作　　者： ; ; ; ;

机构地区： 广东工业大学材料与能源学院

出　　处： 《南京大学学报（自然科学版）》 2009年第2期297-303,共7页

摘　　要： 纳米铝粉由于具有较小的粒径和较高的比表面积因此在含能材料中具有很大的潜在应用,但由于纳米铝粉的高化学反应活性,因而其对所处环境特别敏感,极易在空气和潮湿环境中被氧化而失去活性.碳包覆技术是近年来采用的新型纳米粒子包覆技术,是指在金属纳米粒子表面形成碳包覆层从而可有效地保护纳米粒子不受环境的影响而发生氧化反应或者其它反应,同时也为研究封闭环境中纳米材料的性质提供了一种新途径.本文采用碳弧法制备了碳包铝复合纳米粒子,研究影响其形貌的因素和室温抗氧化性能.结果表明:碳弧法制备的碳铝复合物是20～60nm之间的具核壳结构的球形纳米粒子,内核为fcc结构的Al,外壳为4～10层类石墨碳膜;碳铝比例、放电电压和反应气压都能对碳铝复合纳米粒子的包覆性能和粒径产生直接的影响.铝含量低时碳层包覆性能较好并且粒径较小,铝含量增大包覆性能会下降、纳米粒子粒径会随金属含量增加而增加;包覆性能随放电电流反应气体压强增大会有所下降,在200A时纳米粒子的粒径达到最大值;粒径随反应气压增大而增大.当金属含量为60%、电流为125A、惰性气体气压为0.06MPa时制备的碳铝纳米粒子包覆比较完整,粒径较小,通过对工艺参数调整和优化,可制备出包覆比较完整、大小均匀、粒径较小、纯度高的核壳型碳包铝纳米粒子. Aluminum nanopowder is a new kind of energetic material, which holds considerable promise due to its small size and high specific surface area. While the aluminum nanopowder has high chemical activity, it is sensitive to the surroundings and easy to be oxidized when being exposed to air or humid environment. Carbon-encapsulated technique is the lasted method to synthesize core-shell structure carbon metal compounds. Carbon-encapsulated technique is coating carbon shell in the surface of metal particles. These shells will isolate metal particles from air and moisture, at the same time being coated by carbon shells the metal nanoparticles exhibit distinctive chemical and physical phenomenon. This method provides us a new way to study metal nanoparticles in capsulation environment. In this paper we prepare carbon-aluminum composite nanoparticles by carbon discharge method. The formation theo- ry and room temperature antioxidation property of the particles are investigated by XRD and TEM. The results show that the core of the particles is face centered aluminum crystal, and the shell of them is onion shaped carbon. The size of Carbon coated aluminum nanoparticles are 20 ~ 60 nm in diameter; The influence of AI content, dis- charge current and reaction pressure on the coating property and particle diameter of Carbon coated aluminum nanop- articles are studied. The coating property decreases and particle size increases with the A1 volume increasing; The coating property decreases with the increase of discharge current; particles size reaches maximum when current is 200 A; particle size increases with the increase of reaction air pressure. The optimum process is with 60% AI in con tent, 125 A in current and 0.06 MPa in pressure.

关 键 词： 碳弧法 碳包铝复合纳米粒子 抗氧化性

领　　域： [理学] [理学]