FUNCTIONAL ION MEMBRANES SUPPORTED INSIDE MICROPOROUS POLYPROPYLENE MEMBRANES TO TRANSPORT CHROMIUM IONS: DETERMINATION OF MASS TRANSPORT COEFFICIENT

Abstract

Polypropylene (PP) membranes incorporating interpenetrating polymer networks of poly[(ar-vinylbenzyl) trimethylammonium chloride](P(ClVBTA)) and poly[sodium (styrenesulfonate)] P(SSNa) were modified via an “ in-situ” radical polymerization synthesis inside the pores. The modified polypropylene membranes were characterized using SEM, ATR/FTIR, DRX, TGA, and Donnan dialysis for the transport of chromium ions. The modified membranes exhibited a percent modification between 2.5% and 4.0% in weight gain and a hydrophilic character with a water uptake capacity between 15% and 20%. The mass transport coefficient was determined using the non-linear fit of the experimental data to the exponential equation. Hexavalent chromium ions were efficiently transported by the modified membranes containing P(ClVBTA). At pH 3.0, the M4Cl.PEI (11.0 ×10-6 m s-1), and at pH 9.0, the M3Cl (14.4×10-6 m s-1) could transport hexavalent chromium ions efficiently using a 1 mol L -1 NaCl extraction agent. In the same way, the transport of trivalent chromium could be performed using membranes modified with P(SSNa). At pH 3.0 and 4.0×10 -2 mol L-1 trivalent chromium in the food chamber, the M9Na.PVA (16.3×10-6 m s-1) performed efficient transport using 1×10-3mol L-1 HNO 3 as the extraction agent.