Grouchko Michael, Popov Inna, Uvarov Vladimir, Magdassi Shlomo, Kamyshny Alexander
Casali Institute for Applied Chemistry, The Unit for Nanocharacterization, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Langmuir. 2009 Feb 17;25(4):2501-3. doi: 10.1021/la803843k.
It was found that during the evaporation of water from a droplet of a silver nanoparticles dispersion a self-assembly process leads to the coalescence of the nanoparticles at room temperature and eventually results in a 3D, micrometer-sized dendrite. Direct in situ HR-TEM observation of coalescence events of individual nanoparticles revealed that during this process a transformation of the nanoparticles' crystal structure takes place, from the common fcc silver structure to the unusual hcp structure. It was found that even-though a majority of the nanoparticles in the dispersion have the fcc structure the obtained dendrites are characterized by the hcp structure, reflecting the crystal structure transformation due to the coalescence process.
研究发现，在银纳米颗粒分散液滴中的水蒸发过程中，自组装过程会导致纳米颗粒在室温下聚结，并最终形成三维微米级枝晶。对单个纳米颗粒聚结事件的直接原位高分辨透射电子显微镜观察表明，在此过程中，纳米颗粒的晶体结构发生了转变，从常见的面心立方银结构转变为不寻常的六方密堆积结构。研究发现，尽管分散液中的大多数纳米颗粒具有面心立方结构，但所获得的枝晶却以六方密堆积结构为特征，这反映了由于聚结过程导致的晶体结构转变。
