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Colloids on curved surfaces: nucleation, migration and frustration

By: Mark Miller
From: Department of Chemistry, University of Durham, United Kingdom.
At: zoom (https://videoconf-colibri.zoom.us/j/82713324766)
[2021-11-04] 11:00

Colloidal particles trapped at an interface constitute a (pseudo)two-dimensional material embedded in three-dimensional space.  Any curvature of the interface can profoundly alter the material's structural, thermodynamic and dynamic properties.  In this talk, I will cover three broad phenomena that arise from different types of curvature.  Firstly, I will show how to account for constant Gaussian curvature when describing the nucleation of a liquid-like droplet from the gas-like state when the particles are confined to a spherical surface.  Here, confinement, ensemble and geometry must all be accounted for.  Moving to torus, I will explain how non-uniform curvature leads to a coupling between location and the phase of matter.  New thermodynamically stable states may arise, and phase transitions are accompanied by the wholesale migration of matter.  Finally, inspired by recent experimental work, I will present preliminary results for conical surfaces, which have mean curvature but zero Gaussian curvature.  In this case, crystal growth is almost always frustrated, giving rise to unusual structural defects.