以中空多孔聚丙烯腈(PAN)预氧化纤维为原料,固定炭化温度为800℃,时间为60min时改变炭化升温速率制备了中空多孔炭纤维,借助于压汞法和SEM对其多孔结构进行表征,并对其影响规律进行了分析。结果表明,不同炭化升温速率下所得中空多孔炭纤维的孔径存在3个分布区域,分别为6~17nm、90-430nm和90um处附近,孔径分布的高峰在90-430nm处。在此条件下,以5℃/min升温速率烧成纤维的孔隙率和比表面积分别为63.17%和88.672m^2/g。SEM分析显示,随着炭化升温速率的升高,纤维的截面变形程度加剧,孔径增大。
A series of polyacrylonitrile-based hollow-porous carbon fibers were prepared by carbonizing PAN hollow-porous cured fibers at 800 ℃ and different heating rate in nitrogen. The effects of carbonization heating rate on the pore structure and microstructure were investigated by mercury intrusion method coupling with SEM analysis. The results show that the pore size distributes in the range of 6-17 nm, 90-430 nm and 90 μm. The peak of pore size distribution exists in the 90-430 nm. The porosity and specific pore furface area of fiber carbonized at a heating rate of 5 ℃/min are 63.17% and 88.672 m^2/g, respectively. The SEM analysis results also show that the pore of hollow-porous carbon fiber regularly varies as the carbonization heating rate increases.