The nature of organic species associated with clay minerals plays a significant role in several processes, from hydrocarbon recovery in oil sands to contaminated soil remediation and water treatment. In this work, we address the use of scanning transmission X-ray microscopy (STXM) in conjunction with near edge X-ray absorption fine structure (NEXAFS) spectroscopy to study the microstructure and chemistry of organic–clay associations in situ. A model system based on methylene blue and illite is used to explore the sensitivity of NEXAFS microscopy to these interactions, and to identify and resolve experimental challenges in these measurements. We find that sample contamination from X-ray induced photodeposition is a significant problem in STXM microscopy, but also that this problem can be substantially reduced with a liquid nitrogen cooled anticontaminator. With appropriate sample preparation and experimental procedures, we find that STXM microscopy is sensitive to thin carbon adsorbates on clay surfaces.

Sodium A-zeolite with different platinum contents were prepared by directly incorporating platinum precursor (Pt(NH3)4Cl2) into the zeolite during synthesis. Pt/KA-zeolite was then obtained by ion-exchange with KCl solution. The effect of platinum concentration on the crystal morphology and platinum dispersion was investigated by hydrogen chemisorption, scanning electron microscopy (SEM), X-ray diffraction (XRD), and time-of-flight secondary ion mass spectrometer (TOF-SIMS). SEM results revealed a bimodal crystal size distribution for NaA-zeolite with low platinum concentration (<1wt%). Chamfered edges were found for all the larger cubic crystals (∼4μm). Two types of cubic crystals, smooth surface cubes with chamfered edges and rough surface cubes, were observed for the smaller crystals (∼400nm). The proportion of the rough surface nanosized cubes increased as the platinum content increased. At about 4wt% platinum, only nanosized rough surface cubic crystals were obtained, which were transformed into nanocrystals of KF-zeolite after ion-exchange with KCl, as indicated by X-ray diffraction results. TOF-SIMS data taken before and after sputtering the surface layers revealed that platinum was distributed homogeneously inside of the zeolite, which was supported by hydrogen chemisorption results, indicating that platinum particles were confined in the zeolitic cages for both the microsized and nanosized cubic crystals. A mechanism was proposed to elucidate the role of platinum precursor on the nucleation and growth of nanosized zeolite, which is consistent with all of the characterization results.

Conventional laboratory x-ray diffraction techniques are generally used to characterize minerals in oil sand ores and other extraction process streams and can usually provide mineralogical insight into reasons for poor processability. Often, however, a greater level of detail is required to quantify low levels of mixed layering in clay minerals and the multitude of non-clay minerals in the ores. The more intense x-ray sources available at synchrotrons with their inherent high resolution and tunable wavelength can often help in providing this level of detail. In addition, x-ray microscopy can help to characterize the organic contaminants that commonly affect clay behaviour in industrial processes. In this study, low levels of mixed layering of smectite were observed in the kaolinite and illite phases using synchrotron x-ray diffraction, in addition to heavy minerals undetectable using a laboratory rotating anode x-ray source. Using scanning transmission x-ray microscopy, the speciation of carbon components adsorbed on clay minerals after bitumen extraction suggests a preferential affinity of the clay minerals for high-molecular-weight aromatics in bitumen.

The surface area of the individual phyllosilicates (clay minerals) in Athabasca oil sands determined from XRD crystallite size measurements was found to be comparable to the bulk surface area measured by ethylene glycol monoethyl ether adsorption. The primary phyllosilicates are kaolin and illite but the large surface area is imparted by varying degrees of smectitic interstratifications in the primary phyllosilicates. The crystallite size information of each phyllosilicate was extracted from the 00l X-ray diffraction peaks using both the BertautWarren-Averbach (BWA) technique and Williamson-Hall (W-H) plots. The surface area was then determined from the aspect ratios that had been observed for the individual phyllosilicates. The ability to quantify the surface area contributions from individual phyllosilicates in the oil sands solid matrix is important for developing models to predict tailings behaviour and the release water chemistry.

A chemical kinetics study of the functional groups -OC2H5, SH-, and S2- was carried out for the sol-gel processing of GeS2 from hydrogen sulfide and germanium ethoxide in toluene. A mass balance of the reaction components was monitored by potentiometric titrations of SH- and S2- with the Ag/Ag2S ion-selective electrode. The study was performed for different concentrations of precursors at different molar ratios and temperatures. The results indicate that the proposed reaction mechanism was simplified under appropriate reaction conditions. Experimentally determined rate constants of thiolysis and condensations demonstrate that thiolysis is slow and that condensations are fast steps, regardless of reaction conditions (concentration, rate, and temperature). A study of the temperature effect on the reaction rate constants shows that they increase with temperature in accord with both Arrhenius law and transition-state theory. Activation energies, E,, and activation parameters DeltaS(double dagger), DeltaH(double dagger), and DeltaG(double dagger) were determined for thiolysis and condensation reactions.

A GeS2 gel was prepared by sol–gel processing of Ge(OEt)4 and H2S in toluene solution. The effects of H2S and germanium ethoxide concentrations, concentration ratio, and temperature on the microstructure of the prepared GeS2 gels were studied. It was found that the concentrations of the reactants had the most significant influence on primary particle size and gel morphology. The microstructure of the dried gels was characterized by nitrogen BET analysis, SEM, powder XRD analysis, and infrared spectroscopy. Results indicate that the GeS2 gels are amorphous colloidal xerogels regardless of the reaction conditions and length of aging.

Low energy, replica-based, and cryogenic scanning electron microscopy, and reflected visible light and fluorescence modes of confocal laser scanning microscopy, were applied to the imaging of mobile, non-equilibrium polymer-thickened and gelled-foams in porous media. As a result information was obtained about the morphology of some non-equilibrium foam lamellae in real porous media. In contrast to equilibrium (or near-equilibrium) foam, the structure of these non-equilibrium, viscous foams flowing through porous rock is quite similar to that observed in etched-glass micromodels. The foam films are lamellar, three-dimensionally arranged in various structures, and exhibit foam lamellae thicknesses ranging from about 1–12 μm. This thickness range is much narrower than is observed for bulk dynamic foams. The present measurements also show that foam lamellae in porous media can extend for considerable distances, greater than the length of individual pores, if oriented parallel to the overall direction of flow. In other cases, foam lamellae can span across the entrances to multiple pores. In the context of improved oil recovery, the latter configuration would cause blocking and diverting of injected fluids whereas the former configuration would cause only reduced permeability of the pores to injected fluids. These results are important to the optimal design of polymer-thickened and delayed-gelling foams for water shut-off applications in the near-wellbore regions of oil and gas producing wells, and for blocking and diverting applications in reservoirs undergoing secondary and tertiary flooding processes.

Synthesis of metal sulfides has been demonstrated by the example of monoclinic germanium disulfide produced by reaction of the sol-gel product with sulfur. The elemental sulfur, in turn, was obtained as the result of oxidation of H2S in the presence of concentrated sulfuric acid. This sulfur was transported into a toluene solution of germanium ethoxide and found to be homogeneously distributed within the gel. Heat treatment of the sol-gel product yielded single-phase GeS2. Products before and after heat treatment were characterized by IR, XRD, SEM and EDXA measurements.

A sol-gel process has been developed for the chemical synthesis of ZnS at room temperature using zinc tert-butoxide and H2S as precursors in a toluene solution. The obtained reaction product was a yellow semi-transparent gel which dried to a reddish-orange solid. Characterization of the dried gel by XRD, IR and EDS confirmed that the product is ZnS with a Zn5 atomic ratio ≈ 1:1.

Synthesis of GeS2 via a sol-gel process using germanium ethoxide and hydrogen sulfide in toluene resulted in a gel aggregate with an apparent Ge/S ratio 1:1.8. Special precautions were necessary to protect the reaction mixture from water contamination which produced GeO2. Results indicated that the main source of water was the hydrogen sulfide gas, Heat treatment of the produced GeSx gel yielded a product with Ge/S ratio 1:2.3. The sol-gel prepared materials and their heat-treated products were characterized by various methods.

Significant incentives remain for decreasing the mean solids and water content and their variability in combined extraction froth from Athabasaca oil sands, both in the hot water processes now commercially implemented, and in projected processes typically operating at lower temperatures. The oil sand can be conditioned in different ways to generate aerated bitumen droplets which can be recovered as a froth by flotation. The froth formation processes determine the quantities of entrained water and solids, and hence froth quality is related to the vertical progression of physical structures in the froth layer. A sampling method was developed to take frozen samples simultaneously from different depths in the froth layer, for the first time, and applied in pilot plant extractions of Athabasca oil sands, operating in either the commercial (Clark) or a development (OSLO) configuration at various temperatures. The patterns of froth structures were rather similar, with minor differences more related to the process temperature than to the oil sand conditioning procedure. The froth structure progressed from loosely packed aerated bitumen droplets at the bottom to bitumen-continuous at the top with an extensive water-continuous middle region containing distorted aerated bitumen droplets and comprising approximately 70% of the total froth depth. An abrupt phase inversion had been expected but was dearly absent. A key factor determining the froth quality appears to be the ability of the bitumen droplets to distort without coalescing, and so to pack more closely allowing continued drainage of the aqueous phase. Implications for froth quality improvement are discussed.

Interface structure of a YBa 2 Cu 3 0 7 .x /N/ YBa 2 Cu 3 0 7 .x superconductor/normal metal/superconductor Josephson junction using YBa 2 Cu 2 79 Co 0 21 O 7 .X as the normal barrier N

The results of an experimental study aimed at evaluating the spontaneous combustion characteristics of two western Canadian low rank coals thermally upgraded in steam at varying temperatures are discussed. The spontaneous combustion characteristics of the coals were determined using a method developed at CANMET's Coal Research Laboratory in Devon, Alberta. The liability to spontaneous combustion of the two coals was reduced when thermally treated and further decreased with increase in treatment temperature. The decrease in liability was also found to be a function of loss of both the equilibrium moisture and oxygen-containing functional groups from the coal. The oxygen absorption capacity of the coal was also reduced after thermal treatment.

Leaching experiments have been carried out on samples of ordinary portland cement (OPC), sulphate-resistant portland cement (SRPC) with fly ash (FA) added and an alumina cement (AC), with each receiving various concentrations (0.1–1.0 M of chromium (Cr6+), vanadium (V5+) and cadmium (Cd2+. The samples were prepared and evaluated with a statistical experimental matrix corresponding to a Box-Behnken fractional factorial design. Leaching was done in PTFE vessels using the standard TCLP (toxicity characteristic leaching procedure of the U.S. Environmental protection Agency). Analyses of the leachates were carried out for elements Cr, Cd, V, Si, Al, Ca and Fe by inductively coupled plasma spectroscopy. Selected solid samples were investigated before and after leaching by scanning electron microscopy, in conjunction with energy dispersive X-ray spectrometry, and by scanning transmission electron microscopy on thinned specimens. The normalized mass losses of chromium varied between 3.3 103-tand 3.5 101-t kg/m2. Calculated maximum release was found for a hypothetical cement with approximately 20% alumina, while minimum release was found for AC with 36.7% alumina. The normalized mass losses of vanadium varied between 110−3 and 810−2 kg/m2. Calculated maximum release was found for a hypothetical cement with approximately 25% alumina and minimum release was found for OPC. All samples of the cadmium series except three showed solution concentrations below the detection limit (0.1 ppm), suggesting very effective retention of this element by all three cement matrices investigated.

This chapter outlines emulsion charaterization techniques ranging from those commonly found in field environments to those in use in research laboratories. Techniques used in the determination of bulk emulsion properties, or simply the relative amount of oil, water, and solids present, are discussed, as well as those characterization methods that measure the size distribution of the dispersed phase, rheological behaviour, and emulsion stability. A particular emphasis is placed on optical and scanning electron microscopy as methods of emulsion characterization. Most of the common and many of the less frequently used emulsion characterization techniques are outlined, along with their particular advantages and disadvantages.

The relatively fine size consist of western Canadian coals can occasionally contribute to dustiness. Coal dustiness is generally evaluated on the basis of the ASTM test D547. However, the ASTM test is often inadequate when one is determining the effectiveness of dust control agents in field situations and this has prompted the development of several alternatives The limitations of the ASTM test are discussed along with alternatives which have been developed for use at CANMET' s Coal Research Laboratory in Devon, Alberta. The results of selected dust control tests will be presented along with the implications of dust control on product specifications