摘要
首次以 K2 CO3 、Ca( OH) 2 为催化剂制备 RF炭气凝胶 ,相同条件下溶胶转变为凝胶的时间 ( tg )最低达到 40 m in,且密度优于 Na2 CO3 催化得到的 RF气凝胶 ,最低为 0 .0 47g/cm3 .TEM表征结果显示 :Ca( OH) 2 催化得到的气凝胶具有纳米级网络结构 ,构成网络的球状颗粒均匀 ,平均直径 5～ 10 nm 。
The polycondensation of resorcinol with formaldehyde under Na 2CO 3 conditions results in the formation of RF aerogels by sol gel process, supercritical drying. The gelation time ( t g ) is always longer than 9 hours. In this paper, Ca(OH) 2 and K 2CO 3 are firstly taken as catalysts to prepare RF carbon aerogels. TEM is used to study the structure of RF aerogels. The results show: the minimum of t g is 40 min, and the density of RF aerogels decreases to 0.047 g/cm 3 under the same conditions. Carbon aerogels prepared under Ca(OH) 2 have a cross linked network in nanometer scale while the colloid particles are well distributed and the size of particles is about 5~10 nm.
出处
《大连理工大学学报》
CAS
CSCD
北大核心
2000年第4期417-419,共3页
Journal of Dalian University of Technology
基金
国家自然科学基金资助项目 !( 596 72 0 2 6 )
关键词
超临界干燥
气凝胶
间苯二酚
甲醛
催化剂
种类
sol gel process
supercritical drying
potassium carbonate
calcium hydroxide/RF aerogels
