3D Size and Shape Characterization of Particles

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Author Last Name: 
Prof. Eric Pirard, Max Gregoire
Report Type: 
ARR - Annual Report
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This report presents the results of a ten month ongoing research on 3D size and shape characterization of particles. This work has been performed at the GeMMe Laboratory under the responsibility of Prof. Eric Pirard and was supported by a research grant from the International Fine Particle Research Institute. This research has two main aspects, firstly reviewing and validating the existing 3D imaging techniques and secondly developing 3D dedicated image analysis and 3D dedicated size and shape parameters. The first part is dedicated to 3D imaging techniques. A set of powder samples with different physical properties was gathered and tested on three optical imaging techniques and two imaging techniques based respectively on x-ray and electron beams. The structured lighting is an optical imager based on the Moiré principle. The infinite focus is a reflected light microscope coupled with a digital image processing taking advantage of the finite depth of focus. The confocal microscope is based on laser reflection and is also associated with a digital image processing. All three techniques are surfometric imaging instruments giving the elevation for the entire image. X-ray and electron tomography are imaging from sections techniques. Their scales of investigation are respectively micrometric and nanometric. The advantages and drawbacks of each 3D imaging technique were enumerated regarding particle characterization specifications. The second part of the report is about 3D image analysis and measurement. Programs were implemented to compute size and shape parameters of individual particles. At this stage of the research, volume, surface area, sieve diameter, aspect ratios and convexity index can be calculated for a particle. All the programs were validated on synthetic particles for which the geometry is completely known. Then, they were tested on 3D images of real powder samples obtained from x-ray and electron tomographies. The last part presents the ongoing researches with intermediate results and the perspectives for the short and medium terms.