SYNTHESIS AND PROPERTIES OF POLYPYRROLE VANADIUM-OXIDE HYBRID AEROGELS

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(OC3H7)(3) us ing pyrrole/water/acetone mixtures over a range of compositions yielde d monolithic green-black gels. Supercritical drying yielded aerogels ( 150-257 m(2)/g, 0.1-0.2 g/cm(3)). These polypyrrole/V2O5 'nanocomposit es' exhibited lower electrical conductivity with increased polypyrrole content. The second method involved oxide gel formation in the presen ce of a dispersion of preformed colloidal polypyrrole. SEM studies of the resulting 'microcomposites' aerogels (80-140 m(2)/g) show the pres ence of polypyrrole particles encapsulated in the fibrous V2O5 network . These materials exhibit conductivity equivalent to that of vanadium pentoxide. The interaction between polypyrrole and V2O5 in the materia ls was probed using infrared spectroscopy. (C) 1998 Elsevier Science B .V. All rights reserved.