含中孔和微孔的多孔炭的孔结构表征

Characterization of pore structure of carbons containing micro-and meso-pores

采用低温氮气吸附法表征了由硬模板法制备的含微孔和无序中孔、由软模板法制备的含微孔和贯通中孔的偏氯乙烯聚合物(PVDC)基多孔炭的孔隙结构,计算了比表面积、孔径分布、孔体积和平均孔径等孔隙结构参数。结果表明:氮气吸附法分析结果与电子显微镜结果一致,碳化物含一定量的微孔和中孔,含中孔和微孔多孔炭的比表面积小于PVDC直接碳化得到的微孔炭,但孔容远大于PVDC基微孔炭;使用NLDFT模型计算得到硬模板制备的多孔炭比表面积为1 669m2/g,孔容为2.07cm3/g,中孔孔径约18nm,与电镜观察结果相同。由软模板法制备的多孔炭比表面积为1 267m2/g,中孔孔径25nm,小于观察到的实际孔径,这可能由于吸附点在大孔部分较少而影响了拟合精度所致。

The carbons containing micro-and meso-pores have good application in supercapacitors,and the pore structures have significant influences on their application performance.Thus,the effective characterization of the pore structure of micro-and meso-porous carbons is important for their application.Two kind of vinylidene chloride polymer based micro-and meso-porous carbons prepared by hard and soft template methods,and the exhibited disordered meso-pores and micro-pores and the interconnected meso-pores and micro-pores are characterized by N2absorption/desorption methods.The specific surface area,pore volume,distribution of pore dimension and average pore dimension are calculated from N2adsorption/desorption isotherms.The structure of porous carbons is mainly composed of micro-and meso-pores with tiny amorphous carbons,which is also approved by the scanning electron microscopy.The carbon developed more meso-pores with higher specific surface area and pore volume than PVDC carbon by using templating methods.The meso-pore size of porous carbon prepared by the hard template method is calculated to be 18 nm by using the NLDFT method,which is close to the result of FESEM.The meso-pore size of porous carbon prepared by the soft template method is calculated to be 25 nm by using the NLDFT method,which is lower than the pore size obtained from FESEM.