不同有机官能团对室温下纳米银形貌控制合成的影响

Effects of Different Organic Functional Groups on Morphology-controlled Synthesis of Silver Nanoparticles at Room Temperature

选择10种含有不同官能团的有机物为表面修饰剂,如聚乙烯吡咯烷酮、吐温-80、十二烷基硫酸钠、聚丙烯酸钠、聚乙二醇、山梨醇、十二烷基磺酸钠、聚乙烯醇、十二烷基苯磺酸钠和十六烷基三甲基溴化铵等,在室温下进行了平均粒径在2～131nm范围内纳米银颗粒的控制合成研究。有机修饰剂中含有的不同官能团对制得的纳米银形貌的影响主要取决于有机修饰剂的官能团特性和还原剂的还原能力。在不同还原条件下,含多醚键的聚乙二醇、吐温-80皆易于合成出平均粒径为几纳米、粒径分布窄、分散性好的纳米银。在弱还原剂条件下,十六烷基三甲基溴化铵诱导生成了三角形片状纳米银,但是在强还原剂存在条件下生成了粒状纳米银。粒径大于10nm的纳米银晶体的生长是通过小颗粒的聚集与熔合而成,而不是经过小颗粒的溶解-沉积过程形成。

Silver nanoparticles with average particle size ranging from 2 to 131nm were manipulatively synthesized starting from silver nitrate using 10 kinds of different functional group-containing organic modifiers, such as polyvinylpyrrolidone, tween-80, sodium dodecyl sulfate, sodium polyacrylate, polyethylene glycol, D-sorbitol, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, polyvinyl alcohol, cetyltrimethylammonium bromide, at room temperature The effects of the organic modifiers on the morphology of resulting silver nanoparticles were strongly dependent on the intrinsic properties of the functional groups and the reducibility of reductants. Numerous ether bonds （-O-） presented in polyethylene glycol and tween-80 were beneficial to the formation of silver nanoparticles with particle sizes of several nanometers in a narrow size distribution in both weak and strong reducing environments. Cetyltrimethylammonium bromide induced to form the nanosized silver triangle plates in a weak reducing environment, and to form the grained silver powders in a strong reducing condition. The crystal growth of the silver nanoparticles with particle sizes of more than 10nm was postulated through an adhesion process of small sized ones followed by a subsequent coalescence process under the present reaction conditions.