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Complementary state-of-the-art optical, scanning electron, and X-ray microscopy techniques have been used to study the morphology of Apollo 11 lunar soil particles (10084-47). The combination of innovative lighting geometries with image processing of a through focal series of images has allowed us to obtain a unique collection of high-resolution light micrographs of these fascinating particles. Scanning electron microscopy (SEM) stereo-pair imaging has been exploited to illustrate some of the unique morphological properties of lunar regolith. In addition, for the first time, X-ray micrographs with submicron resolution have been taken of individual particles using X-ray ultramicroscopy (XuM). This SEM-based technique lends itself readily to the imaging of pores, cracks, and inclusions and allows the internal structure of an entire particle to be viewed. Rotational SEM and XuM movies have also been constructed from a series of images collected at sequential angles through 360°. These offer a new and insightful view of these complex particles providing size, shape, and spatial information on many of their internal features.

An industrial V-P-O catalyst (DuPont), comprising vanadyl pyrophosphate crystallites encapsulated by a silica shell, has been investigated. Reaction evaluation for butane oxidation was conducted over (i) the catalyst precursor, (ii) the calcined precursor and (iii) equilibrated material (2 years on-line) in a fixed-bed reactor. Characterization was conducted on these three samples by XRD, SEM, TEM and XPS. The core–shell particles have also been examined with a novel X-ray ultramicroscopy (XuM) technique which reveals the internal structure without having to section the material. The microstructural and surface compositional changes that have occurred over the course of its industrial lifespan in a fluidized bed reactor are correlated with the catalytic activity measurements.

Development of optimal scaffolds for bone tissue engineering and regeneration is still a challenge, since many materials and structures have been proposed but few have reached clinical expectations. This work reports on the preparation and characterization of SiO2-CaO and SiO2-CaO-P2O5 sol–gel derived monoliths, with potential application as glass scaffolds for bone regeneration, exhibiting a nano/macro trimodal pore size distribution, including pores of ~100’s of micrometers (μm), several microns and just a few nanometers (nm) in size. Interconnected macropores (~20–200 μm) have been obtained in the present work by polymerization-induced spinodal phase separation along with the sol–gel transition, when a water soluble polymer [poly(ethylene oxide)] was added to the sol–gel solution; the several-micron pores are spherical and isolated and might be the result of secondary phase separation by nucleation-growth mechanism; the interconnected nanopore (~5–25 nm) structure of the macroporous gel skeleton, on the other hand, was tailored by solvent exchange procedures. The morphological and textural characterization of these materials was performed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray ultra microscopy (XuM), nitrogen adsorption and mercury intrusion porosimetry. The factors affecting the porosity exhibited by the scaffolds, such as glass composition and solvent exchange conditions, have been assessed.

The catalytic properties of (VO)2P2O7/α-Sb2O4 mixed oxides system for n-butane mild oxidation have been investigated on two mechanical mixtures (M1 and M2) of the same well crystallized (VO)2P2O7 (reference vanadyl pyrophosphate) with two different morphologies of α-Sb2O4. The M1 mixture of (VO)2P2O7 with α-Sb2O4 (1), prepared by oxidation of Sb2O3, leads to the oxidative dehydrogenation (ODH) of n-butane, whereas the M2 mixture of (VO)2P2O7 with a commercial α-Sb2O4 (2) (Aldrich) with a different morphology improves the maleic anhydride selectivity as compared to the reference (VO)2P2O7 catalyst (synergetic effect). After reaction, no ternary VPSbO phase is detected by XRD and DTA and it was controlled that the two α-Sb2O4 oxides are catalytically inactive. The (VO)2P2O7 reference catalyst which produced only maleic anhydride as mild oxidation product shows by XPS a slightly oxidized surface (14% V5+–86% V4+). Contamination of the (VO)2P2O7 phase by migration of Sb species occurs after catalytic reaction in the case of the M1 mixture as shown by XPS, LEIS and TEM–EDX analysis. XPS showed that (VO)2P2O7 is partially superficially reduced (86% V4+–14% V3+). This feature is consistent with the decrease of acidity as observed by pyridine adsorption–desorption. In opposition with the M1 mixture, no contamination of the (VO)2P2O7 phase is observed after catalytic reaction in the case of the M2 mixture. The XPS study shows, in this case, that (VO)2P2O7 is partially oxidized (30% V5+–70% V4+) at a higher level than for the reference (VO)2P2O7 catalyst. This situation is associated with the increase of selectivity observed for maleic anhydride (synergetic effect). The difference in the catalytic results for the two M1 and M2 mixtures, as compared to the (VO)2P2O7 reference catalyst, can be explained by the alteration of the surface composition of (VO)2P2O7 and the distribution of vanadium oxidation state due to different interaction between Sb2O4and (VO)2P2O7, depending on the orientation of the α-Sb2O4 crystals.

A series of mechanical tests have been performed on composites consisting of high-strength carbon fibres in an amine-cured epoxy resin. A comparison has been made between composites containing untreated, commercially treated (electrochemically), and plasma treated fibres. While both treatments improve interfacial adhesion, the manner in which the composite fails is totally different. In composites that contain electrochemically treated fibres failure is, in most cases, matrix dominated, whereas interfacial failure always occurs in samples made from plasma-treated fibres. This behaviour can be explained in terms of the nature of the fibre surface after each type of treatment.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

Supported tungsten oxide catalysts offer a promising alternative for many practical industrial applications involving acidic catalytic reactions. In the past two decades, significant progress has been made in this field and a better understanding of these materials is now developing. However, revealing the structure-activity relationships in supported tungsten oxide catalyst systems is still a great challenge. Previous studies suggest that the catalytic performance is directly related to the charge transfer that occurs during catalytic reaction, including that (i) between the metal oxide active component and the underlying oxide support material, and (ii) between the reactant molecules and the catalytically active tungstate sites.

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

Tungsten oxide supported on ZrO2 is receiving increased attention as a solid acid catalyst due to its important industrial applications, such as the isomerization of C4-C8 alkanes to upgrade gasoline octane number. It is known that the catalytic activity depends on the structure of WOx species and their interaction with ZrO2 support [1], so a thorough structural characterization is essential for establishing any structure-property relationships. Previous studies using a combination of XRD, optical spectroscopy and HRTEM revealed that WOx at low loadings is highly dispersed on ZrO2 as mono-tungstate or poly-tungstate species (Figure 1). Additional disordered WOx clusters appear on samples having intermediate WO3 loadings, which correlate with improved catalytic activity [2]. To date, however, no direct imaging studies of WOx configuration or their interaction with the ZrO2 support, which are important factors for catalytic activity, have been documented.

Vanadium phosphorus oxide (VPO) is commercially used to catalyse the oxidation of n-butane to maleic anhydride (MA). The catalyst itself is formed by activating the hemihydrate precursor VOHPO4.0.5H2O in an n-butane/air mixture at about 400°C for at least 100 hours [1]. Although many authors believe that this reaction is dependent solely on the presence of the crystalline (VO)2P2O7 phase [2], Hutchings et al have argued that the initial reaction step requires a V5+ phase and that selectivity and activity improve if a significant amount of a disordered V4+-V5+ phase is present [3].

Using High Resolution Electron Microscopy, we have investigated the structure/function relationships of the Nd2O3/MgO and MgO/Nd2O3 catalyst systems which are active in the oxidative coupling of methane. In both cases catalytic performance was found to depend critically on the morphology of Nd2O3. We demonstrate that high selectivities are associated with a thin disordered film of neodymia on the MgO surface for the Nd2O3/MgO system whilst for the reverse catalyst, the dominant morphology is a highly disordered cubic form of Nd2O3.

When CoSi2 is grown onto a Si(111) surface it can form in two distinct orientations. A-type CoSi2 has the same orientation as the Si substrate and B-type is rotated by 180° degrees about the [111] surface normal.One method of producing epitaxial CoSi2 is to deposit Co at room temperature and anneal to 650°C.If greater than 10Å of Co is deposited then both A and B-type CoSi2 form via a number of intermediate silicides .The literature suggests that the co-existence of A and B-type CoSi2 is in some way linked to these intermediate silicides analogous to the NiSi2/Si(111) system. The phase which forms prior to complete CoSi2 formation is CoSi. This paper is a crystallographic analysis of the CoSi2/Si(l11) bicrystal using a theoretical method developed by Pond. Transmission electron microscopy (TEM) has been used to verify the theoretical predictions and to characterise the defect structure at the interface.

CoSi2 layers grown on clean Si(111) substrates can form in two distinct orientations. A-type CoSi2 has the same orientation as the Si substrate, whereas the B-type CoSi2 is rotated by 180° about the [111] surface normal. The epitaxial films studied were prepared by depositing Co on to a Si(111) surface at room temperature under UHV conditions and annealing at 650°C. This produces mixed A and B-type CoSi2 of approximately 50Å thickness. Fig.1a shows a diffraction pattern taken on tilting the bicrystal such that the beam direction is [114] in the Si and [110] in B-type CoSi2, the corresponding schematic diagram is shown in Fig.1b. Dark field microscopy can be used to image g=111 B-type CoSi2 reflections which, if at the exact Bragg condition, give rise to images such as Fig.2.The micrograph shows B-type CoSi2 with some strongly diffracting areas and at least three other different weaker contrasts. This paper is a study of the origins of the contrast effects noted in Fig.2.

For several decades vanadyl pyrophosphate, (VO)2P2O7, has been used commercially as a catalyst for the partial oxidation of n-butane into maleic anhydride (MA) [1]. However due to the moderate specificity to MA production, many research groups still continue to investigate the V-P-O catalyst system with the aim of further improving its overall performance. Now a specialized form of V-P-O catalyst has been developed by DuPont for use in a fluidized bed reactor, which consists of a V-P-O core encased by a mechanically protective porous silica shell. Selected research centers worldwide have received samples of this material for analysis, aiming at combining the results generated, in an effort to further understand the functionality of the V-P-O catalyst.

The oxidation of 5-hydroxymethyl-2-furfural was studied under mild reaction conditions using TiO2-supported Au and Au–Cu catalysts synthesized from pre-formed nanoparticles. Bimetallic gold-copper catalysts display superior activity as compared to monometallic gold. Moreover, after reaction, the bimetallic Au–Cu catalysts can be recovered by filtration and reused without significant loss of activity and selectivity whereas gold materials are not stable. STEM-HAADF imagining and XEDS spectra obtained from bimetallic materials show that particles are homogeneous AuCu alloys. No AuCu ordering or segregation effects were noted from these analyses, and the Au:Cu ratio was quite consistent from particle-to-particle irrespective of its absolute size, proving the efficiency of the original method of synthesis utilized. Isolation effects of gold by copper in the alloy nanoparticles is imagined to play a pivotal role in the reaction. The effect of oxygen pressure, metal loading, reaction time, amount of base and temperature were studied in detail and a 99% yield of furandicarboxylic acid was achieved under optimized reaction conditions.