Powder X-ray diffraction unit for the characterization of food and soft materials

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A powder X-ray diffraction (XRD) unit is a widely-used instrument in multiple disciplines. It is mainly used to fingerprint crystalline and liquid crystalline materials. Lattice strain as well as crystallite size can also be studied with this technique. In Food Science, XRD is widely used to study the polymorphism of edible fats, the crystallinity of starch and other polysaccharide polymers, like cellulosics. It is also used in the study of packaging films where the balance of crystalline and amorphous states of polymers strongly influence package mechanical properties and permeability. The instrument is popular among academic researchers, but it is also in very high demand by industry (national and international), since industry rarely/never has such instruments in-house. The Marangoni lab is considered to be one of the main laboratories in the world for the study of the solid-state structure and nanostructure of edible fats and fat mimetics. Many advances in the crystallography of these materials have taken place here, using a Rigaku Multiflex diffractometer purchased with CFI funds in 2002. The intrument has now failed and is not supported by Rigaku any longer. Specifically, the pressure and flow gauges in the instrument are damaged and the gears on the goniometer, the "heart" of the instrument, are worn down and loose. Thus, it is not possible to accurately control angular resolution anymore. This instrument is central and essential to Marangoni's NSERC-funded Discovery program and used by all of the students, post-docs and technicians in his group, not to mention everyone else at the University of Guelph who uses the machine as well. We cannot accept any more industrial contracts at this time either. This breakdown happened in mid September and has been a bit of a serious "show-stopper". We cannot support the work of Pensini, Wright, Rogers Joye, Lim, Keener and others either. On a positive note, the new powder X-ray diffraction, the Miniflex machine, is truly remarkable. First of all, these machines are now benchtop machines about 1/5th of the original size - gone are the large transformers and Haskis refrigeration units. The detectors are ultra-fast, cutting down on analysis time by 1/10th of the time, allowing for the study of the kinetics of processes! The instrument comes with a dedicated Anton Paar cooling and heating unit, and Rigaku has recently added a special lens, allowing measurements to be made below 1 degree 2theta. (Near) small-angle X-ray scattering work can now be reliably carried out! All of this plus new advances in the software used for the analysis of spectra, makes this instrument an amazing deal for CAD$150,000. This new instrument would guarantee the continued high productivity and world-class quality of the research programs in the Departments of Food Science and Engineering at Guelph, would continue help support the Canadian Food Manufacturing Industry, and help develop the foods of the future.