Electrochemical Impedance Spectroscopy—A Simple Method for the Characterization of Polymer Inclusion Membranes Containing Aliquat 336

Abstract

Electrochemical impedance spectroscopy (EIS) has been used to estimate the non-frequency dependent (static) dielectric constants of base polymers such as poly(vinyl chloride) (PVC), cellulose triacetate (CTA) and polystyrene (PS). Polymer inclusion membranes (PIMs) containing different amounts of PVC or CTA, along with the room temperature ionic liquid Aliquat 336 and plasticizers such as trisbutoxyethyl phosphate (TBEP), dioctyl sebecate (DOS) and 2-nitrophenyloctyl ether (NPOE) have been investigated. In this study, the complex and abstract method of EIS has been applied in a simple and easy to use way, so as to make the method accessible to membrane scientists and engineers who may not possess the detailed knowledge of electrochemistry and interfacial science needed for a rigorous interpretation of EIS results. The EIS data reported herein are internally consistent with a percolation threshold in the dielectric constant at high concentrations of Aliquat 336, which illustrates the suitability of the EIS technique since membrane percolation with ion exchangers is a well-known phenomenon.

Electrodriven Selective Transport of Cs+ Using Chlorinated Cobalt Dicarbollide in Polymer Inclusion Membrane: A Novel Approach for Cesium Removal from Simulated Nuclear Waste Solution

“…However, the R mem for the PIMs are reported to be much higher (of the order of kΩ). 48,49 In the present work, the R mem for the CTA based PIM, as obtained from electrochemical impedance measurement, has been found to be 1 kΩ-cm 2 . The impedance measurement within the frequency region 1 MHz-1 Hz has been carried out following the method as described in ref 50 and the impedance spectra for the CTA based PIM has been given in the Supporting Information (SI) Figure S3).…”

Use of Plasticizers for Electrochemical Sensors

“…The desirable properties of a plasticizer used in the membrane preparation of the ionselective electrodes are: compatibility with the polymer, low volatility and low solubility in aqueous solution, low viscosity, low cost and low toxicity (O'Rourke et al, 2011). In order to select the best plasticizer usually some tests are necessary.…”

Simultaneous AuIII Extraction and In Situ Formation of Polymeric Membrane‐Supported Au Nanoparticles: A Sustainable Process with Application in Catalysis

“…[15] The Au III transport experiments from HCl media of PVC membranes werec haracterized by al ow extraction percentage and no in situ reduction,a so nly ay ellow color typical of the AuCl 4 À speciesw ithin the membrane was observed, as reported in the Supporting Information (Figure S4). [21] As the electrostatic interactions between electric charges depend on the relative permittivity of the medium, this fact may explain the results obtained for the CTAm embrane in terms of the in situ reduction compared to the studied PVC membrane. The authors attributed theser esults to the lack of water within the membrane owing to its hydrophobic nature.M oreover,t he static dielectric constant or relative electrical permittivity (e r )o f PVC-PIMsw as reportedb yO 'Rourke et al as being lower (e r = 13.2 AE 1) than that obtained by using CTA( e r = 21.4 AE 1) as ap olymeric support.…”