Electrochemical Characterization of a Polymer Inclusion Membrane Made of Cellulose Triacetate and Aliquat 336 and Its Application to Sulfonamides Separation

Abstract

An electrochemical characterization of a polymer inclusion membrane (PIM) fabricated with the ionic liquid (IL) Aliquat 336 (26%) and the polymer cellulose triacetate (CTA) (76%) is presented. Considering the use of PIMs in separation systems to remove pollutants from water, the characterization was performed with NaCl solutions by measuring membrane potential, electrochemical impedance spectroscopy, and salt diffusion and results were compared with those obtained from dry membranes. Results showed a significant reduction in the membrane diffusive permeability and electrical conductivity as well as the transport number of cation Na+ across the PIM when compared with solution values, which could be mainly related to the dense character of the membrane. Membrane application in the separation of different sulfonamides (sulfathiazole, sulfapyridine, sulfamethazine, and sulfamethoxazole) from water, with 1 M NaCl solution as striping phase, was also considered. These results indicated that the different chemical characteristics of the compounds, as well as the compact structure of the PIM, limited the transport of the organic molecules though it