title: Spreading of triboelectrically charged granular matter.
abstract: We report on the spreading of triboelectrically charged glass particles on an oppositely charged surface of a plastic cylindrical container in the presence of a constant mechanical agitation. The particles spread via sticking, as a monolayer on the cylinder's surface. Continued agitation initiates a sequence of instabilities of this monolayer, which first forms periodic wavy-stripe-shaped transverse density modulation in the monolayer and then ejects narrow and long particle-jets from the tips of these stripes. These jets finally coalesce laterally to form a homogeneous spreading front that is layered along the spreading direction. These remarkable growth patterns are related to a time evolving frictional drag between the moving charged glass particles and the countercharges on the plastic container. The results provide insight into the multiscale time-dependent tribolelectric processes and motivates further investigation into the microscopic causes of these macroscopic dynamical instabilities and spatial structures.
authors.affiliation: Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400-005, India.
authors.forename: Deepak
authors.initials: D
authors.lastname: Kumar
authors.affiliation: Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400-005, India.
authors.forename: A
authors.initials: A
authors.lastname: Sane
authors.affiliation: Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400-005, India.
authors.forename: Smita
authors.initials: S
authors.lastname: Gohil
authors.affiliation: 1] Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400-005, India [2] Program in Materials Science, Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, California 92093, USA.
authors.forename: P R
authors.initials: PR
authors.lastname: Bandaru
authors.affiliation: Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400-005, India.
authors.forename: S
authors.initials: S
authors.lastname: Bhattacharya
authors.affiliation: Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400-005, India.
authors.forename: Shankar
authors.initials: S
authors.lastname: Ghosh