Determining the size distribution-defined aspect ratio of rod-like particles

Mineral particles are used in many industrial applications as fillers, in coatings, as ad- and absorbers or in catalysis. In these fields the particle size and shape may control the final performance and properties of the minerals. This work aims to develop a size distribution and surface area defined particle aspect ratio for rod-like particles, using a previously discussed improvement of the input parameters to the Hohenberger model. The tested aragonite particles were shown to have an aspect ratio of ~ 2 determined using laser scattering particle size data and surface area data, proven by image analysis. Palygorskite showed the limitation of the current model with respect to the surface area input parameter as measured by nitrogen adsorption due to its internal porosity. An aspect ratio of 21 of the fibrous material was calculated in contrast to the value of 7 found by image analysis. The calculation procedure can thus be recommended to approximate the aspect ratio of non-porous fibrous and rod-like particles in a fast, easy and reproducible way.

► Development of a model for the calculation of aspect ratio of rod-like minerals.
► Evaluation of different particle size measurement techniques.
► Comparison with image analysis and other particle size based aspect ratio models.
► Determination of aspect ratios for micro- and nano-sized materials.