Work Andrew H, Williams Stuart J
University of Louisville, Mechanical Engineering, Louisville, Kentucky, USA.
Soft Matter. 2015 Jun 7;11(21):4266-72. doi: 10.1039/c5sm00184f.
We report the results of a study characterizing the behavior of colloid aggregations under manipulation of a technique known as Rapid Electrokinetic Patterning (REP) - this technique is capable of dynamically manipulating the crystallinity of 2D colloid aggregations, potentially enabling dynamically tunable photonic crystals. Herein, aggregations of spherical polystyrene particles 1.0 μm in diameter suspended in a low conductivity aqueous solution were collected at the surface of an indium-tin oxide coated glass slide. The uniform AC field coupled with laser-induced heating produced electrothermal hydrodynamics which is responsible for the self-assembly characteristics of the planar colloidal aggregation. REP was characterized experimentally by analyzing the mutual particle spacing within the aggregation as a function of the AC signal and laser power. Numerical simulations justified the assumption that the primary forces responsible for colloidal patterning herein are Stokes drag forces and dipole-dipole repulsive forces.
我们报告了一项研究结果，该研究对一种称为快速电动图案化（REP）技术操作下的胶体聚集体行为进行了表征——这种技术能够动态操纵二维胶体聚集体的结晶度，有可能实现动态可调谐光子晶体。在此，将直径为1.0μm的球形聚苯乙烯颗粒悬浮在低电导率水溶液中的聚集体收集在氧化铟锡涂层载玻片的表面。均匀的交流电场与激光诱导加热产生了电热流体动力学，这是平面胶体聚集体自组装特性的原因。通过分析聚集体内相互粒子间距作为交流信号和激光功率的函数，对REP进行了实验表征。数值模拟证实了这样的假设，即此处负责胶体图案化的主要力是斯托克斯阻力和偶极 - 偶极排斥力。
