Green solvents in polymeric membrane fabrication: A review

Increasing consumption of toxic and non-renewable materials forces researchers to replace them with less dangerous, bio-based, and renewable materials. Green chemistry principles are one of the worldwide strategies for reducing the hazardous materials consumption in chemical applications. Although membrane technology has been considered a convenient method for environmental issues such as wastewater treatment, pharmacy, medicine, food and etc., it was addressed as an important technology that should be revised in its fabrication and applications. Polymeric membrane fabrication is the considered section that should satisfy the principles of green chemistry since a wide range of toxic solvents has been generally used for polymer dissolution. Many investigations have been implemented to replace them with less toxic or bio-based solvents mentioned as green solvents. This review is prepared to cover the recent works implemented for membrane fabrication using green solvents as a major solvent for polymer dissolution. The most eminent classification of green solvents can be assigned as water, bio-sourced solvents, ionic liquids (ILs), deep eutectic solvents (DESs), green synthetic organic solvents, and supercritical fluids (SCF). In addition, in this review, the Hansen solubility parameters (HSP) of some DESs are calculated and their possibility as green solvents for polymeric membrane fabrication is indicated.