Proton-conducting sorption-active cyclam-based layers on chemically modified PVC surfaces of cellulose fabric

Abstract

At different concentrations of hydrochloric, sulfuric, and phosphoric acids, the conductivity of the following electrochemical cell was measured: anode-acid solution-in-air bridge-acid solution-cathode. Cellulose fabric, the fibers of which are encapsulated in polyvinyl chloride, the surface of which is chemically modified with porous layers of aggregates formed by acid molecules and salt groups of ethanol and acetate cyclams, served as the bridge. The range where the logarithmic conductivity is proportional to the acid concentration is found. In this range, the molar contents of acids and water in the layers are estimated, the presence of aggregates composed of acid hydrates and cyclam salt groups is determined, the structure of layer is studied, and the similarity between the H⁺ conductivity of the layers on fabric and the conductivity of membranes based on polymers involving the skeleton ammonia salt groups is followed. For the aggregate layers, the specific surface; the limiting volume of pores; and the adsorption capacities for water, alcohol, benzene, and hexane vapors are measured. The formation of aggregates is shown to produce an insubstantial effect on the adsorption characteristics of the surface. During migration of H⁺ ions in the fabric and on its surface, the following process was carried out in the electrochemical cell: adsorption of NH₃, formation of NH ⁺₄ ions, and transfer of NH ⁺₄ ions to the catholyte. The migration velocity of H⁺ ions is shown to correspond to the measured current in the circuit, and NH ⁺₄ ions formed are found to be accumulated in the catholyte.