Transportation of Cr(VI) through calix[4]arene based supported liquid membrane

The present study describes a comparative transportation of Cr(VI) across supported liquid membranes (SLMs) containing p-tert-butylcalix[4]arene diamide derivative bearing pyridinium units (3 and 4). These carriers were impregnated onto the supported membrane i.e. Celgard (R) 2500. The impregnated membranes were characterized by using various analytical techniques such as Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Atomic Force Microscopy (AFM) and contact angle measurements. The transport efficiency of 3 and 4 for Cr(VI) from the source to stripping phase has been evaluated. The experiments have been conducted involving the effect of pH, role of NaOH in stripping phase, concentration of Cr(VI), amount of carrier and contact time. Moreover, from the results of stability test, the effect of other co-existing metal ions and field study confirmed the applicability of p-tert-butylcalix[4]arene diamide derivative bearing pyridinium units (4) for the selective recovery of Cr(VI) in the acidic medium. The study also confers its impact on human health, reinstatement of polluted sites and other fields of material science. (C) 2013 Elsevier B.V. All rights reserved.