A qualitative evaluation of water and monomethyl hydrazine in ethylcellulose membrane

Specific interaction sites of ethylcellulose (EC) with water and monomethyl hydrazine (MMH) and its hydrate have been studied by Fourier transform inf rared spectra. Measurements of diffusion and sorption coefficients of MMH a nd water in EC were made from the reduced sorption curves to determine the overall selectivity of the membrane. Flow patterns across the membrane were examined under an optical microscope (OM) equipped with a differential int erference contrast (DIC) facility. Correlation of the front velocity and th e diffusivity has been used to calculate and compare these values of diffus ion coefficient with that obtained from reduced sorption curve. Desorption of MMH hydrate from EC has been attributed to polymer relaxation phenomena. The physical aging process of the membrane has been monitored by FTIR anal ysis and mechanical strength evaluation. These studies showed that the EC m embrane can be used for prolonged periods in MMH and, as such, is suitable for the separation of MMH-water solutions. (C) 1999 John Wiley & Sons, Inc.