A study of precursory, original, and oxidized graphitic matrix A3-3 by small angle neutron scattering

✍ Scribed by E Hoinkis; A.J Allen

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 847 KB
• Volume: 29
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(91)90099-5

✦ Synopsis

The precursor of Matrix A3-3 is made by quasi-isostatic cold moulding of graphite grains which had previously been covered by a phenolic resin as a binder. The graphitic Matrix is produced by heat-treatment of this precursory material. Compact specimens of precursory, original, and oxidized A3-3 were studied by SANS. The coherent macroscopic differe~tiai neutron scattering cross sections dH/dQ are very similar for the precursory A3-3 and the previously studied binder carbon-free Poco graphite AXM-SQI over a wide range of the scattering vector h. dX/dCl data for original and oxidized (burn-off of 2 wt%) A3-3 are almost identical and the plots In dUda versus In h show a shoulder at h -0.08 A-", which is due to a large concentration (1.5 vol%) of pores with a radius of gyration R, = 12 A in the binder carbon. Assuming spherical pore shape, the volume fraction/radius distribution was estimated using the Harwell Maximum Entropy Code. The interfacial area and the volume of pores with a radius <200 A were calculated and are compared with data obtained previously from nitrogen adsorption isotherms. It is concluded that the main effect of oxidation is the opening of pores in the binder carbon.