Hydrodynamic interactions in concentrated suspensions

Abstract

We study the effects of hydrodynamic interactions on the diffusion of hard spheres in concentrated suspensions. Using a multiple-light-scattering technique that measures the early-time behavior, we find Defr/Do^l -(1.86 ±0.07)0, where 0 is the volume fraction of spheres, Z) e ff is the effective diffusion coefficient, and Do is the free-particle diffusion coefficient. This agrees with the linear 0 term calculated theoretically for short-time self-diffusion. The short-time diffusion coefficient is also found to be continuous across the freezing transition.

The rennet coagulation mechanism of skim milk as observed by transmission diffusing wave spectroscopy

“…There also the first small increases occur about 80% removal of the CMP, and suggest that, starting at that point, there are significant inter-particle forces between the casein micelles although no aggregated particles are formed at that stage. It should be pointed out that there is an additional factor which comes into play, namely the hydrodynamic interaction factor H (q) [46]. However, although this factor may be relevant in circumstances where the volume fraction of the particles changes we believe that it is not important in the case of the casein micelles which we describe here, which maintain an approximately constant volume fraction throughout the reaction.…”

Sedimentation of concentrated monodisperse colloidal suspensions: Role of collective particle interaction forces

“…Qiu et al [36] also investigated the effects of collective hydrodynamic interactions in concentrated suspensions probed by the short-time self-diffusion coefficient of hard-sphere polystyrene particles (diameter = 0.412 micron and 0.913 micron). The dynamic light scattering technique and diffusing wave spectroscopy were employed to measure the short-time particle diffusion.…”

Influence of boundary reflection and refraction on diffusive photon transport

“…INTRODUCTION Dispersed forms of condensed matter such as colloids, foams, and emulsions all strongly scatter light so that even thin samples can appear white in the absence of absorption [1]. Many previously inaccessible aspects of their structure and dynamics are now being studied experimentally [2][3][4][5][6][7][8][9] with recent techniques, such as difFusing-wave spectroscopy [10,11] and interferometry [12], which exploit the difFusive nature of light propagation. Biological tissues also strongly scatter visible light, and efforts are underway to develop noninvasive medical probes [13,14] based on this feature.…”