Average cluster sizes and cluster size distributions of superfine nickel particles in light media

Abstract

Effects of shear rates on average cluster sizes (ACSs) and cluster size distributions (CSDs) in uni-and bi-systems of partly charged superfine nickel particles were investigated by Brownian dynamics, and clustering properties in these systems were compared with those in non-polar systems. The results show that the ACSs in bi-polar systems are larger than those in the non-polar systems. In uni-polar systems the behavior of clustering property differs: at the lower ionic concentration (10%), repulsive force is not strong enough to break clusters, but may greatly weaken them. The clusters are eventually cracked into smaller ones only when concentration of uni-polar charged particles is large enough. In this work, the ionic concentration is 20%. The relationship between ACS and shear rates follows power law in a exponent range of 0.176−0.276. This range is in a good agreement with the range of experimental data, but it is biased towards the lower limit slightly.