RF有机气凝胶的合成

Preparation of RF Organic Aerogels

有机气凝胶是一种80年代末问世的新型纳米材料。本研究以间苯二酚和甲醛为原料,在碳酸钠催化作用下,经水相溶胶-凝胶聚合、溶剂置换和超临界二氧化碳干燥合成了透明、暗红色、无裂纹的块状RF有机气凝胶,所得气凝胶密度可低至0.032g·cm-3。考察了溶胶-凝胶过程中的催化剂浓度、反应物总浓度及酸交联对气凝胶特性的影响。TEM表征表明,所得气凝胶具有典型的纳米网络结构,固体相由直径约10nm的粒子组成,孔直径小于100nm。

Organic aerogels are novel nano-materials d eveloped at the end of 1980s. The aqueous sol-gel polymerization of r esorcinol with formaldehyde catalyzed by sodium carbonate results in the formation of RF aquagels. The bulk crack-free RF aerogels was obtai ned through the following solvent exchange and supercritical drying of RF aquagels. The resulting aerogels are transparent and dark red in color with the density as low as 0.032g·cm-3. The main factors that affect the properties of aerogels such as the molar ratio of re sorcinol to formaldehyde R/C and total solid content S(wt/v%) w as investigated. The nanometer-networks of RF aerogels were characteriz ed by TEM. The solid phase in the network composes of particles with diameter about 10nm. The pore size is smaller than 100nm.