Morphology and methanol permeability of sulfosuccinic acid cross-linked polyvinyl alcohol and polyvinyl alcohol/Nafion nanofibrous membranes

Abstract

Cross-linking of polyvinyl alcohol (PVA) and polyvinyl alcohol/Nafion (PVA/Nafion) electrospun nanofibers with sulfosuccinic acid (SSA) was investigated to assess their characterization and the effects of cross-linking on the methanol permeability performance of the nanofibrous membranes. SSA was directly incorporated into the electrospinning polymer solution. The morphology, chemical functional groups, thermal stability, water stability and water swelling of the resulting nanofibers were examined. The effects of SSA concentration on ion exchange capacity (IEC) and methanol permeability of the nanofibrous membranes were discussed. Bead-free and smooth nanofibers were produced for all SSA concentrations with a mean nanofiber diameter of 240-270 nm. It was shown that 15% SSA concentration was suitable for preserving the morphology of PVA nanofibers against water, while the morphology of PVA/Nafion nanofibers was preserved even without cross-linking. The increase in SSA concentration led to increase in swelling in water. SSA cross-linking was also shown to increase the thermal stability of the produced nanofibers. IEC increased by the increase in SSA concentration, while increase in SSA concentration led to a decrease in methanol permeability.