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Zabar MK, Phan CM, Barifcani A. Quantifying the Influence of Electrolytes on the Kinetics of Spontaneous Emulsification. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:100-108. [PMID: 38109722 DOI: 10.1021/acs.langmuir.3c02107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
This study quantifies the influence of electrolytes on the kinetics of the spontaneous emulsification phenomenon (SEP) of heavy hydrocarbons in a nonionic surfactant solution. The rate of emulsifying hexadecane in Triton X-100, with the presence of sodium chloride and potassium chloride, has been measured using a technique of monitoring single oil droplet photography. The emulsion droplet size produced in the process was measured under the same conditions by using dynamic light scattering. The data obtained from the two experiments were employed to investigate the mass transfer coefficient of the surfactant molecules through the intermediate layer formed between hexadecane and the surfactant solution. It was found that the electrolytes in an aqueous solution increase the surfactant diffusion rate through the intermediate layer and reduce the emulsion droplet size. As a result, both electrolytes reduce the rate of spontaneous emulsification, with potassium chloride having a more substantial reduction. A model was developed to quantify the influence of electrolytes on the kinetics of the SEP. The data and modeling results verify the influence of ions on the kinetics of spontaneous emulsification. The results provide a significant foundation for predicting the solubilization of heavy hydrocarbons in an electrolyte solution.
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Affiliation(s)
- Muhannad K Zabar
- Discipline of Chemical Engineering, WASM: MECE, Curtin University, Perth, Western Australia 6845, Australia
| | - Chi M Phan
- Discipline of Chemical Engineering, WASM: MECE, Curtin University, Perth, Western Australia 6845, Australia
| | - Ahmed Barifcani
- Discipline of Chemical Engineering, WASM: MECE, Curtin University, Perth, Western Australia 6845, Australia
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2
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Ray S, Roy A. Simple model for self-propulsion of microdroplets in surfactant solution. Phys Rev E 2023; 108:035102. [PMID: 37849129 DOI: 10.1103/physreve.108.035102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/23/2023] [Indexed: 10/19/2023]
Abstract
We propose a simple active hydrodynamic model for the self-propulsion of a liquid droplet suspended in micellar solutions. The self-propulsion of the droplet occurs by spontaneous breaking of isotropic symmetry and is studied using both analytical and numerical methods. The emergence of self-propulsion arises from the slow dissolution of the inner fluid into the outer micellar solution as filled micelles. We propose that the surface generation of filled micelles is the dominant reason for the self-propulsion of the droplet. The flow instability is due to the Marangoni stress generated by the nonuniform distribution of the surfactant molecules on the droplet interface. In our model, the driving parameter of the instability is the excess surfactant concentration above the critical micellar concentration, which directly correlates with the experimental observations. We consider various low-order modes of flow instability and show that the first mode becomes unstable through a supercritical bifurcation and is the only mode contributing to the swimming of the droplet. The flow fields around the droplet for these modes and their combined effects are also discussed.
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Affiliation(s)
- Swarnak Ray
- Soft Condensed Matter Group, Raman Research Institute, Bangalore 560080, India
| | - Arun Roy
- Soft Condensed Matter Group, Raman Research Institute, Bangalore 560080, India
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3
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Quantifying the spontaneous emulsification of a heavy hydrocarbon with the presence of a strong surfactant. Colloids Surf A Physicochem Eng Asp 2023. [DOI: 10.1016/j.colsurfa.2022.130425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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4
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Baglioni M, Guaragnone T, Mastrangelo R, Sekine FH, Ogura T, Baglioni P. Nonionic Surfactants for the Cleaning of Works of Art: Insights on Acrylic Polymer Films Dewetting and Artificial Soil Removal. ACS APPLIED MATERIALS & INTERFACES 2020; 12:26704-26716. [PMID: 32394706 PMCID: PMC8007071 DOI: 10.1021/acsami.0c06425] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
The use of nanostructured fluids (NSFs), that is, micellar solutions and microemulsions, in art conservation is often associated with cleaning purposes as the removal of polymeric coatings and/or soil from artistic surfaces. In both cases, the use of NSFs grants significant improvements over the use of traditional cleaning techniques that employ neat unconfined organic solvents, water, or aqueous solutions. The study of the nature and properties of surfactants present in NSF formulations is important to boost the effectiveness of these systems in applicative contexts and in the search of innovative and highly performing amphiphiles. This work reports on the methoxy-pentadeca(oxyethylene) dodecanoate (MPD) surfactant in two different NSFs, whose utilization in conservation of cultural heritage is new. Its effectiveness is compared to the conventional nonionic amphiphiles used in conservation practice, as pentadeca(oxyethylene) dodecyl ether, for the cleaning of poly(ethyl methacrylate/methyl acrylate) 70:30, p(EMA/MA), and artificially soiled surfaces. The mechanism, through which NSFs interact with polymeric coatings or soiled surfaces, was investigated by confocal laser scanning microscopy, fluorescence correlation spectroscopy, photographic observation, contact angle, surface tension measurements, and small-angle X-ray scattering. The results highlighted the superior MPD's performance, both in inducing polymer removal and in detaching the soil from coated surfaces. At the microscale, the cleaning involves dewetting-like processes, where the polymer or the soil oily phase is detached from the surface and coalesce into separated droplets. This can be accounted by considering the different surface tensions and the different adsorption mechanisms of MPD with respect to ordinary nonionic surfactants (likely due to the methyl capping of the polar head chain and to the presence of the ester group between the hydrophilic and hydrophobic parts of the MPD surfactant molecule), showing how a tiny change in the surfactant architecture can lead to important differences in the cleaning capacity. Overall, this paper provides a detailed description of the mechanism and the kinetics involved in the NSFs cleaning process, opening new perspectives on simple formulations that are able to target at a specific substance to be removed. This is of utmost importance in the conservation of irreplaceable works of art.
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Affiliation(s)
- Michele Baglioni
- Department
of Chemistry and CSGI, University of Florence, via della Lastruccia, 3, 50019 Sesto Fiorentino, Florence, Italy
| | - Teresa Guaragnone
- Department
of Chemistry and CSGI, University of Florence, via della Lastruccia, 3, 50019 Sesto Fiorentino, Florence, Italy
| | - Rosangela Mastrangelo
- Department
of Chemistry and CSGI, University of Florence, via della Lastruccia, 3, 50019 Sesto Fiorentino, Florence, Italy
| | - Felipe Hidetomo Sekine
- NIKKOL
GROUP Nikko Chemicals Co., Ltd., 1-4-8, Nihonbashi-Bakurocho, Chuo-ku, 103-0002 Tokyo, Japan
| | - Taku Ogura
- NIKKOL
GROUP Nikko Chemicals Co., Ltd., 1-4-8, Nihonbashi-Bakurocho, Chuo-ku, 103-0002 Tokyo, Japan
- NIKKOL
GROUP Cosmos Technical Center Co., Ltd., 3-24-3 Hasune, Itabashi-ku, 174-0046 Tokyo, Japan
- Research
Institute for Science & Technology, Tokyo University of Science, 2641, Yamazaki, Noda-shi, Chiba 278-8510, Japan
| | - Piero Baglioni
- Department
of Chemistry and CSGI, University of Florence, via della Lastruccia, 3, 50019 Sesto Fiorentino, Florence, Italy
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Endo C, Ito Y, Akabane C, Kaneko Y, Sakai H. Spontaneous Emulsification of Triolein Induced by Mixed Micellar Solutions of Sodium Polyoxyethylene Alkyl Ether Sulfate and Dodecyldimethyl Amine Oxide. J Oleo Sci 2015; 64:953-62. [DOI: 10.5650/jos.ess15080] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Chika Endo
- Functional Materials Science Research Laboratories, R & D, LION CORPORATION
| | - Yoshiko Ito
- Functional Materials Science Research Laboratories, R & D, LION CORPORATION
| | - Chika Akabane
- Functional Materials Science Research Laboratories, R & D, LION CORPORATION
| | - Yukihiro Kaneko
- Functional Materials Science Research Laboratories, R & D, LION CORPORATION
| | - Hideki Sakai
- Faculty of Science and Technology, Tokyo University of Science
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6
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Abstract
Oily wastewater is a potential source for biohydrogen production due to its high organic content. Incorporation of surfactant could enhance the solubilization of oil in water, and thus increase its biodegradability. The first part of this work studied the influence of surfactant concentrations (0-240 CMC) and temperatures (28-70 °C) on oil solubilization in aqueous solution. Results from batch tests showed that the oil solubilization improved as the surfactant concentration increased up to 100 CMC. As high as 0.002 mg/L oil concentration could be solubilized at 1 CMC and 55 °C, which was 90 times higher than that obtained without surfactant application. Moreover, the time to reach oil-in-liquid equilibrium could be shortened by increasing the temperature. In the second part, the effect of surfactant addition on hydrogen production was investigated at pH 5.5 and 55 °C. In 148 h batch assays, the highest hydrogen production observed was 19.3 mL at 1 CMC while it was 8.7 mL at no surfactant. Further investigation at 1 CMC revealed that surfactant degradation to H2 was 2.36 mL, thus the effect of surfactant to enhance oil degradability was 0.24 L H2 per liter of aqueous solution under excess oil condition.
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Bae M, Kim D, Cho SY, Lim J. Effect of Cosurfactant on Solubilization of Hydrocarbon Oils by Pluronic L64 Nonionic Surfactant Solution. KOREAN CHEMICAL ENGINEERING RESEARCH 2014. [DOI: 10.9713/kcer.2014.52.2.219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Dunstan TS, Fletcher PDI. The Removal of Thermally Aged Films of Triacylglycerides by Surfactant Solutions. J SURFACTANTS DETERG 2013. [DOI: 10.1007/s11743-013-1514-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Bernardez LA. EFFECTS OF FLOW RATE AND TEMPERATURE ON THE DISSOLUTION OF POLYCYCLIC AROMATIC HYDROCARBONS TRANSFERRING FROM A NONAQUEOUS PHASE LIQUID TO NONIONIC SURFACTANT SOLUTIONS. CHEM ENG COMMUN 2011. [DOI: 10.1080/00986445.2011.560514] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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10
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Dissolution Study of Salt of Long Chain Fatty Acids (Soap Scum) in Surfactant Solutions. Part II: Kinetics of Dissolution. J SURFACTANTS DETERG 2010. [DOI: 10.1007/s11743-010-1209-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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11
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On-line flow injection-cloud point preconcentration of polycyclic aromatic hydrocarbons coupled with high-performance liquid chromatography. J Chromatogr A 2008; 1214:11-6. [DOI: 10.1016/j.chroma.2008.10.062] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Revised: 10/08/2008] [Accepted: 10/15/2008] [Indexed: 11/21/2022]
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12
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Solubilization kinetics for polycyclic aromatic hydrocarbons transferring from a non-aqueous phase liquid to non-ionic surfactant solutions. J Colloid Interface Sci 2008; 320:298-306. [DOI: 10.1016/j.jcis.2007.12.035] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Revised: 12/20/2007] [Accepted: 12/22/2007] [Indexed: 11/22/2022]
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13
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Ariyaprakai S, Dungan SR. Solubilization in monodisperse emulsions. J Colloid Interface Sci 2007; 314:673-82. [PMID: 17603068 DOI: 10.1016/j.jcis.2007.06.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 06/03/2007] [Accepted: 06/05/2007] [Indexed: 10/23/2022]
Abstract
The kinetics of oil solubilization into micelles from nearly monodisperse alkane-in-water emulsion droplets was investigated. Emulsions containing either hexadecane or tetradecane oils were fractionated to be narrowly distributed, using a method developed by Bibette [J. Bibette, J. Colloid Interface Sci. 147 (1991) 474]. These monodisperse emulsions were mixed with SDS or Tween 20 aqueous micellar solutions of various concentrations. Time-dependent solubilization was monitored using light scattering and a decrease in average droplet size over time was observed, in contrast to what has been observed previously with polydisperse emulsions. The rate at which the droplet size decreased was found to be independent of the initial droplet size. Turbidity measurements were also used to track the solubilization kinetics, and a population balance analysis used on both types of measurements to extract effective mass transfer coefficients. The dependence of these transfer coefficients on droplet size, alkane type, surfactant type and concentration provide insights into plausible mechanisms of emulsion droplet solubilization within micellar solutions.
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Affiliation(s)
- Suwimon Ariyaprakai
- Department of Food Science and Technology, Department of Chemical Engineering and Materials Science, University of California, One Shields Avenue, Davis, CA 95616, USA
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14
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Peña AA, Miller CA. Solubilization rates of oils in surfactant solutions and their relationship to mass transport in emulsions. Adv Colloid Interface Sci 2006; 123-126:241-57. [PMID: 16860285 DOI: 10.1016/j.cis.2006.05.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Information on solubilization rates of oils in aqueous micellar solutions is reviewed. For ionic surfactants electrostatic repulsion prevents close approach of micelles to the oil-water interface, so that solubilization results from oil molecules dissolving individually in the solution and being taken up by micelles during and/or after transport across a diffusion boundary layer to the bulk solution. Experiments with SDS solutions and single oil drops having low (but not negligible) solubility indicate that mass transfer is often not rate-controlling. Instead phenomena near the oil-water interface including, but not limited to, the rates of micellar uptake of oil from the aqueous solution seem to control the solubilization rate. In contrast, Ostwald ripening experiments involving multiple oil drops in SDS solutions are often interpreted in terms of molecular dissolution and diffusion alone since ripening rates are typically only slightly different from those observed in the absence of surfactant micelles, where this mechanism is considered to hold. For many nonionic surfactant systems and oils of low or negligible solubility the principal mechanism of solubilization is incorporation of surfactant at the oil-water interface from micelles, which coalesce or "adsorb" at the interface or else dissociate nearby, permitting individual surfactant molecules to be adsorbed. Subsequently the excess surfactant is emitted as oil-containing micelles. Most experiments have indicated that this process, which appears in the analyses as an interfacial resistance, is rate controlling. New results are presented here supporting this model and showing that resistance to mass transfer is often quite low because natural convection can arise near an oil drop owing to the density change produced by solubilized oil in micelles near the drop surface. Provided that polydispersity of drop sizes is properly accounted for, experiments on solubilization and compositional ripening in emulsions stabilized with nonionic surfactants can be interpreted using the interfacial resistance model with values of resistance obtained from single-drop experiments. However, it is unclear whether mass transfer, interfacial resistance or perhaps some combined mechanism controls the rate of Ostwald ripening. One uncertainty limiting predictions of the interfacial resistance model is the lack of information on the oil-to-surfactant ratio in micelles when the concentration of individually dissolved oil molecules slightly exceeds the equilibrium value for a plane oil-water interface, the situation during Ostwald ripening.
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Affiliation(s)
- Alejandro A Peña
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX 77005, USA
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15
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Swe MM, Yu LE, Hung KC, Chen BH. Solubilization of selected polycyclic aromatic compounds by nonionic surfactants. J SURFACTANTS DETERG 2006. [DOI: 10.1007/s11743-006-5003-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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16
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Wu RC, Papadopoulos KD, Campbell CB. Visualization test for neutralization of acids by marine cylinder lubricants. AIChE J 2006. [DOI: 10.1002/aic.690450917] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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17
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Transport mechanisms in the micellar solubilization of alkanes in oil-in-water emulsions. Colloids Surf A Physicochem Eng Asp 2003. [DOI: 10.1016/s0927-7757(02)00549-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Zhong L, Mayer AS, Pope GA. The effects of surfactant formulation on nonequilibrium NAPL solubilization. JOURNAL OF CONTAMINANT HYDROLOGY 2003; 60:55-75. [PMID: 12498574 DOI: 10.1016/s0169-7722(02)00063-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Surfactant-enhanced aquifer remediation (SEAR) involves the injection of surfactant solutions into aquifers contaminated with nonaqueous phase liquids (NAPL). Batch and column experiments were used to assess the effect of surfactant formulation on the rate of NAPL solubilization. The experimental variables were surfactant type, surfactant concentration, electrolyte concentration, and cosolvent concentration. Model equations were proposed and solved to describe solubilization under the conditions of each type of experiment. Using these models, a solubilization rate constant, kappa(b), and an overall mass transfer rate coefficient, kappa, were estimated from the batch and column experiments, respectively. The solubilization rate constant was consistently sensitive to surfactant type, surfactant concentration, and electrolyte concentration. The estimated solubilization rate constants varied over two orders of magnitude. The results of the column experiments also were sensitive to the surfactant formulation. Variations in the fitted mass transfer rate coefficient parameter, beta(0), were related to variations in the surfactant formulations. A comparison between the results of the batch and column experiments yields an apparent relationship between beta(0) and kappa(b). This relationship suggests that the mass transfer rate coefficient is directly related to the formulation of the surfactant solution.
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Affiliation(s)
- Lirong Zhong
- Center for Petroleum and Geosystems Engineering, The University of Texas at Austin, Austin, TX 78712, USA
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19
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Shah R, Neogi P. Interfacial Resistance in Solubilization Kinetics. J Colloid Interface Sci 2002; 253:443-54. [PMID: 16290876 DOI: 10.1006/jcis.2002.8449] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2002] [Accepted: 04/30/2002] [Indexed: 11/22/2022]
Abstract
An experiment has been designed to measure the kinetics of solubilization of oils in a micellar solution. The results show a very large range of behaviors, but in one system the solubilization rate is determined completely by what is called the interfacial resistance, which quite likely arises out of the structural changes that micelles see. The model given here is successful in showing that this resistance is not the usual resistance due to diffusion and that it is quite prelevant in systems that are chemically similar but other conditions varying widely (Appendix). We conclude by showing that some of the existing theories of interfacial resistance are not reasonable, suggest how the real system may be more complex, and show that the interfacial conductance k* proportional c(m)(-1) at large surfactant concentrations where c(m) is the concentration of micelles.
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Affiliation(s)
- Rajesh Shah
- Department of Chemical Engineering, University of Missouri--Rolla, Rolla, Missouri 65409-1230, USA
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20
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Li JL, Chen BH. Solubilization of model polycyclic aromatic hydrocarbons by nonionic surfactants. Chem Eng Sci 2002. [DOI: 10.1016/s0009-2509(02)00169-0] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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21
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Peña AA, Miller CA. Transient Behavior of Polydisperse Emulsions Undergoing Mass Transfer. Ind Eng Chem Res 2002. [DOI: 10.1021/ie0109861] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alejandro A. Peña
- Chemical Engineering Department, Rice University, 6100 Main Street, Mail Stop 362, Houston, Texas 77005
| | - Clarence A. Miller
- Chemical Engineering Department, Rice University, 6100 Main Street, Mail Stop 362, Houston, Texas 77005
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22
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Todorov PD, Kralchevsky PA, Denkov ND, Broze G, Mehreteab A. Kinetics of Solubilization of n-Decane and Benzene by Micellar Solutions of Sodium Dodecyl Sulfate. J Colloid Interface Sci 2002; 245:371-82. [PMID: 16290371 DOI: 10.1006/jcis.2001.8031] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2001] [Accepted: 10/05/2001] [Indexed: 11/22/2022]
Abstract
We observed the diminishing of single microscopic oil drops to study the kinetics of solubilization of n-decane and benzene by micellar solutions of sodium dodecyl sulfate (SDS). Each drop is located in a horizontal glass capillary of inner diameter 0.06 cm filled with a thermostated surfactant solution; the small vertical dimension of the cell prevents the appearance of uncontrollable thermal convections. The experiments show that the radius of an n-decane drop decreases linearly with time, whereas for benzene this dependence is nonlinear. To interpret the data, a kinetic model of solubilization is developed. It accounts for the diffusion and capturing of dissolved oil molecules by the surfactant micelles, as well as for the finite rate of oil dissolution at the oil-water interface. By processing the data, we determined the rate constant of solubilization for a given oil and surfactant. It turns out that the elementary act of catching a dissolved oil molecule by a surfactant micelle occurs under a barrier (rather than diffusion) control. The effective rate of solubilization is greater for the oil, which exhibits a higher equilibrium solubility in pure water (benzene), despite the lower value of the solubilization rate constant for this oil.
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Affiliation(s)
- P D Todorov
- Laboratory of Chemical Physics & Engineering, Faculty of Chemistry, University of Sofia, Sofia, 1164, Bulgaria
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23
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Kinetics of Compositional Ripening in Emulsions Stabilized with Nonionic Surfactants. J Colloid Interface Sci 2001. [DOI: 10.1006/jcis.2001.7928] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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24
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Bai D, Li J, Chen SB, Chen BH. A novel cloud-point extraction process for preconcentrating selected polycyclic aromatic hydrocarbons in aqueous solution. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2001; 35:3936-3940. [PMID: 11642455 DOI: 10.1021/es0108335] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A novel but simple cloud-point extraction (CPE) process is developed to preconcentrate the trace of selected polycyclic aromatic hydrocarbons (PAHs) with the use of the readily biodegradable nonionic surfactant Tergitol 15-S-7 as extractant. The concentrations of PAHs, mixtures of naphthalene and phenanthrene as well as pyrene, in the spiked samples were determined with the new CPE process at ambient temperature (23 degrees C) followed by high performance liquid chromatography(HPLC) with fluorescence detection. More than 80% of phenanthrene and pyrene, respectively, and 96% of naphthalene initially present in the aqueous solutions with concentrations near or below their aqueous solubilities were recovered using this new CPE process. Importantly Tergitol 15-S-7 does not give any fluorometric signal to interfere with fluorescence detection of PAHs in the UV range. No special washing step is, thus, required to remove surfactant before HPLC analyses. Different experimental conditions were studied. The optimum conditions for the preconcentration and determination of these selected PAHs at ambient temperature have been established as the following: (1) 3 wt% surfactant; (2) addition of 0.5 M Na2SO4; (3) 10 min for equilibration time; and (4) 3000 rpm for centrifugal speed with duration of 10 min.
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Affiliation(s)
- D Bai
- Department of Chemical and Environmental Engineering, The National University of Singapore, Crescent
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25
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Chen BH, Miller CA, Garrett PR. Dissolution of nonionic surfactant mixtures. Colloids Surf A Physicochem Eng Asp 2001. [DOI: 10.1016/s0927-7757(01)00547-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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26
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27
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Wen L, Papadopoulos KD. Visualization of water transport in W1/O/W2 emulsions. Colloids Surf A Physicochem Eng Asp 2000. [DOI: 10.1016/s0927-7757(00)00508-2] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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28
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Williams CL, Bhakta AR, Neogi P. MASS Transfer of a Solubilizate in a Micellar Solution and Across an Interface. J Phys Chem B 1999. [DOI: 10.1021/jp984448m] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Christie L. Williams
- Chemical Engineering Department, University of MissouriRolla, Rolla, Missouri 65409-1230
| | - Ashok R. Bhakta
- Chemical Engineering Department, University of MissouriRolla, Rolla, Missouri 65409-1230
| | - P. Neogi
- Chemical Engineering Department, University of MissouriRolla, Rolla, Missouri 65409-1230
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29
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Kabalnov A. Thermodynamic and theoretical aspects of emulsions and their stability. Curr Opin Colloid Interface Sci 1998. [DOI: 10.1016/s1359-0294(98)80071-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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