Effect of extended ball milling on graphite
Welham, N.J., Berbenni, V. and Chapman, P.G. (2003) Effect of extended ball milling on graphite. Journal of Alloys and Compounds, 349 (1-2). pp. 255-263.
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Graphite has been milled for up to 1000 h in a laboratory scale tumbling ball mill under vacuum. Raman spectroscopy of the powders indicated the increasing dominance of D-type graphitic sp2 bonding over G-type bonding with increasing milling time. Diamond-like sp3 bonding and possibly fullerene-like bonding also became evident after milling. TEM of the 100 h sample showed the presence of ribbons which were composed of sheets showing defects, delamination, translation, warping and curvature. Interplanar spacings of 0.40–0.50 nm were measured with the spacing increasing towards the edge of the ribbons where delamination was evident. Thermogravimetric analysis in argon of the powder after exposure to air showed an increasing mass loss with milling time indicating the presence of chemisorbed gas. Using TG–FTIR the gas was found to be a mixture of CO2 and an unidentified gas (probably oxygen). BET surface area measurements showed a maximum in the surface area; however, this was shown to be massively in error for the longer milling times due to the presence of the chemisorbed gas.
|Publication Type:||Journal Article|
|Copyright:||2002 Elsevier Science B.V.|
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