纤维包覆纱改性PVA基气凝胶的制备及吸波性能研究OA北大核心CSTPCD

SiO2/PVDF and PAN/PVDF fibers were prepared by electrospinning instrument with wet spinning polyvinylidene fluoride(PVDF)fiber as the core layer and ethyl orthosilicate and polyacrylonitrile(PAN)as the skin layer,and the fiber-coated yarn was carbonized,and then added to polyvinyl alcohol(PVA)to prepare aerogel by freeze-drying.The effects of two kinds of fiber-coated yarns on compressibility properties,thermal insulation properties and electromagnetic wave absorption properties of PVA-based aerogels were studied.The results show that the addition of fiber-coated yarn can enhance the compression resistance of PVA-based aerogels,and the aerogels with PAN/PVDF coated yarns have the best compression resistance,with a compressive stress of 112.3 kPa,which is 45%higher than that of unmodified aerogels,and recovery rate can still be maintained by more than 90%after five rounds of compression rebound experiments.In addition,when the thickness of the aerogel modified by PAN/PVDF coated yarn is 1 mm,the effective absorption bandwidth is 1.08 GHz,and the maximum absorption peak reaches-40.4 dB,showing excellent electromagnetic wave absorption performance.