Experimental Methods in Chemical Engineering: Particle Size Distribution by Laser Diffraction—PSD

Abstract

Particle size is the top cited physical property researchers report in The Canadian Journal of Chemical Engineering and among the top properties in all science disciplines. [1] Techniques to measure particle size distribution (PSD) include physical operations like sieving and sedimentation, and spectroscopic techniques like laser diffraction image analysis based on optical and electron microscopy, and elecro-zone instruments. Here we concentrate on laser diffraction analysis (LDA) and review its basic principles, operations, limitations, uncertainties, and mention how it compares to other techniques. LDA is an instantaneous, user-friendly, convenient, and non-destructive method to assess PSD of inorganic powders. It measures the scattering angle and intensity of light after it passes through diluted particle dispersions suspended in either a gas or liquid. The Mie theory is an exact solution to resolve the diffraction intensity of light caused by particles that applies to while the Fraunhoffer approximation applies only to particles greater than 20 μm. The 95 % confidence interval of five measurements of 56 μm and 0.1 μm irregularly shaped polyhedrons was ± 2.5 %. Based on a bibliometric analysis of LDA of the top 10 000 cited articles in 2016 and 2017, the major research clusters are: particle measurement, powder behaviour, pharmacy, comminution, and adsorption. Future work will continue to introduce more laser sources, combine multiple technologies, implement mobile light sources (dynamic light scattering), and better define characterize irregularly shaped particles.

Experimental methods in chemical engineering: Zeta potential

“…journal published 16 articles that mention the technique. [43,48,[50][51][52][53][54][55][56][57][58][59][60][61][62][63] The hot topics in the journal relate to the oil industry including asphaltene adsorption on calcite packs, [56] improved heavy oil recovery by injecting alkaline ionic slugs (blue cluster), [54] and rheological properties for composite fluids for fracturing and in mineral processing (green cluster). [58,61] Other topics relate to nanoparticles in polymers (red cluster) and bioimaging, [43,48] drug delivery (red cluster), [50] and environmental remediation (yellow cluster).…”

The Effect of Drop Shape, Sensing Volume and Raindrop Size Statistics to the Scattered Field on 300 GHz

“…The largest differences in polarization ratios between the elliptical and spherical drop models could be seen at grazing angles and at angles close to perpendicular to the incident wave. This may be of interest if rain is analyzed in the THz range with methods similar to polarization sensitive laser diffraction techniques [44].…”

Experimental methods in chemical engineering: Scanning electron microscopy andX‐ray ultra‐microscopy—SEMandXuM

“…However, as with all microscopy, the small field of view limits the sample size that compromises determining morphological properties such as average particle size, porosity, and characteristic shape. [ 2 ] Furthermore, unlike visible light microscopy (photons), energetic electron beams require a vacuum (0.01–100 μPa) and cause sample damage and sample charging. Although modern electron microscopes are commonplace and more user‐friendly than ever, only experienced practitioners get the most out of an instrument and avoid pitfalls and artefacts associated with the nature of the technique.…”