Platinum recovery using inherently conducting polymers and common fabrics

The recovery of platinum from solutions containing [PtCl6]2− using inherently conducting polymer (ICP) powders, membranes and coated fabrics has been investigated. Polyaniline (PAn) powders were able to recover platinum from solution, whereas polypyrrole (PPy) powders and membranes displayed almost no ability to perform this task. Uncoated pieces of nylon and nylon-lycra showed a significant capacity to recover platinum metal, unlike each of the other common fabrics investigated. Surprisingly the amount of platinum recovered by nylon-lycra was not improved by coating the fabric with a layer of ICP. Pieces of nylon-lycra that had previously been soaked in solutions containing [PtCl6]2− released only a small percentage of the bound metal when treated with 5 % HCl. However, subsequent treatment with aqua regia released all of the remaining platinum. A mechanism of platinum recovery by nylon and nylon-lycra involving coordination to functional groups present in their polymeric structures is proposed.