Amorphous to amorphous transition in particle rafts

Abstract

Space-filling assemblies of athermal hydrophobic particles floating at an air-water interface, called particle rafts, are shown to undergo an unusual phase transition between two i.e., a low density `less-rigid and a high density `more-rigid' amorphous states as a function of particulate number density ($\Phi$). The former is shown to be a capillary-bridged solid and the later a frictionally-coupled one. Simultaneous studies involving direct imaging as well as measuring its mechanical response to longitudinal and shear stresses show that the transition is marked by a subtle structural anomaly and a weakening of the shear response. The structural anomaly is identified from the variation of the mean coordination number, mean area of the Voronoi cells and the spatial profile of the displacement field with $\Phi$. The weakened shear response is related to local plastic instabilities caused by the depinning of the contact-line of the underlying fluid on the rough surfaces of the particles.

References in corpus (8)

• Unified study of glass and jamming rheology in soft particle systems
• Elasticity of an interfacial particle raft
• Do Athermal Amorphous Solids Exist?
• Non-affine response: jammed packings versus spring networks
• Jaming and Geometry of Two-Dimensional Foams
• Granular Character of Particle Rafts
• New jamming scenario: From marginal jamming to deep jamming
• Heterogeneous structure of granular aggregates with capillary interactions

Cited by in corpus (5)

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• Avalanches, Plasticity, and Ordering in Colloidal Crystals Under Compression
• Mechanics of a granular skin
• Cluster Formation and Relaxation in Particle Rafts under Uniform Radial Expansion