Rotational diffusion of spherical colloids close to a wall

Phys Rev Lett. 2012 Aug 31;109(9):098305. doi: 10.1103/PhysRevLett.109.098305. Epub 2012 Aug 30.

Abstract

There is currently no experimental technique available to probe spatially resolved rotational diffusion of nanoparticles in the vicinity of a wall. We present the first experimental study of rotational diffusion of small spherical colloids, using dynamic evanescent wave scattering. A setup is used where the wave vector components parallel and perpendicular to the wall can be varied independently, and an expression is derived for the first cumulant of the intensity correlation function in VH evanescent wave geometry for optically anisotropic spheres. The experimental results are in agreement with theoretical predictions that take particle-wall hydrodynamic interactions into account.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anisotropy
  • Colloids / chemistry*
  • Diffusion
  • Fluorocarbons / chemistry
  • Hydrodynamics
  • Light
  • Models, Chemical*
  • Optics and Photonics / methods
  • Scattering, Radiation

Substances

  • Colloids
  • Fluorocarbons
  • tetrafluoroethylene