Feasibility of Polysulfone as Base Polymer in a Polymer Inclusion Membrane: Synthesis and Characterisation

Polysulfone was investigated as an alternative base-polymer for polymer inclusion membranes (PIM’s) that could withstand harsh environmental conditions and have good transport efficiency of metal ions. PIM’s were prepared using polysulfone as a base polymer and Aliquat 336 as a carrier in the absence of a plasticizer. Chromium (VI) was used as standard to study the extraction efficiency of the membranes. The optimal composition ratio for the membrane with the highest extraction efficiency during passive sampling of the chromium (VI) from solution was 40:60 (w/w) polysulfone: Aliquat 336. This membrane had a flux of 8.68×10-7 mol.m-2.s-1 and had increased chemical stability over a range of pH 2 – 12 compared to poly(vinyl chloride) based membranes. The presence of functional groups on the polysulfone, Aliquat 336 and the synthesized polymer inclusion membrane were confirmed using Fourier Transformed Infrared Spectroscopy. The results showed that only physical interaction exists between the carrier and the polymer matrix. Scanning electron microscopy and atomic force microscopy indicated that the membrane surface was dense and the roughness increased with an increase in carrier concentration. The hydrophilicity of the membranes was studied using a drop shape analyser. The results revealed that an increase in carrier concentration increases the membrane’s hydrophilicity. Thermal stability was investigated and the membranes were found to be stable up to 180 ⁰C.