Preparation and comparative properties of membranes based on PANI and three inorganic fillers

In this study, we compare the effects of aniline-modified mesoporous silica (AMS), raw silica (ARS) and non-modified raw silica (NRS) particles on the physical properties of as-prepared polyaniline (PANI)-silica mesocomposites (PSM) and nanocomposites (PSN) and PANI-raw silica (PRSN) membranes. First, aniline-modified silica particles were synthesized by a conventional base-catalyzed sol-gel reaction of tetraethyl orthosilicate (TEOS) in the presence or absence of N-[3-(Trimethoxysilyl) propyl] aniline (PAPTMS). Subsequently, PSM, PSN and PRSN materials were prepared through in situ oxidation polymerization reaction of aniline monomer in the presence of AMS, ARS and NRS particles. It should be noted that all the properties of PSM membranes improved substantially from those of PSN and PRSN. For example, upon 3 wt% loading of AMS particles, 10, 25, 10, and 85% increases in thermal stability, mechanical strength, surface hydro-philicity and gas permeability were observed for PSM membranes, respectively, as well as more than 45% reduction in the thermal conductivity.