INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany.
Nanoscale. 2016 Jul 21;8(27):13377-84. doi: 10.1039/c6nr01940d. Epub 2016 Jun 24.
Binary mixtures of nanoparticles self-assemble in the confinement of evaporating oil droplets and form regular supraparticles. We demonstrate that moderate pressure differences on the order of 100 kPa change the particles' self-assembly behavior. Crystalline superlattices, Janus particles, and core-shell particle arrangements form in the same dispersions when changing the working pressure or the surfactant that sets the Laplace pressure inside the droplets. Molecular dynamics simulations confirm that pressure-dependent interparticle potentials affect the self-assembly route of the confined particles. Optical spectrometry, small-angle X-ray scattering and electron microscopy are used to compare experiments and simulations and confirm that the onset of self-assembly depends on particle size and pressure. The overall formation mechanism reminds of the demixing of binary alloys with different phase diagrams.
纳米粒子的二元混合物在蒸发油滴的限制下自组装，并形成规则的超粒子。我们证明，适度的压力差（约 100kPa）会改变粒子的自组装行为。在改变工作压力或设置液滴内拉普拉斯压力的表面活性剂时，同样的分散体中会形成晶体超晶格、双面粒子和核壳粒子排列。分子动力学模拟证实，压力相关的粒子间势能会影响受限粒子的自组装路径。光谱、小角 X 射线散射和电子显微镜用于比较实验和模拟，并证实自组装的开始取决于颗粒尺寸和压力。整体形成机制类似于不同相图的二元合金的分相。
