EFFECT OF DRYING METHOD ON MESOPOROSITY OF RESORCINOL–FORMALDEHYDE DRYGEL AND CARBON GEL
EFFECT OF DRYING METHOD ON MESOPOROSITY OF RESORCINOL–FORMALDEHYDE DRYGEL AND CARBON GEL
复制标题
干燥方法对间苯二酚-甲醛干凝胶和碳凝胶介孔性能的影响
DOI：
10.1081/drt-100105291
复制
发表时间：
2001
影响因子：
3.3
通讯作者：
H. Tamon
中科院分区：
文献类型：
--
作者：
Takuji Yamamoto;T. Nishimura;Tetsuo Suzuki;H. Tamon
以间苯二酚和甲醛为原料，在弱碱性水溶液中进行溶胶-凝胶缩聚反应，合成了间苯二酚-甲醛水凝胶。以RF水凝胶为原料，分别采用冷冻干燥、热风干燥和微波干燥法制备了RF冻凝胶、RF干凝胶和RF干凝胶（MW凝胶）。随后通过在惰性气氛中热解RF干凝胶获得碳冻凝胶、碳干凝胶和碳MW凝胶。冷冻干燥和微波干燥是制备介孔RF干凝胶和炭凝胶的有效方法。RF cryogels和碳cryogels在溶胶-凝胶缩聚中使用的间苯二酚与催化剂的摩尔比（R/C）和间苯二酚与水的摩尔比（R/W）的宽范围内显示出高的介孔性。虽然RF干凝胶有一些介孔，碳干凝胶没有介孔。如果选择合适的R/C和R/W值，RF MW凝胶和碳MW凝胶显示出中孔性。
Resorcinol–formaldehyde hydrogels were synthesized by sol–gel polycondensation of resorcinol with formaldehyde in a slightly basic aqueous solution. RF cryogels, RF xerogels, and RF xerogels (MW gels) were respectively prepared from RF hydrogels by freeze drying, hot air drying, and microwave drying. Carbon cryogels, carbon xerogels and carbon MW gels were subsequently obtained by pyrolyzing RF drygels in an inert atmosphere. Freeze drying and microwave drying were effective to prepare mesoporous RF drygels and carbon gels. RF cryogels and carbon cryogels showed high mesoporosity over wide ranges of the molar ratio of resorcinol to catalyst (R/C) and the ratio of resorcinol to water (R/W) used in sol–gel polycondensation. Although RF xerogels had a few mesopores, carbon xerogels had no mesopores. RF MW gels and carbon MW gels showed mesoporosity if appropriate values of R/C and R/W were selected.