Determining the size distribution-defined aspect ratio of platy particles

Mineral particles are used in many industrial applications as fillers, in coatings, as ad- and absorbers or in catalysis. In these manifold fields the particle size and shape control the final performance and properties of the minerals. Much has been published using different techniques to describe the aspect ratio of platy particles. This study describes a simple method to calculate aspect ratios for platy particles based on particle size data and specific surface area determined by nitrogen adsorption, exemplified with three different talc grades which vary in their amount of specific surface area and geological origin, as well as with one nano-sized synthetic Laponite (Laponite® RD) to illustrate the sensitivity to input parameters and their physical interpretation. The contrast between mass/volume and number probability distribution of particle size is discussed and illustrated. ► Development of a model for the calculation of aspect ratio of disc-like minerals. ► Evaluation of different particle size measurement techniques. ► Determination of aspect ratios for micro- and nano-sized materials. ► Comparison with other aspect ratio models that base on particle size data.