Water Vapor Adsorption on Chemically Treated Activated Carbon Cloths

Water vapor adsorption on activated carbon cloth (ACC20) which has been oxidized to a level of 32% oxygen exhibits a unique isotherm with uniform hysteresis of small magnitude upon desorption. In contrast the adsorption on untreated ACC20 and chemically modified ACC20 (7.8% Cl), ACC20 (16% Cl), and ACC20 (4% N), exhibits sigmoidal isotherms with hysteresis loops of varying magnitudes. The latter ACCs display high capacity for moisture removal at relative humidities >50%. At saturation, all treated cloths exhibit high adsorption capacities for water (0.5-0.67 mL/g of fiber) and 100% desorption upon heating to 100 °C. The untreated and treated ACC20 samples exhibited no degradation upon heating to 100 °C. Total water adsorption volumes are lower than the total nitrogen pore volumes for all samples except for the ACC20 (32% O), which adsorbs similar volumes of both adsorbates.