Slow dynamics of a colloidal lamellar phase

TL;DR

This study investigates the slow dynamics of a colloidal lamellar phase using x-ray photon correlation spectroscopy, revealing how particle concentration influences hydrodynamic interactions without structural changes at phase transition.

Contribution

It provides new insights into the concentration-dependent hydrodynamic interactions and collective diffusion in colloidal lamellar phases.

Findings

Hydrodynamic interactions increase with concentration.

No structural change at the fluid-gel phase transition.

Quantitative description of particle dynamics at microscopic scales.

Abstract

We used x-ray photon correlation spectroscopy to study the dynamics in the lamellar phase of a platelet suspension as a function of the particle concentration. We measured the collective diffusion coefficient along the director of the phase, over length scales down to the interparticle distance, and quantified the hydrodynamic interaction between the particles. This interaction sets in with increasing concentration and can be described qualitatively by a simplified model. No change in the microscopic structure or dynamics is observed at the transition between the fluid and the gel-like lamellar phases.