爆炸法制备超细金刚石粉末的提纯与性质研究

Study on Purification and Properties of Ultrafine Diamond Prepared by Explosive Technique

研究了利用爆炸合成法制备的超细金刚石的提纯工艺；对提纯样品的晶粒尺寸分布和平均晶粒尺寸进行了表征和分析，并对超细金刚石的热稳定性做了研究。结果表明，浓硝酸和浓硫酸混合液的沸腾处理及氢氟酸水浴处理，除了残留极少量无定形碳，基本除去了超细金刚石以外的其它杂质，高氯酸沸腾处理在去除无定形碳方面作用不大。根据Ｘ－Ｒａｙ衍射谱，利用谢乐公式计算晶粒平均尺寸为３ｎｍ左右，小角Ｘ－Ｒａｙ散射晶粒尺寸分布分析可得其最大分布在２．８ｎｍ。由于超细金刚石表面活性的作用，使其氧化燃烧温度低于大块金刚石的表面起始氧化温度。

The purificaton technique of ultrafine diamond(UFD) prepared by Explosive method had been studied. The distribution of the crystallites size and their average size of the purified sample had determined and analyzed. The thermal stability had also been examined. The experimental results showed that the impurities in samples had been almost removed after heating up to boil in a mixture of concentrated HNO 3/H 2SO 4 and then reacting with hydrofluoric acid in a water bath, except a little residual amorphous carbon. However, the treatment in boiling HClO 4 had little effect on removing the amorphous carbon. Using Scherre formula, the average crystallites size were calculated to be 3nm. Through the small angle X ray diffraction, the crystallites size distribution showed that the maximum distribution was 2.8nm. The oxidizing burning temperature was much lower than the starting oxidizing temperature of bulk diamond surface for the surface activity of the UFD.