Elaboration of polyaniline-based composites and study of their physicochemical properties

Abstract

In this work, thin polyaniline layers were prepared by chemical deposition, a simple, costeffective, and eco-friendly method. To ensure proper film deposition on glass substrates, the effects of four main factors were examined, including aniline concentration, ammonium persulfate concentration, medium temperature, and reaction time. The optimization process employed a multivariate approach using the Box-Behnken design to identify the optimal conditions for these variables with the response surface method and the composite desirability function. Results indicated that the optimal precipitation conditions were aniline concentration (0.10 mol/L), ammonium persulfate concentration (0.0427 mol/L), medium temperature (55°C), and reaction time (52.42 minutes), resulting in an expected band gap energy of 1.693 eV. The deposited polyaniline thin films were characterized to analyze their morphological, structural, optical, and electrical properties. Techniques such as infrared spectroscopy, X-ray diffraction, optical microscopy, scanning electron microscopy, and visible and ultraviolet spectroscopy confirmed successful polymerization of aniline on the glass surface. These findings demonstrated the formation of amorphous, hydrophilic polyaniline layers under optimal conditions, with the films exhibiting semiconducting behavior and an energy gap of 1.735 eV. Electrical property analysis showed that the polyaniline layers have a roomtemperature conductivity of 4.30 S/cm, an absolute conductivity of 0.52 S/cm, and a thermal activation energy of 2.2 × 10⁻³ eV.