Highly Hydrophobic, Electrospun, Reduced Graphene Oxide (rGO)/PVDF-HFP Membranes for Use in Membrane Distillation

Membrane distillation has observed a growing degree of interest due to its low operating pressure, minimal temperature requirements, and high salt rejection. This work involves the fabrication of microporous nanocomposite membranes with enhanced hydrophobicity for use in a direct-contact membrane distillation (DCMD) process. Reduced graphene oxide/poly(vinylidene fluoride-­co-­hexafluoropropylene) (rGO/PVDF-­HFP) flat sheet membranes were prepared via electrospinning. These fabricated membranes were characterized via SEM, Raman spectroscopy, liquid entry pressure (LEP), and contact angle measurement. Results indicate that a maximum water contact angle of 139° was achieved with increased liquid entry pressures (LEP) up to 103.42 kPa. The anti-­fouling and anti-wetting performance of the fabricated membranes was investigated during the DCMD process, using 60 g/L sodium chloride as a feed solution over a period of 2520 min. The rGO incorporated membranes exhibited excellent stability and durability with a salt rejection of over 99.97% and an average flux of 20.37 kg/ (m²h), indicating the potential application of reduced­-graphene oxide based hydrophobic membranes in desalination, wastewater disposal, and food processing.