摘要
Chemically crosslinked poly (vinyl alcohol) (CPVA) membranes are attractive for pervaporation desalination. This work aims on enhance the water permeation fluxes of CPVA membranes with 4-sulfocalix [4]arene (SCA4) as a modifying agent. Both sulfonic acid groups and cavity structure of SCA4 promote water molecule diffusion rates in the membrane. The surface hydrophilicity of the membrane is also enhanced with the sulfonic acid groups of SCA4, consequently to result in an increase in the water dissolution rate into the membrane. Based on the solution-diffusion model, the SCA4 modification significantly brings a 2.4-times of water permeation flux to the CPVA membrane. The CPVA membrane modified with 3 wt% SCA4 (membrane thickness: 50 mu m) shows a water permeation flux and a salt rejection of 22.3 kgm- 2h- 1 and 99.9 %, respectively, in a permeation desalination test on a 3.5 wt% NaCl(aq) feeding solution at 80 degrees C. A simple and effective modification of CPVA membrane for pervaporation desalination is demonstrated, and could be potentially applied to other polymerbased membranes.