超低密度碳气凝胶的制备与研究

Preparation and Study of Ultra-low Density Carbon Aerogel

采用溶胶-凝胶技术制备了超低密度的间苯二酚-甲醛(RF)有机气凝胶(10mg/cm3),将此气凝胶高温碳化,得到了密度只有20mg/cm3的碳气凝胶,并用扫描电镜、透射电镜、N2吸附法等表征了低密度碳气凝胶的微观结构、孔特征等性质。研究发现,低密度碳气凝胶是由粒径10～15nm的碳纳米粒子以单链珍珠链状连接组成的三维网络结构;而这些纳米颗粒是由更小的石墨微晶构成,微孔主要存在于碳纳米颗粒中,比表面积达1 783.7m2/g。氢吸附测试发现,此低密度碳气凝胶常压下在液氮温度时吸氢量可达4.4%(质量分数)。

The ultra-low density resorcinol （R）-formaldehyde （F） aerogel and carbon aerogel were prepared via a sol-gel route, which density are 10 mg/cm3 and 20 mg/cm3 , respectively. The microstructures and properties of the carbon areogel were investigated by using scanning electron microscope, transmission electron microscope, pore size distribution measurement, and so on. The ultra-low density products are some tortuous chains consisting of carbon nanospheres ranging from 10 to 15 nm. The carbon nano-sphere consists of nanoparticles whose sizes are about several nanometers. The surface area of the low-density carbon aerogel is 1 783.7 m2/g. The hydrogen adsorption capacity of the ultra-low density carbon aerogel is 4.4% （mass fraction） at liquid nitrogen temperature under atmospheric pressure.