2014/12/17 by Joost de Graaf, de Graaf, Joost, Georg Rempfer +3
Chemistry · Materials Science · Physics and Astronomy · #Electrostatics and Colloid Interactions #FOS: Physical sciences #Micro and Nano Robotics #Pickering emulsions and particle stabilization #Soft Condensed Matter (cond-mat.soft)
paper · pdf · doi:10.48550/arxiv.1412.5331
openalex publication_date 2014/12/17 · openalex created_date 2022/10/01 · openalex updated_date 2026/07/28
Colloidal spheres with a partial platinum surface coating perform\nauto-phoretic motion when suspended in hydrogen peroxide solution. We present a\ntheoretical analysis of the self-propulsion velocity of these particles using a\ncontinuum multi-component, self-diffusiophoretic model. With this model as a\nbasis, we show how the slip-layer approximation can be derived and in which\nlimits it holds. First, we consider the differences between the full\nmulti-component model and the slip-layer approximation. Then the slip model is\nused to demonstrate and explore the sensitive nature of the particle's velocity\non the details of the molecule-surface interaction. We find a strong asymmetry\nin the dependence of the colloid's velocity as a function of the level of\ncatalytic coating, when there is a different interaction between the solute and\nsolvent molecules and the inert and catalytic part of the colloid,\nrespectively. The direction of motion can even be reversed by varying the level\nof the catalytic coating. Finally, we investigate the robustness of these\nresults with respect to variations in the reaction rate near the edge between\nthe catalytic and inert parts of the particle. Our results are of significant\ninterest to the interpretation of experimental results on the motion of\nself-propelled particles.\n