Physics of Gas Marbles
PhyGaMa is an ANR PRC 2020 project conjointly leaded by Laboratoire NAVIER, Rhéophysique team and Laboratoire FAST, Granulaire et Suspension team
with F. Rouyer, Y. Khidas, V. Langlois, O. Pitois, X. Chateau - Georges Gauthier, Antoine Seguin
Research in line with the pioneer work of Pickering succeeded recently to produce new objects which can be described as gas pockets in air and are named gas marbles[1]. They are made of gas surrounded by a layer of grains constrained by thin liquid film in gas environment. The exceptional mechanical strength of their granular shell promise them to many applications [2]. Among these, we note here that using gas marbles can be relevant for the generation of materials with hierarchical porosity. Moreover, these new hollow marbles offer a promising route to new vibration dampers. Gas marbles were created by closing over itself after detachment under gravity of a granular film created by dipping and removing of a solid horizontal frame through a particle raft at the interface of a soap solution.
2 PhDs have started in automn 2020 :
Rheology of granular films , J. Lalieu
Before using gas marbles, this new meta-material needs to be characterized and its behavior understood. This peculiar material belongs to the global class of granular suspension which rheology still is under development.
The goal the thesis is to study the granular film response to a shear solicitation and to compare it to classical granular suspension. In addition to Strain-Stress measurement, the particle motions will be studied through visualization of the particle laden. In a further step, the influence of the liquid film thickness will be studied. Finally, the results will be confronted to the now used mu(I) rheological law
Granular Film and Gas Marble: controlled creation, N. Retailleau
The main objective of the thesis is to study the physics that control de creation of this new material, in aim to create a gas marble with controlled properties. Experiments at the scale of a granular film will be performed to tune the properties of the liquid film and the grains (size, capillary pressure that controls grains cohesion). Then, different input forces (air jet, gravity) will be tested to evaluate their influence on the formation of gas marbles.
During the PhD, a second step would be to correlate the static behavior of one gas marble and a gas marbles assembly to the properties of the membrane and/or shell.
Finally, the dynamical properties of one gas marbles and gas marbles assembly will be studied by vibrational waves propagation and interpreted in regards to the damping properties of the granular films and the network assembly of the gas marbles. The multi-scale and ternary structure of the material might reveal different coupling modes of propagation (waves propagation in air and in the granular skeleton).
Internships
New proposal might come soon...
If you are interested in working on the subject of gas marbles and granular film, please contact us.