Effect of Equilibration Time on Hysteresis of Water Adsorption Isotherm of Microporous Carbon Fiber

摘要

Effect of equilibration time on hysteresis of water adsorption isotherm was studied at 303-323 K using pitch-based activated carbon fiber (ACFs) having less amount of surface functional groups. Adsorption below P/P_0 = 0.2 was negligible for all ACFs, showing their hydrophobic nature. The smaller the pore width, the less predominant the adsorption hysteresis loop. The adsorption isotherm of ACF of w = 0.6 nm has almost no hysteresis loop. The adsorption branch of adsorption isotherm of ACF of w =1.1nm shifts to a lower relative pressure with the increase of equilibration time from 5 min to 16 h.