2009/01/31 by Pietro Cicuta, Dominic Vella · 2 citations
Agricultural and Biological Sciences · Engineering · Materials Science · Physics and Astronomy · #Granular flow and fluidized beds #Pickering emulsions and particle stabilization #Proteins in Food Systems #cond-mat.soft
paper · pdf · doi:10.1103/physrevlett.102.138302
published as Phys. Rev. Lett. 102, 138302 (2009) · 4 pages, 4 figures, revised according to referees comments
openalex publication_date 2009/04/03 · arxiv created 2009/04/04 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We consider a monolayer of particles floating at a horizontal liquid-gas interface-a particle raft. Upon compressing the monolayer in a Langmuir trough, the particles at first pack but ultimately the monolayer buckles out of the plane. We measure the stress profile within the raft at the onset of buckling and show for the first time that such systems exhibit a Janssen effect: the stress decays exponentially away from the compressing barriers over a length scale that depends on the width of the trough. We find quantitative agreement between the rate of decay and the simple theory presented by Janssen and others. This demonstrates that particle rafts have a granular, as well as elastic, character, which is neglected by current models. Finally, we suggest that our experimental setup may be suitable for exploring granular effects in two dimensions without the complications of gravity and basal friction.