Polyacrylonitrile supported thin film composite hollow fiber membranes for forward osmosis

• Shell-side TFC hollow fiber for FO was fabricated.
• Polyacrylonitrile was used as the support polymer material.
• Different pore structures of fibers were considered by altering the fabrication technique.
• Our best membrane exhibited a structural parameter of ~ 300 μm.

Thin film composite (TFC) hollow fiber membranes have shown great promise as a platform for osmotic processes such as forward osmosis (FO) and pressure retarded osmosis (PRO). Previous work on asymmetric FO membranes demonstrated that employing a hydrophilic supporting structure is essential to promote wetting and mitigate concentration polarization. In this study, we have developed an intrinsically hydrophilic polyacrylonitrile (PAN) hollow fiber supported TFC membrane. A selective polyamide thin film was synthesized on the membrane shell side via interfacial polymerization. The impact of fiber pore structure was investigated during our study with some of our membranes exhibiting water flux of 36.6 L m− 2 h− 1 using 1 M sodium chloride draw solution against deionized water in PRO mode. These results suggest the potential of utilizing intrinsically hydrophilic polymeric hollow fibers with finely tuned pore structures as support for TFC membranes for osmotic processes.

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