Effects of interactions among polyaniline, dodecylbenzylsulfonic acid and silica on the morphology and properties of their sol–gel hybrids

In this work, the effects of interactions among polyaniline (PAn), dodecylbenzylsulfonic acid (DBSA) and silica on the morphology and properties of their sol–gel hybrids are investigated. DBSA acts as dopant for PAn and an efficient catalyst for the formation of SiO₂ network. Also, DBSA promotes the dissolution of PAn in organic solvent for preparing uniform hybrids. The interaction between DBSA and PAn components raises conductivities of the DBSA-doped PAn/SiO₂ (d-PAn/SiO₂) hybrids. Moreover, the hydrogen bonding interaction between d-PAn and SiO₂ precursor (silicic acid) leads to a less degree of three-dimensional network structure of the SiO₂ component in a hybrid with higher d-PAn content. In addition, because of the interactions among DBSA, PAn, and SiO₂, the conductive d-PAn-rich phase distributes uniformly in the hybrids. Besides, the d-PAn/SiO₂ hybrid with higher SiO₂ content exhibits lower conductivity, higher thermal resistance and more significant blue-shift of its polaron band.