Abstract
Poly(acrylonitrile)(PAN) solutions in dimethylformamide(DMF) were electrospun to prepare webs consisting of 400nm ultra-fine fibers. The webs were oxidatively stabilized, activated by steam and resulted to be activated carbon fibers(ACFs). The specific surface area was $800\~1230 m^2/g$, which showed a trend of a decrease of the surface area with an increase in activation temperature, showing opposite behavior to the other ACFs. The activation energy of the stabilized fibers for the steam activation was determined as 29.2 kJ/mol to be relatively low indicating the easier activation than that of other carbonized fibers. The ACF webs were characterized by pore size and specific surface uea which would be related to the specific capacitance of the electrical double layer capacitor (EDLC). The specific capacitances measured were 27 F/g, 25 F/g, 22 F/g at the respective activation temperature of $700^{circ}C,\;750^{\circ}C\;800^{\circ}C$, showing similar trend with the specific surface area i.e., the higher activation temperature was, the lower specific capacitance resulted.
PAN(polyacrylonitrile)을 DMF(dimethylformamide) 용매에 용해하여 정전방사법에 의해 평균 직경 400 nm의 나노섬유 웹을 제조하였다. 제조된 나노섬유 웹은 산화 안정화, 활성화 공정을 거쳐 활성화 탄소 나노섬유를 제조하여, 전기화학적 특성과 비축전 용량을 측73하였다. 활성화 탄소 나노섬유의 비표면적은 $1230m^2/g-800m^2/g$으로 일반 활성탄소 섬유의 거동과는 다르게 활성화 온도가 증가할수록 감소하는 경향을 나타냈으며, 활성화 에너지 값은 29.2kJ/mol로 활성화 온도에 크게 영향을 받지 않고, 급격한 반응이 일어남을 알 수 있었다. 비축전 용량은 활성화 온도가 $700^{\circ}C,\;750^{\circ}C,\;800^{\circ}C$의 경우 27 F/g, 25 F/g, 22 F/g으로 활성화 온도가 증가할수록 비표면적에 비례하여 낮아지는 경향을 나타냈다.
