Solvent-resistant polyvinyl alcohol nanofilm with nanopores for high-flux degumming

Vegetable oil degumming is the first step of edible oil processing industry. Achieving highly efficient degumming by the polymeric membrane requires specific separation of phospholipid with endurance in organic solvent. Here, we show a method to fabricate solvent resistant polyvinyl alcohol (PVA) membranes from a colloidal aqueous system of nanoparticles made up of maleic acid (MA) molecules and PVA chains. The MA molecules associated physically over the PVA chains by electrostatic interaction in liquid phase, which in turn control cross-linking density of the final solid PVA membrane. The system produces a membrane layer of nanometer-scale thickness having mean pore radius of 1.55 nm with functional hydrophilic groups and exhibited membrane flux of 14 L m−2 h−1 bar−1 with phospholipid rejection selectivity of 92% for potential degumming of crude vegetable oil.