Preparation and characterisation of thiol functionalised p-tert-butylcalix[4]arene-embedded polymer inclusion membranes: performance and selectivity

Here in we report the syntheses of the thiol functionalised p-tert-butylcalix[4]arene from the reaction of p-tert-butylcalix[4]arene-dialkylbromide derivative with thiourea. The structure of the thiol functionalised p-tert-butylcalix[4]arene was determined by using (HNMR)-H-1, (CNMR)-C-13 and elemental analysis techniques. Furthermore, the thiol functionalised p-tert-butylcalix[4]arene, cellulose triacetate (CTA) and 2-nitrophenyl octyl ether (o-NPPE) in dichloromethane were used to make a new calixarene-embedded polymer inclusion membrane (Bu-t-C@PIM). The surface and structure morphology of Bu-t-C@PIM was detected using thermogravimetric analysis, elemental analysis techniques and scanning electron microscopy. The affinity (the percentage of metal ion transferred from the source solution) of a PIM towards a range of divalent cations was found to follow the order Pb2+ > Zn2+ > Ni2+ > Cu2+ > Cd2+ > Co2+. The results also indicated that the transport efficiency of Bu-t-C@PIM was repeatable and may be beneficial in the development of a simplistic and highly influential trace metal recovery method from aqueous solution.