微波辅助4-十二烷氧基苄胺保护的憎水性纳米金原位还原合成

In Situ Reducing Synthesis of p-Dodecyloxybenzenmethanamine-protected Hydrophobic Gold Nanoparticles under Microwave Irradiation

利用新型表面活性剂4-十二烷氧基苄胺(C12OBA)构成的C12OBA/正庚烷/正丁醇/HAuCl4/NaOH(aq.)W/O型微乳液作为微反应器,通过微波辐射加热的正丁醇原位还原法制备了C12OBA包裹的憎水性金纳米粒子,并通过紫外可见光谱(UV-vis)、透射电镜(TEM)、X射线衍射(XRD)、红外光谱(FT-IR)和接触角(CA)等分别进行了表征和分析.结果显示,C12OBA既可参与形成稳定的W/O型微乳液,又可作为金粒子的良好保护剂.微乳液内核中碱度的增加能增强位于膜相的正丁醇分子的还原能力.在固定氯金酸用量时,C12OBA/金的物质的量比增加有利于获得小尺寸、高单分散性的憎水性纳米金颗粒,而体系的极性增加则导致金粒子的尺寸增大、单分散性下降.通过本实验方法可方便快速地合成尺寸约为5nm的具有高度单分散的憎水性金纳米粒子.

The hydrophobic gold nanoparticles were fabricated through n-butanol reduction in situ under microwave irradiation by using p-dodecyloxybenzenmethanamine （C12OBA）/n-butanol/n-heptane/HAuCl4/ NaOH（aq.） W/O microemulsion as a microreactor. The C12OBA-stabilized gold nanoparticles were charac-terized by UV-vis, TEM, XRD, FT-IR and CA （contact angle）, respectively. The results showed that C12OBA, a novel surfactant, could not only take part in the formation of a stable W/O microemulsion, but also be used as a good protecting reagent for gold nanoparticles. The increase of alkalinity within the inner-core of microemulsion enhanced the reducing ability of n-butanol located in the membrane phase. As the amount of HAuCl4 was fixed, the increase of molar ratios of C12OBA/gold was beneficial to obtain hydro-phobic gold nanoparticles with small-size and higher monodispersity; while the increase of polarity of reaction system led to the increase of size and decline of monodispersity of particles. And thus by this method, the hydrophobic gold nanoparticles with about 5 nm-diameter and high monodispersity could be easily and quickly synthesized.