不同焙烧温度对有序介孔炭孔结构参数的影响

Influence of carbonization temperature on pore structures of ordered mesoporous carbon

以三嵌段共聚物F127为模板剂,线性酚醛树脂(PF)为炭前驱体,在F127与PF的质量比mF127∶mPF=1∶1时,利用溶剂挥发诱导自组装制备介孔炭材料,对在不同焙烧温度下制备的介孔材料进行表征,研究焙烧温度对所得介孔材料结构的影响。采用XRD、TEM、N2吸附/脱附等方法对介孔材料的结构进行了表征,研究了焙烧温度对上述介孔炭结构的影响。结果表明:介孔材料的晶面间距随着温度的升高而降低,当焙烧温度为600℃时,介孔材料的骨架从高分子材料转变为炭材料。其比表面积和C/H摩尔比均随着焙烧温度升高而增加,但其孔壁厚度和孔径却随着焙烧温度的升高而降低。孔径大小和孔壁厚度在600℃以后降低的幅度较小,基本上趋于稳定,碳骨架的收缩变得缓慢。随着焙烧温度的升高,其介观结构基本不发生改变。

Ordered mesoporous carbon had been synthesized through solvent evaporation induced organic-organic self-assembly method （EISA）, by using triblock copolymer F127 as template and novalac phenolic resin （mF127∶mPF=1∶1） as carbon precursor. The structure of ordered mesoporous carbon was characterized by X-ray diffraction, transmission electron microscopy and N2 adsorption/desorption measurements. Influence of calcination temperatures on the pore structures of ordered mesoporous carbon was investigated. The results showed that, when the calcination temperatur was 600℃, the skeleton of mesoporous matter was transformed from polymer material to carbon material. As the calcination temperature increased from 400℃to 900℃, the interplanar spacing of ordered mesoporous materials decreased, both the pore wall thickness and pore size reduced, but the surface area and molar ratio of C/H increased. The shrinkage of carbon skeleton became slow above 600℃. The mesostructure retained well with the increase of carbon temperature.