Accession Number : ADA310639

Title :   Vanadium Oxide/Polypyrrole Aerogel Nanocomposites.

Descriptive Note : Technical rept. 1 Jun 95-31 May 96,

Corporate Author : CALIFORNIA UNIV LOS ANGELES DEPT OF MATERIALS SCIENCE AND ENGINEERING

Personal Author(s) : Dave, B. C. ; Bunn, B. ; Leroux, F. ; Nazar, L. F. ; Wong, H. P.

PDF Url : ADA310639

Report Date : 18 JUN 1996

Pagination or Media Count : 8

Abstract : Vanadium pentoxide/polypyrrole aerogel (ARG) nanocomposites were prepared by hydrolysis of VO(OC3H7)3 using pyrrole/water/acetone mixtures. Monolithic green-black gels with polypyrrole/V ratios ranging from 0.15 to 1.0 resulted from simultaneous polymerization of the pyrrole and vanadium alkoxide precursors. Supercritical drying yielded high surface (150-200 sq meters/g) aerogels, of sufficient mechanical integrity to allow them to be cut without fracturing. TEM studies of the aerogels show that they are comprised of fibers similar to that of V2O5 ARG's, but with a much shorter chain length. Evidence from IR that the inorganic and organic components strongly interact leads us to propose that this impedes the vanadium condensation process. The result is ARG's that exhibit decreased electronic conductivity with increasing polymer content. Despite the unexpected deleterious effect of the conductive polymer on the bulk conductivity, at low polymer content, the nanocomposite materials show enhanced electrochemical properties for Li insertion compared to the pristine aerogel. p1

Descriptors :   *POLYMERS, *COMPOSITE MATERIALS, *OXIDES, *PYRROLES, *VANADIUM, FIBERS, MECHANICAL PROPERTIES, CONDUCTIVITY, WATER, POLYMERIZATION, ELECTROCHEMISTRY, BULK MATERIALS, MIXTURES, SURFACES, ELECTRONS, CHAINS, ORGANIC MATERIALS, SUPERCRITICAL FLOW, HYDROLYSIS, ACETONES, DRYING, CONDENSATION, INORGANIC MATERIALS.

Subject Categories : Inorganic Chemistry
      Organic Chemistry
      Physical Chemistry
      Polymer Chemistry
      Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE