Effects of inorganic acid in DBSA-PANI polymerization on transparent PANI-SiO2 hybrid conducting films

Transparent hybrid conducting films were prepared by dodecylbenzene sulfonic acid-doped polyaniline (DBSA-PANI) and 3-glycidoxypropyltrimethoxysilane (GPTMS) through a sol–gel process. DBSA-PANI was synthesized via emulsion polymerization, and inorganic acid (nitric or sulfuric acid) was added to adjust the structure of the emulsion system and obtain the higher conductivity of polyaniline. When nitric acid was used in the emulsion system, structure of the hybrid films became more stable and sheet resistance of the hybrid films was lower. Visible light transmittance of the hybrid films was over 75%. Various properties of the hybrid material were analyzed by the infrared spectra (IR), UV–visible absorption spectra, thermogravimetric analysis (TG) and digital four-point probe meter.