Water effect on physical–chemical and elastic parameters for a dense cellulose regenerated membrane: Transport of different aqueous electrolyte solutions

Water effect in different physical–chemical and elastic parameters determined for a dense cellulose regenerated (RC) membrane is presented. Membrane samples characterization was carried out by obtaining XPS spectra, X-ray diffraction patterns and elasticity curves, and the significant differences determined when dry and wet samples are compared are basically associated to the water plasticization effect in this high hydrophilic material. Transport of different aqueous electrolyte solutions (NaCl, KCl, LiCl, MgCl2 and CaCl2) was study by measuring membrane potentials and diffusion, which allows the determination of effective membrane fixed charge concentration, ion transport numbers and permselectivity as well as diffusional permeability and diffusion coefficient of the different salts across the RC membrane. Differences associated to the kind of electrolyte (1:1 or 2:1 electrolytes) were obtained as a result of membrane–solute electrical interactions. Membrane dense structure significantly reduce both salt and water diffusional transport, being this latter determined by using tritiated water as permeate.