Stokes drag on a sphere in a nematic liquid crystal
Stokes drag on a sphere in a nematic liquid crystal
复制标题
DOI：
10.1126/science.1102864
复制
发表时间：
2004-11-26
期刊：
影响因子：
56.9
通讯作者：
Poulin, P
中科院分区：
文献类型：
--
作者：
Loudet, JC;Hanusse, P;Poulin, P
斯托克斯-爱因斯坦关系将粘性流体中的球形布朗粒子的扩散系数与其摩擦系数联系起来。对于悬浮在各向异性液体中的颗粒，理论预测阻力系数也应该是各向异性的。使用视频显微镜加上粒子跟踪例程，微米级颗粒的布朗波动进行了分析，以产生平行和垂直于扩散系数的定量测量的方向。最近的数值计算，考虑到在粒子附近的导演场的扭曲的实验值同意得很好。
The Stokes-Einstein relation relates the diffusion coefficient of a spherical Brownian particle in a viscous fluid to its friction coefficient. For a particle suspended in anisotropic liquid, theory predicts that the drag coefficient should also be anisotropic. Using video microscopy coupled with particle tracking routines, the Brownian fluctuations of micrometer-sized particles were analyzed to yield a quantitative measurement of the diffusion coefficients parallel and perpendicular to the nematic director. The experimental values agree quite well with recent numerical calculations that take into account the distortions of the director field in the vicinity of the particles.