炸药爆轰法制备纳米石墨粉及其在高压合成金刚石中的应用

介绍了一种制备纳米石墨粉的新方法——负氧平衡炸药爆轰法. 对合成的黑粉产物进行x射线衍射分析，确认其为石墨结构，平均晶粒度为2.58 nm. 透射电子显微分析的结果表明，炸药爆轰法制备的黑粉为六方结构的纳米石墨粉，颗粒呈球形或椭球形. 用小角x射线散射法测定纳米石墨粉的粒度分布在1—50 nm，有92.6wt%的粉末粒度小于16 nm. 平均粒径为8.9 nm. 纳米石墨粉的比表面积约为500—650 m²/g. 在六面顶压机中用纳米石墨粉在Fe粉触媒的作用下进行金刚石的高压合成实验 关键词： 纳米石墨粉 爆轰 金刚石 合成

Nano-graphite synthesized by explosive detonation and its application in preparing diamond under high-pressure and high-temperature

In this article, preparation of nano-graphite powders in a steel chamber by using pure TNT (trinitrotoluene) explosives has been reported. X-ray diffraction results indicated that the black solid powders which were collected from the wall and the bottom of the chamber after detonation have the graphite structure and the average size of the particles of the graphite is 1.86-2.58 nm. Transmission electron microscopy confirms that the black powder is hexagonal-graphite structure with ball or ball-like shape. The grain size of the nano-graphite measured by small angle x-ray scattering lies in the range of 1-50 nm, 92.6wt% of the powder particles is smaller than 16 nm and the average diameter of the grains is 8.7 nm. Specific surface area of the nano-graphite is about 500-650 m²/g. Using nano-graphite as carbon source and choosing Fe powders as the catalyst, the ball-like and lumpy diamonds of 5-15 μm have been synthesized under high-temperature and high-pressure conditions of 1250-1330 K and 5.1 GPa. The synthesized temperature is about 300 K lower than that of bulk graphite synthetic diamond.