Design and Optimization of an Electrochemical Equipment for the Synthesis and Evaluation of Conducting Polymers

Abstract

A potentiostat system, focused towards the synthesis and evaluation of conducting polymers, was developed. This equipment consists of two main modules: the acquisition and control module, activated by means of a microcontroller which is connected through serial port to a computer, and the potentiostatic module, specially designed for handling the signals from the synthesis and characterization processes of the polymers. The user environment was programmed with Visual Basic 6. The resolution of the system AD/DA is of 12 bits; this allows sensibilities of 1 nA in current measurements. The achieved potential sweep is between −2 and +2 V. By means of this equipment, ClO₄ ⁻doped polypyrrole (PPy) and biphthalate doped PPy films were synthesized. The conducting polymers were synthesized by potential square waves. The thicknesses of the polymeric films were determined throughout the polymerization charge. The error percentage in the polymerization charge recorded by the developed potentiostat, relative to a commercial potentiostat, was about 6%. The ability to store the charge of the biphthalate PPy (biphthalate) films in potassium biphthalate aqueous solution was determined by cyclic voltammetry at various scan rates.

Keywords:

• Polypyrrole
• Potentiostat system
• ClO₄ ⁻
• Biphthalate