Partner: Maciej Lisicki


Recent publications
1.Lisicki M., Cichocki B., Wajnryb E., Near-wall diffusion tensor of an axisymmetric colloidal particle, JOURNAL OF CHEMICAL PHYSICS, ISSN: 0021-9606, DOI: 10.1063/1.4958727, Vol.145, pp.034904-1-8, 2016
Abstract:

Hydrodynamic interactions with confining boundaries often lead to drastic changes in the diffusive behaviour of microparticles in suspensions. For axially symmetric particles, earlier numerical studies have suggested a simple form of the near-wall diffusion matrix which depends on the distance and orientation of the particle with respect to the wall, which is usually calculated numerically. In this work, we derive explicit analytical formulae for the dominant correction to the bulk diffusion tensor of an axially symmetric colloidal particle due to the presence of a nearby no-slip wall. The relative correction scales as powers of inverse wall-particle distance and its angular structure is represented by simple functions in sines and cosines of the particle’s inclination angle to the wall. We analyse the correction for translational and rotational motion, as well as the translation-rotation coupling. Our findings provide a simple approximation to the anisotropic diffusion tensor near a wall, which completes and corrects relations known from earlier numerical and theoretical findings.

Affiliations:
Lisicki M.-other affiliation
Cichocki B.-University of Warsaw (PL)
Wajnryb E.-IPPT PAN
2.Liu Y., Bławzdziewicz J., Cichocki B., Dhont J.K.G., Lisicki M., Wajnryb E., Youngf Y.N., Lang P.R., Near-wall dynamics of concentrated hard-sphere suspensions: comparison of evanescent wave DLS experiments, virial approximation and simulations, SOFT MATTER, ISSN: 1744-683X, DOI: 10.1039/c5sm01624j, Vol.11, pp.7316-7327, 2015
Abstract:

In this article we report on a study of the near-wall dynamics of suspended colloidal hard spheres over a broad range of volume fractions. We present a thorough comparison of experimental data with predictions based on a virial approximation and simulation results. We find that the virial approach describes the experimental data reasonably well up to a volume fraction of ϕ ≈ 0.25 which provides us with a fast and non-costly tool for the analysis and prediction of evanescent wave DLS data. Based on this we propose a new method to assess the near-wall self-diffusion at elevated density. Here, we qualitatively confirm earlier results [Michailidou, et al., Phys. Rev. Lett., 2009, 102, 068302], which indicate that many-particle hydrodynamic interactions are diminished by the presence of the wall at increasing volume fractions as compared to bulk dynamics. Beyond this finding we show that this diminishment is different for the particle motion normal and parallel to the wall.

Affiliations:
Liu Y.-Forschugszentrum Jülich, Institute of Complex Systems (DE)
Bławzdziewicz J.-Texas Tech University (US)
Cichocki B.-University of Warsaw (PL)
Dhont J.K.G.-Forschugszentrum Jülich, Institute of Complex Systems (DE)
Lisicki M.-other affiliation
Wajnryb E.-IPPT PAN
Youngf Y.N.-New Jersey Institute of Technology (US)
Lang P.R.-Forschugszentrum Jülich, Institute of Complex Systems (DE)