Method for preparing TiO2/SiO2 aerogel microspheres by emulsion method

Abstract

The invention relates to a method for preparing TiO2/SiO2 aerogel microspheres by an emulsion method. The method for preparing TiO2/SiO2 aerogel microspheres by the emulsion method comprises the following steps: (1) preparing titanium dioxide suspension; (2) preparing a silicon dioxide alcoholic solution; (3) mixing the titanium dioxide suspension and the silicon dioxide alcoholic solution, adding formamide in the mixture, and stirring to obtain mixed sol; (4) preparing an oil phase by using sorbitan oleate, polysorbate, n-butyl alcohol and n-heptane; (5) adding the mixed sol in the oil phase under the condition of stirring, adding ammonia water to regulate pH value, and centrifugally separating to obtain TiO2/SiO2 aerogel microspheres; and (6) adding a cyclohexane solution of trimethylchlorosilane in the TiO2/SiO2 aerogel microspheres, carrying out surface treatment, and drying after ageing to obtain the finished product. According to the method disclosed by the invention, reaction conditions are mild, requirements on equipment are not high, and the TiO2/SiO2 aerogel microspheres prepared by the method do not have cracks, are high in transparency, good in super-hydrophobic property and infrared thermal reflectivity and low in thermal conductivity, and have a wide application prospect in the building fields of coatings, coiled materials and the like.

Description

technical field [0001] The present invention relates to nanoporous SiO 2 The technical field of gel materials, specifically relating to the preparation of TiO by an emulsion method 2 / SiO 2 Airgel microspheres approach. Background technique [0002] Silicon dioxide (SiO 2 ) airgel, as a new type of nanoporous super heat insulation material, has two forms of powder and block, and its porosity is as high as 80% to 99.8%. It is a low-density nanoporous amorphous material. Silica airgel contains particles and pore structures with a scale of 1-100nm, and has a large specific surface area (200-1000m 2 / g), higher porosity (80%~99.8%), lower density (1~500kg / m 3 ) and thermal conductivity as low as 0.02W / (m·K). Based on the above characteristics, silica airgel shows unique properties in mechanics, acoustics, heat, optics and other aspects, such as strong adsorption, low thermal conductivity, low refractive index, low elastic modulus, low acoustic impedance, etc. , and has a ...

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