Abstract
The purpose of this study is to develop new composite membrane which has hi선 selectivity and acceptable permeation rates for separating the organic solvent-water mixture systems by pervaporation technique. Therefore, CMC and PVA, which are highly absorbent polymeric materials, were used to prepare the composite membrane. A 2∼3wt% aqueous ChIC solution and a 7∼10wt% aqueous PVA solution were mixed together to from a homogeneous blended solution. The composite membrane was prepared by casting a polymer solution on the nonwoven fabric and then removing the solvent. The thickness of the active layer of CMC/PVA composite membrane was about 20∼30wt The experimental results indicated that the composite membrane obtained from the CUC/PVA was very effective for a selective separation of water from aqueous organic solution by Pervaporation technique. The composite membrane showed very stable permeation and separation characteristics in the experimental temperature range. The activation energies for pervaporation were 27.85(25.95), 34.20(29.68), and 35.59(39.11) kl/mole for the 75, 85, and 90wt% ethanol(acetic acid) concentrations, respectively. The permeation rates of the membrane for the water-organic solvent mixture systems at 60'S were in the range 0.1∼1.4kg/m2/hr and the separation factor was between 12 and 1925. The best pervaporation performance, the highest value of PSI, was 0.36kg/m2/hr for an aqueous 90wt% ethanol at 60℃.