Synthesis and characterization of polyaniline/silica doped with camphorsulfonic acid and dodecylbenzylsulfonic acid

In this study, the effect of the dopant structure on the morphology, structure, optical absorption, conductivity, and thermal properties of conductive polyaniline (PAn)/silica (SiO 2 ) hybrids from a sol–gel process was first investigated. Camphorsulfonic acid (CSA) and dodecylbenzylsulfonic acid (DBSA) were used as the model acid dopants. The polaron absorption peaks of the CSA‐doped PAn/SiO 2 (CSA–PAn/SiO 2 ) hybrids were redshifted compared with those of the DBSA–PAn/SiO 2 hybrids. This indicated that the doped PAn subchains of the CSA–PAn/SiO 2 hybrids had a more rigid conformation and longer conjugation length than those of DBSA–PAn/SiO 2 hybrids. Therefore, the CSA–PAn/SiO 2 hybrids were more conductive than the DBSA–PAn/SiO 2 hybrids with same SiO 2 contents. Moreover, the CSA–PAn/SiO 2 hybrids exhibited higher SiO 2 condensation degrees and thermal resistance than the DBSA–PAn/SiO 2 hybrids with same SiO 2 contents. In addition, the CSA–PAn/SiO 2 films exhibited a nonuniform globular morphology, whereas the DBSA–PAn/SiO 2 films showed an interconnected and rugged fibrillar one. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010