Monodisperse organic-inorganic silica microspheres, methods of making and using the same

Abstract

The application provides a monodisperse organic-inorganic hybrid silica microsphere and a preparation method and application thereof. The preparation method of the monodisperse organic-inorganic hybrid silica microsphere comprises the following steps: S1, adding tetraethoxysilane into a mixed solution of alcohol, water and ammonia water, and reacting for 0.5-2 hours; S2, adding an alcohol solution of tetraethoxysilane and aminopropyl triethoxysilane into the system obtained in step S1 dropwise, and reacting for 2-12 hours. The preparation method provided by the application realizes one-step synthesis of the organic-inorganic hybrid silica microsphere, the obtained organic-inorganic hybrid silica microsphere has controllable particle size and high monodispersity, the preparation and modification of the silica microsphere are simultaneously performed, and the method is suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coating additives, more particularly to a monodisperse organic-inorganic hybrid silica microsphere, a preparation method and application thereof. BACKGROUND

[0002] At present, the preparation methods of monodisperse spherical silica mainly include gas phase method, precipitation method, microemulsion method and sol-gel method. The gas phase method has high requirements for equipment and high energy consumption, and the industrialization cost is high. The product morphology and particle size are difficult to control in the precipitation method, and the number of hydroxyl groups is large, which limits the downstream application. The microemulsion method involves organic substances in the system, which is difficult to recover and pollutes the environment. The sol-gel method can prepare monodisperse nano / micron silica spheres, and the industrialization is feasible. At the same time, the research on the modification of the surface of the silica is also an important step for the application of the downstream products.

[0003] In the prior art, there are methods for preparing monodisperse silica microspheres by adding ionic liquid solvent mixed solvents. There are also methods for preparing monodisperse silica microspheres of different sizes by microwave-assisted organic base, which can realize the particle size control of the silica microspheres by using different concentrations of organic base. However, this method is difficult to realize the preparation of micron-sized silica and causes pollution. There are also prior arts that use seed growth method to prepare SiO2 microspheres with a particle size of 100-600 nm, and the particle size distribution deviation is not more than 2%. The process is complicated and the efficiency is low. At present, the main modification method of silica spheres is through inorganic or organic polymer post-treatment modification, which cannot realize continuous industrial production, and increases the time and production cost.

[0004] The silica sphere industrialization is still in the development stage, and the problem of precise control of the particle size and morphology of the silica microspheres needs to be solved. In addition, the agglomeration phenomenon of the silica during preparation and storage is also a strong resistance to large-scale industrialization. SUMMARY

[0005] In order to solve or at least partially solve the above problems, the present application provides a preparation method of monodisperse organic-inorganic hybrid silica microspheres. The preparation method provided by the present application realizes one-step synthesis of organic-inorganic hybrid silica microspheres, and the obtained organic-inorganic hybrid silica microspheres have controllable particle size and high monodispersity. The preparation method provided by the present application can more accurately control the particle size and morphology of the obtained silica microspheres, effectively solve the agglomeration phenomenon of the silica microspheres during preparation, realize the synchronization of the preparation and modification of the silica microspheres, and is suitable for industrial production. The preparation method of monodisperse organic-inorganic hybrid silica microspheres provided by the present application comprises the following steps:

[0006] S1, adding tetraethoxysilane into a mixed solution of alcohol, water and ammonia water, and reacting for 0.5-2h;

[0007] S2, drop the alcohol solution of tetraethoxysilane and aminopropyl triethoxysilane into the system obtained in step S1, and react for 2-12 h.

[0008] In a preferred embodiment of the present application, the alcohol in step S1 can be methanol, ethanol, butanol, isopropanol, etc., and is preferably ethanol.

[0009] In a preferred embodiment of the present application, in order to further take into account the particle size and the dispersity and uniformity of the obtained microspheres, the molar ratio of the alcohol, water and ammonia in step S1 is (2-10):(1-8):1, and is preferably 8:4:1.

[0010] In a preferred embodiment of the present application, in order to further improve the dispersity and uniformity of the obtained silica microspheres and more effectively control the particle size and morphology, the amount of tetraethoxysilane added in step S1 is 25-100 mL, and the concentration of the tetraethoxysilane in the mixed solution is 0.5-1.2 mol / L.

[0011] In a specific embodiment of the present application, the reaction in step S1 can be carried out at room temperature, and the reaction temperature can be 20-35°C.

[0012] In a preferred embodiment of the present application, the alcohol solution in step S2 can be methanol, ethanol, butanol, isopropanol, etc., and is further preferably ethanol. Preferably, the alcohol solution in step S2 is the same as the alcohol solution in step S1.

[0013] In a preferred embodiment of the present application, in step S2, the mass ratio of tetraethoxysilane, aminopropyl triethoxysilane and the alcohol solution is (0.5-2):(0.2-2):(0.5-3), and is further preferably 1:1:(1.4-1.6). If the mass ratio is too small, the particle size distribution of the obtained microspheres is not uniform, and small particles are prone to adhere to each other. If the mass ratio is too large, the obtained microspheres are prone to agglomerate, and the dispersity is reduced.

[0014] In a preferred embodiment of the present application, in step S2, the dropwise addition speed of the alcohol solution of tetraethoxysilane and aminopropyl triethoxysilane to the system obtained in step S1 is 0.1-2 mL / min. If the dropwise addition speed is too fast, the particle size of the obtained microspheres is small. If the dropwise addition speed is too slow, the obtained microspheres are prone to adhere to each other, the distribution is not uniform, and the dispersity is low.

[0015] In a specific embodiment of the present application, after the reaction in step S2 is completed, the solvent in the system can be concentrated or removed by a method conventional in the art, such as distillation, to obtain monodisperse silica microspheres.

[0016] The prior art usually needs external facilities to monitor the size of the particle diameter to control the particle diameter of the microspheres, and the prior art also needs subsequent secondary configuration of a seed liquid, which is complicated to operate, and the applicant of the present application has unexpectedly found that the organic group-containing silica microspheres with the required size and dispersion degree and good uniformity can be obtained by the above-mentioned specific preparation method (which is also a one-step method) combined with the feeding ratio and the dropping speed in the specific method.

[0017] One object of the present application is to provide monodisperse organic-inorganic hybrid silica microspheres obtained by the above-mentioned preparation method.

[0018] The silica microspheres obtained by the present application have controllable particle diameter and high monodispersity, realize simultaneous preparation and modification of the silica, and can be used for coating additives to improve the comprehensive performance of the coating (especially the strength and ultraviolet aging resistance of the coating).

[0019] Another object of the present application is to provide the application of the above-mentioned preparation method and the monodisperse organic-inorganic hybrid silica microspheres obtained by the above-mentioned preparation method in the preparation of coating additives.

[0020] The preparation method provided by the present application realizes one-step synthesis of organic-inorganic hybrid silica microspheres, and the obtained organic-inorganic hybrid silica microspheres have controllable particle diameter and high monodispersity, high sphericity, no adhesion, uniform size, realize simultaneous preparation and modification of the silica microspheres, and are suitable for industrial production. The silica microspheres obtained by the present application can be applied to coating additives, can effectively improve the strength of the coating, and effectively widen the application range. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 SEM image of the monodisperse organic-inorganic hybrid silica microspheres obtained in Example 1. DETAILED DESCRIPTION

[0022] The specific embodiments of the present application are described in further detail below in combination with examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application.

[0023] Except as specifically stated, the "%" in the present application is the mass percentage.

[0024] Example 1

[0025] The present embodiment provides a kind of monodisperse organic-inorganic hybrid silica microspheres, and the preparation method comprises the following steps:

[0026] (1) Adopting sol-gel method, at room temperature (30℃), configure ethanol, water and ammonia solution system in 8:4:1 molar ratio, after ultrasonic stirring, obtain mixed solution, add 75 mL of tetraethoxysilane into the mixed solution, the concentration of tetraethoxysilane in the mixed solution is 0.8 mol / L, and stir for 0.5 hours.

[0027] (2) Dissolve 35 mL of tetraethoxysilane and 35 mL of aminopropyl triethoxysilane in 66 mL of anhydrous ethanol to obtain an alcohol mixed solution.

[0028] (3) Drop the alcohol mixed solution obtained in step (2) into the solution system obtained in step (1) at a rate of 0.5 mL / min by using a peristaltic pump, and stir for 4 hours.

[0029] (4) After the reaction is completed, the temperature is raised to 80℃, and the solvent in the reaction kettle is concentrated by distillation to obtain monodisperse silica microspheres.

[0030] The SEM image of the silica microspheres obtained in this example is shown in Figure 1 . The silica microspheres obtained in this example have moderate particle size (particle size is about 1.4-1.5 μm), good dispersity and uniformity.

[0031] Example 2

[0032] This example provides a kind of monodisperse organic inorganic hybrid silica microspheres, and the preparation method comprises the following steps:

[0033] (1) Adopting sol-gel method, at room temperature (30℃), configure ethanol, water and ammonia solution system in 2:2:1 molar ratio, after ultrasonic stirring, obtain mixed solution, add 25 mL of tetraethoxysilane into the mixed solution, the concentration of tetraethoxysilane in the mixed solution is 0.5 mol / L, and stir for 1 hour.

[0034] (2) Dissolve 35 mL of tetraethoxysilane and 14 mL of aminopropyl triethoxysilane in 42 mL of anhydrous ethanol to obtain an alcohol mixed solution.

[0035] (3) Drop the alcohol mixed solution obtained in step (2) into the solution system obtained in step (1) at a rate of 0.1 mL / min by using a peristaltic pump, and stir for 5 hours.

[0036] (4) After the reaction is completed, the temperature is raised to 80℃, and the solvent in the reaction kettle is concentrated by distillation to obtain monodisperse silica microspheres.

[0037] The silica microspheres obtained in this example have moderate particle size, good dispersity and uniformity.

[0038] Example 3

[0039] The embodiment provides a monodisperse organic-inorganic hybrid silica microsphere, and a preparation method thereof.

[0040] (1) A mixed solution is prepared by stirring an ethanol, water and ammonia solution system in a molar ratio of 10:8:1 at room temperature (30 DEG C) and then adding 100 mL of tetraethoxysilane to the mixed solution, wherein the concentration of the tetraethoxysilane in the mixed solution is 1.2 mol / L, and the stirring reaction is carried out for 2 hours.

[0041] (2) 35 mL of tetraethoxysilane and 35 mL of aminopropyl triethoxysilane are dissolved in 63 mL of anhydrous ethanol to obtain an alcohol mixed solution.

[0042] (3) The alcohol mixed solution obtained in step (2) is added dropwise into the solution system obtained in step (1) at a rate of 2 mL / min by using a peristaltic pump, and the stirring reaction is carried out for 10 hours.

[0043] (4) After the reaction is completed, the temperature is increased to 80 DEG C, and the solvent in the reaction kettle is concentrated by distillation to obtain monodisperse silica microspheres.

[0044] The silica microspheres obtained in the embodiment have moderate particle size, good dispersity and uniformity.

[0045] Example 4

[0046] The embodiment provides a monodisperse organic-inorganic hybrid silica microsphere, and a preparation method thereof.

[0047] (1) A mixed solution is prepared by stirring a methanol, water and ammonia solution system in a molar ratio of 1:1:1 at room temperature (30 DEG C) and then adding 50 mL of tetraethoxysilane to the mixed solution, wherein the concentration of the tetraethoxysilane in the mixed solution is 0.3 mol / L, and the stirring reaction is carried out for 2 hours.

[0048] (2) 35 mL of tetraethoxysilane and 12 mL of aminopropyl triethoxysilane are dissolved in 70 mL of anhydrous methanol to obtain an alcohol mixed solution.

[0049] (3) The alcohol mixed solution obtained in step (2) is added dropwise into the solution system obtained in step (1) at a rate of 0.05 mL / min by using a peristaltic pump, and the stirring reaction is carried out for 10 hours.

[0050] (4) After the reaction is completed, the temperature is increased to 80 DEG C, and the solvent in the reaction kettle is concentrated by distillation to obtain monodisperse silica microspheres.

[0051] The silica microspheres obtained in the embodiment have poor uniformity, and a small part of the small particles are slightly bonded to each other, and the dispersity is slightly poor.

[0052] Example 5

[0053] The embodiment provides a monodisperse organic-inorganic hybrid silica microsphere, and a preparation method thereof.

[0054] (1) A sol-gel method is used to prepare a mixed solution by mixing butanol, water and ammonia solution at a molar ratio of 15:10:1 under room temperature (30 DEG C) and ultrasonic stirring, 100 mL of tetraethoxysilane is added into the mixed solution, wherein the concentration of the tetraethoxysilane in the mixed solution is 1.5 mol / L, and the stirring reaction is carried out for 2 hours.

[0055] (2) 35 mL of tetraethoxysilane and 35 mL of aminopropyl triethoxysilane are dissolved in 42 mL of butanol to obtain an alcohol mixed solution.

[0056] (3) The alcohol mixed solution obtained in the step (2) is added into the solution system obtained in the step (1) by using a peristaltic pump at a rate of 2.5 mL / min, and the stirring reaction is carried out for 10 hours.

[0057] (4) After the reaction is completed, the temperature is increased to 80 DEG C, and the solvent in the reaction kettle is concentrated by distillation to obtain monodisperse silica microspheres.

[0058] The silica microspheres obtained in the embodiment have poor uniformity, a little more large particles, and a little poor dispersity.

[0059] Experimental example

[0060] 10 wt% of the silica microspheres provided in the embodiment is mixed with water-based paint (water-washing paint is purchased from Zhejiang Anbang New Material Development Co., Ltd.) by mechanical stirring, and after the air bubbles are removed in vacuum, the silica microspheres are coated in a specific mold. The prepared test piece is cured for 96 hours under standard experimental conditions, dried for 48 hours in a 40±2 DEG C dryer after demolding, and dumbbell I samples meeting the requirements of GB / T528 are cut, and the tensile test is carried out by using a universal testing machine. The experimental results are expressed by the arithmetic mean of three test pieces. The comparative example is a paint test piece prepared by not adding the silica of the embodiment, which is used as a blank control group.

[0061] Particle size (pm) Monodispersity Coating strength Comparative Example / / 0.4 Example 1 1.4-1.5 0.07 0.9 Example 2 1.2-1.4 0.09 0.82 Example 3 1.3-1.6 0.1 0.78 Example 4 0.8-1.2 0.5 0.42 Example 5 0.9-1.5 0.6 0.39

[0062] Finally, the method of the embodiment is only a preferred embodiment, and is not used to limit the protection scope of the embodiment. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the embodiment should be included in the protection scope of the embodiment.

Claims

1. A method for preparing monodisperse organic-inorganic hybrid silica microspheres, characterized by, The method comprises the following steps: S1, adding tetraethoxysilane into a mixture of alcohol, water and ammonia water, and reacting for 0.5-2 hours; the alcohol is ethanol; the molar ratio of the alcohol, water and ammonia water is (2-10):(1-8):1; the amount of the tetraethoxysilane added is 25-100 mL, and the concentration of the tetraethoxysilane in the mixture is 0.5-1.2 mol / L; S2, adding dropwise an ethanol solution of tetraethoxysilane and aminopropyl triethoxysilane into the system obtained in step S1, and reacting for 2-12 hours; in step S2, the mass ratio of the tetraethoxysilane, aminopropyl triethoxysilane and the alcohol solution is (0.5-2):(0.2-2):(0.5-3); and the dropping speed is 0.1 mL / min-2 mL / min.

2. The production method according to claim 1, characterized by, In step S1, the molar ratio of the alcohol, water and ammonia water is 8:4:

1.

3. The preparation method according to claim 1, characterized in that, In step S2, the mass ratio of the tetraethoxysilane, aminopropyl triethoxysilane and the alcohol solution is 1:1:(1.4-1.6).

4. The monodisperse organic-inorganic hybrid silica microspheres prepared by the method of any one of claims 1-3.

5. The use of the method of any one of claims 1-3 or the monodisperse organic-inorganic hybrid silica microspheres of claim 4 in preparing a coating additive.

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