Fractional Brownian Motion Run with a Multi-Scaling Clock Mimics Diffusion of Spherical Colloids in Microstructural Fluids

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• 作者：Moongyu Park ; John Howard Cushman ; Dan O鈥橫alley
• 刊名：Langmuir
• 出版年：2014
• 出版时间：September 30, 2014
• 年：2014
• 卷：30
• 期：38
• 页码：11263-11266
• 全文大小：239K
• ISSN：1520-5827

文摘

The collective molecular reorientations within a nematic liquid crystal fluid bathing a spherical colloid cause the colloid to diffuse anomalously on a short time scale (i.e., as a non-Brownian particle). The deformations and fluctuations of long-range orientational order in the liquid crystal profoundly influence the transient diffusive regimes. Here we show that an anisotropic fractional Brownian process run with a nonlinear multiscaling clock effectively mimics this collective and transient phenomenon. This novel process has memory, Gaussian increments, and a multiscale mean square displacement that can be chosen independently from the fractal dimension of a particle trajectory. The process is capable of modeling multiscale sub-, super-, or classical diffusion. The finite-size Lyapunov exponents for this multiscaling process are defined for future analysis of related mixing processes.