Electrokinetic effects in nematic suspensions: Single-particle electro-osmosis and interparticle interactions
Electrokinetic effects in nematic suspensions: Single-particle electro-osmosis and interparticle interactions
复制标题
向列悬浮液中的动电效应：单粒子电渗和粒子间相互作用
DOI：
10.1103/physreve.98.022703
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发表时间：
2018
影响因子：
2.4
通讯作者：
Walkington, Noel J.
中科院分区：
文献类型：
--
作者：
Conklin, Christopher;Tovkach, O. M.;Viñals, Jorge;Calderer, M. Carme;Golovaty, Dmitry;Lavrentovich, Oleg D.;Walkington, Noel J.
当一种或多种介电粒子以其向列相悬浮在液晶基质中时，考虑向列悬浮液中的电动现象。向列相的长程取向顺序构成了具有各向异性特性的流体。这种各向异性使得在施加的电场下能够实现本体中的电荷分离，并且即使在施加的电场是振荡的情况下也会导致流动。在所考虑的情况下，电荷分离被认为是由悬浮颗粒产生的基质中的指向矢场畸变引起的。我们使用最近引入的电动模型来研究单粒子双曲刺猬对的运动。我们发现该运动平行于缺陷粒子中心轴，与场方向无关。对于双粒子配置，我们发现，对于具有垂直导向器锚定的粒子，动电起源的相对力是吸引的，而对于具有切向导向器锚定的粒子来说，动电起源的相对力是排斥的。该研究揭示了大尺度流动特性，这些特性分别源自仅配置的拓扑结构和颗粒和缺陷附近的短尺度流体动力学现象。
Electrokinetic phenomena in a nematic suspension are considered when one or more dielectric particles are suspended in a liquid crystal matrix in its nematic phase. The long-range orientational order of the nematic constitutes a fluid with anisotropic properties. This anisotropy enables charge separation in the bulk under an applied electric field, and leads to streaming flows even when the applied field is oscillatory. In the cases considered, charge separation is seen to result from director field distortions in the matrix that are created by the suspended particles. We use a recently introduced electrokinetic model to study the motion of a single-particle hyperbolic hedgehog pair. We find this motion to be parallel to the defect-particle center axis, independent of field orientation. For a two-particle configuration, we find that the relative force of electrokinetic origin is attractive in the case of particles with perpendicular director anchoring, and repulsive for particles with tangential director anchoring. The study reveals large scale flow properties that are respectively derived from the topology of the configuration alone and from short scale hydrodynamics phenomena in the vicinity of the particle and defect.