Novel halloysite/polyvinyl alcohol composite aerogel and preparation method and application thereof

Abstract

The invention discloses a novel halloysite / polyvinyl alcohol composite aerogel and a preparation method and application thereof. Deionized water is taken as a solvent, a borax solution is taken as a cross-linking agent, an environmentally friendly freeze-drying preparation method is adopted, a result shows that when PVOH: HNTs is 3: 7, composite aerogel with a unique three-dimensional nano porousnetwork structure is obtained, and HNTs is taken as a supporting portion of a structural framework. Polyvinyl alcohol molecules firmly adhere to the outer surface of fibrous HNTs. Along with increasing of the content of HNTs and reduction of the content of PVOH, the density is reduced to be 0.16 cm<3> / g at first and then is increased, the heat conductivity coefficient is opposite exactly, and a change range is between 0.025 Wm-1K-1 and 0.032 Wm-1K-1. An aerogel sample of which the compression strength is from 0.8 to 2.5 MPa is obtained. The representative characteristics show that the HNTs / PVOH composite aerogel has wide application prospect in the field of heat insulation of buildings.

Description

Technical field [0001] The invention relates to the technical field of aerogels, in particular to a novel halloysite / polyvinyl alcohol composite aerogel, and a preparation method and application thereof. Background technique [0002] Aerogel is a porous material with nanostructures, with low density, high porosity, high specific surface area, low thermal conductivity and other characteristics, which makes it an excellent candidate for many fields. However, common traditional aerogel materials, such as silica aerogel, have the disadvantages of low strength, poor agglomeration, complicated preparation process, long preparation period, and solvent pollution, which cannot satisfy the practical application of aerogel materials. , Especially the requirements in the field of building insulation. Therefore, it is very important to find a new type of aerogel using a low-cost, non-polluting raw material and simple, environmentally friendly preparation method. Since Mackenzie and Call fir...

AI Technical Summary

Problems solved by technology

At present, the clay component of most clay aerogels is montmorillonite, but montmorillonite is a micron-sized sheet clay, and the pre-treatment and intercalation modification of montmorillonite will make the clay aerogel and its polymer composite The preparation process of airgel has become complicated and the cost has increased

In addition, the micron-scale size of montmorillonite itself determines that its clay airgel is difficult to form a nano-scale porous structure, which will greatly lose the unique thermal insulation properties of airgel materials

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