Optimization of the conductivity and yield of chemically synthesized polyaniline using a design of experiments

摘要

The electrical conductivity and yield of polyaniline (PANi) were optimized using a design of experiments (DOE). PANi samples were synthesized by the chemical oxidative polymerization of aniline using methane sulfonic acid as the dopant acid and ammonium persulfate as the oxidant. The main factors in the synthesis of PANi that can affect the conductivity were identified as (i) the concentration of dopant acid, (ii) oxidant-to-monomer ratio, and (iii) the addition rate of oxidant to monomer. Using a Box-Behnken DOE method the regression equation, main effects plots, contour plots, and optimization plots for conductivity and yield were generated and analyzed. Under the optimized conditions of dopant acid concentration of 0.9M, an oxidant addition rate of 30 mL/h and an OM ratio of 0.9, PANi with a conductivity of 1.95 S/cm and yield of 95% was obtained. The observed trends in the four-point probe conductivity measurements were correlated with the polymer structure using fourier transform infrared spectroscopy, X-ray diffraction studies, and scanning electron microscopy.