Volume 80, Number 5, December 2007
Article Number 56001
Number of page(s) 6
Section Condensed Matter: Structural, Mechanical and Thermal Properties
Published online 25 October 2007
EPL, 80 (2007) 56001
DOI: 10.1209/0295-5075/80/56001

Dispersal of sticky particles

Ramana Reddy and Sanjeev Kumar

Department of Chemical Engineering Indian Institute of Science - 560 012 Bangalore, India

received 5 August 2007; accepted in final form 3 October 2007; published December 2007
published online 25 October 2007

In this paper, we show through simulations that when sticky particles are broken continually, particles are dispersed into fine dust only if they are present in a narrow range of volume fractions. The upper limit of this range is 0.20 in the 2D and 0.10 in the 3D space. An increase in the dimensionality of space reduces the upper limit nearly by a factor of two. This scaling holds for dispersal of particles in hyperdimensional space of dimensions up to ten, the maximum dimension studied in this work. The maximum values of volume fractions obtained are significantly lower than those required for close packing and random packing of discs in 2D and spheres in 3D space. These values are also smaller than those required for critical phenomena of cluster percolation. The results obtained are attributed to merger cascades of sticky particles, triggered by breakup events. A simple theory that incorporates this cascade is developed to quantitatively explain the observed scaling of the upper limit with the dimensionality of space. The theory also captures the dynamics of the dispersal process in the corresponding range of particle volume fractions. The theory suggests that cascades of order one and two predominantly decide the upper limit for complete dispersal of particles.

64.60.Ht - Dynamic critical phenomena.

© Europhysics Letters Association 2007