3-D Size & Shape Characterization of Particles

Publication Reference: 
53-03
Author Last Name: 
Pirard
Authors: 
Prof. Eric Pirard, Ir. Max Gregoire
Report Type: 
ARR
Research Area: 
Characterisation
Publication Year: 
2007
Publication Month: 
11
Country: 
Belgium

Work carried out this year is essentially focussed on 3-D image analysis. New 3-D shape descriptors completing the range of those introduced last year are defined. A dissolution index is first proposed. It gives an information of how morphology influence the dissolution process. We also implement the decomposition of a particle within its maximum inscribed spheres. From this, we extent in 3-D the computation of particle roundness and roughness. In parallel, we define a new method to quantify and to illustrate the uncertainty related to the assessment of particle size distribution using image analysis.

The two year research have allowed the definition of 3-D size and shape descriptors with a range equivallent to the 2-D one. The 3-D descriptors are optimised in terms of sensitivity and robustness. It will constitute practical tools for the future 3-D size and shape characterization. The methodology developped to quantify particle size distribution uncertainty will be useful for practionners using image analysis (either 2-D or 3-D) to determine the number of particles that must be analysed.

On the other hand, we completely finish the evaluation of 3-D imaging techniques regarding particle characterization specification. Future work will be dedicated to the creation of a new 3-D imaging technique adapted to routine 3-D particle characterization. Finally, X-ray micro-tomography and 3-D image analysis are applied on a real case, size and shape characterization of Zn particles used in battery. Thanks to a satisfying 3-D particle dispersion, the size and the shape of 4500 particles are characterized. The comparaison of the results with 2-D image analysis results and prior knowledges gives credence to the 3-D size and shape characterization.

During the third year of the research, we plan to perform 3-D size and shape characterization of severals real samples. This will fully validate the methods implemented. Another field for future research is the quanfication of cristallinity both in 2-D and 3-D. This issue have not been fully resolved even if it is important in pharmaceutic application.