Thermal study of polypyrrole complexes with vermiculites of different layer charge

We have studied the synthesis of polypyrrole-clay nanocornposites by the in situ oxidative polymerization of pyrrole in the interlayer space of vermiculites with different layer charges from Santa Olalla and Ojen, Spain. Moreover, the influence of different interlayer cations (Na+, Mg2+, Fe3+) on the interaction between pyrrole and the vermiculites was studied. The resulting materials were characterized by means of DTA-TG, XRD, FTIR and Mossbauer spectroscopy. In all samples polymerization of pyrrole was observed, presumably triggered by the structural iron. In most cases it was found to be externally deposited. An uptake of pyrrole in the interlayer space and PPy formation is observed in the case of the Fe3+-intercalated Ojen vermiculite, which has a lower layer charge than the Santa Olalla vermiculite.