Far-from-equilibrium Ostwald ripening in electrostatically driven granular powders

TL;DR

This study experimentally investigates cluster size distributions in electrostatically driven granular powders, revealing dynamic scaling behavior similar to Ostwald ripening but with distinct distribution characteristics influenced by cluster mergers.

Contribution

First experimental analysis of cluster size distributions in electrostatically driven granular powders showing deviations from classical Ostwald ripening models.

Findings

Cluster size distribution exhibits dynamic scaling behavior.

Distribution differs from classical Wagner distribution.

Better agreement with theory accounting for cluster mergers.

Abstract

We report the first experimental study of cluster size distributions in electrostatically driven granular submonolayers. The cluster size distribution in this far-from-equilibrium process exhibits dynamic scaling behavior characteristic of the (nearly equilibrium) Ostwald ripening, controlled by the attachment and detachment of the "gas" particles. The scaled size distribution, however, is different from the classical Wagner distribution obtained in the limit of a vanishingly small area fraction of the clusters. A much better agreement is found with the theory of Conti et al. [Phys. Rev. E 65, 046117 (2002)] which accounts for the cluster merger.