Preparation and characterization of polymeric plasticized membranes (PPM) embedding a crown ether carrier application to copper ions transport

Cellulose triacetate (CTA) membranes containing the crown ether dibenzo-18-crown-6 (DB18C6) as a fixed carrier were prepared and their performance tested for the transport of copper(II) ions. This study showed that PPM properties were influenced by the membrane composition. The transport studies revealed that diffusion rate was dependent on film thickness, the presence of a plasticizer, 2-nitrophenyloctylether, which plays also a critical role on the membrane physical characteristics (especially malleability) and the quantity of fixed crown ether. Porosimetry analyses showed conversely to other works with different carriers that all the membranes prepared are not porous for all membrane compositions. However, SEM analysis revealed a porous texture when the quantity of crown ether is higher than that of CTA. FTIR, X-ray and TGA characterizations showed that all the constituents of the membrane remain unaltered within the membrane without chemical interactions between them (no presence of new bonds in the FTIR spectra). Hence, transport mechanism of the copper(II) ions seems to be a jumping from site to site.