Study on the pervaporation performance and long-term stability of aqueous iso-propanol solution through chitosan/polyacrylonitrile hollow fiber membrane

In this study, chitosan/polyacrylonitrile (PAN) composite hollow fiber membrane was fabricated to investigate the pervaporation performance of aqueous alcohol solution. The chitosan layer of composite hollow fiber membrane was formed by dip-coating chitosan solution onto the outer surface of NaOH-hydrolyzed PAN hollow fiber membrane. γ-Glycidoxypropyltrimethoxysilane (GPTMS) was used as the cross-linking agent of chitosan. The structure and morphology of hydrolyzed PAN hollow fiber membrane were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electronic microscopy (SEM) and atomic force microscopy (AFM). The pervaporation performances of aqueous alcohol solution through hydrolyzed PAN hollow fiber membrane and chitosan/PAN composite hollow fiber membrane were investigated. A pervaporation performance of 145 g/m2 h permeation rate and 99.7 wt.% water content in permeate can be obtained for 90 wt.% aqueous iso-propanol (IPA) solution at 25 °C through chitosan (1.5 wt.%)-GPTMS (2 wt.%)/PAN composite hollow fiber membrane. Furthermore, the long-term pervaporation stability for chitosan/PAN composite hollow fiber membrane was also investigated. The pervaporation efficiency of 70 wt.% aqueous IPA solution at 25 °C can be maintained after 330 days of operation for chitosan-GPTMS/PAN composite hollow fiber membrane while the GPTMS-free chitosan/PAN composite hollow fiber membrane was lost its pervaporation efficiency only after 8 days of operation.