Segregation by friction

Abstract

Granular materials are known to separate by size under a variety of circumstances. Experiments presented here and elucidated by modeling and MD simulation document a new segregation mechanism, namely segregation by friction. The experiments are carried out by placing steel spheres on a horizontal plane enclosed by rectangular sidewalls, and subjecting them to horizontal shaking. Half the spheres are highly smooth; the remainder are identical to the first half, except that their surfaces have been roughened by chemical etching, giving them higher coefficients of friction. Segregation due to this difference in friction occurs, particularly when the grains have a relatively long mean free path. In the presence of an appropriately chosen small ``hill'' in the middle of the container, the grains can be made to completely segregate by friction type.

7 pages, 5 figures (one photo), epl.cls req'd

References in corpus (4)

• Towards granular hydrodynamics in two-dimensions
• Sand as Maxwell's demon
• Dynamics of spherical particles on a surface: About collision induced sliding and other effects
• Dynamics of two-particle granular collisions on a surface

Cited by in corpus (4)

• Segregation induced by inelasticity in a vibrofluidized granular mixture
• Competition of Brazil nut effect, buoyancy, and inelasticity induced segregation in a granular mixture
• The pseudo-two-dimensional dynamics in a system of macroscopic rolling spheres
• Diffusion and velocity correlations of the phase transitions in a system of macroscopic rolling spheres