Accession Number:

ADA234079

Title:

The Effect of Low Power Plasmas on Carbon Fibre Surfaces. Part 2. A comparison between Low and High Modulus Pan Based Fibres with Pitch Based Carbon Fibres

Descriptive Note:

Technical rept.

Corporate Author:

NATIONAL CENTER FOR COMPOSITE MATERIALS RESEARCH URBANA IL

Personal Author(s):

Report Date:

1989-10-01

Pagination or Media Count:

16.0

Abstract:

A comparison of the effects of a variety of low power 1W plasmas air, NH3 and N2 on highly ordered pyrolytic graphite HOPG, polyacrylonitrile PAN-based and pitch based carbon fibres has been studied using X-ray photoelectron spectroscopy. Grazing angle techniques have been used to probe only the first 12-15 A of the fibre surface. Plasma treatments were carried out in an in situplasma cell which was attached to a PHI 5400 X-ray photoelectron spectrometer. This enabled the immediate effects of the plasma to be studied before the treated surface was exposed to air. The reactivity towards a particular plasma is shown to be largely dependent on the structure of the fibre surface. Air plasma proved much more reactive to the fibre surface than either nitrogen or ammonia plasma resulting in alcohol type groups being incorporated onto the basal planes and carboxyl groups onto the edge sites. Ammonia and nitrogen plasmas only attacked the edge sites with the formation of aliphatic and aromatic amines C-NH2 together with small number of immines CNH.

Subject Categories:

  • Ceramics, Refractories and Glass

Distribution Statement:

APPROVED FOR PUBLIC RELEASE