CHANGE IN THE SURFACE STRUCTURE OF SEMICONDUCTOR POLYMER FILMS DURING REVERSE OXIDATION-REDUCTION

Abstract

The surface morphology of films of semiconducting polymers: polyaniline, poly-o-toluidine, poly-naphthylamine was studied by scanning electron microscopy. The films were obtained by electrochemical synthesis from solutions of their monomers acidified with mineral acids by the method of cyclic voltammetry. The films are formed on platinum substrates made according to the principle of bimetallic plates. The processes of reversible oxidation and reduction of the obtained films were carried out using an electric current in aqueous solutions of hydrochloric acid, which led to the doping of polymers with chloride anions. It was shown that the surface of films of polyaniline and poly-o-toluidine has a similar structure, consisting of numerous spherical grains ranging in size from 1 to 5 μm. The surface of poly-α-naphthylamine films is significantly different and consists of dendrons and large pores. In this case, in all cases, the observed supramolecular formations for films in the oxidized state are somewhat larger than for films in the reduced state, which is due to a change in the conformation of macromolecules.

Keywords

• semiconductor polymers
• polyaniline
• poly-o-toluidine
• poly-α-naphthylamine
• electrochemical actuator
• scanning electron microscopy