Colloidal dynamics near a wall studied by evanescent wave light scattering: Experimental and theoretical improvements and methodological limitations

Peter Holmqvist, Jan K. G. Dhont, Peter R. Lang
2007 Journal of Chemical Physics  
The dynamics of colloidal spheres near to a wall is studied with an evanescent wave scattering setup that allows for an independent variation of the components of the scattering wave vector normal and parallel to the wall. The correlation functions obtained with this novel instrumentation are interpreted on the basis of an expression for their short time behavior that includes hydrodynamic interactions between the colloidal spheres and the wall. The combination of the evanescent wave scattering
more » ... ent wave scattering set-up and the exact expression for the short-time behavior of correlation functions allows for an unambiguous measurement of the particle mobility parallel and normal to the wall by means of light scattering. It is possible to measure the viscous wall drag effect on the dynamics of particles with radii as small as 27 nm, where however, the method to reaches it's limits due to the low scattering intensities of such small particles.
doi:10.1063/1.2431175 pmid:17286499 fatcat:emhlbkh5freitds5f3dgtztbsu