A study on high-performance composite membranes comprising heterogeneous polyamide layers on an electrospun substrate for ethanol dehydration

• Published in: Journal of membrane science 2014-11, Vol.470, p.513-523
• Main Authors: Hung, Wei-Song, Lai, Cheng-Lee, An, Quanfu, De Guzman, Manuel, Shen, Tai-Jung, Huang, Yun-Hsuan, Chang, Kuei-Chien, Tsou, Chi-Hui, Hu, Chien-Chieh, Lee, Kueir-Rarn
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemistry; Colloidal state and disperse state; Dynamic interfacial polymerization; Electrospinning; Exact sciences and technology; Exchange resins and membranes; Forms of application and semi-finished materials; Free volume; General and physical chemistry; Heterogeneous polyamide; Membranes; Polymer industry, paints, wood; Positron annihilation lifetime spectroscopy; Surface physical chemistry; Technology of polymers
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2014.07.066

We fabricated a novel high-performance pervaporation membrane for ethanol dehydration through interfacial polymerization integrated with spin-coating, a method we called dynamic interfacial polymerization. Varying amine and acyl chloride monomers were used to assemble heterogeneous polyamide layers on an electrospun polyacrylonitrile substrate. The performance of the composite membrane comprising a highly crosslinked top layer surpassed that of the commercial PERVAP 2210 membrane: the permeation flux (13.9kg/m2h) was eight times higher and the separation factor (4491) 19 times. It also exhibited stability during the pervaporation operation for 20 days. Positron annihilation lifetime spectroscopy indicated the effect of the layers׳ free volume on the membrane performance. Doppler broadening energy spectroscopy gave information on interfacial defects. We also investigated the performance of composite membranes with homogeneous layers; despite assembling five homogeneous layers, the permeate concentration reached only up to 93.7wt% water. A study on high-performance composite membranes comprising heterogeneous polyamide layers on an electrospun substrate for ethanol dehydration. [Display omitted] •High-performance heterogeneous PA /ePAN membrane for pervaporation.•We successfully integrated the technique of spin-coating into the process of IP.•PALS indicated the effect of the layers׳ free volume on the membrane performance.