Fabrication of polyvinylidenefluoride-co-hexafluoropropylene (PVDF-HFP) electrospun membranes for air gap membrane distillation

The main hindrance for membrane distillation (MD) is the availability of optimized design of MD membrane that can produce high surface hydrophobicity, high porosity, appropriate pore sizes and a higher flux. In the past few years, application of electrospun nanofiber has gained intensive attention for MD membrane and exhibit promising results. The aim of this study was to fabricate and optimize Polyvinylidenefluoride-co-hexafluoropropylene (PVDF-HFP) membranes. Response surface methodology (RSM) based on Box-Benkhen design was utilized to design the experiments. The objective was to prepare optimized electrospun nanofiber membrane with mean pore size in the range of 300-500nm, maximum porosity and hydrophobicity. Scanning electron microscopy (SEM), geniometer, gravimetric method and air gap MD (AGMD) setup were used tocharacterize the resultant PVDF-HFP membranes. The optimum electrospinning conditions were obtained to be 23wt%concentration, 13 kV voltages, 24 cm tips to collector distance and 0.4 mL/h flow rate. At the optimal operating condition the fabricated membranes were characterized with mean pore size, porosity and contact angle of 435 nm, 81% and 1410, respectively. The synthesized membrane was applied in desalination via air gap membrane distillation, in which a water flux of 13.6 Lh-1m-2 with a salt rejection ratio of 99.7% was obtained.

کلیدواژه ها:

Membrane distillation ، Electrospun nanofiber membrane ، Response surface methodology ، Box-Benkhen design ، Polyvinylidenefluoride – co -hexafluoropropylene (PVDF-HFP)