Powder characterisation

Introduction

Responsable : Paul Bowen

Powder characterisation is an essential step for all aspects of powder technology including particle synthesis, powder dispersion in liquids, surface modification, processing, forming and sintering. Our capacity to monitor the powder characteristics allows synthesis and processing routes to be evaluated and optimised. Moreover the health and safety aspects can be evaluated as the powder characteristics are well defined.

Particle size distribution (PSD) measurement is a particularly strong point at LTP where several different methods are available to analyse powders with sizes ranging from a few nanometres to around a millimetre. The challenge of how best to interpret the data provided by bench-top commercial instruments, the effect of particle shape and instrument reliability have been of key interest to the Powder Technology Laboratory (LTP) over many years.

However no single analytical method alone can be used to reliably characterise a powder: several complimentary methods should be called upon; even for the interpretation of PSDs an estimate of the particle shape and its deviation from the ubiquitous assumption of a sphere model is essential. Complimentary measurements such as specific surface area, microscopy, x-ray powder diffraction, surface (zeta) potential, porosity, spectroscopy and chemical analysis all contribute to define the powder characteristics best suited for a particular use or application.