以甲基三甲氧基硅烷(MTMS)和N-氨乙基-γ-氨丙基-三甲氧基硅烷(ATAPTES)为硅源,间苯二酚和甲醛为有机增强体,采用溶胶-凝胶法通过常压干燥制备了有机韧性SiO 2气凝胶。研究了MTMS与ATAPTES、甲醛与间苯二酚摩尔比对复合气凝胶结构和性能的影响。采用N 2吸附脱附等温线、SEM、FT-IR及压缩测试等方法对韧性气凝胶进行了表征。结果表明,甲醛与间苯二酚摩尔比为4时,气凝胶孔径分布范围较宽,总孔容积0.15~0.40 cm ^3/g,比表面积5~70 m ^2/g,最大形变率可达50%,对有机溶剂的吸附量可达自身质量的7~11倍。甲醛与间苯二酚摩尔比为2时,气凝胶孔径主要分布范围3~10 nm,总孔容积0.52~0.53 cm^ 3/g,比表面积110~120 m 2/g,有机复合硅气凝胶柔韧性较小,最大形变率为10%。
Cesium tungsten bronze （CsxW03） powders were synthesized by hydrothermal reaction at 190 ℃ by using sodium tungstate and cesium carbonate as raw materials, and the effects of N2 annealing on the microstructure and near-infrared （NIR） shielding as well as heat insulation properties of CsxW03 were investigated. The results indicated that the synthesized CsxW03 powders exhibited hexagohal CSo.32WO3 crystal structure, and subsequent N2 annealing could further improve the crystallinity of CsxW03 particles. Moreover, the NIR shielding and heat insulation properties of CsxW03 could be further improved after N2 annealing at appropriate temperature for a period of time. Particularly, the 500 ℃-annealed CsxW03 products in the N2 atmosphere showed the best NIR shielding and heat insulation properties. When the N2 annealing temperature was higher than 700 ℃, the NIR shielding properties decreased again. The 800 ℃-annealed samples in the N2 atmosphere showed higher visible light transmittance, however, the NIR shielding properties were lower than that of the non-annealed samples.
Fei ShiJingxiao LiuXiaoli DongQiang XuJiayu LuoHongchao Ma
