B is added until the solution A is completely added, and the pH value of the reaction system is regulated to be 3-5.

2. The method for preparing the moisturizing gold-loaded silica micropowder capable of removing ROS according to claim 1, characterized in that: The preparation method specifically comprises: Aging the suspension G for 3 hours; or, The suspension G was filtered and washed with pure water and anhydrous ethanol in sequence, washed twice with 100 mL of pure water and once with 100 mL of anhydrous ethanol.

3. The method for preparing the moisturizing gold-loaded silica micropowder capable of removing ROS according to claim 1, characterized in that: The mass volume ratio of the silica microspheres: sodium alginate SA: chloroauric acid: reducing agent solution is 4g: 0.02g-0.04g: 0.001g-0.003g: 0.24mL, wherein the concentration of the sodium alginate solution is 0.2wt%; the reducing agent solution is at least one of a sodium ascorbate solution, a sodium citrate solution and a hydrazine hydrate solution, and the concentration of the sodium ascorbate solution or the sodium citrate solution is 0.07mol·L -1 , the concentration of the hydrazine hydrate solution is 80v / v; the concentration of the chloroauric acid solution is 1.0wt%.

4. The method for preparing the moisturizing gold-loaded silica micropowder capable of removing ROS according to claim 1, characterized in that: The preparation method specifically comprises: The sufficient stirring reaction t1 is a reaction time of 0.5h; The sufficient stirring reaction t2 is a reaction time of 15min; The sufficient stirring reaction t3 is a reaction time of 30 minutes.

5. The method for preparing the moisturizing gold-loaded silica micropowder capable of removing ROS according to claim 1, characterized in that: The preparation method specifically comprises: The suspension M was filtered, washed with pure water and anhydrous ethanol in sequence, and then dried. It was washed twice with 100 mL of pure water, washed once with 100 mL of anhydrous ethanol, and dried at 55°C.

6. A moisture-retaining gold-loaded silica micropowder capable of removing ROS, characterized in that: The invention is prepared by the method for preparing the moisture-retaining gold-loaded silica micropowder capable of scavenging ROS as described in any one of claims 1 to 5. The moisture-retaining gold-loaded silica micropowder capable of scavenging ROS is formed by combining sodium alginate and gold particles loaded on the surface of positively charged silica microspheres.

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