(373c) Effect of Ionic Liquid Cations and Anions on the Cellulose Acetate Membrane Characteristics and Performance for Water Treatment

The use of ionic liquids (ILs) as green solvents has gained a lot of interest in recent years due to their tunability and environmentally friendly compatibility as solvents. ILs have great potential as a new generation of solvents to replace the conventional organic solvents for the fabrication of membranes. In this work, the effect of three ILs, including 1-butyl-3-methylimidazolium chloride [C₄mim][Cl], 1-Butyl-3-methylimidazolium acetate [C₄mim][OA], and 1-dodecyl-3-methylimidazolium chloride [C₁₂mim][Cl] on cellulose acetate ultrafiltration membranes characteristics (pore size, pore morphology, physical integrity, hydrophilicity, etc.) and consequently on membrane performance (permeability, rejection and antifouling) were studied. A concentration of 10 wt.% of cellulose acetate was dissolved in 90 wt.% of each of these ILs at 110 rpm at 90°C for 72 hours and then degassed for 8 hours. The phase inversion method was employed for the synthesis of membranes using DI water as the nonsolvent. The scanning electron microscopy (SEM), Fourier transform infrared (FTIR), zeta potential and water contact angle of all three membranes were measured and compared to identify the effect of IL structure on membrane characteristics. Dead-end filtration was used to determine the permeability, dye rejection (methylene blue and methylene orange) and flux recovery ratio (FRR%) of all membranes.