X-ray structural study of membranes based on Na-CMC and CS-Cl for water purification

Abstract

The level of environmental pollution is increasing year by year. Solving this problem requires the development and application of new effective technologies and materials for wastewater treatment and processing of accumulated waste. One of the alternative directions is membrane technologies, in particular, the development of biodegradable nanocomposite membranes. Anionic polyelectrolyte – Na-carboxymethyl cellulose with molecular weight Mw ~ 90000 and cationic polyelectrolyte – low molecular weight chitosan were used to create these membranes. Polymeric membranes were formed by mixing aqueous solutions of chitosan hydrochloride and Na-carboxymethylcellulose in different ratios. Analysis of X-ray diffractograms of polyelectrolyte complexes showed that with a gradual increase in the content of cationic polyelectrolyte from 5 % to 17 %, the structure of polyelectrolyte complexes changes dramatically. Whereas, the diffractograms of polyelectrolyte complexes with chitosan content from 29 % to 84 % are similar. The effectiveness of the obtained membranes was tested on a barometric device at different pressures. It was established that membranes based on polyelectrolyte complexes with a stoichiometric ratio of anionic and cationic polyelectrolytes turned out to be the most productive. The degree of water purification was checked by indicators of color selectivity. The obtained results allow us to conclude that with an increase in the duration of purification, the selectivity increases