SRNF membranes for edible oil purification: Introducing free amines in crosslinked PEEK to increase membrane hydrophilicity

Abstract PEEK membranes with good stability in polar aprotic solvents are developed for the separation of edible oils from acetone. PEEK membranes are hydrophobic in nature, and thus suitable to achieve high fluxes in organic solvents. Chemical crosslinking with amines provides the membranes with robust solvent stability. In this research, three types of modified PEEK were synthesized. All were crosslinked with both the well-known difunctional crosslinker hexanediamine as with the multifunctional polyallylamine. Performance of membranes prepared with both crosslinkers was compared for rose Bengal solutions in isopropanol and acetone, and for sunflower oil dissolved in acetone. Using polyallylamine as a crosslinker introduced free amines into the membrane structure, increasing the hydrophilicity of the membrane which improved the retention of edible oil significantly.