超低密度碳气凝胶的制备与研究

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(10 mg/cm³)，将此气凝胶高温碳化，得到了密度只有20 mg/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10～15 nm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1 783.7 m²/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）。

Preparation and Study of Ultra-low Density Carbon Aerogel

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 nanosphere 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.