Department of Physics Papers

Document Type

Journal Article

Date of this Version

7-21-2009

Comments

Suggested Citation:
Han, Y., A. Alsayed, M. Nobili, and A.G. Yodh. (2009). "Quasi-two-dimensional diffusion of single ellipsoids: Aspect ratio and confinement effects." Physical Review E. 80, 011403.

© 2009 The American Physical Review
http://dx.doi.org/10.1103/PhysRevE.80.011403.

Abstract

We report on video-microscopy measurements of the translational and rotational Brownian motions of isolated ellipsoidal particles in quasi-two-dimensional sample cells of increasing thickness. The long-time diffusion coefficients were measured along the long (Da) and short (Db) ellipsoid axes, respectively, and the ratio, Da /Db, was determined as a function of wall confinement and particle aspect ratio. In three dimensions (3D), this ratio (Da /Db) cannot be larger than 2, but in quasi-two dimensions, wall confinement was found to substantially alter diffusion anisotropy and substantially slow particle diffusion along the short axis compared to 3D.

Date Posted: 06 January 2011

This document has been peer reviewed.