Molecular mechanism for formation of polyaniline lamella from a lyotropic liquid crystal: an NMR study.

摘要: Polyaniline (PANI) microlamellas with an average interlamellar distance of 2.6 nm were prepared from a nematic lyotropic liquid crystal system composed by sodium dodecyl sulfate (SDS) aqueous solution. To reveal the formation mechanism these lamellas, series NMR studies have been performed. At first, variable-temperature (VT) 13C experiments suggested that, prior to polymerization, anilines are predominantly located in vicinity SDS polar head region limited mobility at low temperature, whereas they become more mobile and penetrate into hydrophobic domain elevated temperature. Subsequent situ measurements 310 K indicated that overall polymerization can be taken place two stages. In beginning, reaction sites within micelles, resulting oligomeric PANI species benzenoid quinoid structures. Interestingly, fall off micellar domains reorganize layered structures support SDS. second stage, further continued interlayers. This paper provides good example studying roles surfactants nucleation stage qualitatively during synthesis morphology-specific polymers application techniques, period difficult examined other approaches currently.