Publications
295 results found
Eguagie E, Berg S, Crawshaw J, et al., 2019, Flexible coiled polymer dynamics in a single pore throat with effects of flow resistance and normal stresses
© 2019 European Association of Geoscientists and Engineers, EAGE. All Rights Reserved. We investigate the challenges involved in the use of polymer flooding as a chemical enhanced oil recovery (cEOR) technique for improving mobility ratio and enhancing macroscopic sweep efficiency. Flexible coiled polymers in porous media undergo stretching in a spatially heterogeneous structure. Due to the viscoelasticity of these polymers, they stretch continuously depending on their previous deformation until their elastic limit is reached and relaxation occurs. Previous research has proposed that at a certain critical flow rate, the relaxation of polymers cause an increase in viscosity and in turn a better mobility for enhancing microscopic sweep in porous media. However, others have reported that the increased viscosity in porous media is not so much related to the elasticity but more on the normal stresses that occur when polymers are sheared in porous media flow. One similar fact is that as increased viscosity is observed an enhanced pressured drop occurs and the flow becomes highly unstable even at laminar flow regime. This unstable flow is termed the elastic instability or turbulence but the details of this kind of turbulence, its consequences and applicability on the impact of oil recovery is not understood. In this work, we experimentally investigate the flow behaviors of flexible coiled polymers of hydrolyzed polyacrylamide (HPAM) based on a single pore throat geometry using a microfluidic device. The aim is to adequately parameterize the effects of the normal stress difference in shear and extension as a function of the geometry and intrinsic characteristics of the polymer solutions at different Deborah (De) numbers. Hence, we carry out pressure drop and particle image velocimetry experiments and results showed a critical De at which polymer viscosity increases as well as the normal stress difference. It was also observed that the flow resistance might be a functio
Eguagie E, Berg S, Crawshaw J, et al., 2019, Flexible coiled polymer dynamics in a single pore throat with effects of flow resistance and normal stresses
We investigate the challenges involved in the use of polymer flooding as a chemical enhanced oil recovery (cEOR) technique for improving mobility ratio and enhancing macroscopic sweep efficiency. Flexible coiled polymers in porous media undergo stretching in a spatially heterogeneous structure. Due to the viscoelasticity of these polymers, they stretch continuously depending on their previous deformation until their elastic limit is reached and relaxation occurs. Previous research has proposed that at a certain critical flow rate, the relaxation of polymers cause an increase in viscosity and in turn a better mobility for enhancing microscopic sweep in porous media. However, others have reported that the increased viscosity in porous media is not so much related to the elasticity but more on the normal stresses that occur when polymers are sheared in porous media flow. One similar fact is that as increased viscosity is observed an enhanced pressured drop occurs and the flow becomes highly unstable even at laminar flow regime. This unstable flow is termed the elastic instability or turbulence but the details of this kind of turbulence, its consequences and applicability on the impact of oil recovery is not understood. In this work, we experimentally investigate the flow behaviors of flexible coiled polymers of hydrolyzed polyacrylamide (HPAM) based on a single pore throat geometry using a microfluidic device. The aim is to adequately parameterize the effects of the normal stress difference in shear and extension as a function of the geometry and intrinsic characteristics of the polymer solutions at different Deborah (De) numbers. Hence, we carry out pressure drop and particle image velocimetry experiments and results showed a critical De at which polymer viscosity increases as well as the normal stress difference. It was also observed that the flow resistance might be a function of both the elasticity and the normal stresses in shear flow, however, extensional stresse
Reinoso D, Martin-Alfonso MJ, Luckham PF, et al., 2019, Rheological characterisation of xanthan gum in brine solutions at high temperature, Carbohydrate Polymers, Vol: 203, Pages: 103-109, ISSN: 0144-8617
Xanthan gum solutions are used in the oil industry for flooding, drilling and completion operations. The stabilization of the structure of xanthan gum solutions in presence of salts increases the value of both the order-disorder transition temperature and the gel strength. This effect is very important in order to design drilling and completion fluids since not only density and viscosity of the fluid can be improved by increasing the concentration of salts but also the range of temperature where the solution shows viscoelastic behaviour can be extended.This paper presents results from a study on the rheological behaviour of xanthan gum solutions in different saturated brines. Chloride and formate potassium brines not only increase the viscosity of the solution but also extend the shear thinning behaviour to temperatures near 200 °C, maintaining a simple relaxation mechanism over the whole range of temperature where the ordered conformation dominates the rheological behaviour.
Elizarova IS, Luckham PF, 2018, Layer-by-layer adsorption: Factors affecting the choice of substrates and polymers, Advances in Colloid and Interface Science, Vol: 262, Pages: 1-20, ISSN: 0001-8686
The electrostatic layer-by-layer technique for fabrication of multi-layered structures of various sizes and shapes using flat and colloidal templates coupled with polyelectrolyte layer-forming materials has attracted significant interest among both academic and industrial researchers due to its versatility and relative simplicity of the procedures involved in its execution. Fabrication of the multi-layered structures using the electrostatic layer-by-layer method involves several distinct stages each of which holds great importance when considering the production of a high-quality product. These stages include selection of materials (both template and a pair of construction polyelectrolytes), adsorption of the first polyelectrolyte layer onto the selected templates, formation of the second layer comprised of the oppositely charged polyelectrolyte and guided by the interactions between the two chosen polyelectrolytes, and multi-layering, where a selected number of layers are produced, and which is conditioned by both intrinsic properties of the involved construction materials and external fabrication conditions such as temperature, pH and ionic strength. The current review summarises the most important aspects of each stage mentioned above and gives examples of the materials suitable for utilization of the technique and describes the underlying physics involved.
Butler E, Reid B, Petit C, et al., 2018, Extended DLVO interactions of a metal-organic framework: Implications on colloidal dispersion, 256th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nanoscience, Nanotechnology and Beyond, Publisher: AMER CHEMICAL SOC, ISSN: 0065-7727
Ahmad A, Iqbal T, Yasin S, et al., 2018, Stability of Amorphous PEEK in Organic Solvents, JOURNAL OF THE CHEMICAL SOCIETY OF PAKISTAN, Vol: 40, Pages: 810-818, ISSN: 0253-5106
Collini H, Mohr M, Luckham P, et al., 2018, The effects of polymer concentration, shear rate and temperature on the gelation time of aqueous Silica-Poly(ethylene-oxide) "Shake-gels", Journal of Colloid and Interface Science, Vol: 517, Pages: 1-8, ISSN: 0021-9797
HypothesisAqueous mixtures of silica and Poly(ethylene-oxide) (PEO) are known as “Shake-gels” due to the formation of reversible gels when subject to an applied force, such as shaking. This shear-thickening effect can be observed using a rheometer, via distinct and abrupt increases in the viscosity of the material. Preliminary experiments qualitatively showed that the time elapsed before this occurs, termed the gelation time, varied depending on the conditions used. This paper reports on a systematic study into the effects of polymer concentration, shear rate and temperature on the gelation time, to quantify any relationships that exist between the variables and develop understanding of the gelation mechanism and kinetics.ExperimentsDifferent constant shear rates were applied to samples at various polymer concentrations and temperatures using a rheometer with concentric cylinder geometry.FindingsThe gelation time varied significantly from several seconds to an hour or more and was exponentially accelerated by shear rate. A peak in gelation time occurred at medium polymer concentrations of 0.35–0.40% (25% silica) and at a temperature about 20 °C. Higher temperatures also exponentially accelerated the gelation time as kinetic effects dominated the thermodynamic and structural resistances to gel formation.
Iqbal T, Yasin S, Shakeel A, et al., 2018, Analysis of Solvent Effect on Mechanical Properties of Poly(ether ether ketone) Using Nano-indentation, CHINESE JOURNAL OF CHEMICAL PHYSICS, Vol: 31, Pages: 211-215, ISSN: 1674-0068
Matar O, Lee RY, Shaffee A, et al., 2018, Sand agglomeration in oil & gas reservoirs: Chemistry, experiments and simulations, 255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, Publisher: AMER CHEMICAL SOC, ISSN: 0065-7727
Muratalin M, Luckham PF, Esimova A, et al., 2017, Study of N-isopropylacrylamide-based microgel particles as a potential drug delivery agents, COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, Vol: 532, Pages: 8-17, ISSN: 0927-7757
Elizarova IS, Luckham PF, 2017, Layer-by-layer encapsulated nano-emulsion of ionic liquid loaded with functional material for extraction of Cd(2+) ions from aqueous solutions, Journal of Colloid and Interface Science, Vol: 491, Pages: 286-293, ISSN: 0021-9797
Ionic liquids can serve as an environmentally-friendly replacement for solvents in emulsions, therefore they are considered suitable to be used as an emulsified medium for various active materials one of which are extractors of metal ions. Increasing the extraction efficiency is considered to be one of the key objectives when working with such extraction systems. One way to improve the extraction efficiency is to increase the contact area between the extractant and the working ionic solution. This can be accomplished by creating a nano-emulsion of ionic liquid containing such an extractant. Since emulsification of ionic liquid is not always possible in the sample itself, there is a necessity of creating a stable emulsion that can be added externally and on demand to samples from which metal ions need to be extracted. We propose a method of fabrication of a highly-stable extractant-loaded ionic liquid-in-water nano-emulsion via a low-energy phase reversal emulsification followed by continuous layer-by-layer polyelectrolyte deposition process to encapsulate the nano-emulsion and enhance the emulsion stability. Such a multilayered stabilized nano-emulsion was tested for extraction of Cd(2+) and Ca(2+) ions in order to determine its extraction efficiency and selectivity. It was found to be effective in the extraction of Cd(2+) ions with near 100% cadmium removal, as well as being selective since no Ca(2+) ions were extracted. The encapsulated emulsion was removed from samples post-extraction using two methods - filtration and magnetic separation, both of which were shown to be viable under different circumstances - larger and mechanically stronger capsules could be removed by filtration, however magnetic separation worked better for both smaller and bigger capsules. The long-term stability of nano-emulsion was also tested being a very important characteristic for its proposed use: it was found to be highly stable after four months of storage time.
Yasin S, Luckham PF, Iqbal T, 2016, Investigating the Conformation of Polymeric Dispersant Molecules on Nanoparticle Surface, JOURNAL OF THE CHEMICAL SOCIETY OF PAKISTAN, Vol: 38, Pages: 446-453, ISSN: 0253-5106
Luckham PF, Elizarova I, 2016, Fabrication of polyelectrolyte multilayered nano-capsules using a continuous layer-by-layer approach, Journal of Colloid and Interface Science, Vol: 470, Pages: 92-99, ISSN: 0021-9797
The layer-by-layer approach is a highly versatile method for the fabrication of multilayered polymeric films and capsules. It has been widely investigated in research for various polyelectrolyte pairs and core template particles. However, the fabrication of nano-sized capsules at the larger scale is difficult and time consuming, due to the necessity of washing and centrifugation steps before the deposition of each polyelectrolyte layer. This results not only in a very long fabrication time, but also in the partial loss of particles during those intermediate steps. In this study, we introduced a continuous approach for the fabrication of multilayer polyelectrolyte based nano-capsules using calcium phosphate core nanoparticles and a tubular flow type reactor with the potential for synthesizing tens of milligrams of capsules per hour. Adsorption of the polyelectrolyte layer occurred in the tubing where particles and polyelectrolyte solution of choice were mixed, creating a layer of polyelectrolyte on the particles. After this, these newly surfaced-modified particles passed into the next segment of tubing, where they were mixed with a second polyelectrolyte of opposite charge. This process can be continuously repeated until the desired number of layers is achieved. One potential problem with this method concerned the presence of any excess polyelectrolyte in the tubing, so careful control of the amount of polymer added was crucial. It was found that slightly under dosing the amount of added polyelectrolyte ensured that negligible unadsorbed polyelectrolyte remained in solution. The particles created at each deposition step were stable, as they all had a zeta potential of greater than ±25 mV. Furthermore the zeta potential measurements showed that charge reversal occurred at each stage. Having achieved the necessary number of polyelectrolyte layers, the calcium phosphate cores were easily removed via dissolution in either hydrochloric or acetic acid.
Martin HP, Brooks NJ, Seddon JM, et al., 2016, Microfluidic processing of concentrated surfactant mixtures: online SAXS, microscopy and rheology, Soft Matter, Vol: 12, Pages: 1750-1758, ISSN: 1744-6848
Mar Ramos-Tejada M, Luckham PF, 2015, Shaken but not stirred: The formation of reversible particle - polymer gels under shear, COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, Vol: 471, Pages: 164-169, ISSN: 0927-7757
Mar Ramos-Tejada M, Luckham PF, 2015, Shaken but not stirred: The formation of reversible particle - polymer gels under shear, COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, Vol: 471, Pages: 164-169, ISSN: 0927-7757
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- Citations: 12
Naden BJ, Kessell LM, Luckham PF, et al., 2015, Adsorption of poly(hydroxystearic acid) to TiO2 nanoparticles, studied using gel permeation chromatography, Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol: 478, Pages: 36-44, ISSN: 1873-4359
TiO2 nanoparticles are becoming increasingly important as sunscreens due to their propensity to absorb UV light. It is crucial that the particles are nanoscale so that scattering of visible light is minimal and UV attenuation is optimised, thus stabilisation is essential to prevent particles from aggregating. In this study we investigate the adsorption of dispersant based on stearic acid to TiO2 nanoparticles by adsorption isotherm determination. The methods used to determine dispersant concentration (acid value titration and gel permeation chromatography, GPC) provided information regarding the chemical nature of the polymers and insights into the way the molecules interacted with particle surfaces in different solvent conditions. It was observed that the smaller dispersant molecules adsorb preferentially, contrary to the behaviour of adsorbing homopolymers that display a direct relationship between molecular weight and strength of adsorption. Adsorption in this case is a result of single point adsorption that occurs via interaction of the carboxylate group of the dispersant to the TiO2 surface, the thermodynamics of which favours low molecular weight components. This is clearly demonstrated by GPC which was able to resolve and quantify the non-adsorbed molecules by size. Discrepancies between GPC and acid value measurement for dispersant concentration reinforce this observation.
Yasin S, Luckham PF, Iqbal T, et al., 2014, Atomic Force Microscopy of Polymer Coated Graphitic Carbon Surfaces, SOFT MATERIALS, Vol: 12, Pages: 427-432, ISSN: 1539-445X
Iqbal T, Yasin S, Luckham PF, et al., 2014, Scratch Deformations of Poly (ether ether ketone) Composites, FIBERS AND POLYMERS, Vol: 15, Pages: 1042-1050, ISSN: 1229-9197
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- Citations: 4
Iqbal T, Briscoe BJ, Yasin S, et al., 2014, Nanosurface Mechanical Properties of Polymers Based on Continuous Stiffness Indentation, JOURNAL OF MACROMOLECULAR SCIENCE PART B-PHYSICS, Vol: 53, Pages: 1522-1532, ISSN: 0022-2348
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- Citations: 8
Yasin S, Luckham PF, Iqbal T, et al., 2014, Interaction Forces Between Graphitic Carbon Black Surfaces Coated with Polymers Using Atomic Force Microscopy, JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY, Vol: 35, Pages: 1163-1168, ISSN: 0193-2691
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- Citations: 2
Iqbal T, Briscoe BJ, Yasin S, et al., 2013, Nanoindentation Response of Poly(ether ether ketone) Surfaces-A Semicrystalline Bimodal Behavior, JOURNAL OF APPLIED POLYMER SCIENCE, Vol: 130, Pages: 4401-4409, ISSN: 0021-8995
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- Citations: 23
Al-Hashmi AR, Luckham PF, Grattoni CA, 2013, Flow-induced-microgel adsorption of high-molecular weight polyacrylamides, JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING, Vol: 112, Pages: 1-6, ISSN: 0920-4105
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- Citations: 6
Zhang X, Luckham PF, Hughes AD, et al., 2013, Towards an understanding of the release behavior of temperature-sensitive liposomes: a possible explanation of the "pseudoequilibrium'' release behavior at the phase transition temperature, JOURNAL OF LIPOSOME RESEARCH, Vol: 23, Pages: 167-173, ISSN: 0898-2104
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- Citations: 8
Iqbal T, Briscoe BJ, Yasin S, et al., 2013, Continuous stiffness mode nanoindentation response of poly(methyl methacrylate) surfaces, CHINESE JOURNAL OF POLYMER SCIENCE, Vol: 31, Pages: 1096-1107, ISSN: 0256-7679
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- Citations: 9
Yasin S, Luckham PF, Iqbal T, et al., 2013, Adsorption and Rheology of Graphitic Carbon Black Nonaqueous Dispersions Prepared Using Nonionic Surfactants, JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY, Vol: 34, Pages: 737-746, ISSN: 0193-2691
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- Citations: 5
Al-Hashmi AR, Luckham PF, Heng JYY, et al., 2013, Adsorption of High-Molecular-Weight EOR Polymers on Glass Surfaces Using AFM and QCM-D, ENERGY & FUELS, Vol: 27, Pages: 2437-2444, ISSN: 0887-0624
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- Citations: 19
Muratalin M, Luckham PF, 2013, Preparation and characterization of microgels sensitive toward copper II ions, JOURNAL OF COLLOID AND INTERFACE SCIENCE, Vol: 396, Pages: 1-8, ISSN: 0021-9797
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- Citations: 19
Yasin S, Luckham PF, Iqbal T, et al., 2013, Scaling in Electrical Conductivity Measurements and Rheological Measurements of Monarch 700 Dispersions Stabilized by Polymers, JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY, Vol: 34, Pages: 268-272, ISSN: 0193-2691
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- Citations: 2
Yasin S, Luckham PF, Iqbal T, et al., 2013, Investigating the Role of Aromaticity of Copolymers for Graphitic Carbon Black Aqueous Dispersions, SOFT MATERIALS, Vol: 11, Pages: 440-447, ISSN: 1539-445X
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- Citations: 3
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