XRD: Phase Identification & Crystallography in Industry 24th May 2012, University of Leicester Registration is open for our XRD one-day meeting. The meeting covers practical topics including Optimising Your Diffractometer and a question and answer forum with experts available to help resolve you problems. There are also speakers on topics including Phase ID of geological materials and Polymorphism. A one-day XRF meeting will take place at the same venue on the 23rd. Fees are £80 (£40 concessions) for one day or both days for £120 (£60 concessions). Some free student places can be offered, please apply for these on the registration form, as always early booking is recommended to secure these places.
Registration is on-line with a secure card payment option and the form gives the choice of either XRF, XRD or both days. NOTE: The catering order has been placed, so just a few extra places left and registration will close as soon as they are taken. These limited places cannot be guaranteed and are strictly on a first come basis. However, a rush of applications before the registration form can be closed may exceed this limit and any oversubscribed places may be revoked.
Abstracts:
Optimising your Diffractometer Judith Shackleton NSG Pilikington There are many wonderful machines on the market today with all sorts of fantastic accessories which are easy fit and make instruments much more flexible. We will talk about various types of diffractometers and where they most useful. Data collection strategies, instrument settings, calibration checks and suitable standards will also be discussed.
Phase ID with the Powder Diffraction File David Taylor Treasurer, International Centre for Diffraction Data. This presentation will touch briefly on the 75 year heritage of the Powder Diffraction File (PDF) and the lasting legacy that still influences the databases of today. A walk through some of the main features of the database will give an insight into some of the ways that the data can be manipulated. With the aid of examples and live demonstrations, the search/match and data mining tools will be used to demonstrate how to find the perfect match of an unknown phase or phases from the 700,000+ phases in the databases. Some of the newer features will be demonstrated and a brief insight given into new some features in the upcoming September release. Phase ID of Geological Materials Cheryl Haidon, University of Leicester The qualitative phase identification of geological materials by powder diffraction is a well established technique. It is, however, not without its challenges and not all minerals can be identified and distinguished with equal certainty. With up to a dozen or more phases present in some samples, peak assignment and overlap become a major factor. Amorphous or fluorescing materials increase the background and make minor phases harder to detect. It is often necessary to include information from other sources, such as sample provenance and chemical (XRF) analysis to achieve a confident identification. Solid solution is common in geological materials, and some minerals have both ordered and disordered forms, depending on the prevailing geological conditions at the time of formation. Certain framework and sheet silicates crystallize in both monoclinic and triclinic systems. Whilst it is possible to discriminate many of these forms in pure phases or with extensive chemical treatment, it is more difficult in a “whole-rock” flat-plate sample, which represents the routine part of mineralogical identification.
“The Knowledge” - A question and answer forum The aim of this session is to generate informal discussion and audience participation with Dave Taylor taking the lead. There will be plenty of experts in the audience to help resolve problems and answer specific questions on any diffraction related topic. You are encouraged to come prepared to share useful hints and tips, bring a few slides on a memory stick and make a short presentation. The success of this session depends on you, so please spare a little time, and come prepared with a question to ask or an answer to share. Holding a phase identification workshop next year will also be discussed to discover the level of support and the topics you would covered. Polymorphism and the Formulation Process Sandie Dann, Department of Chemistry, Loughborough University, Loughborough LE11 3TU Sugars are the most commonly used excipients in direct compression formulations [1]. The compounds are either used as a diluent to make up the required bulk of a solid dosage form when the amount of the drug itself is inadequate or as a carrier in inhalation devices where the sugar is used to carry the drug past the mouth into the alveoli. Technological advances in the way excipients are produced for drug applications has had a number of benefits such as better drug delivery e.g. more particles in the respirable range in inhaler devices or a higher β yield for longer life tablets. However, these new technologies use different conditions of temperature, pressure, solvent and hydration to the traditional methods meaning more polymorphs, hydrates and solvates of both drugs and excipients alike are being discovered all the time. As suggested by McCrone ‘ the number of forms of a known compound is simply relative to the time and money spent in research for the compound ‘[2]. The importance of identifying and determining new polymorphs (and hydrates) and the presence of amorphous forms of compounds used in drug formulations has been recognised by the pharmaceutical industry and led to the implementation of decision trees such as those produced by Byrn [3]. This presentation will focus on how the formulation process, from freeze drying to high shear processing, can change the form of various components in a formulation and with it the material properties. [1] B.B. Sheth, F.J. Bandeling and R.F. Shangrow ‘ Pharmaceutical Dosage Forms: Tablets Volume B. H.A. Lieberman and L. Lachman Eds. Marcel Dekker. New York (1988) [2] W.C. McCrone ‘Physics and Chemistry of the Organic Solid State; D. Fox, M.M. Labe and A. Weissberger. Eds. Interscience New York. (1965) [3] S. Bryn, R.R. Pfeiffer, M. Gatney, B. Hoiburg and G. Poochikan. Pharm Res. 12. 945 (1995)
Uses of X-ray and other Diffraction Methods in Unfolding and Discovering New Materials Paul O’ Brien*, Schools of Chemistry and Materials, University of Manchester Manchester, M13 9PL; UK The use of diffraction methods in understanding new and potentially complex materials will be described. Including: · Novel mesocrystals of anatase · The internal structure of quantum dots · Phase identification in iron chalcogenides and · Phase identification in complex systems Using PXRD in support of the investigation of lithofacies in Carboniferous mudstones · Organic-rich fine-grained successions in the USA, such as the Barnett Shale, are significant shale gas plays. Broadly time equivalent successions exist in the UK; however, the exploration of these is in the early stages. This study examines the temporal and spatial changes in the character and distribution of lithofacies in a stratigraphically well constrained mudstone succession at locations across the UK onshore Carboniferous outcrop belt. · Textures and mineralogy identified by optical and electron optical methods of unusually thin thin sections, combined with geochemical (XRF, XRD and Carbon/Sulphur) and total organic carbon (TOC) data, highlight a range of lithofacies. Key lithofacies, common to all locations, include homogeneous clay-rich or silt-rich mudstones, lenticular silt-bearing/silt-rich mudstones and thinly-bedded mudstones. Individual lithofacies packages vary in thickness from tens of millimetres to a few metres in thickness, and represent changes in the predominant delivery mechanisms for a given period, from suspension settling to advective transport by turbidity and debris flows. · The distribution of the different lithofacies varies between locations. Closer to the sediment supply, mudstones contain a higher proportion of silt-sized grains, exhibit a greater proportion of homogeneous and bedded lithofacies and have average SiO2 of 52%. In contrast, lenticular mudstones dominate the more distal location and are characterised by lower SiO2 (ca. 45%). Organic matter is primarily derived from terrestrial plant debris and microscopic spores with a component of marine algal matter. Higher TOC abundances (typically >2%; up to 6.5%) are associated with the lenticular lithofacies and the thinly bedded lithofacies also contain significant (>2%) TOC. The XRD analysis contributes to this study by highlighting the variation in the composition of the samples, both between lithofacies and location.
X-Ray Diffraction without Sample Preparation G. M. Hansford, Space Research Centre, University of Leicester. A novel X-ray diffraction (XRD) technique which exhibits almost complete insensitivity to the sample morphology has recently been invented at the University of Leicester. A consequence of this unique property is that whole rock specimens become amenable to XRD analysis without sample preparation. The method is suitable for planetary applications, avoiding the need for resource-intensive and technically-challenging sample processing and distribution systems. A diverse range of industrial applications may also potentially benefit from this technology including, for example, geological surveying/prospecting, soil analysis, mining and quarrying, cement manufacture, and archaeology. In this talk I will describe the fundamental principles of the method, and show the results of proof-of-principle experiments. The intrinsic geometry of the method enables a compact, lightweight instrument design with no moving parts, and data acquisition is fast, on the timescale of minutes. The technique also returns x-ray fluorescence (XRF) information about the sample. The main drawback of the method is its low resolution, though I will suggest ways in which this can be overcome at the expense of additional complexity and acquisition time. In addition, I will give an overview of planetary XRD and XRF activities at the Space Research Centre.
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