Use of γ-valerolactone and glycerol derivatives as bio-based renewable solvents for membrane preparation

Abstract

Current solvents used in membrane preparation are often toxic, environmentally unfriendly and prepared from non-sustainable resources. It would be beneficial to replace common solvents, like N,N-dimethylacetamide (DMA), N,N-dimethylformamide (DMF) and tetrahydrofuran, by “green” solvents. Among these, bio-based solvents were selected for this research, more specifically γ-valerolactone (GVL) and a set of glycerol derivatives. They were screened for their potential use as solvent for membrane preparation by determining solubility of a variety of common membrane polymers and by verifying their applicability in the process of phase inversion to create useful membranes with appropriate pore structures and separation properties. Polymer solubility was rationalized by Hansen solubility parameters. Membrane morphology was characterized by using scanning electron microscopy, while membrane performance was investigated using rose bengal (1017 Da) in water as feed to screen the potential to tune these polymer/solvent systems even toward the nanofiltration range.