A contribution of radial electron density distribution measurements to the study of PTFE-Carbon

✍ Scribed by L. Červinka; F.P. Dousek; J. Jansta; H.G. Neumann; H. Steil

• Publisher: Elsevier Science
• Year: 1981
• Tongue: English
• Weight: 660 KB
• Volume: 19
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(81)90024-5

✦ Synopsis

The sp-hybridized bonds in elemental carbon expected as primary product of low temperature electrochemical reduction of poly(tetrafluoroethylene) were proved by determination of C-C bond length from radial electron density distribution measurements. A value of (0.139 + 0.002) nm was found for the C-C bonding distance for the carbon phase in the "as received" reduction products. This value, lower than 0.142 nm for graphitic sp2 bonds, can be explained only by the presence of a remainder (about 5-20%) of sp-hybridized bonds with a length of about 0.120 nm, whereas the majority of very reactive sp carbon chains was transformed to six-membered rings (spz bonds). On the contrary, a higher bonding distance of (0.145 t 0.001) nm was found for carbons isolated from the reduction products, an evidence for the formation of a portion of tetrahedral sp, bonds in edge-to-edge cross-linkages. Interlayer distances of 0.342nm. constituted at 950°C. were unusually low in comparison with polymeric carbons prepared by pyrolysis.