Geometry and kinetics determine the packing structure on evolving surfaces*

We consider the evolution, arrest and jamming of particulate media on an evolving surface. As the shape changes, local regions of compression and rarefaction induce local solidification or melting and, consequently, rich kinetic effects. Here we resolve the relative influence of kinetics and geometry in determining the structure of a model system: the coalescence of Pickering emulsion droplets that can be arrested by the solid particles coated on the surface. By Monte Carlo simulations, we demonstrate that in the quasi-static regime, the geometry still governs the microstructure of these particles, resembling the spherical crystallography regime explored in previous literature. Conversely if the evolution of surface is fast, the kinetics can change the structure at the arrest point depending on the local surface deformation, with jamming fronts that develop from the compressed area. Other surfaces and particles are explored and we propose a new class "metric jamming" to describe the transition to rigidity under shape deformation.