Studies on cellulose acetate aminated polyethersulfone and carboxylated polyethersulfone blend ultrafiltration membranes

Abstract

Ultrafiltration is a pressure driven membrane separation process that uses molecular size differences to separate macro molecules and colloidal matter from solvents and smaller solutes. Ultrafiltration (UF) techniques have particular advantages for simultaneous purification, concentration and fractionation of macromolecules. Cellulose Acetate (CA) is one of the first polymer membranes that have been used for aqueous based separations. Cellulose acetate and its derivatives are suitable raw materials for membrane preparation, because of the advantages such as moderate flux, high salt rejection properties, cost effectiveness, relatively easy manufacture, renewable source of raw material and non-toxicity. Another important membrane material, Polyethersulfone is an amorphous, brittle, high temperature engineering thermoplastic. It possesses high thermal stability, high heat resistance, and excellent high and low pH tolerance. In the present investigation, flat sheet ultrafiltration blend membranes based on cellulose acetate/aminated polyethersulfone(APES), cellulose acetate/carboxylated polyethersulfone (CPES) with a thickness of 0.20 ± 0.02mm were prepared by solution blending and phase inversion technique. Water content of the CA/APES, CA/CPES blend membranes is an indirect indication of the hydrophilicity and flux behavior of membranes. The protein separation such as trypsin, pepsin, egg albumin and bovine serum albumin (BSA) in terms of permeate flux and percent rejection have been investigated at dilute concentrations, BSA was found to have the highest separation with lowest product rate of all membranes respectively. Heavy metal ions such as Cu2+, Ni2+, Zn2+ and Cd2+ were complexed with polyethyleneimine. The percent rejection of metal ions complex shows an higher separation but lower flux for Cu ion complex for both the systems owing to its higher size. This has paved solution to the emerging problem of pollution abatement by recycling of chemicals. newline newline newline