Electrically conductive aerogels composed of cellulose and carbon nanotubes
Electrically conductive aerogels composed of cellulose and carbon nanotubes
复制标题
DOI：
10.1039/c3ta11734k
复制
发表时间：
2013-01-01
影响因子：
11.9
通讯作者：
Liu, Jianwen
中科院分区：
文献类型：
--
作者：
Qi, Haisong;Maeder, Edith;Liu, Jianwen
采用湿凝胶前体，采用速冻/冻干工艺制备了由碳纳米管和纤维素组成的气凝胶。湿凝胶前体是由碳纳米管和纤维素均匀分散在碱-尿素水溶液中再生而成。通过透射电子显微镜、扫描电子显微镜、x射线衍射、拉曼光谱和氮吸附-脱附实验研究了复合气凝胶的形貌和结构特性。所有制备的材料都具有纳米结构的固体网络(比表面积在140 ~ 160 m（2) g（-1）之间）和纳米孔网络（包括大孔、中孔和微孔）。热重分析和拉伸试验结果表明，复合气凝胶具有良好的热稳定性和优异的力学性能。复合气凝胶的杨氏模量可调至90 MPa左右。含有3-10 wt% CNTs的复合气凝胶的电导率约为2.3 × 10（-4）至2.2 × 10(-2) S cm(-1)， MWCNT体积分数下的电导率阈值低至3 × 10（-3）。此外，这些纤维素-碳纳米管复合气凝胶对环境压力表现出良好的敏感性。
Aerogels composed of carbon nanotubes (CNTs) and cellulose were fabricated by the flash freezing/lyophilization process using wet-gel precursors, which were regenerated from a homogeneous dispersion of CNTs and cellulose in alkaline-urea aqueous solution. The morphology and textural properties of the resultant composite aerogels were investigated by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and nitrogen adsorption-desorption tests. All the prepared materials exhibited both a nanostructured solid network (specific surface areas between 140 and 160 m(2) g(-1)) and a nanoporous network (including macropores, mesopores and micropores). The results from thermogravimetric analysis and tensile tests revealed that the composite aerogels have good thermal stability and excellent mechanical properties, respectively. The Young's modulus of the composite aerogels could be tuned to reach about 90 MPa. And composite aerogels with 3-10 wt% CNTs have a conductivity of about 2.3 x 10(-4) to 2.2 x 10(-2) S cm(-1), with the conductivity threshold at MWCNT volume fractions being as low as 3 x 10(-3). Furthermore, these cellulose-CNT composite aerogels showed good sensitivity to ambient pressure.