Evaluation of poly(vinylidene chloride) as a matrix for polymer membrane ion-selective electrodes

Poly(vinylidene chloride)(PVDC) was evaluated as a matrix for ion-selective electrodes. The glass-transition temperature of this polymer is below room temperature, hence, plasticizers are not required in order to make viable membranes. Quaternary ammonium salts [Aliquat 336 and tridodecylmethylammonium thiocyanate (TDMAT)] were used as the ionophores. It was possible to make functional unplasticized PVDC electrodes based on Aliquat 336. No deterioration in the slope of the calibration graph was observed over a period of 7 months. A mediator, octanol, was required in the preparation of electrodes based on TDMAT. Poly(vinylidene chloride) membrane electrodes based on this ionophore had a lifetime of about 2 months.