Eco-friendly forward osmosis membrane manufacturing using dihydrolevoglucosenone

Abstract

Semipermeable membranes are generally synthesized using solvents which harm the environment and human health. Common organic solvents like n-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMA), and dimethyl sulfoxide (DMSO) have been proven to cause damages to the environment and the human body. Therefore, finding environmentally friendly or green solvents to create what so called a green membrane has been a great interest. The green solvent should have little to no potential hazard and derived from renewable sources to make the membranes sustainable. Dihydrolevoglucosenone (Cyrene™) is an alternative green solvent derived from cellulose and eco-friendly as it does not release harmful emissions to the environment. In this study, CTA and CA as polymer were fabricated by using Cyrene™ as solvent to create green membranes via phase inversion methods. Six different polymer concentration variations were used along with Cyrene™, to produces forward osmosis (FO) membranes. The membranes were produced as an asymmetric structure with a dense skin layer and subporous middle layer with various pore sizes and thicknesses. Hydrophilic properties can be found in almost every Cyrene™-fabricated membrane. The membranes were then tested by using 1 M NaCl solution as the draw solution (DS) and deionized water as the feed solution (FS). The reasonably good flux, ranging from 1464.21 LMH to 1627.12 LMH were achieved. However, the membrane reverse solute flux (RSF) surpassed the usual range of RSF, ranging from 164.79 gMH to 870.44 gMH.