Modified titanium dioxide as well as preparation method and application thereof

Abstract

The invention relates to the technical field of cosmetics, and discloses modified titanium dioxide as well as a preparation method and application thereof. The invention relates to modified titanium dioxide, which is titanium dioxide synergistically modified by a coupling agent and a bioactive component. According to the modified titanium dioxide provided by the invention, the coupling agent and the bioactive component are used for carrying out surface modification on the titanium dioxide, the original physical characteristics of the titanium dioxide are not changed, and the defects of serious agglomeration and poor dispersity of the titanium dioxide are overcome; the ultraviolet resistance of the modified titanium dioxide is enhanced, and the modified titanium dioxide has a certain free radical scavenging effect; the preparation method of the modified titanium dioxide is simple in step, mild in process condition and suitable for industrial application; a sunscreen product taking modified titanium dioxide as a preparation raw material has a good sunscreen effect; when the modified titanium dioxide and the sunscreen product are applied to sunscreen, not only can the damage of ultraviolet rays to the skin be reduced, but also the harm caused by free radicals can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of cosmetics, and in particular to modified titanium dioxide and a preparation method and application thereof. Background Art

[0002] Ultraviolet rays from the sun are unavoidable for humans, and long-term exposure to ultraviolet rays can cause biological damage to the skin. If effective measures are taken for ultraviolet protection and prevention, the harm to the skin can be greatly reduced. Sunscreen products are roughly divided into biological sunscreen, chemical sunscreen and physical sunscreen. Biological sunscreen refers to achieving the purpose of sunscreen by repairing ultraviolet damage to the skin, which plays an indirect role in sunscreen; chemical sunscreen absorbs ultraviolet energy according to the characteristics of the product's chemical structure and weakens the ultraviolet energy through electron transitions; physical sunscreen mainly uses reflective particles and physical covering methods to block, scatter or reflect ultraviolet rays, thereby reducing the amount of ultraviolet rays reaching the skin, thereby achieving the purpose of sunscreen.

[0003] Chemical sunscreen has a significant sunscreen effect and a large market demand. Chemical sunscreen products can be divided into two categories: organic and inorganic. However, most existing organic sunscreens have defects such as strong skin irritation, poor stability, and easy to cause skin allergies and inflammation. Titanium dioxide (TiO2) and zinc oxide (ZnO) particles are currently the most important inorganic sunscreens on the market; but titanium dioxide that has not been surface treated is prone to agglomeration due to its small particle size and large surface energy. Surface modification can solve the problems of poor dispersion and easy agglomeration of titanium dioxide to a certain extent, but the modifier itself may be toxic. The use of toxic substances in the modification process not only has the potential to harm the human body, but also increases the cost. In addition, under the irradiation of ultraviolet rays, titanium dioxide will produce free radicals ROS that are harmful to the human body, combine with oxygen on the surface, and react with conduction band electrons as reducing agents, eventually producing hydrogen peroxide and superoxide, which pose a risk of damage to human skin. Summary of the invention

[0004] The present invention aims to solve at least one of the above-mentioned technical problems existing in the prior art. To this end, one of the purposes of the present invention is to provide a modified titanium dioxide; the second purpose of the present invention is to provide a method for preparing the modified titanium dioxide; the third purpose of the present invention is to provide a sunscreen product; the fourth purpose of the present invention is to provide modified titanium dioxide, or the application of a sunscreen product.

[0005] The basic principle of the present invention is described as follows:

[0006] The present invention performs surface functionalization modification on titanium dioxide with excellent anti-ultraviolet performance to overcome the defects of titanium dioxide such as large surface energy, poor dispersibility, easy agglomeration, and easy generation of free radicals under ultraviolet irradiation. First, a coupling agent is used to perform surface modification on titanium dioxide to form a stable chemical bond on the surface of titanium dioxide, increase the interface compatibility between titanium dioxide and other materials, and improve the performance of the material. Then, a bioactive component containing a benzene ring or a conjugated structure is used to continue the modification. The active functional group in the bioactive component can further react with the active group on the coupling agent, and the bioactive component is fixed on the surface of titanium dioxide through chemical bonds. Through the modification, the bioactive component can be effectively wrapped on the surface of titanium dioxide, thereby increasing the particle size of titanium dioxide and giving it rich multifunctional functional groups, solving the defects of titanium dioxide, giving it more excellent dispersibility, anti-ultraviolet performance and free radical elimination performance, and realizing the practical application of one dose with multiple effects.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] The first aspect of the present invention provides a modified titanium dioxide, which is titanium dioxide modified synergistically by a coupling agent and a bioactive component.

[0009] Preferably, the modified titanium dioxide comprises the following preparation raw materials: titanium dioxide, a surfactant, a coupling agent, a bioactive component and a solvent.

[0010] Preferably, the solid-liquid ratio of titanium dioxide to the coupling agent is 1 g: (7-10) mL; further preferably, the solid-liquid ratio of titanium dioxide to the coupling agent is 1 g: (8-10) mL.

[0011] Preferably, the particle size of the titanium dioxide is 20 to 500 nm.

[0012] Preferably, the coupling agent comprises a silane coupling agent.

[0013] Preferably, the silane coupling agent includes at least one of KH570, KH560 and KH550.

[0014] Specifically, a silane coupling agent is used to modify the surface of titanium dioxide. The silane coupling agent contains a siloxy group, which can undergo a hydrolysis reaction in water to form silanol. The silanol can undergo a condensation reaction with the hydroxyl groups on the surface of titanium dioxide to form a stable chemical bond. The silane coupling agent is grafted onto the surface of titanium dioxide. Through the modification of the silane coupling agent, the interface compatibility between titanium dioxide and other materials can be increased, thereby improving the performance of the material.

[0015] Preferably, the bioactive ingredient contains a benzene ring or a conjugated structure.

[0016] Preferably, the bioactive ingredients include at least one of flavonoids, phenylpropanoids, glycosides, polyphenols, and carotenoids; further preferably, the bioactive ingredients include at least one of resveratrol, salidroside, and quercetin.

[0017] Preferably, the mass ratio of the surfactant to titanium dioxide is (0.5-3):100; further preferably, the mass ratio of the surfactant to titanium dioxide is (1-3):100.

[0018] Preferably, the surfactant includes at least one of sodium dodecyl sulfate, sodium lauryl sulfate, hexadecyltrimethylammonium bromide, and sodium fatty acid methyl ester sulfonate; more preferably, the surfactant is sodium dodecyl sulfate.

[0019] Preferably, the raw materials for preparing the modified titanium dioxide also include an initiator.

[0020] Preferably, the mass ratio of the initiator to titanium dioxide is (0.1-0.5):100; further preferably, the mass ratio of the initiator to titanium dioxide is (0.1-0.4):100.

[0021] Preferably, the initiator includes at least one of azobisisobutyronitrile and azobisisobutylamidine dihydrochloride; further preferably, the initiator is azobisisobutyronitrile.

[0022] Specifically, the initiator is used when the silane coupling agent and the bioactive ingredient undergo diene polymerization.

[0023] Preferably, the solvent comprises an alcohol solvent; further preferably, the solvent comprises ethanol.

[0024] The second aspect of the present invention provides a method for preparing the modified titanium dioxide described in the first aspect of the present invention, comprising the following steps:

[0025] S1, mixing titanium dioxide, a solvent and a surfactant to obtain a mixed solution;

[0026] S2, adding a coupling agent dropwise to the mixed solution to obtain coupling agent-modified titanium dioxide;

[0027] S3, dissolving the coupling agent modified titanium dioxide in a solvent, adding a bioactive component, and obtaining the modified titanium dioxide.

[0028] Preferably, in step S1, the specific operations for preparing the mixed solution are: dispersing titanium dioxide in an alcohol solvent to obtain a dispersion; and adding a surfactant to obtain the mixed solution.

[0029] Preferably, after dispersing the titanium dioxide in the alcohol solvent, the method further comprises adding a pH adjuster to adjust the pH of the dispersion.

[0030] Preferably, the pH adjuster includes at least one of acetic acid, citric acid and ascorbic acid.

[0031] Preferably, a pH adjuster is added to adjust the pH value of the dispersion to 2.5-5.5.

[0032] Preferably, in the step S1, the titanium dioxide is vacuum dried before use.

[0033] Preferably, in step S1, the solid-liquid ratio of titanium dioxide to solvent is 1 g:(120-135) mL; further preferably, the solid-liquid ratio of titanium dioxide to solvent is 1 g:(120-130) mL.

[0034] Preferably, in the step S1, the titanium dioxide is dispersed in the alcohol solvent and then stirred.

[0035] Preferably, in step S1, the volume concentration of the alcohol solvent is 5-20%; more preferably, the volume concentration of the alcohol solvent is 10-15%.

[0036] Preferably, step S2 further comprises using a catalyst.

[0037] Preferably, the catalyst includes an organic base catalyst; further preferably, the organic base catalyst includes triethylamine; the alkaline catalyst participates in the esterification reaction between the hydroxyl groups on the surface of titanium dioxide and the silane coupling agent, while ensuring an alkaline environment to protect the amino groups on the silane coupling agent.

[0038] Preferably, in step S2, the reaction time is 3 to 5 hours; more preferably, the reaction time is 3.5 to 4.5 hours.

[0039] Preferably, in step S2, the reaction temperature is 20-30°C; more preferably, the reaction temperature is 23-27°C.

[0040] Preferably, in the step S2, after the reaction is completed, the coupling agent-modified titanium dioxide is obtained by centrifugal washing and drying; the coupling agent-modified titanium dioxide is in granular form.

[0041] Preferably, in step S2, the reagents used for the centrifugal washing include ethanol and deionized water.

[0042] Preferably, in step S2, the drying temperature is 115-125° C. and the drying time is 7-9 hours.

[0043] Preferably, in the step S3, the coupling agent-modified titanium dioxide is dissolved in a solvent, and then ultrasonic treatment is performed; the ultrasonic treatment time is 25 to 35 minutes.

[0044] Preferably, in step S3, the solid-liquid ratio of the coupling agent-modified titanium dioxide to the solvent is (50-200) mg:1 mL; further preferably, the solid-liquid ratio of the coupling agent-modified titanium dioxide to the solvent is (70-100) mg:1 mL.

[0045] Preferably, in step S3, the solvent is anhydrous ethanol.

[0046] Preferably, in step S3, the mass ratio of the coupling agent-modified titanium dioxide to the bioactive component is 1:(0.8-1.5); further preferably, the mass ratio of the coupling agent-modified titanium dioxide to the bioactive component is 1:(1-1.3).

[0047] Preferably, the step S3 further comprises the operation of adding an initiator or an acid catalyst.

[0048] Preferably, the mass ratio of the acid catalyst to titanium dioxide is 1:(1100-1300); further preferably, the mass ratio of the acid catalyst to titanium dioxide is 1:(1200-1300).

[0049] Preferably, the acid catalyst comprises zinc chloride; the acid catalyst is used to catalyze the reaction between the hydroxyl groups on the biologically active ingredient and the epoxy groups on the silane coupling agent.

[0050] Preferably, in step S3, the reaction time is 7 to 9 hours; further preferably, the reaction time is 7.5 to 8.5 hours.

[0051] Preferably, in step S3, the reaction temperature is 75-95°C; further preferably, the reaction temperature is 85-90°C.

[0052] Preferably, in step S3, the reaction is carried out in an inert atmosphere.

[0053] Preferably, in the step S3, after the reaction is completed, the modified titanium dioxide is obtained by washing and drying; the modified titanium dioxide is in granular form.

[0054] Preferably, in step S3, the frequency of the centrifugal washing is 11500-12500 r / min, and the time is 7-9 min.

[0055] Preferably, in step S3, the washing reagents include ethanol and deionized water.

[0056] Preferably, in step S3, the drying temperature is 60-70° C. and the drying time is 7-9 hours.

[0057] The third aspect of the present invention provides a sunscreen product, comprising the modified titanium dioxide described in the first aspect of the present invention; the mass percentage of the modified titanium dioxide is 10-20%.

[0058] Preferably, the sunscreen product includes one of sunscreen lotion, sunscreen cream and sunscreen cream.

[0059] Preferably, the modified titanium dioxide is directly used as a raw material for preparing sunscreen products.

[0060] The fourth aspect of the present invention provides the use of the modified titanium dioxide described in the first aspect of the present invention, or the sunscreen product described in the third aspect in sun protection.

[0061] Compared with the prior art, the present invention has the following beneficial effects:

[0062] 1) The modified titanium dioxide provided by the present invention uses a coupling agent and a bioactive component to modify the surface of titanium dioxide without changing the original physical properties of titanium dioxide, thereby overcoming the defects of severe agglomeration, poor dispersibility, and easy generation of free radicals by ultraviolet irradiation of titanium dioxide; the modified titanium dioxide has enhanced anti-ultraviolet ability and has a certain free radical scavenging effect;

[0063] 2) The preparation method of modified titanium dioxide provided by the present invention has simple steps and mild process conditions, and is suitable for industrial use;

[0064] 3) The sunscreen product provided by the present invention uses modified titanium dioxide as a preparation raw material, is a biological and environmentally friendly sunscreen product, is low in toxicity and safety, and has a good sunscreen effect;

[0065] 4) When the modified titanium dioxide and sunscreen products provided by the present invention are used for sunscreen, they can not only reduce the damage of ultraviolet rays to the skin, but also reduce the harm caused by free radicals, which is helpful to solve the problems of matte skin, spots and wrinkles caused by free radical damage to the skin. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 Fourier infrared spectra of TiO2 and TiO2-KH570 in the embodiment;

[0067] Figure 2 The Fourier transform infrared spectra of the resveratrol standard sample and TiO2-KH570-resveratrol in the embodiment;

[0068] Figure 3 Thermogravimetric analysis curves of TiO2, TiO2-KH570 and TiO2-KH570-resveratrol in the examples;

[0069] Figure 4 X-ray polycrystalline diffraction patterns of TiO2, TiO2-KH570 and TiO2-KH570-resveratrol in the examples;

[0070] Figure 5 The SEM field emission scanning electron microscope images of TiO2 (a) and TiO2-KH570-resveratrol (b) in the examples;

[0071] Figure 6 The dispersibility test diagram of TiO2, TiO2-KH570 and TiO2-KH570-resveratrol in the examples;

[0072] Figure 7 The UV ultraviolet-visible powder diffuse reflectance spectra of TiO2, TiO2-KH570 and TiO2-KH570-resveratrol in the examples;

[0073] Figure 8 These are UV-sensing card test images of TiO2 (a), TiO2-KH570 (b), and TiO2-KH570-resveratrol (c) in the examples. DETAILED DESCRIPTION

[0074] The present invention is further described in detail below by specific examples. The raw materials, reagents or devices used in the examples can be obtained from conventional commercial sources or by prior art methods unless otherwise specified. Unless otherwise specified, the experiments or test methods are conventional methods in the art.

[0075] Example 1

[0076] This embodiment provides a modified titanium dioxide, which is titanium dioxide modified by a silane coupling agent KH570 and a bioactive ingredient resveratrol, and is prepared by the following steps:

[0077] S1. Place 1.0 g of titanium dioxide (particle size 20-80 nm) in a vacuum drying oven at 120° C. for 12 h and dry it. Add 100 mL of 10% ethanol by volume to 0.8 g of the dried titanium dioxide. While stirring at high speed, add acetic acid dropwise to adjust the pH value to 3-4. Add 0.008 g of sodium dodecyl sulfate to form a mixed dispersion.

[0078] S2. 8 mL of silane coupling agent KH570 was measured and placed in a beaker. The silane coupling agent KH570 was slowly dripped into the dispersion and reacted for 4 h to obtain KH570 slurry. The KH570 slurry was centrifugally washed twice with ethanol and twice with deionized water, and then placed in a vacuum drying oven at 120° C. for 8 h to obtain silane coupling agent modified titanium dioxide (TiO2-KH570).

[0079] S3. Weigh 0.8 g TiO2-KH570, add 100 mL anhydrous ethanol and ultrasonically disperse for 30 min, add 0.8 g resveratrol, add 0.8 mg azobisisobutyronitrile, set the reaction temperature to 80 ° C, and react continuously for 8 h in an inert gas environment to obtain KH570-resveratrol modified titanium dioxide slurry. Centrifuge the slurry at 12000 r / min for 8 min, wash twice with ethanol and deionized water respectively, and place it at 65 ° C for vacuum drying for 8 h to obtain modified titanium dioxide (TiO2-KH570-resveratrol).

[0080] In this embodiment, the reaction between KH570 and resveratrol is a diene polymerization, which requires an initiator.

[0081] Example 2

[0082] This embodiment provides a modified titanium dioxide, which is titanium dioxide modified by a silane coupling agent KH560 and a biologically active ingredient salidroside, and is prepared by the following steps:

[0083] S1. Place titanium dioxide (particle size 20-50 nm) in a vacuum drying oven at 120°C for 12 h and dry it. Then, take 0.8 g of the dried titanium dioxide and add it to 100 mL of 10% ethanol by volume. While stirring at high speed, add acetic acid dropwise to adjust the pH value to 3-4, and add 0.008 g of sodium dodecyl sulfate to obtain a mixed dispersion.

[0084] S2. 8 mL of silane coupling agent KH560 was measured and placed in a beaker. The silane coupling agent KH560 was slowly dripped into the dispersion and reacted for 4 h to obtain KH560 slurry. The KH560 slurry was centrifugally washed twice with ethanol and twice with deionized water, and then placed in a vacuum drying oven at 120° C. for 8 h to obtain silane coupling agent modified titanium dioxide (TiO2-KH560).

[0085] S3. Weigh 0.8 g TiO2-KH560 and add 100 mL anhydrous ethanol. Ultrasonic dispersion is performed for 30 min. 1.0 g salidroside and 0.66 mg zinc chloride are added. The reaction temperature is set to 80 ° C. The reaction is continued for 8 h in an inert gas environment to obtain KH560-salidroside modified titanium dioxide slurry. The slurry powder is centrifuged at 12000 r / min for 8 min, washed twice with ethanol and deionized water respectively, and placed at 65 ° C for vacuum drying for 8 h to obtain modified titanium dioxide (TiO2-KH560-salidroside).

[0086] In this embodiment, the reaction between KH560 and salidroside utilizes the reaction between the epoxy group on KH560 and the hydroxyl group on salidroside. The hydroxyl group and the ether group are highly polar, so that the active epoxy molecules produce strong intermolecular forces with the adjacent interface, and the epoxy group reacts with the free bonds on the surface of the medium to form chemical bonds.

[0087] Example 3

[0088] This embodiment provides a modified titanium dioxide, which is titanium dioxide modified by a silane coupling agent KH550 and a bioactive ingredient quercetin, and is prepared by the following steps:

[0089] S1. Place titanium dioxide (particle size 20-50 nm) in a vacuum drying oven at 120°C for 12 h to dry, take out 1.0 g of the dried titanium dioxide and add 100 mL of 10% ethanol by volume, and while stirring at high speed, add 0.01 g of sodium dodecyl sulfate to obtain a mixed dispersion;

[0090] S2, 9 mL of silane coupling agent KH550 was measured and put into a beaker, 50 μL of triethylamine was added and mixed to obtain a mixed solution, the mixed solution was slowly dripped into the dispersion, and the mixture was reacted at 95° C. for 4 h to obtain KH550 slurry, the KH550 slurry was centrifugally washed twice with ethanol, centrifugally washed twice with deionized water, and then placed in a vacuum drying oven at 120° C. for 8 h to obtain silane coupling agent modified titanium dioxide (TiO2-KH550);

[0091] S3. Weigh 1.0 g TiO2-KH550 and add 100 mL anhydrous ethanol. Ultrasonic dispersion is performed for 30 min. 1.0 g quercetin is added. The pH is adjusted to 4.5. The reaction temperature is set to 90 ° C. The reaction is continued for 6 h in an inert gas environment to obtain KH550-quercetin modified titanium dioxide slurry. The slurry is centrifuged at 12000 r / min for 8 min, washed twice with ethanol and deionized water respectively, and placed at 65 ° C for vacuum drying for 8 h to obtain modified titanium dioxide (TiO2-KH550-quercetin).

[0092] In this embodiment, the reaction between the primary amine in KH550 and the carbonyl group in quercetin is a nucleophilic addition reaction. The pH needs to be controlled during the reaction. An appropriate acid is conducive to the dehydration reaction. Excessive acid will cause the amino group of the nucleophile to be protonated and lose its nucleophilic activity. The reaction conditions are adjusted to pH 4.5.

[0093] Related characterization and performance testing

[0094] 1. Fourier transform infrared spectroscopy:

[0095] The dried TiO2, silane coupling agent modified titanium dioxide (TiO2-KH570), resveratrol standard, and modified titanium dioxide (TiO2-KH570-resveratrol) in the examples were tested using a Fourier transform infrared spectrometer (model Spectrum Two). Potassium bromide was used as the background. The sample and potassium bromide were mixed, ground, and pressed into tablets. The scanning range was 4000 cm -1 ~400cm -1 .

[0096] Figure 1 is the Fourier infrared spectrum of TiO2 and TiO2-KH570 in Example 1, Figure 1 It can be seen that after TiO2 is modified with silane coupling agent KH570, the Fourier transform infrared spectrum of TiO2-KH570 is at 2958.2 cm -1 and 2926.8cm -1 New absorption peaks appeared at 1715.6cm, which are the antisymmetric stretching vibration absorption peaks of -CH3 and -CH2. -1 The stretching vibration absorption peak of C=O appears nearby; at 1450.7cm -1 The bending vibration absorption peak of -CH3 appears near 1289.5cm -1 Compared with the Fourier transform infrared spectrum of TiO2, the stretching vibration absorption peak of COC appears near 3418.6cm -1 The absorption peak near is weakened, because after KH570 is grafted onto nano-TiO2, silanol occupies the hydroxyl (-OH) on the surface of nano-TiO2, causing the absorption intensity of hydroxyl to weaken. From the above analysis, it can be seen that the silane coupling agent KH570 has been successfully grafted onto nano-TiO2.

[0097] Figure 2 is the Fourier transform infrared spectrum of the resveratrol standard sample and TiO2-KH570-resveratrol in Example 1, Figure 2 It can be seen that the Fourier infrared spectrum curve of resveratrol standard sample is at 964.1cm -1 Nearby is the characteristic absorption of trans-C=C-, proving that the configuration of resveratrol is trans; the Fourier infrared spectrum curve of TiO2-KH570-resveratrol is at 3400cm -1 The characteristic absorption peak of -OH bond appears at 2929.8cm -1 and 2876.1cm -1 Nearby are the antisymmetric stretching vibration absorption peaks of -CH3 and -CH2, proving the presence of silane coupling agent KH570; at 1500cm -1 ~1680cm -1Nearby is the characteristic absorption peak of C=C on the benzene ring and the characteristic infrared absorption peak of a carbon-carbon double bond in resveratrol, at 952.9 cm -1 Nearby is the characteristic absorption of trans-C=C-, at 500-700cm -1 It is the characteristic peak of titanium dioxide. At 1500cm -1 ~1680cm -1 The absorption peak of the nearby TiO2-KH570-resveratrol Fourier infrared spectrum curve is weakened. This is because the amount of resveratrol grafted on KH570 is not large, and the corresponding peak absorption is weakened. Secondly, the double bond of resveratrol reacts with the double bond of KH570, which weakens the infrared characteristic absorption intensity of the double bond. From the above analysis, it can be seen that resveratrol is successfully grafted on TiO2-KH570 in the embodiment.

[0098] 2. Thermogravimetric analysis

[0099] The dried TiO2, silane coupling agent-modified titanium dioxide (TiO2-KH570), and modified titanium dioxide (TiO2-KH570-resveratrol) in the examples were analyzed using a thermogravimetric analyzer (model TG 209, NETZSCH) and the temperature was raised at a rate of 10 K / min to obtain a thermogravimetric analysis curve.

[0100] Figure 3 is the thermogravimetric analysis curve of TiO2, TiO2-KH570 and TiO2-KH570-resveratrol in Example 1, Figure 3 It can be seen that the mass of TiO2 hardly changes within the heating range. The weight loss rate of TiO2-KH570 within the range of 100-200℃ is almost the same as that of TiO2. The weight loss rate of TiO2-KH570 changes greatly within the range of 250-600℃. This is because the surface of nano-TiO2 is grafted with silane coupling agent KH570, and the CC and CH in the surface molecular chain break and decompose to cause weight loss. The weight loss of TiO2-KH570-resveratrol at 100℃ is due to insufficient drying of the sample. This part of the mass loss is caused by the volatilization of moisture on the sample surface. Since the loading rate of resveratrol is not high, it is relatively stable after the double bond addition reaction and is not easy to break. Therefore, within the range of 250-600℃, the weight loss is mainly caused by the break and decomposition of CC and CH in the surface molecular chain.

[0101] 3. X-ray polycrystal diffraction analysis

[0102] X-ray polycrystalline diffraction analysis was performed on the dried TiO2, silane coupling agent modified titanium dioxide (TiO2-KH570), and modified titanium dioxide (TiO2-KH570-resveratrol) in Example 1. The instrument model was BRUKER D8 ADVANCEDAVINCI, the tube current was 40 mA, the scanning speed was 5° / min, and the scanning range was 10-90°. The diffraction angle (2θ) of the sample was analyzed and compared with the data of the standard JCPDS card to obtain the crystal form of nano-TiO2, and compared with the modified TiO2-KH570 and TiO2-KH570-resveratrol to analyze whether the crystal form changed before and after the modification.

[0103] Figure 4 is the X-ray polycrystalline diffraction pattern of TiO2, TiO2-KH570 and TiO2-KH570-resveratrol in Example 1, Figure 4 It can be seen that the shape and peak height of the diffraction peak of nano-TiO2 polycrystalline before and after modification in the implementation case are almost the same, indicating that the crystal structure of nano-TiO2 has not changed significantly after surface modification by KH570 and resveratrol, and the physical properties of nano-TiO2 are determined by its crystal structure, so surface modification by KH570 and resveratrol will not affect the original physical properties of nano-TiO2.

[0104] 4. SEM scanning electron microscope analysis

[0105] Field emission scanning electron microscopy (Gemini500, Zeiss) was used to observe the surface morphology, distribution and particle size of unmodified nano-TiO2 and TiO2-KH570-resveratrol particles. The preparation method of the scanning sample is: grind the solid sample into powder with a mortar, evenly spread it on a silicon wafer, spray gold on it and wait for it to solidify. The sample processing method for observing the particle size is: dissolve the sample in methanol and dilute it, use a rubber-tipped dropper to draw a small amount of sample and drop it on the silicon wafer, and wait for the methanol to evaporate to complete the processing.

[0106] Figure 5 The SEM field emission scanning electron microscope images of TiO2 (a) and TiO2-KH570-resveratrol (b) in Example 1 are shown in FIG. Figure 5 It can be seen that in the implementation case, after the nano-TiO2 was modified to form TiO2-KH570-resveratrol particles, a layer of substance was coated on the surface of TiO2, which was the result of grafting of KH570 and resveratrol. However, it can be seen from the SEM image that the loading rate of the two was not high. The modification increased the particle size of the nano-TiO2, improved the dispersibility, and reduced the degree of agglomeration. Grafting resveratrol can eliminate the free radicals generated by the nano-TiO2.

[0107] 5. Dispersion detection

[0108] Weigh 30 mg of nano-TiO2, TiO2-KH570 and TiO2-KH570-resveratrol particles respectively into flat-bottom colorimetric tubes, add 10 mL of deionized water to each tube and shake it, observe the phenomenon, and observe the phenomenon again after standing for 24 hours.

[0109] Figure 6 This is a dispersibility test diagram of TiO2, TiO2-KH570 and TiO2-KH570-resveratrol in Example 1, wherein: Figure 6 (a) represents the dispersion at the end of shaking, from left to right: TiO2, TiO2-KH570, and TiO2-KH570-resveratrol. Figure 6 (b) represents the dispersion after standing for 24 h, from left to right: TiO2, TiO2-KH570, and TiO2-KH570-resveratrol. Figure 6 (a) It can be seen that before standing, TiO2, TiO2-KH570 and TiO2-KH570-resveratrol are all turbid liquids after mixing with water; Figure 6 (b) It can be seen that after standing for 24h, the powder in the colorimetric tube of TiO2 precipitates at the bottom of the colorimetric tube, and the upper part is clear and transparent deionized water, indicating that the unmodified TiO2 has poor dispersibility and serious agglomeration; while in the colorimetric tubes of TiO2-KH570 and TiO2-KH570-resveratrol, only the local color above the liquid becomes lighter, and the liquid in the middle and lower parts is not significantly different from that before standing. This is because the nano-TiO2 modified by KH570 has a relatively long organic molecular chain, and the density of this organic molecular chain is less than that of water. It is spread upward in water, which can effectively reduce the coagulation of nano-TiO2. The molecular chain spread outward can also play a role of spatial hindrance, effectively preventing the agglomeration of nano-TiO2. It can be seen that the dispersibility of the modified titanium dioxide TiO2-KH570-resveratrol provided by the present invention has been greatly improved, and the phenomenon of powder agglomeration has been greatly reduced, which can make the nano-TiO2 better play its performance.

[0110] 6. UV-Visible powder diffuse reflectance analysis

[0111] The solid powder UV reflectivity of nano-TiO2, TiO2-KH570 and TiO2-KH570-resveratrol in the examples was tested using a U-3900H UV-visible spectrophotometer. The UV absorption capacity of the modified powder in the wavelength range of 200 to 400 nm can be inferred through the reflectivity test.

[0112] Figure 7 The UV-visible powder diffuse reflectance spectra of TiO2, TiO2-KH570 and TiO2-KH570-resveratrol in Example 1 are shown in FIG. Figure 7 It can be seen that the UV ultraviolet-visible light powder diffuse reflectance spectrum curves of nano-TiO2, TiO2-KH570 and TiO2-KH570-resveratrol are roughly the same in shape. Therefore, the structure and organization of nano-TiO2 are not significantly changed after modification, and the light diffuse reflectance of the three in the wavelength range of 200-400nm shows a trend of TiO2>TiO2-KH570>TiO2-KH570-resveratrol. It can be seen that the light absorption capacity of the three in the wavelength range of 200-400nm is TiO2-KH570-resveratrol>TiO2-KH570>TiO2, so the modification enhances TiO2's absorption capacity of ultraviolet light.

[0113] 7. Anti-ultraviolet performance test

[0114] An analytical balance was used to accurately weigh 20 mg each of nano-TiO2, TiO2-KH570 and TiO2-KH570-resveratrol in the embodiment, 4 mL of anhydrous ethanol was added to dissolve and ultrasonically dispersed for 30 min to obtain a slurry, the slurry was evenly spread on a glass plate, placed in a 65°C vacuum drying oven for 8 h to form a thin layer of coated glass plate, and then the glass plate was placed above an ultraviolet sensor card and exposed to sunlight for a real outdoor ultraviolet irradiation test, and the glass plate was removed to observe the color change of the ultraviolet sensor card.

[0115] Figure 8 The UV-sensing card test images of TiO2 (a), TiO2-KH570 (b) and TiO2-KH570-resveratrol (c) in Example 1 are shown in FIG. Figure 8 (a) It can be seen that the anti-ultraviolet effect of the slurry made of nano-TiO2 is relatively general, the smearing and dispersion are uneven, and some parts are not completely blocked; Figure 8 (b) It can be seen that the anti-ultraviolet effect of the slurry prepared by TiO2-KH570 is improved, and the ultraviolet shielding effect is better than that of nano-TiO2; Figure 8 (c) It can be seen that the thin plate coated with TiO2-KH570-resveratrol slurry can not only reduce the strong ultraviolet light to a weaker one, but also has a more uniform ultraviolet shielding effect.

[0116] 8. Free radical elimination test (DPPH free radical scavenging method)

[0117] (1) Qualitative analysis of controlled variables: In order to test whether the obtained product has the ability to eliminate free radicals, 9.7 mg of 2,2-biphenyl-1-picrylhydrazyl (DPPH) was weighed on an analytical balance and dissolved in 250 mL of anhydrous ethanol to prepare a DPPH solution with a concentration of 0.2 mmol / L for later use. Then, 15 mL of the prepared solution was taken into four centrifuge tubes. The first centrifuge tube was not treated in any way. 3 mg of nano-TiO2 was added to the second centrifuge tube, 3 mg of TiO2-KH570 was added to the third centrifuge tube, and 3 mg of TiO2-KH570-resveratrol was added to the fourth centrifuge tube. The solution was left for a period of time to observe the color change. Qualitative analysis can be used to determine whether the obtained product has the ability to eliminate free radicals.

[0118] (2) Quantitative analysis: The specific operation method is: use an analytical balance to weigh 9.7 mg of DPPH and dissolve it in a small amount of anhydrous ethanol, then dilute it with 95% ethanol solution to a total volume of 250 mL to prepare a DPPH solution with a concentration of 0.2 mmol / L. Take 2 mL of DPPH solution, add 1 mL of the sample solution to be tested, and then use 95% ethanol to make the volume to 4 mL. Let the mixed solution stand for 30 minutes, use 95% ethanol as a blank control, and measure the absorbance at a wavelength of 518 nm, which are recorded as A1 (absorbance of the sample) and A0 (absorbance of the initial DPPH solution).

[0119] Calculate the DPPH free radical scavenging rate of the sample: DPPH free radical scavenging rate (%) = (1-A1 / A0) × 100%.

[0120] Table 1 shows the scavenging rate of DPPH free radicals of TiO2-KH570-resveratrol in Example 1. It can be seen from Table 1 that after modification with silane coupling agent KH570 and resveratrol, the modified titanium dioxide (TiO2-KH570-resveratrol) can eliminate free radicals to a certain extent. A small amount of TiO2-KH570-resveratrol already has a relatively good free radical scavenging performance, and as the mass of TiO2-KH570-resveratrol increases, the free radical elimination effect gradually increases and can reach 64.0%, which can achieve the effect of eliminating and inhibiting the generation of harmful free radicals under ultraviolet irradiation.

[0121] Table 1 DPPH free radical scavenging rate of TiO2-KH570-resveratrol in the examples

[0122]

[0123] The modified titanium dioxide provided by the present invention does not change the original physical properties of nano titanium dioxide after being modified by a silane coupling agent and a bioactive component. The silane coupling agent and the bioactive component are sequentially grafted onto the surface of the nano titanium dioxide, so that the particle size of the nano titanium dioxide is increased, thereby improving its dispersibility and reducing the degree of agglomeration; the anti-ultraviolet ability of the modified titanium dioxide is enhanced; after the surface is grafted with the bioactive component, the free radicals generated by the nano titanium dioxide can also be eliminated to a certain extent. The modified titanium dioxide can be directly used as a raw material to participate in the preparation of liquid, paste or cream-like sunscreen products, so that the sunscreen products have both sunscreen and free radical scavenging effects, and reduce the harm caused by free radicals generated by light during the use of the titanium dioxide-containing sunscreen products.

Claims

1. A modified titanium dioxide, characterized in that: Titanium dioxide modified synergistically by coupling agents and bioactive ingredients.

2. The modified titanium dioxide according to claim 1, characterized in that The modified titanium dioxide comprises the following preparation raw materials: titanium dioxide, a surfactant, a coupling agent, a bioactive component and a solvent.

3. The modified titanium dioxide according to claim 1 or 2, characterized in that The solid-liquid ratio of the titanium dioxide to the coupling agent is 1g:(7-10)mL; And / or, the particle size of the titanium dioxide is 20 to 500 nm; And / or, the coupling agent includes a silane coupling agent.

4. The modified titanium dioxide according to claim 1 or 2, characterized in that The bioactive ingredient contains a benzene ring or a conjugated structure; And / or, the bioactive ingredients include at least one of flavonoids, phenylpropanoids, glycosides, polyphenols, and carotenoids.

5. The modified titanium dioxide according to claim 2, characterized in that The mass ratio of the surfactant to titanium dioxide is (0.5-3):100; And / or, the surfactant includes at least one of sodium dodecyl sulfate, sodium lauryl sulfate, hexadecyltrimethylammonium bromide, and sodium fatty acid methyl ester sulfonate.

6. The modified titanium dioxide according to claim 2, characterized in that The raw materials for preparing the modified titanium dioxide also include an initiator; Preferably, the mass ratio of the initiator to titanium dioxide is (0.1-0.5):100; Preferably, the initiator comprises at least one of azobisisobutyronitrile and azobisisobutylamidine dihydrochloride.

7. The method for preparing modified titanium dioxide according to claim 2, characterized in that: The following steps are involved: S1, mixing titanium dioxide, a solvent and a surfactant to obtain a mixed solution; S2, adding a coupling agent dropwise to the mixed solution to react and obtain coupling agent-modified titanium dioxide; S3, dissolving the coupling agent modified titanium dioxide in a solvent, adding a biologically active component, and reacting to obtain the modified titanium dioxide.

8. The preparation method according to claim 7, characterized in that: In the step S3, the mass ratio of the coupling agent-modified titanium dioxide to the bioactive component is 1:(0.8-1.5).

9. A sunscreen product, characterized in that: The modified titanium dioxide according to claim 1 or 2; The mass percentage of the modified titanium dioxide is 10-20%.

10. Use of the modified titanium dioxide according to claim 1 or 2, or the sunscreen product according to claim 9 in sunscreen.

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