Synthesis and properties of polypyrrole–vanadium oxide hybrid aerogels

Abstract

Vanadium pentoxide/polypyrrole aerogel composites were synthesized by two sol–gel routes. The first utilized simultaneous polymerization of pyrrole and vanadyl alkoxide precursors. Hydrolysis of VO(OC 3H 7) 3 using pyrrole/water/acetone mixtures over a range of compositions yielded monolithic green–black gels. Supercritical drying yielded aerogels (150–257 m 2/g, 0.1–0.2 g/cm 3). These polypyrrole/V 2O 5 `nanocomposites' exhibited lower electrical conductivity with increased polypyrrole content. The second method involved oxide gel formation in the presence of a dispersion of preformed colloidal polypyrrole. SEM studies of the resulting `microcomposites' aerogels (80–140 m 2/g) show the presence of polypyrrole particles encapsulated in the fibrous V 2O 5 network. These materials exhibit conductivity equivalent to that of vanadium pentoxide. The interaction between polypyrrole and V 2O 5 in the materials was probed using infrared spectroscopy.