Improved Stober method for preparing tio2/sio2 aerogel microsphere

Abstract

The invention relates to an improved Stober method for preparing a TiO2 / SiO2 aerogel microsphere. The improved Stober method comprises the steps of (1) preparing a titanium dioxide suspension liquid; (2) preparing mixed sol of tetramethoxysilane or tetraethoxysilane and alcohol; (3) preparing a mixed solution of ammonia water and ethanol; (4) reacting the mixed sol and the mixed solution; (5) adding fluoroalkyl silane self-assembly solution into the solution obtained in the step (4), and further reacting; and (6) centrifugally cleaning the solution obtained in the step (5), and drying to obtain the TiO2 / SiO2 aerogel microsphere. The improved Stober method provided by the invention is carried out at normal pressure and is mild in condition, low in reaction temperature not higher than 80 DEG C, not high in equipment requirement and capable of reducing production cost and improving production safety. The TiO2 / SiO2 aerogel microsphere prepared by using the method disclosed by the invention has the particle size of 200-750nm, is smooth in surface, relatively good in monodispersity, good in integrity and free of fragmentation or cracks, has the advantages of high transparency, good hydrophobicity and infrared reflectivity, low heat conductivity and the like and has a wide application prospect in the field of buildings such as coatings and coiled materials.

Description

technical field [0001] The present invention relates to nanoporous SiO 2 The technical field of gel materials, specifically relating to an improved TiO 2 / SiO 2 Airgel microspheres approach. Background technique [0002] SiO 2 Airgel is a new type of super thermal insulation material developed in recent years. It is a light porous amorphous solid material, the typical size of pores in its network structure is 1-100nm, the porosity is as high as 80%-99.8%, and the specific surface area is even as high as 200m 2 / g~1000m 2 / g, while the density can be as low as 1kg / m 3 ~400kg / m 3 , the thermal conductivity can be as low as 0.005W / (m·K). SiO 2 A very important reason why airgel has the above-mentioned excellent properties is that by controlling the process parameters in the preparation process, the SiO 2 The pore diameter of airgel is about 50nm, and the pore diameter is lower than the mean free path of air molecules, so that the movement of air molecules is blocked...

AI Technical Summary

Problems solved by technology

Silica airgel prepared by the supercritical method has relatively good performance, but the equipment system is complex and expensive and needs to work under high temperature and high pressure, so the risk is high

However, the existing normal temperature and pressure method will shrink the gel during the drying process, making it easy to break or crack

In addition, the SiO produced by the prior art 2 The nature of airgel is relatively simple. Although its thermal insulation performance is good, it cannot meet the multi-functional requirements when it is applied in the field of materials such as coatings and coils.

In southern my country where the climate is humid and there is a lot of rain, the walls are often washed by rain. The service life of exterior wall coatings and coils containing silica airgel is not long. If a super-hydrophobic coating is developed, it can prolong its life. service life

Images