Study the solvent’s effects on the PVDF-HFP electrospun nanofiber membranes morphology and performance in membrane distillation
Paper ID : 1367-MST2015-FULL
1alimohammad hemmat, 2Javad Karimi-Sabet *, 1Seyyed Mohammad Ghoreishi
1Isfahan University of Technology
2NFCRS, Nuclear Science and Technology Research Institute, Tehran, Iran
Polyvinylidenefluoride-co-hexafluoropropylene (PVDF-HFP) membranes were prepared via the electrospinning method. All the spinning parameters were maintained constant except the solvent used to prepare the polymer dope solution. Different solvents namely, single N,N-dimethyl acetamide (DMAC) and mixed solvents, DMAC and acetone with different weight ratio (80:20, 60:40, 50:50, 40:60, 20:80) were employed. The morphological properties, hydrophobicity, porosity and permeation performance of the electrospun membranes were investigated. Scanning electron microscopy (SEM), geniometer, gravimetric method and air gap membrane distillation (AGMD) setup were used to characterize the synthesized PVDF-HFP membranes. It was observed that the beaded fiber structure was obtained when the dope solution was prepared using DMAC as the solvent. Also the membrane made from the dope with single DMAC as the solvent possessed the highest hydrophobicity of 138o. Addition of acetone in the solvent combination improved the electrospinability of polymer dope solution and changes the morphology of fibers from beaded fiber to a uniform fiber structure. Furthermore, existence of acetone in the solvents mixture resulted in increase of the porosity of the electrospun membranes and the AGMD permeate flux enhancement as consequence.
Membrane distillation, Electrospun nanofiber membrane, Solvent effect, Polyvinylidenefluoride-co-hexafluoropropylene(PVDF-HFP)
Status : Paper Accepted (Poster Presentation)