Carbon tunnels formed in carbon/carbon composite cryogels
Carbon tunnels formed in carbon/carbon composite cryogels
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DOI：
10.1016/j.micromeso.2011.12.008
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发表时间：
2012-05-01
影响因子：
5.2
通讯作者：
Tamon, Hajime
中科院分区：
文献类型：
--
作者：
Kraiwattanawong, Kriangsak;Sano, Noriaki;Tamon, Hajime
以棉纤维为主要原料，采用间苯二酚-甲醛（RF）溶胶填充，经叔丁醇溶剂交换、冷冻干燥和惰性气氛热解等工艺制备了炭/炭（C/C）复合晶胶。用扫描电镜（SEM）观察了C/C复合晶胶的介孔结构，用氮气吸附法和压汞法对晶胶的孔结构进行了表征。SEM照片证实了C/C复合冻凝胶是一种非均质碳材料，具有普通的碳冻凝胶和碳隧道结构。这里，隧道由（i）碳纤维、（ii）碳纤维和纳米多孔碳球之间的空间、（iii）具有周围纳米笼的纳米多孔碳球和（iv）致密环结构组成。提出了碳隧道的形成模型。棉纤维的添加量和合成条件可以改变冻凝胶的多孔性。结果表明，RF溶胶的合成条件决定了C/C复合冻凝胶的多孔性。皇冠版权所有（C）2011由爱思唯尔公司出版。All rights reserved.
A carbon/carbon (C/C) composite cryogel was prepared by putting almost the maximum content of cotton fibers in vials and then filling them with resorcinol-formaldehyde (RF) sols, followed by solvent exchange with t-butanol, freeze drying and pyrolysis under inert atmosphere. The mesopore structure of C/C composite cryogels was observed by a scanning electron microscope (SEM) and their porous structures were characterized by nitrogen adsorption and mercury porosimetry. The SEM images confirm that the C/C composite cryogels, being heterogeneous carbon materials, possess ordinary carbon cryogels and carbon tunnels. Here, the tunnels are comprised of (i) carbon fibers, (ii) spaces between carbon fibers and nanoporous carbon spheres, (iii) nanoporous carbon spheres with surrounding nanocages, and (iv) dense ring structures. The formation model of carbon tunnels is also proposed. The porous properties of cryogels could be changed by the cotton fiber addition and the synthesis conditions. The results support that the synthesis condition of RF sol determines the porous properties of C/C composite cryogels. Crown Copyright (C) 2011 Published by Elsevier Inc. All rights reserved.