EFFECT OF MEMBRANE PREPARATION ON THE LIFETIME OF SUPPORTED LIQUID MEMBRANES

A new observation on the stability of supported liquid membranes (SLMs ) is reported, Membranes prepared with 'dry' outer surfaces, free from organic wetting, were found to be more stable than the conventional S LM prepared with external surfaces wetted with a film of the organic m embrane liquid phase. For copper transport the 'dry' surface SLM had a similar initial flux to the 'wet' surface SLM, and 2 to 4 times the f lux after 100 h. Over a 50 h period the 'dry' SLM lost about 10% of it s membrane liquid, whereas the 'wet' SLM lost about 50%. The differenc e is ascribed to the loss of membrane by emulsion formation at one of the aqueous-organic interfaces which would be greater for the 'wet' SL M with a continuous liquid film over the surface of the support.