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Ismail E, Sha’arani SS, Azuma S, Uchikoshi T, Ichinose I. Video Processing Electrophoretic Measurements under High Electric Fields for Sub-millimeter Particles in Oil. J Oleo Sci 2022; 71:445-457. [DOI: 10.5650/jos.ess21367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Edhuan Ismail
- Research Center for Functional Materials, National Institute for Materials Science
| | | | - Shota Azuma
- Research Center for Functional Materials, National Institute for Materials Science
| | - Tetsuo Uchikoshi
- Research Center for Functional Materials, National Institute for Materials Science
| | - Izumi Ichinose
- Research Center for Functional Materials, National Institute for Materials Science
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2
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Shaparenko NO, Demidova MG, Bulavchenko AI. Electrophoretic mobility and stability of SiO 2 nanoparticles in the solutions of AOT in n-hexadecane-chloroform mixtures. Electrophoresis 2021; 42:1648-1654. [PMID: 34213016 DOI: 10.1002/elps.202100060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 05/24/2021] [Accepted: 06/10/2021] [Indexed: 11/11/2022]
Abstract
Electrophoretic mobility of SiO2 nanoparticles in a n-hexadecane-chloroform mixture depending on AOT concentration and chloroform content was determined. It was shown that an increase in chloroform content and a decrease in AOT concentration cause a growth in electrophoretic mobility. The use of the values of Debye lengths (characteristic thickness) of the diffuse part of the electric double layer (EDL) that were determined previously allowed us to calculate the electrokinetic potential and to evaluate the stability of organosols. The obtained data were in good correlation with the dynamics of temporal changes of hydrodynamic radius and the intensity of light scattering. Organosols may be used for heteroaggregation (sorption) of Au and Ag nanoparticles on SiO2 .
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Affiliation(s)
| | - Marina G Demidova
- Nikolaev Institute of Inorganic Chemistry SB RAS, Novosibirsk, Russia
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3
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Ponto BS, Berg JC. Nanoparticle charging with mixed reverse micelles in apolar media. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2019.124275] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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4
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Bulavchenko AI, Shaparenko NO, Kompan’kov NB, Popovetskiy PS, Demidova MG, Arymbaeva AT. The formation of free ions and electrophoretic mobility of Ag and Au nanoparticles in n-hexadecane–chloroform mixtures at low concentrations of AOT. Phys Chem Chem Phys 2020; 22:14671-14681. [DOI: 10.1039/d0cp02153a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The electrophoretic mobility of Ag and Au nanoparticles in n-hexadecane–chloroform mixtures was studied as a function of the chloroform content (from 0 to 100 vol%).
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Affiliation(s)
| | - Nikita O. Shaparenko
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
| | - Nikolay B. Kompan’kov
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
| | - Pavel S. Popovetskiy
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
| | - Marina G. Demidova
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
| | - Aida T. Arymbaeva
- Nikolaev Institute of Inorganic Chemistry
- Russian Academy of Sciences
- Novosibirsk
- Russia
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5
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Fan Z, Zhang L, Liu S, Luan L, Li G, Sun D. Mechanism of high temperature induced destabilization of nonpolar organoclay suspension. J Colloid Interface Sci 2019; 555:53-63. [PMID: 31376768 DOI: 10.1016/j.jcis.2019.07.072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 07/22/2019] [Accepted: 07/24/2019] [Indexed: 11/28/2022]
Abstract
HYPOTHESIS High temperatures can reduce the colloidal stability and rheological properties of nonpolar organoclay suspensions. The desorption of surfactants from organoclay has been proposed to explain this effect, but the mechanism remains unclear. In this work, it was hypothesized that the high-temperature-induced desorption of ion-exchanged surfactants is the main factor affecting the stabilization of suspensions. EXPERIMENTS Using the cationic surfactant dimethyldioctadecylammonium chloride (DODMAC) and Na-montmorillonite (Na-MMT), the high-temperature-induced reestablishment of the adsorption-desorption equilibrium of DODMAC in organoclay suspensions was studied. Thermogravimetric analysis combined with infrared spectroscopy and gas chromatography/mass spectrometry experiments were performed to determine the thermal decomposition products and, ultimately, infer the adsorption modes and locations of DODMAC on Na-MMT. Thermal analysis and rheology were utilized to demonstrate the high-temperature-induced desorption and transfer of DODMAC in organoclay suspensions. FINDINGS High temperatures induced the complete desorption of physically adsorbed DODMAC molecules from particle surfaces, the partial desorption of ion-exchanged dimethyldioctadecylammonium ions (DODMA+ ions) from particle surfaces, and the partial transfer of ion-exchanged DODMA+ ions from the surfaces to the interlayers. Importantly, desorption of ion-exchanged DODMA+ ions resulted in destabilization of the organoclay suspensions at high temperatures.
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Affiliation(s)
- Zhe Fan
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan, Shandong 250100, PR China
| | - Li Zhang
- Shandong Analysis and Test Centre, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong 250014, PR China.
| | - Shangying Liu
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan, Shandong 250100, PR China
| | - Lingyu Luan
- Shandong Analysis and Test Centre, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong 250014, PR China
| | - Gongrang Li
- Drilling Technology Research Institute, Shengli Petroleum Engineering Corporation Limited of SINOPEC, Dongying, Shandong 257017, PR China
| | - Dejun Sun
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan, Shandong 250100, PR China.
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6
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Geng T, Qiu Z, Zhao C, Zhang L, Zhao X. Rheological study on the invert emulsion fluids with organoclay at high aged temperatures. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2019.04.056] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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7
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Shaparenko NO, Beketova DI, Demidova MG, Bulavchenko AI. Regulation of the Charge and Hydrodynamic Diameter of Silica Nanoparticles in AOT Microemulsions. COLLOID JOURNAL 2019. [DOI: 10.1134/s1061933x19010101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Farrokhbin M, Stojimirović B, Galli M, Khajeh Aminian M, Hallez Y, Trefalt G. Surfactant mediated particle aggregation in nonpolar solvents. Phys Chem Chem Phys 2019; 21:18866-18876. [DOI: 10.1039/c9cp01985e] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The aggregation behavior of particles in nonpolar media is studied with time-resolved light scattering.
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Affiliation(s)
- Mojtaba Farrokhbin
- Department of Inorganic and Analytical Chemistry
- University of Geneva
- Sciences II
- 1205 Geneva
- Switzerland
| | - Biljana Stojimirović
- Department of Inorganic and Analytical Chemistry
- University of Geneva
- Sciences II
- 1205 Geneva
- Switzerland
| | - Marco Galli
- Department of Inorganic and Analytical Chemistry
- University of Geneva
- Sciences II
- 1205 Geneva
- Switzerland
| | | | - Yannick Hallez
- Laboratoire de Génie Chimique
- Université de Toulouse
- CNRS
- INPT
- UPS
| | - Gregor Trefalt
- Department of Inorganic and Analytical Chemistry
- University of Geneva
- Sciences II
- 1205 Geneva
- Switzerland
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9
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Lee J. Charge carriers created by interaction of a nonionic surfactant with water in a nonpolar medium. Colloids Surf A Physicochem Eng Asp 2018. [DOI: 10.1016/j.colsurfa.2018.06.050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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10
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Abstract
Highly hydrophobic, water-insoluble nonionic surfactants are often considered irrelevant to the ionization of interfaces at which they adsorb, despite observations that suggest otherwise. In the present study, we provide unambiguous evidence for the participation of a water-insoluble surfactant in interfacial ionization by conducting electrophoresis experiments for surfactant-stabilized nonpolar oil droplets in aqueous continuous phase. It was found that the surfactant with amine headgroup positively charged the surface of oil suspended in aqueous continuous phase (oil/water interface), which is consistent with its basic nature. In nonpolar oil continuous phase, the same surfactant positively charged the surface of solid silica (solid/oil interface) which is often considered acidic. The latter observation is exactly opposite to what the traditional acid-base mechanism of surface charging would predict, most clearly suggesting the possibility for another charging mechanism.
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Affiliation(s)
- Joohyung Lee
- Department of Chemical Engineering , Myongji University , Yongin , Gyeonggi 17058 , Korea
| | - Zhang-Lin Zhou
- Hewlett-Packard Company , 16399 W Bernardo Drive , San Diego , California 92127 , United States
| | - Sven Holger Behrens
- School of Chemical & Biomolecular Engineering , Georgia Institute of Technology , 311 Ferst Drive NW , Atlanta , Georgia 30332 , United States
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11
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Bleier BJ, Yezer BA, Freireich BJ, Anna SL, Walker LM. Droplet-based characterization of surfactant efficacy in colloidal stabilization of carbon black in nonpolar solvents. J Colloid Interface Sci 2017; 493:265-274. [DOI: 10.1016/j.jcis.2017.01.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 01/06/2017] [Accepted: 01/09/2017] [Indexed: 10/20/2022]
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12
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Michor EL, Berg JC. The particle charging behavior of ion-exchanged surfactants in apolar media. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2016.10.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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13
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Michor EL, Ponto BS, Berg JC. Effects of Reverse Micellar Structure on the Particle Charging Capabilities of the Span Surfactant Series. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:10328-10333. [PMID: 27649769 DOI: 10.1021/acs.langmuir.6b02959] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This paper investigates the effects of reverse micellar core size on the particle charging behavior of a series of acidic surfactants in apolar media. A series of Span surfactants was dissolved in deuterated decane at concentrations above the critical micelle concentration. The structures of the reverse micelles were measured using small-angle neutron scattering. It was determined that as the tail length of the surfactant increased, the size of the polar reverse micellar core decreased. Tritailed surfactants formed reverse micelles with the smallest polar cores, with radii of ∼4 Å. The sizes of the polar cores were correlated with the particle charging behavior of the Span surfactant series, as measured in a previous study. It was found that reverse micelles with intermediate core sizes imparted the largest electrophoretic mobilities to the particles. Reverse micelles with very small cores did not offer a large enough polar environment to favor charge stabilization, while very large polar cores favored disproportionation reactions in the bulk, resulting in increased electrostatic screening.
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Affiliation(s)
- Edward L Michor
- Department of Chemical Engineering, University of Washington , Box 351750, Seattle, Washington 98195-1750, United States
| | - Benjamin S Ponto
- Department of Chemical Engineering, University of Washington , Box 351750, Seattle, Washington 98195-1750, United States
| | - John C Berg
- Department of Chemical Engineering, University of Washington , Box 351750, Seattle, Washington 98195-1750, United States
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14
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Lee J, Zhou ZL, Behrens SH. Charging Mechanism for Polymer Particles in Nonpolar Surfactant Solutions: Influence of Polymer Type and Surface Functionality. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:4827-4836. [PMID: 27135950 DOI: 10.1021/acs.langmuir.6b00583] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Surface charging phenomena in nonpolar dispersions are exploited in a wide range of industrial applications, but their mechanistic understanding lags far behind. We investigate the surface charging of a variety of polymer particles with different surface functionality in alkane solutions of a custom-synthesized and purified polyisobutylene succinimide (PIBS) polyamine surfactant and a related commercial surfactant mixture commonly used to control particle charge. We find that the observed electrophoretic particle mobility cannot be explained exclusively by donor-acceptor interactions between surface functional groups and surfactant polar moieties. Our results instead suggest an interplay of multiple charging pathways, which likely include the competitive adsorption of ions generated among inverse micelles in the solution bulk. We discuss possible factors affecting the competitive adsorption of micellar ions, such as the chemical nature of the particle bulk material and the size asymmetry between inverse micelles of opposite charge.
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Affiliation(s)
- Joohyung Lee
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , 311 Ferst Drive Northwest, Atlanta, Georgia 30332, United States
| | - Zhang-Lin Zhou
- HP Incorporated, 16399 West Bernardo Drive, San Diego, California 92127, United States
| | - Sven Holger Behrens
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , 311 Ferst Drive Northwest, Atlanta, Georgia 30332, United States
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15
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Demidova MG, Bulavchenko AI, Podlipskaya TY, Zubareva AP, Popovetskiy PS. A study of sodium bis(2-ethylhexyl) sulfosuccinate adsorption on silica from silver and gold organosols. COLLOID JOURNAL 2016. [DOI: 10.1134/s1061933x16020046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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16
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Lee J, Zhou ZL, Alas G, Behrens SH. Mechanisms of Particle Charging by Surfactants in Nonpolar Dispersions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:11989-11999. [PMID: 26484617 DOI: 10.1021/acs.langmuir.5b02875] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Electric charging of colloidal particles in nonpolar solvents plays a crucial role for many industrial applications and products, including rubbers, engine oils, toners, or electronic displays. Although disfavored by the low solvent permittivity, particle charging can be induced by added surfactants, even nonionic ones, but the underlying mechanism is poorly understood, and neither the magnitude nor the sign of charge can generally be predicted from the particle and surfactant properties. The conclusiveness of scientific studies has been limited partly by a traditional focus on few surfactant types with many differences in their chemical structure and often poorly defined composition. Here we investigate the surface charging of poly(methyl methacrylate) particles dispersed in hexane-based solutions of three purified polyisobutylene succinimide polyamine surfactants with "subtle" structural variations. We precisely vary the surfactant chemistry by replacing only a single electronegative atom located at a fixed position within the polar headgroup. Electrophoresis reveals that these small differences between the surfactants lead to qualitatively different particle charging. In the respective particle-free surfactant solutions we also find potentially telling differences in the size of the surfactant aggregates (inverse micelles), the residual water content, and the electric solution conductivity as well as indications for a significant size difference between oppositely charged inverse micelles of the most hygroscopic surfactant. An analysis that accounts for the acid/base properties of all constituents suggests that the observed particle charging is better described by asymmetric adsorption of charged inverse micelles from the liquid bulk than by charge creation at the particle surface. Intramicellar acid-base interaction and intermicellar surfactant exchange help rationalize the formation of micellar ions pairs with size asymmetry.
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Affiliation(s)
- Joohyung Lee
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , 311 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - Zhang-Lin Zhou
- Hewlett-Packard Company, 16399 W Bernardo Drive, San Diego, California 92127, United States
| | - Guillermo Alas
- School of Chemistry and Biochemistry, Georgia Institute of Technology , 901 Atlantic Drive NW, Atlanta, Georgia 30332, United States
| | - Sven Holger Behrens
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , 311 Ferst Drive NW, Atlanta, Georgia 30332, United States
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17
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Smith GN, Hallett JE, Eastoe J. Celebrating Soft Matter's 10th Anniversary: Influencing the charge of poly(methyl methacrylate) latexes in nonpolar solvents. SOFT MATTER 2015; 11:8029-8041. [PMID: 26369696 DOI: 10.1039/c5sm01190f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Sterically-stabilized poly(methyl methacrylate) (PMMA) latexes dispersed in nonpolar solvents are a classic, well-studied system in colloid science. This is because they can easily be synthesized with a narrow size distribution and because they interact essentially as hard spheres. These PMMA latexes can be charged using several methods (by adding surfactants, incorporating ionizable groups, or dispersing in autoionizable solvents), and due to the low relative permittivity of the solvents (εr ≈ 2 for alkanes to εr ≈ 8 for halogenated solvents), the charges have long-range interactions. The number of studies of these PMMA particles as charged species has increased over the past ten years, after few studies immediately following their discovery. A large number of variations in both the physical and chemical properties of the system (size, concentration, surfactant type, or solvent, as a few examples) have been studied by many groups. By considering the literature on these particles as a whole, it is possible to determine the variables that have an effect on the charge of particles. An understanding of the process of charge formation will add to understanding how to control charge in nonaqueous solvents as well as make it possible to develop improved technologically relevant applications for charged polymer nanoparticles.
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Affiliation(s)
- Gregory N Smith
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
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18
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Gacek MM, Berg JC. Effect of surfactant hydrophile-lipophile balance (HLB) value on mineral oxide charging in apolar media. J Colloid Interface Sci 2015; 449:192-7. [DOI: 10.1016/j.jcis.2014.11.075] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 11/20/2014] [Accepted: 11/20/2014] [Indexed: 11/24/2022]
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19
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Smith GN, Grillo I, Rogers SE, Eastoe J. Surfactants with colloids: Adsorption or absorption? J Colloid Interface Sci 2015; 449:205-14. [DOI: 10.1016/j.jcis.2014.12.048] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 12/07/2014] [Accepted: 12/08/2014] [Indexed: 11/30/2022]
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20
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Gacek MM, Berg JC. The role of acid-base effects on particle charging in apolar media. Adv Colloid Interface Sci 2015; 220:108-23. [PMID: 25891860 DOI: 10.1016/j.cis.2015.03.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 03/24/2015] [Accepted: 03/25/2015] [Indexed: 11/30/2022]
Abstract
The creation and stabilization of electric charge in apolar environments (dielectric constant≈2) have been an area of interest dating back to when an explanation was sought for the occurrence of what are now known as electrokinetic explosions during the pumping of fuels. More recently attention has focused on the charging of suspended particles in such media, underlying such applications as electrophoretic displays (e.g., the Amazon Kindle® reader) and new printing devices (e.g., the HP Indigo® Digital Press). The endeavor has been challenging owing to the complexity of the systems involved and the large number of factors that appear to be important. A number of different, and sometimes conflicting, theories for particle surface charging have been advanced, but most observations obtained in the authors' laboratory, as well as others, appear to be explainable in terms of an acid-base mechanism. Adducts formed between chemical functional groups on the particle surface and monomers of reverse micelle-forming surfactants dissociate, leaving charged groups on the surface, while the counter-charges formed are sequestered in the reverse micelles. For a series of mineral oxides in a given medium with a given surfactant, surface charging (as quantified by the maximum electrophoretic mobility or zeta potential obtained as surfactant concentration is varied) was found to scale linearly with the aqueous PZC (or IEP) values of the oxides. Different surfactants, with the same oxide series, yielded similar behavior, but with different PZC crossover points between negative and positive particle charging, and different slopes of charge vs. PZC. Thus the oxide series could be used as a yardstick to characterize the acid-base properties of the surfactants. This has led directly to the study of other materials, including surface-modified oxides, carbon blacks, pigments (charge transfer complexes), and polymer latices. This review focuses on the acid-base mechanism of particle charging in the context of the many other factors that are important to the phenomenon, including the presence of water, of other components (e.g., synergists and contaminants), and of electric field effects. The goal is the construction of a road map describing the anticipated particle charging behavior in a wide variety of systems, assisting in the choice or development of materials for specific applications.
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Affiliation(s)
| | - John C Berg
- Department of Chemical Engineering, University of Washington, Seattle, WA, USA.
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21
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Lee J, Zhou ZL, Behrens SH. Characterizing the Acid/Base Behavior of Oil-Soluble Surfactants at the Interface of Nonpolar Solvents with a Polar Phase. J Phys Chem B 2015; 119:6628-37. [DOI: 10.1021/jp510748q] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joohyung Lee
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive Northwest, Atlanta, Georgia 30332, United States
| | - Zhang-Lin Zhou
- Hewlett-Packard Company, 16399 West Bernardo
Drive, San Diego, California 92127, United States
| | - Sven Holger Behrens
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive Northwest, Atlanta, Georgia 30332, United States
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22
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Magnetically-responsive electrophoretic silica organosols. J Colloid Interface Sci 2014; 426:252-5. [DOI: 10.1016/j.jcis.2014.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 03/31/2014] [Accepted: 04/01/2014] [Indexed: 11/24/2022]
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23
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Wirth CL, Furst EM, Vermant J. Weak electrolyte dependence in the repulsion of colloids at an oil-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:2670-2675. [PMID: 24598009 DOI: 10.1021/la404538s] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The two-particle interaction between 3.1-μm-diameter polystyrene latex particles at a decane-water interface was measured with time-shared optical tweezers. The water subphase contained either 0.103 mM RbCl or 0.0342 mM MgCl2, which have hydrated cations of different size but identical anions. The choice of both the anion and the concentrations makes a comparison with published data on NaCl possible and also isolates the effect of the nature of the cation on the electrostatic interaction. The measured magnitude of the dipolar force and the relative changes as a function of electrolyte were in quantitative agreement with predictions from a recently published model that uses the Langevin-Poisson-Boltzmann equation including steric effects and the polarization saturation of the medium to predict the dipolar interaction (Frydel, D.; Oettel, M. Phys. Chem. Chem. Phys. 2011, 13, 4109-4118). These results support the hypothesis that a condensed layer of counterions contributes to the electrostatic interaction between colloidal particles at an oil-water interface. Although it has been suggested that the electrostatic interactions between particles at liquid interfaces could serve as a sensitive probe of the structural details of the electric double layer, both the model predictions and experimental measurements showed a maximum change of only ~25% in the magnitude of the interaction with a change in electrolyte under the conditions tested. The ability to resolve this small change was confounded by the heterogeneous nature of the interaction. Thus, despite the apparent importance of the choice of electrolyte, the subtlety of competing effects makes it unlikely that colloidal force measurements could be used to probe the fine structure of the electric double layer.
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Affiliation(s)
- Christopher L Wirth
- Department of Chemical Engineering, KU Leuven , W. de Croylaan 46, B-3001 Leuven, Belgium
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24
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Effect of synergists on organic pigment particle charging in apolar media. Electrophoresis 2014; 35:1766-72. [DOI: 10.1002/elps.201300593] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 01/21/2014] [Accepted: 01/26/2014] [Indexed: 11/07/2022]
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25
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Surfactant mediated charging of polymer particles in a nonpolar liquid. J Colloid Interface Sci 2013; 392:83-89. [DOI: 10.1016/j.jcis.2012.09.070] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 09/26/2012] [Indexed: 11/22/2022]
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26
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Smith GN, Eastoe J. Controlling colloid charge in nonpolar liquids with surfactants. Phys Chem Chem Phys 2013. [DOI: 10.1039/c2cp42625k] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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Gacek MM, Berg JC. Investigation of surfactant mediated acid-base charging of mineral oxide particles dispersed in apolar systems. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:17841-17845. [PMID: 23157688 DOI: 10.1021/la303943k] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The current work examines the role of acid-base properties on particle charging in apolar media. Manipulating the polarity and magnitude of charge in such systems is of growing interest to a number of applications. A major hurdle to the implementation of this technology is that the mechanism(s) of particle charging remain a subject of debate. The authors previously conducted a study of the charging of a series of mineral oxide particles dispersed in apolar systems that contained the surfactant AOT. It was observed that there was a correlation between the particle electrophoretic mobility and the acid-base nature of the particle, as characterized by aqueous point of zero charge (PZC) or the isoelectric point (IEP). The current study investigates whether or not a similar correlation is observed with other surfactants, namely, the acidic Span 80 and the basic OLOA 11000. This is accomplished by measuring the electrophoretic mobility of a series of mineral oxides that are dispersed in Isopar-L containing various concentrations of either Span 80 or OLOA 11000. The mineral oxides used have PZC values that cover a wide range of pH, providing a systematic study of how particle and surfactant acid-base properties impact particle charge. It was found that the magnitude and polarity of particle surface charge varied linearly with the particle PZC for both surfactants used. In addition, the point at which the polarity of charge reversed for the basic surfactant OLOA 11000 was shifted to a pH of approximately 8.5, compared to the previous result of about 5 for AOT. This proves that both surfactant and particle acid-base properties are important, and provides support for the theory of acid-base charging in apolar media.
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Affiliation(s)
- Matthew M Gacek
- Department of Chemical Engineering, University of Washington, Box 351750, Seattle, Washington 98195-1750, USA
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Li L, Zhang J, Sun H, Xu J, Sun D. Dispersion stability of organoclay in octane improved by adding nonionic surfactants. Colloids Surf A Physicochem Eng Asp 2012. [DOI: 10.1016/j.colsurfa.2012.09.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Michor EL, Berg JC. Extension to the charge fluctuation model for the prediction of the conductivity of apolar, reverse micellar systems. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15751-15755. [PMID: 23098157 DOI: 10.1021/la303455n] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This paper presents an extension to current theory regarding charging behavior in apolar, micellar systems. Electrical conductivity in such systems accompanying the formation of neutral reverse micelles is commonly explained by the possibility of intermicellar collisions resulting in a pair of oppositely charged micelles. The sequestration of the resulting charges within the micelles prevents their immediate recombination. The current theory underlying the charging process has thus far been applied in only approximate form, and is only used to validate experimental trends and to abstract values for the fraction of charged micelles. The extended theory proposed here uses knowledge of the solvent and surfactant characteristics, together with water content, to predict solution conductivity in absolute terms. It is verified in experiments with the solvent Isopar-L and surfactants Aerosol OT, OLOA 11000, and Span 80, in which significant differences from the approximate theory are observed.
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Affiliation(s)
- Edward L Michor
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195-1750, United States
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Gacek M, Bergsman D, Michor E, Berg JC. Effects of trace water on charging of silica particles dispersed in a nonpolar medium. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:11633-11638. [PMID: 22812928 DOI: 10.1021/la302806y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This paper presents an investigation of the effects of trace water on the charging of silica (SiO(2)) particles dispersed in a nonpolar medium. There are a growing number of applications that seek to use electrostatic effects in apolar media to control particle movement and aggregation stability in such systems. One factor that is often overlooked in the preparation of nonpolar colloidal dispersions is the amount of water that is introduced to the system by hygroscopic particles and surfactants. The amount and location of this water can have significant effects on the electrical properties of these systems. For nonpolar surfactant solutions it has been shown that water can affect the conductivity, and it has been speculated that this is due to swelling of the polar cores of inverse micelles, increasing the fraction of them that are charged. Some studies have suggested that particle surface charging may also be sensitive to water content, but a clear mechanism for the process has not been fully developed. The situation with particles is further complicated by the fact that it is often unclear whether the water resides on the particle surfaces or in the polar cores of inverse micelles. The current work explores not only the effect of water content on reverse micelle and particle charging but seeks to differentiate between water bound to the particles and water located in the micelles. This is accomplished by measuring the solution conductivity and the electrophoretic mobility of silicon dioxide particles dispersed in solutions of Isopar-L and OLOA 11000. The water content is determined for both the dispersion and the supernatant after centrifuging the particles out. It is found that at equilibrium the majority of the water in the system adsorbs to the surface of the hygroscopic silica particles. In addition, the effect of water on particle electrophoretic mobility is found to be dependent on surfactant concentration. At small OLOA concentrations, additional water results in an increase in particle mobility due to increased particle charging. However, at large OLOA concentrations, additional water leads to a decrease in particle mobility, presumably as a result of increased electrostatic screening or neutralization. Thus, particle charging and electrophoretic mobility in an apolar surfactant solution are found to be highly sensitive to both the total water content in the system and to its concentration relative to the amount of surfactant present.
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Affiliation(s)
- Matthew Gacek
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195-1750, United States
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