关键词: ZrO₂/SiO₂改性纤维素, 纤维素气凝胶, 隔热性能, 气凝胶复合织物

Abstract: The new thermal insulation materials mainly achieve the thermal insulation effect by increasing the internal pores of the materials to accommodate more static air. Aerogel has the characteristics of high porosity, low thermal conductivity and low refractive index, and is widely used in the field of thermal insulation. Cellulose aerogels have the advantages of renewability, biocompatibility and biodegradability, and overcome the shortcomings of traditional inorganic gels, such as friability and difficulty in repeated use. However, the thermal stability of cellulose itself is poor, and cellulose aerogels cannot maintain stability in high temperature environment. Therefore, in order to improve its thermal stability, the cellulose is modified to make the aerogel prepared from the modified cellulose have good thermal insulation performance under high temperature environment. The strength of aerogel is generally low, so it is difficult to use it as an insulation material alone. In order to improve the low strength of the aerogel and give the fabric good thermal insulation performance, the modified cellulose aerogel is compounded with ordinary fabrics to obtain a cellulose aerogel composite fabric with good mechanical strength and thermal insulation performance.
The precursor solution was prepared with a certain proportion of zirconium oxychloride /tetraethyl silicate as the precursor and yttrium nitrate as the stabilizer. The cellulose microfibers (CMF) after pre-oxidation treatment are uniformly dispersed in the precursor solution to form a mixed solution. The CMF aerogel composite fabric modified by ZrO₂ and SiO₂ was prepared by casting the mixed solution on the fabric, adopting the sol gel method and freeze drying treatment. Fourier infrared spectroscopy (FTIR) was used to analyze the degree of crosslinking of CMF, and thermal imaging was used to measure the thermal insulation effect of the aerogel composite fabric. The mechanical properties and wearability of the aerogel composite fabric were explored by measuring the breaking elongation, permeability and thickness of the fabric. The results show that the aerogel layer of the aerogel composite fabric is well bonded to the surface of the fabric; the CMF aerogel is successfully doped with Zr and Si; the aerogel composite fabric has good heat insulation performance on 37 ℃ and 100 ℃ hot plates; the air gel composite fabric can still maintain good heat insulation performance after washing and friction test.
In this paper, the modified CMF aerogel composite fabric is prepared by compounding the ordinary fabric with a new modified CMF aerogel thermal insulation material. The preparation process is simple and environmentally friendly. The aerogel composite fabric has excellent heat insulation performance and good wearability. The research results can lay a foundation for the application of cellulose aerogels in the field of heat insulation and warmth preservation.

Key words: ZrO₂/SiO₂ modified cellulose, cellulose aerogel, thermal insulation, aerogel composite fabric