Vutukuri Hanumantha Rao, Smallenburg Frank, Badaire Stéphane, Imhof Arnout, Dijkstra Marjolein, van Blaaderen Alfons
Soft Condensed Matter, Debye Institute for NanoMaterials Science, Utrecht University, 3584 CC Utrecht, The Netherlands.
Soft Matter. 2014 Dec 7;10(45):9110-9. doi: 10.1039/c4sm01778a.
When a suspension of colloidal particles is placed in an oscillating electric field, the contrast in dielectric constant between the particles and the solvent induces a dipole moment in each of the colloidal particles. The resulting dipole-dipole interactions can strongly influence the phase behavior of the system. We investigate the phase behavior of cube-shaped colloidal particles in electric fields, using both experiments and Monte Carlo simulations. In addition to a string fluid phase and a body centered tetragonal (BCT) crystal phase, we observe a columnar phase consisting of hexagonally ordered strings of rotationally disordered cubes. By simulating the system for a range of pressures and electric field strengths, we map out the phase diagram, and compare the results to the experimentally observed phases. Additionally, we estimate the accuracy of a point-dipole approximation on the alignment of cubes in string-like clusters.
当将胶体颗粒悬浮液置于振荡电场中时，颗粒与溶剂之间介电常数的差异会在每个胶体颗粒中诱导出偶极矩。由此产生的偶极 - 偶极相互作用会强烈影响系统的相行为。我们使用实验和蒙特卡罗模拟来研究立方体形胶体颗粒在电场中的相行为。除了线串流体相和体心四方（BCT）晶相外，我们还观察到一种柱状相，它由旋转无序的立方体组成的六边形有序线串构成。通过在一系列压力和电场强度下对系统进行模拟，我们绘制出相图，并将结果与实验观察到的相进行比较。此外，我们估计了点偶极近似对丝状簇中立方体排列的准确性。
