Sedimentation path theory for mass-polydisperse colloidal systems

T. Eckert, M. Schmidt, D. de las Heras
Arxiv, 2210.04862, , (2022)    
Full text: journal, pdf

Both polydispersity and the presence of a gravitational field are inherent to essentially any colloidal experiment. While several theoretical works have focused on the effect of polydispersity on the bulk phase behavior of a colloidal system, little is known about the effect of a gravitational field on a polydisperse colloidal suspension. We extend here sedimentation path theory to study sedimentation of a mass-polydisperse colloidal system: the particles possess different buoyant masses but they are otherwise identical. The model helps to understand the interplay between gravity and polydispersity on sedimentation experiments. Since the theory can be applied to any parent distribution of buoyant masses, it can be also used to study sedimentation of monodisperse colloidal systems. We find that mass-polydispersity has a strong influence in colloidal systems near density matching for which the bare density of the colloidal particles equals the solvent density. To illustrate the theory, we study crystallization in sedimentation-diffusion-equilibrium of a suspension of mass-polydisperse hard spheres.

Related publications:

1 The phase stacking diagram of colloidal mixtures under gravity (+ info)
2 Sedimentation stacking diagram of binary colloidal mixtures and bulk phases in the plane of chemical potentials (+ info)
3 The role of sample height in the stacking diagram of colloidal mixtures under gravity (+ info)
4 Floating nematic phase in colloidal platelet-sphere mixtures (+ info)
5 Reentrant Network Formation in Patchy Colloidal Mixtures under Gravity (+ info)
6 Sedimentation of colloidal plate-sphere mixtures and inference of particle characteristics from stacking sequences (+ info)
7 Gravity-induced phase phenomena in plate-rod colloidal mixtures (+ info)

Other papers.