材料期刊网

采用模板法可制备孔径分布窄、中孔率和比表面积高的中孔碳。本文采用纳米氧化硅静电吸附十六烷基三甲基溴化铵（CTAB）及乳液聚合制备不同纳米氧化硅含量的聚丙烯腈/纳米氧化硅复合粒子,进一步通过高温碳化和氢氟酸刻蚀得到高纯度的中孔碳。发现当纳米氧化硅添加量不超过单体质量的50%时,纳米氧化硅主要以被聚合物包覆的形式存在,所制备的中孔碳的比表面积均大于800m2/g,孔径在5～10nm之间;随着纳米氧化硅/单体质量比从30%增加到60%,所制得的中孔碳的总孔容从1.111cm3/g增加至1.949cm3/g,中孔率从66.0%增至82.4%。结合中孔碳的形貌分析,认为纳米氧化硅的模板作用是形成中孔的主要因素。

Mesoporous carbon materials with a narrow pore size distribution and high degree of mesoporosity and high surface areas can be prepared via inorganic template method. Electrostatic absorption of cetyltrimethylammonium bromide （CTAB） onto nanometer silica （nano-silica） particles and emulsion polymerization of acrylonitrile （AN） in the presence of modified nano-silica particles were carried out to prepare polyacrylonitrile（PAN）/nano-silica composite particles with different silica contents. Mesoporous carbon materials with high purity were prepared through the carbonization of PAN/nano-silica composites and removing of silica by etching with HF aqueous solution. It shows that nano-silica particles are encapsulated in the inner of composite particles, when the mass ratio of silica to monomers is below 50%. Surface areas of mesoporous carbon materials prepared from PAN/nano-silica composite particles with different compositions are greater than 800m2/g. Total pore capacity of the resulted carbons is increased from 1. 111cm3/g to 1. 949cm3/g, and the degree of mesoporosity is increased from 66.0% to 82.4% as the mass ratio of silica to monomers increased from 313 % to 60%. Combined with the morphology analysis of mesoporous carbons, nano- silica particles are proved to be acted as templates in the formation of mesopores.