The preparation of polyamide/polyacrylonitrile thin film composite hollow fiber membranes for dehydration of ethanol mixtures

• Published in: Separation and purification technology 2017-10, Vol.187, p.221-232
• Main Authors: Tsai, Hui-An, Wang, Teng-Yi, Huang, Shu-Hsien, Hu, Chien-Chieh, Hung, Wei-Song, Lee, Kueir-Rarn, Lai, Juin-Yih
• Format: Article
• Language: English
• Subjects: Hollow fiber membrane; Interfacial polymerization; Pervaporation; Thin film composite membrane
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2017.06.060

•PA/PAN TFC hollow fiber membranes are fabricated via interfacial polymerization.•Pervaporation dehydration of ethanol by prepared TFC hollow fiber membrane is studied.•The monomer structure can affect the physicochemical properties and separation performance of TFC hollow fiber membrane. In this study, Polyamide (PA)/polyacrylonitrile (PAN) thin-film composite (TFC) hollow fiber membranes were fabricated to investigate the dehydration performances of ethanol mixtures by pervaporation. Amine monomers (ethylenediamine (EDA), 1, 6-hexanediamine (HDA), diethylenetriamine (DETA), and tetraethylenepentamine (TEPA)) with difference number of functional groups or chain length were selected to react with trimesoyl chloride (TMC) to prepare a PA dense thin-film onto the surface of asymmetric PAN hollow fiber membranes by way of interfacial polymerization. Attenuated total reflection infrared spectroscopy (FTIR-ATR), scanning electron microscope (SEM), atomic force microscope (AFM), light transmission, contact angle and positron annihilation spectroscopy (PAS) were used to characterize the physicochemical properties, morphologies and microstructure of the PA thin layer. The pervaporation performances of aqueous ethanol solution showed the permeation flux decreased while water content in permeate increased with increasing number of amine groups. The effects of monomer concentration and reaction time on the pervaporation performances of aqueous ethanol solution through TEPA-TMC/PAN TFC hollow fiber membranes were also investigated. A 342.0±22.3g/m2h permeation flux and 97.6±0.3wt.% water content in permeate were obtained for the pervaporation of 90wt.% aqueous ethanol solution at 25°C through the PA/PAN TFC hollow fiber membrane which was fabricated by immersing PAN hollow fiber membrane into 2wt.% TEPA aqueous solution for 1min and then contacting 1wt.% TMC solution for 0.5min.