Papers by Masliyah, Masliyah
Energy & Fuels, Feb 23, 2017
Atomic force microscopy (AFM) is frequently used to elucidate complex interactions in emulsion sy... more Atomic force microscopy (AFM) is frequently used to elucidate complex interactions in emulsion systems. However, comparing results obtained with "model" planar surfaces to curved emulsion interfaces often proves unreliable, since droplet curvature can affect adsorption and arrangement of surface-active species, while droplet deformation affects the net interaction force. In the current study, AFM was utilized to study the interactions between a colloidal probe and water droplet. Force magnitude and water droplet deformation were measured in asphaltene and bitumen solutions of different concentrations at various droplet aging times. Interfacial stiffening and an increase in particle-droplet adhesion force were observed upon droplet aging in bitumen solution. As reported in our previous study (Kuznicki, N. P.; Harbottle, D.; Masliyah, J.; Xu, Z. Dynamic Interactions between a Silica Sphere and Deformable Interfaces in Organic Solvents Studied by Atomic Force Microscopy. Langmuir 2016, 32 (38), 9797−9806), a viscoelasticity parameter should be included in the high force Stokes-Reynolds-Young-Laplace (SRYL) equations to account for the interfacial stiffening and non-Laplacian response of the water droplet at longer aging times. However, following the addition of a biodegradable demulsifier, ethyl cellulose (EC), an immediate reduction in both the particle-droplet adhesion force and the rigidity of the water droplet occurred. Following EC addition, the interface reverted back to a Laplacian response and droplet deformation was once again accurately predicted by the classical SRYL model. These changes in both droplet deformation and particle-droplet adhesion, tracked by AFM, imply a rapid asphaltene/bitumen film displacement by EC molecules. The colloidal probe technique provides a convenient way to quantify forces at deformable oil/water interfaces and characterize the in-situ effectiveness of competing surface active species.
Journal of Heat Transfer, 1976
Heat transfer characteristics for a laminar forced convection fully developed flow in an internal... more Heat transfer characteristics for a laminar forced convection fully developed flow in an internally finned circular tube with axially uniform heat flux with peripherally uniform temperature are obtained using a finite element method. For a given fin geometry, the Nusselt number based on inside tube diameter was higher than that for a smooth tube. Also, it was found that for maximum heat transfer there exists an optimum fin number for a given fin configuration. The internal fins are of triangular shape.
Langmuir, 2006
Mica and alumina were coated with nanoparticles using aqueous suspensions while managing attracti... more Mica and alumina were coated with nanoparticles using aqueous suspensions while managing attractive substrate-particle electrostatic forces. Using nanoparticle-coated substrates, structural forces were measured for 10 nm silica particles deposited on the alumina substrate and 5-80 nm alumina particles on mica using an atomic force microscopy technique. For nanoparticles forming clusters, oscillation of structural forces was recorded with a periodicity that is close to the size of nanoparticles used. Positioning the AFM tip over the single particles allowed, on the other hand, the study of probe-nanoparticle colloidal forces.
Journal of Fluid Mechanics, 2002
An electrokinetic model is proposed to describe a slight drop deformation which is induced by a w... more An electrokinetic model is proposed to describe a slight drop deformation which is induced by a weak external electric field. The fluids forming the system are considered Newtonian incompressible dielectric liquids containing free electric charge carriers. According to the model, the charge carriers take part in migration, diffusion and convection transport and there is no solute adsorption at the interface. Thermodynamic quasi-equilibrium at the interface is assumed for the charge carriers in the contacting liquids. The interfacial thermodynamic equilibrium is described using a common distribution coefficient for all the carriers. The problem is simplified by assuming equal diffusion coefficients for the different charge carriers within the same liquid. An analytical expression is obtained for slight drop deformation which is proportional to the second power of the applied field strength magnitude. The expression derived represents the drop deformation as a function of the paramete...
Journal of Dispersion Science and Technology, 2009
This article is dedicated to Dr. Per Stenius, a prominent surface and colloid scientist. In this ... more This article is dedicated to Dr. Per Stenius, a prominent surface and colloid scientist. In this study, colloidal science was applied to understanding of the role of bicarbonate ions, a dominant anionic component in industrial recycle process water, in bitumen extraction from oil sands. Denver cell flotation tests, zeta potential measurements, water chemistry analysis, and atomic force microscope colloidal force
Journal of Colloid and Interface Science, 2006
Colloidal forces between atomic force microscopy probes of 0.12 and 0.58 N/m spring constant and ... more Colloidal forces between atomic force microscopy probes of 0.12 and 0.58 N/m spring constant and flat substrates in nanoparticle suspensions were measured. Silicon nitride tips and glass spheres with a diameter of 5 and 15 mum were used as the probes whereas mica and silicon wafer were used as substrates. Aqueous suspensions were made of 5-80 nm alumina and 10 nm silica particles. Oscillatory force profiles were obtained using atomic force microscope. This finding indicates that the nanoparticles remain to be stratified in the intervening liquid films between the probe and substrate during the force measurements. Such structural effects were manifested for systems featuring attractive and weak repulsive interactions of nanoparticles with the probe and substrate. Oscillation of the structural forces shows a periodicity close to the size of nanoparticles in the suspension. When the nanoparticles are oppositely charged to the probes, they tend to coat the probes and hinder probe-substrate contact.
Journal of Colloid and Interface Science, 2000
The hydrophobicity of fine particles is important for their behavior at interfaces, for example, ... more The hydrophobicity of fine particles is important for their behavior at interfaces, for example, in stabilizing emulsions. In this study, contact angles were evaluated for silanized fumed silica nanospheres with mean primary diameter of about 12 nm, using heat flow microcalorimetry. Three systems were investigated: water-air-nanospheres, toluene-air-nanospheres, and toluenewater-nanospheres. For the water-air-nanospheres system, npropanol at various concentrations in water was used to aid in dispersing the nanospheres, and the enthalpy of immersion between water, air, and nanospheres was obtained by extraploting to zero n-propanol concentration. Measurements of enthalpy of immersion for toluene-air-nanospheres system were straightforward, as all the nanospheres samples were dispersible in toluene. The enthalpy of immersion for toluene-water-nanospheres system was calculated from the data for the aforementioned first and the second systems. For water-air-nanosphere systems, contact angles were in the range of 14 to 118 • , corresponding to enthalpy of immersion from −0.0905 to 0.0041 J/m 2. For the case of toluene-air-nanospheres systems, the contact angles varied from 72 to 94 • with corresponding enthalpy of immersion from −0.0295 to −0.0189 J/m 2. For toluene-waternanospheres systems, however, contact angles were in the range of 0 to 96 • , corresponding to enthalpy of immersion from −0.0717 to −0.0175 J/m 2 .
Journal of Colloid and Interface Science, 2001
Electrostatic interactions are considered in the framework of the cell model to predict the osmot... more Electrostatic interactions are considered in the framework of the cell model to predict the osmotic pressure in concentrated disperse systems. A procedure was developed to represent the osmotic pressure as a function of two parameters, namely, the dispersed phase volume fraction and the electric potential attributed to the interface between the continuous and dispersed phases. The procedure is based on a general formula which was derived to express the electrostatic contribution to the osmotic pressure through the electric potential at the cell boundary. The potential of the cell boundary is predicted from the solution of the Poisson-Boltzmann problem which was specified for the cell model approach. The Poisson-Boltzmann problem is solved by a perturbation technique using a normalized interface potential as the perturbation parameter. Three leading terms were obtained in the expansion of the osmotic pressure in terms of the normalized interface potential. Two options for the formation of the interface electric potential are discussed in the analysis of the interface potential dependency on the volume fraction of the dispersed phase. The first one is associated with the difference between the individual ionic distribution coefficients characterizing the equilibrium ratio between the concentrations in the bulk of the constituent phases. The second one deals with preferential adsorption of the carriers having a given electric charge sign. The dependency of the osmotic pressure on the system parameters is discussed and interrelated with other relevant theories. Special discussion is presented concerning the theory's application for the study of hydrocarbon disperse systems, e.g., water-in-oil emulsions.
Journal of Colloid and Interface Science, 2006
The atomic force microscope (AFM) has been used to measure surface forces between silicon nitride... more The atomic force microscope (AFM) has been used to measure surface forces between silicon nitride AFM tips and individual nanoparticles deposited on substrates in 10(-4) and 10(-2) M KCl solutions. Silica nanoparticles (10 nm diameter) were deposited on an alumina substrate and alumina particles (5 to 80 nm diameter) were deposited on a mica substrate using aqueous suspensions. Ionic concentrations and pH were used to manage attractive substrate-particle electrostatic forces. The AFM tip was located on deposited nanoparticles using an operator controlled offset to achieve stepwise tip movements. Nanoparticles were found to have a negligible effect on long-range tip-substrate interactions, however, the forces between the tip and nanoparticle were detectable at small separations. Exponentially increasing short-range repulsive forces, attributed to the hydration forces, were observed for silica nanoparticles. The effective range of hydration forces was found to be 2-3 nm with the decay length of 0.8-1.3 nm. These parameters are in a good agreement with the results reported for macroscopic surfaces of silica obtained using the surface force apparatus suggesting that hydration forces for the silica nanoparticles are similar to those for flat silica surfaces. Hydration forces were not observed for either alumina substrates or alumina nanoparticles in both 10(-4) M KCl solution at pH 6.5 and 10(-2) M KCl at pH 10.2. Instead, strong attractive forces between the silicon nitride tip and the alumina (nanoparticles and substrate) were observed.
Journal of Adhesion Science and Technology, 2009
Energy & Fuels, 2012
Mining and processing of Athabasca oil sands in Alberta, Canada, is a great success story of gove... more Mining and processing of Athabasca oil sands in Alberta, Canada, is a great success story of government−industry collaboration, fulfilling increased domestic and worldwide demands for oil. However, economic and environmental incentives still exist in the oil sands industry to enhance oil recovery and reduce energy consumption and water use, while minimizing greenhouse gas emissions and tailings ponds. The current industrial bitumen extraction processes, after surface mining, are exclusively water-based and operate at elevated temperatures, typically between 45 and 50°C. Robust low-temperature processes, with reduced intake of feedwater, that are less sensitive to ore characteristics are in a strong demand from both environmental and economical point of views. In response to this demand, we propose a robust aqueous−nonaqueous hybrid bitumen extraction process, in which diluent such as kerosene and naphtha is added to the oil sands prior to oil sands slurry preparation to decrease bitumen viscosity and enhance bitumen liberation. With the proposed hybrid bitumen extraction process, the oil sand processing temperature can be reduced to ambient temperature. To prove this concept, bitumen recovery tests were carried out on four Athabasca oil sand ores of good to poor processability, using a Denver flotation cell operated at ambient temperature. Adding kerosene or naphtha to oil sands at 4−11 wt % of the bitumen content was found to significantly enhance flotation recovery of bitumen and bitumen froth quality, especially for poor processing ores. It was found that kerosene addition not only increased bitumen liberation kinetics determined using our novel in situ bitumen liberation visualization flow cell (BLVFC) but also improved bitumen aeration measured by induction time apparatus.
Energy & Fuels, 2009
Understanding mineralogy and surface properties of clays is very vital in oil sands processing an... more Understanding mineralogy and surface properties of clays is very vital in oil sands processing and tailings management. Clay-sized minerals (CSM) in oil sands are often contaminated by tightly adsorbed organics during hydrocarbon removal, thereby increasing surface hydrophobicity and making characterization of CSM problematic. This study evaluates the use of low temperature ashing (LTA) and hydrogen peroxide (H 2 O 2) for the removal of adsorbed organic matter (OM) from CSM without changing its mineralogy. CSM isolated from tailings and bitumen froth of a Denver flotation cell after oil sands extraction was treated by H 2 O 2 and LTA. Both techniques were found to be effective in removing OM from the CSM as shown by the infrared spectra of the samples. The wettability of the CSM increased with treatment. Elemental analysis showed a reduction in carbon, hydrogen, and nitrogen. Infrared band for siderite at 864 cm-1 was observed for the isolated and LTA-treated CSM but was absent for those treated by H 2 O 2. The absence of siderite in the X-ray diffraction patterns of the H 2 O 2-treated CSM further substantiates its oxidation by H 2 O 2. Cation exchange capacity of model clays and samples was found to be unaffected by LTA treatment, unlike those treated with H 2 O 2. Overall, LTA appears to be a more suitable method than H 2 O 2 for organic matter removal from the isolated CSM because of its selectivity for decomposing only organics.
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2001
The stability of water-in-oil emulsions stabilized by fine solids with different hydrophobicities... more The stability of water-in-oil emulsions stabilized by fine solids with different hydrophobicities were studied with model organic solvents, such as light mineral oil (Bayol-35), decane and toluene. The fine solids used in this study include kaolinite clay particles treated with asphaltenes, hydrophilic and hydrophobic colloidal silica, hydrophobic polystyrene latex microspheres, as well as fumed silica dry powders treated with silanization. Experimental results showed that hydrophilic colloidal silica could only stabilize oil-in-water emulsions for a short period of time. If hydrophobic particles (colloidal silica or polystyrene latex microspheres) were suspended in the aqueous phase prior to emulsification, they could only produce oil-in-water emulsions. Only hydrophobic particles suspended in organic phase prior to emulsification could stabilize water-in-oil emulsions. The size of the water droplets in emulsion was as small as 2 mm when the solids were 12 nm in diameter. The stability of the produced emulsions depended on the hydrophobicity of the particles. Only particles with intermediate hydrophobicity could produce very stable water-inoil emulsions, and in some cases the volume of the produced emulsions was triple that of water present in the system.
The Canadian Journal of Chemical Engineering, 2008
A photometer was utilized to measure the intensity of scattered light in toluene / heptane / asph... more A photometer was utilized to measure the intensity of scattered light in toluene / heptane / asphaltenes mixtures. On the scattering‐intensity versus heptane‐to‐toluene ratio functions, two linear regions can be observed. The intersection of these regions determines the heptane‐to‐toluene ratio at which the precipitation of asphaltenes starts. The onset of asphaltene precipitation was determined as a function of asphaltene concentration in the presence and in the absence of maltenes as well as water. The onset is dependent on the asphaltene concentration. The presence of water promoted while the presence of maltenes inhibited the precipitation of asphaltenes.
The Canadian Journal of Chemical Engineering, 1987
Pipeline transportation of heavy oils as oil-in-water emulsions has been proposed as an alternati... more Pipeline transportation of heavy oils as oil-in-water emulsions has been proposed as an alternative to blending the crude oil with natural gas condensate or other diluent. An 18 m long, 0.02 m I.D. closed loop was constructed to investigate the behaviour of an emulsified Cold Lake crude oil under pipeline flow. Pressure drop was measured as a function of flow rate for freshly produced emulsions to establish correlations of friction factor versus Reynolds number. Stability was observed for long term pipeline flow. The time at which the emulsion breakdown occurred was found to be a function of oil concentration and shear rate. The breakdown of the emulsion was clearly indicated by a simultaneous change in the system variables of pressure drop, temperamre and power required to turn the pump at constant speed. Le transport par gazoduc des huiles lourdes sous forme d'Cmulsions d'huile dans I'eau a CtC suggCrC comme alternative au mCIange de brut avec un condensat de gaz nature1 ou un autre diluant. On a construit un circuit en boucle de 18 m de long et 0.02 m de diametre intkrieur pour Ctudier le comportement h I'tcoulement dans un pipeline d'un brut de Cold Lake CmulsifiC. On a mesure la perte de charge en fonction du dCbit pour des Cmulsions fraichement produites. afin d'ttablir des corrCIations du facteur de friction en fonction du nombre de Reynolds. La stabilitC a CtC observCe pour un Ccoulement en pipeline de longue durke. Le temps auquel se produit la rupture de I'tmulsion s'avere &tre une fonction de la concentration de I'huile et du gradient de vitesse. Cette rupture se manifeste clairement par un changement simultanC dans le systeme de la perte de charge, de la temp6rature et de la puissance requise pour faire tourner la pompe a vitesse constante.
The Canadian Journal of Chemical Engineering, 2010
Solids isolated from weathered oil sands ores and those having low‐ and high‐fine solids content ... more Solids isolated from weathered oil sands ores and those having low‐ and high‐fine solids content were studied. The organic matter (OM) adsorbed on the solids was found insoluble in most common solvents, contributing significantly to the change of solid surface properties. The surface properties of these solids were found to affect the entire process cycle of obtaining synthetic crude oil from surface‐mined oil sands using a water‐based extraction process, and managing the existing tailings ponds. In this study, the low‐fine solids ore possessed the lowest amount of organic‐coated solids and highest bitumen recovery. Siderite and pyrite, which tend to concentrate in the hydrocarbon phase were observed in the isolated solids from the weathered and high‐fine ores but were absent in the low‐fine ores. In all the ores studied, the solids from the bitumen froth possess less quartz, and more carbonates compared with solids from the tailings. Elemental analysis by energy dispersive X‐ray sp...
The Canadian Journal of Chemical Engineering, 2008
the fluid/solid interface and the outer boundaries of the whole system. At the fluid/solid interf... more the fluid/solid interface and the outer boundaries of the whole system. At the fluid/solid interface, the boundary conditions impose zero velocity of the fluid with reference to the particles. The outer boundary conditions impose the applied pressure difference and the fluid velocity through the system outer boundary. This paper is concerned with the Cell Model method of addressing hydrodynamic flow through system of solid particles. The starting point of the analysis is the general problem formulation intended for describing a pressure driven flow through a diaphragm which can be considered as a set of representative cells having arbitrary shape and containing any number of particles. Using the general problem formulation, the hydrodynamic field inside an individual representative cell is interrelated with the applied pressure difference and the external flow velocity. To this end, four relationships containing integrals over the outer boundary of a representative cell are derived in the paper. Assuming that the representative cell is a sphere containing a single particle in the centre, the derived general relationships are transformed into outer cell boundary conditions employed in the literature by different authors. The general number of the obtained outer boundary conditions is more than the required number. Accordingly, by choosing different sets of the outer boundary conditions, different models are considered and compared with each other and with the results obtained by others for regular particle arrays. The common and different features of the hydrodynamic and electrodynamic versions of the Cell Model approaches are analyzed. Finally, it is discussed which version of the cell model gives the best approximation while describing pressure and electrically driven flows through a diaphragm and sedimentation of particles. On s'intéresse dans cet article à la méthode du Modèle de Cellules pour traiter l'écoulement à travers un système de particules solides. Le point de départ de l'analyse consiste à formuler le problème général dans le but de décrire un écoulement sous pression dans un diaphragme qui peut être considéré comme un ensemble de cellules représentatives de forme arbitraire et contenant un nombre quelconque de particules. À l'aide de cette formulation générale du problème, l'hydrodynamique dans une cellule représentative donnée est reliée à la différence de pression appliquée et à la vitesse d'écoulement externe. À cette fin, quatre relations contenant des intégrales sur la frontière d'une cellule représentative sont établies dans cette étude. Si l'on suppose que la cellule représentative est une sphère contenant une particule unique en son centre, les relations générales calculées peuvent être transformées en conditions à la frontière des cellules semblables à celles employées dans la littérature scientifique par différents auteurs. Le nombre général de conditions limites obtenues dépasse le nombre requis. Par conséquent, en choisissant différents ensembles de conditions limites, différents modèles sont considérés et comparés entre eux ainsi qu'avec les résultats obtenus pour des arrangements réguliers de particules. Les caractéristiques des versions hydrodynamiques et électrodynamiques des approches du Modèle de Cellules sont analysées. Finalement, on examine quelle version de modèle de cellule donne la meilleure approximation des écoulements sous pression et des écoulements électrodynamiques à travers un diaphragme et pour la sédimentation des particules.
Advances in Colloid and Interface Science, 2007
Equations are derived which govern the electrokinetic phenomena in a concentrated dispersion of c... more Equations are derived which govern the electrokinetic phenomena in a concentrated dispersion of charged spherical mercury drops in an electrolyte solution on the basis of Kuwabara's cell model. Expressions for the electrophoretic mobility and the sedimentation velocity are obtained. For the case in which the overlapping of the electrical double layers of adjacent drops is negligible, expressions for the electrical conductivity and the sedimentation potential are derived. An Onsager relation between electrophoretic mobility and sedimentation potential is also obtained.
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Papers by Masliyah, Masliyah