Diffraction contrast tomography for powder crystallographic characterization
Powder characterization in the fine chemicals industry is needed to better understand the dry powder behavior and reactivity. This involves acquiring an understanding of the molecular scale as well as crystal structure, microstructure (e.g. inclusions), and macroscale particle morphology (including agglomeration). The first X-ray diffraction study to elucide the structure of an organic crystal was hexamine nearly 100 years ago. Now the authors used the same compound in this work to fully characterize powders of hexamine using a combination of absorption contrast tomography, diffraction contrast tomography and molecular modelling.
The lead author on this work was Parmesh Gajjar, from the Henry Moseley X-ray Imaging Facility, Department of Materials, The University of Manchester. According to Parmesh, “Dragonfly is excellent for us due to its simplicity to combine image data from different modalities as in this case from absorption and diffraction contrast. We use it for its ease of use as well as its powerful segmentation capabilities”.
Video Presentation
Publication
Parmesh Gajjar, Thai T. H. Nguyen, Jun Sun, Ioanna D. Styliari, Hrishikesh Bale, Samuel A. McDonald, Timothy L. Burnett, Benjamin Tordoff, Erik Lauridsen, Robert B. Hammond, Darragh Murnane, Philip J. Withers, Kevin J. Roberts, Crystallographic tomography and molecular modelling of structured organic polycrystalline powders. CrystEngComm, 2021, 23, 2520-2531 (https://doi.org/10.1039/D0CE01712D).
Image and Research Center
NXCT at the Henry Moseley X-ray Imaging Facility
(https://nxct.ac.uk/facilities/manchester/)
Henry Royce Institute - UK National Institute for Advanced Materials Research and Innovation
(https://www.royce.ac.uk/)
Keywords: Powders, Crystalline Powders, Diffraction Constrast Tomography, X-Ray Microscopy
Images
Figure 1: Particles inside tube used for X-ray tomography.
Figure 2: Watershed segmentation reveals particle sizes shown with color coding.
Figure 3: Diffraction contrast CT overlaid to absorption contrast CT image in 2D with color showing different crystal structures in this case.
Figure 4: Overlap of Diffraction contrast CT with regular CT shown in 3D rendering.