Method for preparing elastic silica aerogel bulk material with toughness

Abstract

The invention relates to a method for preparing an elastic silica aerogel bulk material with toughness. The method comprises the following steps of (1), preparation of a silica sol; (2), preparation of a gel: taking a certain amount of precursor solution of which reaction is completed, adding dropwise an alkaline catalyst to adjust the pH value, and stirring rapidly for a certain time; (3), slowlyinjecting the prepared gel into a mold; (4), placing at a certain temperature for a period of time, aging, curing the gel and shaping; (5), drying: drying the obtained gel to obtain the hydrophobic silica aerogel insulating block material. The method has the advantages of simple process, low cost, controllable reaction condition and excellent product performance, the prepared elastic silica aerogel block material has a complete block structure, very small shrinkage and stable shrinkage ratio and can adapt to mold preparation requirements, and the usability of profiled products in the field ofinsulation can be fully met by controlling the appropriate enlargement of the mold.

Description

technical field [0001] The invention relates to an elastic airgel thermal insulation material and a preparation method thereof, in particular to a preparation method of an elastic silica airgel block material with toughness. Background technique [0002] SiO2 airgel is a lightweight nanoporous amorphous solid material with excellent thermal insulation performance, its porosity is as high as 80-99.8%, the typical size of the pores is 1-100nm, and the specific surface area is 200-1000m2 / g , while the density can reach 3Kg / m3, and the thermal conductivity at room temperature can be as low as 0.012W / (m·k). application potential. However, due to the large specific surface area, porosity and low density of SiO2 airgel, its strength is very low, and its inherent brittleness and poor mechanical properties greatly limit the application of airgel materials in some fields. [0003] The Chinese patent with publication number CN 101973752A provides a glass fiber reinforced silica airge...

AI Technical Summary

Problems solved by technology

[0007] 1. Felt is suitable for pipes and equipment, and generally only suitable for parts without joints. For parts with joints, the method of cutting them into specific shapes and then fixing them with iron wire or tape is generally used. The disadvantage of this method is that the construction process is complicated It is time-consuming and wastes materials, and it is impossible to achieve thermal insulation construction on complex surfaces, especially for small equipment that cannot apply airgel-related products

[0008] 2. For surface insulation of complex materials, some people have proposed the method of pouring airgel powder, but due to the low density of airgel powder, the pouring construction environment is poor, and the gaps between the powders after pouring are relatively large, which affects the thermal insulation performance. have a great impact

In this method, the process of making the base material into a specific shape is cumbersome, coupled with the low production efficiency when using traditional felt-type equipment to produce special-shaped parts, resulting in very high product costs