The electrochemistry of vinyl polymer membranes

Abstract

The electrochemical properties of polyvinyl acetate, polyvinyl chloride, and a copolymer of vinyl acetate and polyvinyl chloride have been studied. By means of membrane and bi‐ionic potential measurements, it has been shown that films made from these polymers are cation‐selective with a very low ion‐exchange capacity. The variation of membrane potential with external salt solution concentration occurs in a manner which may be predicted by the Meyer, Teorell, Sievers equations for permselective membranes. These have been used to calculate the fixed ion concentration within the polymers. The results suggest a possible mechanism for the passage of ions through mechanically perfect films.

Responses of site-controlled, plasticized membrane electrodes

“…However the effect is far less than that expected on the basis of the calculated site concentration and on the experimental results with TPB" containing membranes 0 Experiments carried out on freshly prepared membranes in subsequent steps. 6 Data correspond to compositions on the left; boron determined by atomic absorption and is presumed to be residual anions. (20).…”

“…These chelating agents can enhance the levels of dissolved heavy metals by both releasing them from sediments (1,3) and inhibiting removal through precipitation (4). They are synthetic products with undetermined health and toxicological effects (5,6). It has been suggested that they may constitute a source of nutrient nitrogen for aquatic algae (7), although this has been questioned (8).…”

“…In particular, we have previously inferred the prevalence of intrinsic, negative sites in various poly(vinyl chloride) (PVC) samples from different sources (1)(2)(3) and in polysiloxane (silicone rubber) membranes (4). Although this observation is not original with us (5,6), certain response characteristics (potentiometric slopes and selectivities) and electrical properties (current-voltage curves, resistance vs time, etc.) can be conveniently interpreted.…”

Plasticized poly(vinyl chloride) properties and characteristics of valinomycin electrodes. 1. High-frequency resistances and dielectric properties

“…Studies of electrical properties of plasticized PVC, e.g., conductivity, dielectric constant, and dielectric loss, suggest a more heterogeneous structure (5,6). Presence of counterion charge carriers from corresponding weakly dissociated fixed and mobile charged sites have been noted (7)(8)(9)(10). The free, dissociated counterions contribute to conductivity depending on the preparation of PVC.…”

Cross-Linked Polyelectrolyte for Improved Selectivity and Processability of Iontronic Systems

“…Next, we estimated the transport number by measuring the membrane potential, also known as the EMF-method − (electromotive force). Here, electrolytes of different concentrations were placed on each side of the IEM and the membrane potential was measured.…”