Electrical and dynamic properties of non-plasticized potassium selective membranes


New activity-step response times and impedance measurements on silicone-based, potassium-selective, neutral carrier membranes are reported. Neat and solution polymerization procedures permit bulk resistance control. Spontaneously formed surface region resistances are found and these are interpreted by both external generation and removal experiments. Residual surface resistances are interpreted by several models including Butler-Volmer surface activation ion kinetics. Conditions when surface ion exchange kinetics mimic equilibrium extractions are described. Kinetic vs. equilibrium control of potentiometric selectivity parameters is not resolved, and more than one surface resistance component is present for silicone-based membranes as found earlier for poly(vinyl chloride)-based membranes. © 1989.

Publication Title

Journal of Electroanalytical Chemistry