2012/08/04 by Atul Varshney, A. Sane, Shankar Ghosh +1 · 15 citations
Chemistry · Materials Science · Physics and Astronomy · #Amorphous solid #Anomaly (physics) #Chemical physics #Chemistry #Composite material #Condensed matter physics #Crystallography #Geology #Material Dynamics and Properties #Materials science #Mechanics #Particle (ecology) #Phase transition #Physics #Pickering emulsions and particle stabilization #Shear (geology) #Surfactants and Colloidal Systems #cond-mat.dis-nn #cond-mat.soft
paper · pdf · doi:10.1103/physreve.86.031402
published in Physical Review E 86(3), 031402 (American Physical Society)
arxiv created 2012/08/04 · openalex publication_date 2012/09/26 · arxiv updated 2015/06/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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 amorphous states, i.e., a low density "less-rigid" state and a high density "more-rigid" state, as a function of particulate number density (Φ). The former is shown to be a capillary bridged solid and the latter is shown to be 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 spatial profile of the displacement field with Φ. 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.