Improvement of mesoporosity of carbon cryogels by acid treatment of hydrogels
Improvement of mesoporosity of carbon cryogels by acid treatment of hydrogels
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DOI：
10.1016/j.micromeso.2008.02.016
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发表时间：
2008-11-01
影响因子：
5.2
通讯作者：
Lothongkum, Anchaleeporn W.
中科院分区：
文献类型：
--
作者：
Kraiwattanawong, Kriangsak;Mukai, Shin R.;Lothongkum, Anchaleeporn W.
以金合木单宁与糠醛为原料，氢氧化钠为催化剂，在363 K下固化，采用溶胶-凝胶缩聚法制备了金合木单宁-糠醛凝胶。固化后的TFu水凝胶在不同老化温度、HCl浓度和ph的盐酸溶液中进行处理，老化后的TFu冷冻物在惰性气氛下进行冷冻干燥和热解，得到TFu碳冷冻物。用N-2吸附和扫描电镜对TFu和碳冷冻液进行了表征。高HCl浓度使介孔体积增加近2倍，特别是在高温下，高浓度HCl或高温下介孔尺寸分布明显变细、变窄。此外，该方法是开发低孔和高孔TFu水凝胶介孔结构的通用方法，并且处理后没有严重的失重问题。(c) 2008爱思唯尔公司版权所有。
Wattle tannin-furfural (TFu) gels are synthesized by the sol-gel polycondensation of wattle tannin with furfural by using sodium hydroxide as a catalyst and cured at 363 K. After cured, the TFu hydrogels are treated in hydrochloric acid (HCl) solutions with various variables as follows: aging temperature, HCl concentration and pH. TFu cryogels aged are then freeze-dried and pyrolyzed under an inert atmosphere to obtain TFu carbon cryogels. The TFu and carbon cryogels were characterized by N-2 adsorption and scanning electron microscope. The high HCl concentration yields the increase of mesopore volume almost twice especially at high temperature and the mesopore size distribution can be greatly developed sharper and narrower when the high concentration of HCl or/and the high temperature are used. Moreover, this method is the versatile approach for developing the mesopore structure of the low and high porous TFu hydrogels and has no serious problem of weight loss after treatment. (c) 2008 Elsevier Inc. All rights reserved.