炭化过程对聚丙烯腈基活性中空炭纤维性能的影响

聚丙烯腈(PAN)中空纤维在空气中250℃预氧化2 h后,在氮气气氛中炭化,得到PAN基中空炭纤维(PAN-CHF),再在二氧化碳气氛中活化,得到PAN基活性中空炭纤维(PAN-ACHF)。考察了炭化温度和炭化时间对PAN-CHF的收缩率、PAN-ACHF的收缩率、活化收率、比表面积和吸附性能的影响。结果表明:炭化温度为1 000℃时,PAN-CHF和PAN-ACHF的收缩率相同;炭化温度为900℃时,PAN-ACHF的比表面积最大,吸附性能最好,炭化时间对PAN-CHF和PAN-ACHF的收缩率影响不大,但活化收率随炭化时间延长呈上升趋势,比表面积先增后降,炭化时间为60 min时达到最大,其吸附量最大。

Influence of carbonization process on polyacrylonitrile-based activated carbon hollow fiber

Polyacrylonitrile (PAN) hollow fiber was preoxidized for 2 h at 250* in air and carbonized in nitrogen atmosphere to produce PAN-based carbon hollow fiber (PAN-CHF) which was activated in carbon dioxide atmosphere to produce PAN-based activated carbon hollow fiber (PAN-ACHF). The effects of carbonization temperature and time on shrinkages of PAN-CHF and PAN-ACHF,activation yield, specific surface area and adsorption capacity were investigated. The results showed that PAN-CHF and PAN-ACHF had the same shrinkage when the carbonization temperature was 1 000℃; and the specific surface area and adsorption capacity of PAN-ACHF were maximized at 900℃. The carbonization time had no evident effect on the shrinkage of PAN-CHF and PAN-ACHF. The activation yield tended to be upward while prolonging the carbonization time. The specific surface area was increased and then decreased with carbonization time. The specific surface area and adsorption capacity were maximized in 60 min.