Influence of solvent species used in solvent exchange for preparation of mesoporous carbon xerogels from resorcinol and formaldehyde via subcritical drying
Influence of solvent species used in solvent exchange for preparation of mesoporous carbon xerogels from resorcinol and formaldehyde via subcritical drying
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DOI：
10.1016/j.micromeso.2010.10.001
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发表时间：
2011-02-01
影响因子：
5.2
通讯作者：
Praserthdam, Piyasan
中科院分区：
文献类型：
--
作者：
Kraiwattanawong, Kriangsak;Tamon, Hajime;Praserthdam, Piyasan
在所选择的合成条件范围内，炭干凝胶的制备方法是先冷冻干燥3 d，再预冷冻6 h，然后亚临界干燥1 d，但炭干凝胶的中孔率没有得到很好的控制。本文研究了溶剂交换过程中溶剂种类对蒸发干燥和真空干燥协同制备炭干凝胶的影响。在较宽的合成条件范围内，良好的溶剂是制备高介孔炭干凝胶的理想溶剂。以间苯二酚和甲醛为原料制备了炭干凝胶，利用氮气吸附仪和场发射扫描电镜对炭干凝胶进行了表征。结果表明，在两种亚临界干燥条件下，通过溶剂交换法可以很容易地制备出介孔炭干凝胶。在溶剂中，叔丁醇在制备高介孔炭干凝胶中效果最好，且适用条件较宽。FE-SEM图像表明，真空干燥的炭干凝胶比蒸发干燥的炭干凝胶含有更大的颗粒互连。(C)2010年爱思唯尔公司All rights reserved.
Carbon cryogels are dried by 3 days of freeze drying with 6 h of pre-freezing whereas the carbon xerogels are prepared by 1 day of subcritical drying in the selective range of synthesis condition, but the mesoporosity of carbon xerogels are not well controlled. This research is to study the influence of solvent species in the solvent exchange for the preparation of carbon xerogels cooperated by the evaporation drying and the vacuum drying. The good solvent for the high mesoporous properties of carbon xerogels is desirable in the wide range of synthesis condition. The carbon xerogels prepared from resorcinol and formaldehyde were characterized by the nitrogen adsorption apparatus and the field emission scanning electron microscope (FE-SEM). The results illustrate that the mesoporous carbon xerogels in the two subcritical dryings can be easily prepared by solvent exchange. Among the solvents, t-butanol allows the great results in the preparation of high mesoporous carbon xerogels and is well applied in the wide range of synthesis conditions. The FE-SEM images elucidate that the carbon xerogels dried by the vacuum drying contain the particles interconnection larger than the evaporation drying. (C) 2010 Elsevier Inc. All rights reserved.