Composite films of poly-(ester-sulphonated) and poly-(3-methylthiophene) for ion-exchange voltammetry in acetonitrile solutions

摘要: This paper describes the preparation and characterisation of a polymeric electrode coating based on composite poly-(estersulphonated) Eastman AQ55 ® (AQ55) poly-(3-methylthiophene) (PMeT), which is used for controlled uptake partial release electroactive cations in acetonitrile solutions. The film prepared by electrochemical oxidation 3-methylthiophene glassy carbon disks or Pt–quartz crystal electrodes pre-coated with thin AQ55. electropolymerisation process so that overall number positive charges oxidised PMeT equal to negative sulphonate groups Cyclic voltammetry quartz microbalance measurements indicate AQ55/PMeT mixed stable its cation-exchange properties depend applied potential. When moieties are reduced, incorporate cations; following causes incorporated which, however, only partial. Scanning electron microscopy (SEM) examination cross sections polymer layer it really bi-layer, made an inner compact thicker porous grown. outer acts as barrier whose ionic can be changed electrochemically from (oxidation) neutral (reduction). These hinder allow, respectively, permeation redox tend interact negatively charged sulphonic sites layer. Direct self-neutralization part oxidized allows previously when reduced state. By operating solutions without added electrolyte possible increase fraction released consequence PMeT; this suggests slower under such experimental conditions. © 2005 Elsevier Ltd. All rights reserved.