Au纳米粒子在有机溶剂中的电导行为

DC Conductivity of Au Nanoparticles in Organic Solvent

采用化学方法制备出粒径约 1 0 nm的 Au纳米粒子 ,分别用十二、十四和十六烷基硫醇对 Au粒子表面进行修饰 ,再溶入不同有机溶剂中 ,制备得到 Au纳米粒子 /氯仿和 Au纳米粒子 /甲苯溶液 .测试了不同溶液的电导率随溶质浓度的变化规律 ,发现在整个浓度范围内存在一个临界浓度值 .当溶质浓度低于临界浓度值时 ,溶液的电导率随溶质浓度的增加而迅速增加 ;而当溶质浓度超过临界浓度值时 ,溶液电导率的增加缓慢 .在本文测试的浓度范围内 ,当 Au纳米粒子分别被十二、十四和十六烷基硫醇修饰时 ,Au纳米粒子 /氯仿溶液的临界浓度值分别约为 1 1 .2 2 ,7.96和 5 .47g/ L.在相同浓度下 ,Au纳米粒子外面包裹的烷基硫醇的链长越短 ,其溶液的电导率越大 .在整个浓度范围内 ,Au纳米粒子 /氯仿溶液的电导率均高于 Au纳米粒子

Gold nanoparticles were chemically synthesized with a diameter of about 10 nm. Dodecanethiol, tetradecanethiol and hexadecanethiol were used to protect Au nanoparticles. Then Au nanoparticles/chloroform and Au nanoparticles/toluene suspensions were prepared. DC conductivity of different suspensions was investigated. The electrical conductivity of the samples increased with the increase of the concentration of Au nanoparticles, and a rapid increase in conductivity is observed when the concentration increased from a low value to a moderate value. The conductivity increases slowly when the concentration is larger than the moderate value. The moderate concentration values are 11.22, 7.96 and 5.47 g/L in chloroform suspensions when Au nanoparticles were encapsulated by dodecanethiol, tetradecanethiol and hexadecanethiol, respectively. The conductivity for Au nanoparticles/chloroform suspension is higher than that for Au nanoparticles/toluene suspension in the whole concentration range.