Box-Behnken Optimization, Morphological, Optical, and Electrical Properties of Polyaniline Thin Films Deposed Using the Chemical Bath Deposition Method

Polyaniline thin films have been produced via chemical bath deposition (CBD), a cost-effective and eco-friendly method. To achieve adequate deposition of the films on glass substrates, four parameters were optimized using a multivariable appoach based on Box–Behnken design: aniline dose (CAn), ammonium persulfate concentration (CS2O8−2), bath temperature (T°), reaction time (t), were optimized via a multivariable optimization approach based on the Box-Behnken design (DDB). The ideal conditions for the four input variables were determined using the response surface method (RSM) and the composite desirability function (CDF) approach. The optimal deposition conditions were determined to be: an aniline dose (0.10 mol/L), an ammonium persulfate concentration (0.0427 mol/L), a bath temperature (55°C) and reaction time (52.42 min), with a predicted gap energy value (Egpre) reaching 1.693 eV; the as-deposited polyaniline thin layers were characterized to study their morphological, structural, optical, and electrical properties. Various techniques were used to confirm the polymerization of aniline on the surface of a glass substrate, including FTIR, SEM, and UV-Vis. Also, this behavior indicated the formation of amorphous and hydrophilic polyaniline thin layers under the optimal conditions, exhibiting a semiconducting characteristic of as-obtained films with an energy band gap (Egexp) of 1.735 eV.