Stabilization of supported liquid membranes by plasma polymerization surface coating

Plasma polymerization coating is shown to be an effective method for improv ing the stability of supported liquid membranes (SLM) containing LIX 984N f or copper transport. Hexamethyldisiloxane and heptylamine were employed as monomers and hydrophobic microporous microfiltration membranes with pore si zes of 0.05-0.2 mu m were used as substrates. Electronmicroscopy revealed t hat the plasma polymerization film mainly occurred on the surface of the mi croporous membranes. Preliminary results show that either coating can impro ve the stability of the polypropylene Accurel SLMs with a thickness of 150 mu m. For a thin membrane such as the polypropylene Celgard 2500 with a thi ckness of 25 mu m, the heptylamine coating on the stripping side provides b etter stability than on the feed side. (C) 2000 Elsevier Science B.V. All r ights reserved.