Compton Owen C, Osterloh Frank E
Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95161, USA.
J Am Chem Soc. 2007 Jun 27;129(25):7793-8. doi: 10.1021/ja069033q. Epub 2007 Jun 6.
The addition of dodecanethiol to a solution of oleylamine-stabilized gold nanoparticles in chloroform leads to aggregation of nanoparticles and formation of colloidal crystals. Based on results from dynamic light scattering and scanning electron microscopy we identify three different growth mechanisms: direct nanoparticle aggregation, cluster aggregation, and heterogeneous aggregation. These mechanisms produce amorphous, single-crystalline, polycrystalline, and core-shell type clusters. In the latter, gold nanoparticles encapsulate an impurity nucleus. All crystalline structures exhibit fcc or icosahedral packing and are terminated by (100) and (111) planes, which leads to truncated tetrahedral, octahedral, and icosahedral shapes. Importantly, most clusters in this system grow by aggregation of 60-80 nm structurally nonrigid clusters that form in the first 60 s of the experiment. The aggregation mechanism is discussed in terms of classical and other nucleation theories.
将十二硫醇添加到氯仿中油胺稳定的金纳米颗粒溶液中会导致纳米颗粒聚集并形成胶体晶体。基于动态光散射和扫描电子显微镜的结果，我们确定了三种不同的生长机制：直接纳米颗粒聚集、团簇聚集和异质聚集。这些机制产生无定形、单晶、多晶和核壳型团簇。在后者中，金纳米颗粒包裹着一个杂质核。所有晶体结构都呈现面心立方或二十面体堆积，并由（100）和（111）平面终止，这导致了截顶四面体、八面体和二十面体形状。重要的是，该系统中的大多数团簇是通过在实验的前60秒内形成的60 - 80纳米结构非刚性团簇的聚集而生长的。根据经典成核理论和其他成核理论对聚集机制进行了讨论。
