Study by inverse gas chromatography of the surface properties of milled graphites.

A graphite was milled during 1, 2, 3 and 4h. The milled samples were then examined using inverse gas chromatography (IGC), at infinite and finite concentration conditions. The present work reports the study of the surface properties by IGC of milled graphite samples as a function of the milling time parameter and of the oxygen content.

Influence of poly(methyl methacrylate) impregnation ratio on the surface properties of fumed silica and on the glassy temperature of poly(methyl methacrylate) using inverse gas chromatographic analysis.

The surface properties of poly(methyl methacrylate) (PMMA) impregnated fumed silicas, in a large range of impregnation ratios, were examined using inverse gas chromatography at infinite dilution. It was observed that the dispersive component gamma(s)d does not decrease monotonously with the impregnation ratio. Two critical coverage ratios were evidenced corresponding at first to the shielding of the most energetic sites and then to the achievement of total coverage of the silica surface. The influence of the coverage ratio on the glassy temperature (tg) of the adsorbed PMMA was also studied, which was evidenced down to a very low coverage ratio (1 monomer unit/nm2).