Loading...
Search for: surface-active-agents
0.008 seconds
Total 155 records

    Adsorption of proteins at the solution/air interface influenced by added nonionic surfactants at very low concentrations for both components. 3. dilational surface rheology

    , Article Journal of Physical Chemistry B ; Volume 119, Issue 9 , January , 2015 , Pages 3768-3775 ; 15206106 (ISSN) Fainerman, V. B ; Aksenenko, E. V ; Lylyk, S. V ; Lotfi, M ; Miller, R ; Sharif University of Technology
    Abstract
    The influence of the addition of the nonionic surfactants C12DMPO, C14DMPO, C10OH, and C10EO5 at concentrations between 10-5 and 10-1 mmol/L to solutions of β-casein (BCS) and β-lactoglobulin (BLG) at a fixed concentration of 10-5 mmol/L on the dilational surface rheology is studied. A maximum in the viscoelasticity modulus |E| occurs at very low surfactant concentrations (10-4 to 10-3 mmol/L) for mixtures of BCS with C12DMPO and C14DMPO and for mixtures of BLG with C10EO5, while for mixture of BCS with C10EO5 the value of |E| only slightly increased. The |E| values... 

    Study and optimization of amino acid extraction by emulsion liquid membrane

    , Article Separation Science and Technology ; Volume 43, Issue 11-12 , 2008 , Pages 3075-3096 ; 01496395 (ISSN) Mohagheghi, E ; Alemzadeh, I ; Vossoughi, M ; Sharif University of Technology
    2008
    Abstract
    A batch extraction of an essential amino acid, phenylalanine, from an aqueous solution of different concentrations by an Emulsion Liquid Membrane (ELM) was developed using D2EHPA as a cationic carrier, Span 80 as the surfactant, paraffin, and kerosene as the diluents, and HCl as the internal electrolyte. All effective parameters such as the initial pH of the aqueous external phase, the electrolyte concentration in the aqueous internal phase, carrier, and surfactant concentration in the emulsion, the volume ratio of the organic to aqueous internal phase (Roi), the volume ratio of the W/O emulsion to the aqueous external phase (Rew) and time were examined and optimized using the Taguchi... 

    Interfacial tension and wettability change phenomena during alkali-surfactant interactions with acidic heavy crude oil

    , Article Energy and Fuels ; Vol. 29, issue. 2 , January , 2015 , p. 649-658 ; ISSN: 08870624 Dehghan, A. A ; Masihi, M ; Ayatollahi, S ; Sharif University of Technology
    Abstract
    In this work, a newly formulated sulfonate-based surfactant and two other commercial sulfate-based surfactants with the capability of tolerating harsh underground reservoir conditions, such as high-saline formation water and high temperature, were prepared. Sodium metaborate as an effective alkali compound was also used to provide alkali-surfactant combination. Interfacial tension (IFT) measurements as well as wettability examinations for different salinities and mixture conditions were performed for an extended range of the chemical concentrations. The wettability tests including both contact angle measurements and Amott cell tests were performed on saturated Berea sandstone plug samples... 

    Monitoring the effect of discontinuous shales on the surfactant flooding performance in heavy oil reservoirs using 2D glass micromodels

    , Article Petroleum Science and Technology ; Vol. 32, issue. 12 , Apr , 2014 , p. 1404-1417 ; ISSN: 10916466 Mohammadi, S ; Kharrat, R ; Masihi, M ; Ghazanfari, M. H ; Saidian, M ; Sharif University of Technology
    Abstract
    Although most heavy oil reservoirs contain discontinuous shaly structures, there is a lack of fundamental understanding how the shaly structures affect the oil recovery efficiency, especially during surfactant flooding to heavy oils. Here, an experimental study was conducted to examine the effect of discontinuous shales on performance of surfactant flooding by introducing heterogeneities to represent streaks of shale in five-spot glass micromodels. Results show that oil recovery in presence of shale streak is lower than in its absence. Based on the authors' observations, the presence of flow barriers causes premature breakthrough of injected fluids and also an unstable displacement front. As... 

    Evaluation of chemicals interaction with heavy crude oil through water/oil emulsion and interfacial tension study

    , Article Energy and Fuels ; Vol. 27, issue. 10 , September , 2013 , p. 5852-5860 ; ISSN: 08870624 Dehghan, A. A ; Masihi, M ; Ayatollahi, S ; Sharif University of Technology
    Abstract
    A newly-designed surfactant was formulated to tolerate the harsh conditions of oil reservoirs, including high salinity of the formation brine and temperature. The specific emulsion and interfacial tension (IFT) behavior of this new surface active agent were investigated by performing emulsion stability tests, emulsion size analysis, and IFT behavior in the presence of four different types of alkalis. Image processing was utilized to analyze the droplet size distribution using microscopic images of the samples. The results show that depending on the composition of the mixtures, the optimum phase region and interfacial tension behavior change considerably. Solutions containing a higher... 

    Spotlight on kinetic and equilibrium adsorption of a new surfactant onto sandstone minerals: A comparative study

    , Article Journal of the Taiwan Institute of Chemical Engineers ; Volume 50 , May , 2015 , Pages 12-23 ; ISSN: 18761070 Arabloo, M ; Ghazanfari, M. H ; Rashtchian, D ; Sharif University of Technology
    Abstract
    This paper presents a state of the art review of adsorption models for a new plant-based surfactant adsorption onto sandstone minerals. The adsorption data at both kinetic and equilibrium modes were obtained from batch experiments. Four adsorption kinetic models, five two-parameter, and six three-parameter equilibrium models were used for interpretation of the obtained data. Among the two and three-parameter isotherm models applied, the Jovanovic and the Khan isotherms showed the best fit, respectively. And the pseudo-second order model presented a better fit than other kinetic models. Finally, a computer-based modeling approach was developed and used for predicting the kinetics of... 

    Numerical simulation of surfactant flooding in darcy scale flow

    , Article Petroleum Science and Technology ; Vol. 32, Issue. 11 , 2014 , Pages 1365-1374 ; ISSN: 10916466 Morshedi, S ; Foroughi, S ; Beiranvand, M. S ; Sharif University of Technology
    Abstract
    One of the methods that is used nowadays in enhanced oil recovery is surfactant flooding. The main mechanisms of surfactant flooding in reservoir consist of reduction of interfacial tension between water and oil and modification of rock wettability. In this study, the authors simulate the surfactant injection process in Darcy scale and in one-dimensional, multicomponent, multiphase state, and effects of physical phenomena such as adsorption, dispersion, convection, and exchange between fluids and solids are considered. Wettability alteration of reservoir rock due to presence of surfactant in injected fluid is detected in relative permeability and capillary pressure curves. First, the authors... 

    A novel approach for preparation of CL-20 nanoparticles by microemulsion method

    , Article Journal of Molecular Liquids ; Vol. 193, issue , May , 2014 , pp. 83-86 Bayat, Y ; Zarandi, M ; Zarei, M. A ; Soleyman, R ; Zeynali, V ; Sharif University of Technology
    Abstract
    2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) as one of the high energy cage nitramines has been used in various propellants and explosive formulations. The performance of energetic materials depends on its particle size and shape. Therefore, in this research, microemulsion method has been applied for the preparation of CL-20 nanoparticles via oil in water (O/W) microemulsions. The optimized formulation contains water 45%, n-butyl acetate 20.5%, sodium dodecyl sulfate (SDS, as anionic surfactant) 6.5% and 2-propanol (as co-surfactant) 26.5%. CL-20 nanoparticles that were obtained by microemulsion method are spherical with an average diameter of 25 nm, based on TEM image.... 

    Prediction of Surfactant Retention in Porous Media: A Robust Modeling Approach

    , Article Journal of Dispersion Science and Technology ; Vol. 35, issue. 10 , Sep , 2014 , p. 1407-1418 Yassin, M. R ; Arabloo, M ; Shokrollahi, A ; Mohammadi, A. H ; Sharif University of Technology
    Abstract
    Demands for hydrocarbon production have been increasing in recent decades. As a tertiary production processes, chemical flooding is one of the effective technologies to increase oil recovery of hydrocarbon reservoirs. Retention of surfactants is one of the key parameters affecting the performance and economy of a chemical flooding process. The main parameters contribute to surfactant retention are mineralogy of rock, surfactant structure, pH, salinity, acidity of the oil, microemulsion viscosity, co-solvent concentration, and mobility. Despite various theoretical studies carried out so far, a comprehensive and reliable predictive model for surfactant retention is still found lacking. In this... 

    The impact of surfactants on wettability change and level of water imbibition in relation to EOR in carbonate reservoirs

    , Article Petroleum Science and Technology ; Volume 31, Issue 20 , 2013 , Pages 2098-2109 ; 10916466 (ISSN) Zangeneh Var, A ; Bastani, D ; Badakhshan, A ; Sharif University of Technology
    2013

    An experimental investigation of surfactant flooding as a good candidate for enhancing oil recovery from fractured reservoirs using one-quarter five spot micromodels: The role of fracture geometrical properties

    , Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Volume 35, Issue 20 , 2013 , Pages 1929-1938 ; 15567036 (ISSN) Kianinejad, A ; Ghazanfari, M. H ; Kharrat, R ; Rashtchian, D ; Sharif University of Technology
    2013
    Abstract
    Surfactant flooding is known to lower the interfacial tension and, hence, reduces capillary forces responsible for trapping oil. Despite numerous experimental studies, little is known about the role of fracture geometrical properties on oil recovery efficiency during surfactant floods, especially in five-spot systems. In addition, application of sodium dodecyl sulfate for oil recovery in fractured media is not discussed well. In this study, two types of surfactant solutions have been injected into micromodels, which were initially saturated with crude oil, having different length, orientation, and distribution of fractures under oil-wet conditions. Precise analyses of continuously recorded... 

    An experimental review on microbubble generation to be used in echo-particle image velocimetry method to determine the pipe flow velocity

    , Article Journal of Fluids Engineering, Transactions of the ASME ; Volume 135, Issue 3 , Feb , 2013 , Paper No: FE-12-1217 ; 00982202 (ISSN) Salari, A ; Shafii, M. B ; Shirani, S ; Sharif University of Technology
    2013
    Abstract
    Microbubbles are broadly used as ultrasound contrast agents. In this paper we use a low-cost flow focusing microchannel fabrication method for preparing microbubble contrast agents by using some surface active agents and a viscosity enhancing material to obtain appropriate microbubbles with desired lifetime and stability for any in vitro infusion for velocity measurement. All the five parameters that govern the bubble size extract and some efforts are done to achieve the smallest bubbles by adding suitable surfactant concentrations. By using these microbubbles for the echo-particle image velocimetry method, we experimentally determine the velocity field of steady state and pulsatile pipe... 

    Monodispersed polymeric nanoparticles fabrication by electrospray atomization

    , Article International Journal of Polymeric Materials and Polymeric Biomaterials ; Volume 61, Issue 8 , 2012 , Pages 611-626 ; 00914037 (ISSN) Zarrabi, A ; Vossoughi, M ; Alemzadeh, I ; Chitsazi, M. R ; Sharif University of Technology
    2012
    Abstract
    The feasibility of fabricating relatively monodispersed polymeric nanoparticles by the electrospray method in a modified electrospray set-up is demonstrated in this study. The polymer solution is electrosprayed in the single cone-jet regime through a nozzle. After solvent evaporation, during which particles pave from the nozzle to collector, the fabricated nanoparticles can be collected in deionized water, which plays the role of surfactant for particles, not allowing them to aggregate. The results of scanning electron microscope and dynamic light scattering analysis clearly confirm the fabrication of monodispersed spherical polymeric nanoparticles with diameter range from 80 to 120nm with... 

    Optimal well location in surfactant flooding by genetic algorithm

    , Article 74th European Association of Geoscientists and Engineers Conference and Exhibition 2012 Incorporating SPE EUROPEC 2012: Responsibly Securing Natural Resources ; 2012 , Pages 5489-5491 ; 9781629937908 (ISBN) Ravandoust, R ; Chahardahcherik, M ; Sharif University of Technology
    European Association of Geoscientists and Engineers, EAGE  2012
    Abstract
    As many fields around the world are reaching maturity, the need to develop new tools that allows reservoir engineering to optimize reservoir performance is becoming more demanding. One of the more challenging and influential problems along these lines is the well placement optimization problem. Determining of the location of new wells is a complex problem that depends on reservoir and fluid properties, well and surface equipment specifications, and economic criteria. Various approaches have been proposed for this problem. Among those, direct optimization using the simulator as the evaluation function, although accurate, is in most cases infeasible due to the number of simulations required.... 

    Effects of contaminants on the mass-transfer characteristics of a two-impinging-streams gas-liquid reactor

    , Article Chemical Engineering and Technology ; Volume 34, Issue 11 , 2011 , Pages 1797-1806 ; 09307516 (ISSN) Dehkordi, A. M ; Savari, C ; Sharif University of Technology
    Abstract
    The mass-transfer characteristics of a new type of two-impinging-streams reactor (TISR) was studied by means of sodium sulfite solution as the liquid phase and air as the gas phase, in the presence and absence of various types of surface-active agents (SAAs). The influences of anionic, cationic, and nonionic SAAs on the specific interfacial area and overall volumetric mass-transfer coefficient obtained in the TISR were investigated. It was found that the presence of a little amount of the above-mentioned contaminants increases the specific interfacial area and decreases the overall volumetric mass-transfer coefficient. On the basis of the experimental results obtained for various types of... 

    Simulation and control of monomer conversion in a continuous emulsion polymerization reactor

    , Article IFAC Proceedings Volumes (IFAC-PapersOnline), 7 June 2015 through 10 June 2015 ; Volume 48, Issue 8 , 2015 , Pages 315-320 ; 14746670 (ISSN) Barazandegan, M ; Shahrokhi, M ; Abedini, H ; Vafa, E ; Guay, M ; Gopaluni, B ; Huang, B ; Findeisen, R ; Sharif University of Technology
    IFAC Secretariat  2015
    Abstract
    A detailed pseudo-bulk model has been used for prediction of conversion and particle size distribution (PSD) of vinyl acetate in a continuous emulsion polymerization reactor. Finite volume (FV) and moment techniques are applied for solving population balance equation under continuous operation. It is found that both methods can predict sustained oscillations in the monomer conversion, however the FV method matches the experimental data better than the moment method. The monomer conversion and free surfactant concentration are controlled via two single control loops. In this work, a new control strategy for controlling monomer conversion has been proposed. It has been shown that monomer... 

    Interfacial tension and wettability change phenomena during alkali-surfactant interactions with acidic heavy crude oil

    , Article Energy and Fuels ; Volume 29, Issue 2 , 2015 , Pages 649-658 ; 08870624 (ISSN) Dehghan, A. A ; Masihi, M ; Ayatollahi, S ; Sharif University of Technology
    American Chemical Society  2015
    Abstract
    In this work, a newly formulated sulfonate-based surfactant and two other commercial sulfate-based surfactants with the capability of tolerating harsh underground reservoir conditions, such as high-saline formation water and high temperature, were prepared. Sodium metaborate as an effective alkali compound was also used to provide alkali-surfactant combination. Interfacial tension (IFT) measurements as well as wettability examinations for different salinities and mixture conditions were performed for an extended range of the chemical concentrations. The wettability tests including both contact angle measurements and Amott cell tests were performed on saturated Berea sandstone plug samples... 

    Herschel-Bulkley rheological parameters of lightweight colloidal gas aphron (CGA) based fluids

    , Article Chemical Engineering Research and Design ; Volume 93 , 2015 , Pages 21-29 ; 02638762 (ISSN) Ziaee, H ; Arabloo, M ; Ghazanfari, M. H ; Rashtchian, D ; Sharif University of Technology
    Institution of Chemical Engineers  2015
    Abstract
    The proper understanding of rheological characteristics of CGA based fluids is of crucial importance in determining the performance of the fluid, in order to maintain the most effective fluid properties for safe, efficient, and economical drilling operation. This paper presents a concise investigation on the effect of concentration of the three main components of a novel environmentally friendly lightweight CGA based drilling fluid, i.e., xanthan gum biopolymer, starch, and biosurfactant, to the Herschel-Bulkley rheological model parameters. The three parameters of Herschel-Bulkley model, i.e., yield stress, fluid consistency, and fluid flow index were calculated by fitting the experimental... 

    Theoretical and experimental investigations of the inverse emulsion polymerization of acrylamide

    , Article Journal of Applied Polymer Science ; Volume 132, Issue 22 , February , 2015 ; 00218995 (ISSN) Abdi, A ; Shahrokhi, M ; Ahmad Ramazani, S. A ; Vafa, E ; Sharif University of Technology
    John Wiley and Sons Inc  2015
    Abstract
    In this study, the inverse emulsion polymerization modeling of polyacrylamide with population balance equations (PBEs) was performed. The PBEs were derived on the basis of the zero-one kinetic model. The effects of the surfactant steric barrier and surfactant reaction with radicals, including monomeric radicals, on the radical entry rate into the particle were taken into account. In the modified model, the coagulation phenomenon was included through consideration of the effects of forces not included in the Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory; these include hydration and steric forces in addition to DLVO forces. The effects of the surfactant and initiator concentrations on... 

    Characterization of viscous fingering during displacements of low tension natural surfactant in fractured multi-layered heavy oil systems

    , Article Chemical Engineering Research and Design ; Volume 96 , 2015 , Pages 23-34 ; 02638762 (ISSN) Arabloo, M ; Shokrollahi, A ; Ghazanfari, M. H ; Rashtchian, D ; Sharif University of Technology
    Institution of Chemical Engineers  2015
    Abstract
    Characterization of viscous fingering in low tension displacements especially for heavy oil surfactant pair in heterogeneous systems is neither straight forward nor well understood. In this work layered porous models containing fractures with different geometrical properties were used and the finger behavior during displacement of LTNS, as a new EOR agent, in heavy oil was quantified. Dynamic propagation of the fingers independent to the type of heterogeneity is well correlated with the dimensionless displacement time in a linearly form. And also, the rate of finger growth is nearly independent to the type of medium heterogeneity. When injection is scheduled through high permeable region in...