An evaluation of polymer inclusion membrane performance in facilitated transport with sequential membrane reconstitution

This paper describes a method for the reconstitution of polymer inclusion membranes (PIMs) after normal use. PIMs consisting of a mixture of cellulose triacetate (CTA), 2-nitrophenyl octyl ether (NPOE), and the macrocycle undecyl-aza-18-crown-6 (AC) were made using the standard method. After each run, the membranes were dissolved in methylene chloride and reformed as at first. The membranes showed permeability of the perrhenate anion with only partial loss of permeability after being reconstituted 10 times. Along with permeability, the thickness of sequential membranes was measured using both light microscopy and scanning electron microscopy. The membranes thinned slightly with subsequent remakes, although the thinning was more apparent on the outer edges. The results of this experiment may prove useful in reducing the cost of membrane applications which employ expensive carrier molecules, in that carrier can be recovered as the membrane materials are reconstituted and re-used.

Research highlights▶ PIMs can be reconstituted multiple times by redissolving and recasting. ▶ Membranes were successfully remade up to 20 times. ▶ Remade membranes with carrier continued to demonstrate selective permeability. ▶ Material losses caused some membrane thinning.