Water absorption rate of test membranes is shown in Fig. 3. As shown in the figure, the pure CS membranes showed significant higher water absorption than the untreated CS/SF membranes or ADA fixed CS/SF membranes. With SF content increased from 20 to 40 wt%, water absorption of the blending membranes is decreased. The ADA fixed CS/SF membranes showed the less water absorption rate than other groups. Crosslinking affect the water absorption properties of materials through a variety of complex and often interrelated process [18]. In this study, ADA fixation may change the structure of the membrane and reduce the pore number and pore size so that reduce the water absorption of the membranes.