Langmuir-Schaefer films of a poly(o-anisidine) conducting polymer for sensors and displays

Langmuir-Schaefer (LS) films of poly(o-anisidine) (POAS) were fabricated and characterized by means of Brewster-angle microscopy, ellipsometry and electrochemical techniques. The studied optical, cyclic voltammetric and ellipsometric properties of films underlined a regular deposition up to at least 40 monolayers of POAS conducting polymer. The development of surface irregularities beyond 40 monolayers in LS films showed an electrochemical kinetic similar to electrodeposited films. More importantly, the electrochemical kinetic in a small number of monolayers was indicative of the fast transfer process of the electrons. The nature of anions caused meaningful changes in the redox properties of POAS LS films. The electrochromic switching response time and diffusion coefficient of the LS films were estimated through electrochemical surveying. Later, POAS LS films were used as a sensing element for a survey of 0.1 ppm of acid in water through conductimetric measurement.