STUDY OF IMPREGNATED SILICONE RUBBER MEMBRANES FOR POTENTIAL INDICATING ELECTRODES

Electrodes fabricated from silicone rubber membranes and impregnated with various insoluble transition metal salts and chelates were investigated for their responses toward transition metal cations. Only electrodes fabricated from membranes impregnated with metal salts, and not chelates, responded. The crystalline form, the degree of hydration, and the associated anion of the imbedded salt had no effect on a membrane’s response or selectivity. These electrodes were nonspecific in their responses toward cations. The presence of additional electrolytes in the test solutions leveled the responses of the electrodes to the concentrations of the added salts. The primary purpose of the imbedded material is to adsorb water and ions during the conditioning process and to provide sites for rapid metal ion exchange at the membrane interface. The transition metal responsive electrodes were found to possess suitable mechanical properties but the desired selectivity was not attained. © 1968, American Chemical Society. All rights reserved.