Porous conducting membranes based on polypyrrole–PMMA composites

A series of porous membranes consisting of polymethyl methacrylate (PMMA) and polypyrrole (PPy) were prepared using porogen leaching techniques. The liquid porogen used was polypropylene glycol, molecular weight 775 (PPG-775) while sodium chloride powder was used as the solid porogen. The pore structure of the asymmetrical membranes was characterised using scanning electron microscopy (SEM) which demonstrated pore sizes ranging from 2 to 100 μm. The permeability of the membranes was characterised with either lysozyme (molecular weight=14,000) or bovine serum albumin (BSA, molecular weight=67,000). The membranes prepared with sodium chloride demonstrated little resistance to the passage of water or albumin while the membranes prepared with PPG-774 had limited permeability to lysozyme.