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Cai HL, An XQ, Liu B, Qiao QA, Shen WG. Critical Behavior of {DMA + AOT + n-Octane} Nonaqueous Microemulsion with the Molar Ratio (ω=2.66) of DMA to AOT. J SOLUTION CHEM 2010. [DOI: 10.1007/s10953-010-9528-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Cai HL, An XQ, Lü HH, Shen WG. Critical Behavior of {Water + AOT + Decane} Microemulsion with Small Molar Ratio of Water to AOT. J SOLUTION CHEM 2009. [DOI: 10.1007/s10953-009-9451-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Pradeep UK. Critical behavior on approaching a special critical point in a complex fluid. J Chem Phys 2008; 129:204903. [PMID: 19045877 DOI: 10.1063/1.3013540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The critical behavior of osmotic susceptibility is investigated in the re-entrant complex mixture 1-propanol (P)+water (W)+potassium chloride (KCl) through light-scattering measurements. The measurements are performed on approaching a special critical point [i.e., the double critical point (DCP)] in this mixture, along the line of upper critical solution temperatures (T(U)'s), by varying t from the high temperature one-phase region. The light-scattering data analysis emphasizes the need for corrections to the asymptotic Ising behavior and yields very large magnitudes for the correction-to-scaling amplitudes A(1) and A(2), with the first-correction amplitude A(1) being negative, signifying a nonmonotonic crossover behavior of the susceptibility exponent in this mixture. For the T(U) closest to the DCP, the effective susceptibility exponent gamma(eff) displays a nonmonotonic crossover from its nearly doubled three dimensional (3D)-Ising value toward its nearly double mean-field value with an increase in t. While for that far away from the DCP, it displays a nonmonotonic crossover from its single-limit Ising value toward a value slightly lower than its mean-field value of 1 with an increase in t. This feature of the effective susceptibility exponent is interpreted in terms of the possibility of a nonmonotonic crossover to the mean-field value from lower values in the nonasymptotic high t region. The renormalized Ising regime extends over a larger t range for the sample (or T(U)) closest to the DCP when compared to that far away from it. The in-between T(U)'s display a trend toward shrinkage in the renormalized Ising regime as T(U) shifts away from the DCP. Nevertheless, the crossover to the mean-field behavior is completed only beyond t>10(-2) for the T(U)'s studied. The observed crossover behavior is attributed to the presence of strong ion-induced clustering in this mixture, as revealed by various structure probing techniques, while the observed unique trend in the crossover behavior is discussed in terms of the varying influence of the DCP on the critical behavior along the T(U) line. The crossover behavior for the T(U)'s is pronounced and more sharp compared to the T(L)'s (lower critical solution temperatures) [U. K. Pradeep, J. Chem. Phys. 129, 134506 (2008)] in this mixture, although there exists no difference in the growth of the mesoscale clusters in the lower and upper one-phase regions in this mixture. Our observations suggest the need to look at the crossover behavior probably from two perspectives, namely, the dielectric effect and the clustering effect. The effective susceptibility exponent as a function of the field variable t(UL), instead of the conventional variable t, displays a sharp nonmonotonic crossover from its asymptotic 3D-Ising value ( approximately 1.24) toward a value slightly lower than its nonasymptotic mean-field value of 1, as that observed in the t analysis for the T(U) far away from the influence of the DCP.
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Affiliation(s)
- U K Pradeep
- Department of Physics, Indian Institute of Science, Bangalore, India.
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Effects of the dispersed droplet sizes on the critical behavior of pseudobinary microemulsion. ACTA ACUST UNITED AC 2008. [DOI: 10.1007/s11434-007-0171-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Pradeep UK. Tendency toward crossover of the effective susceptibility exponent from its doubled Ising value to its doubled mean-field value near a double critical point. J Chem Phys 2008; 129:134506. [DOI: 10.1063/1.2987344] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Yan Y, Li L, Hoffmann H. Clouding: Origin of Phase Separation in Oppositely Charged Polyelectrolyte/Surfactant Mixed Solutions. J Phys Chem B 2006; 110:1949-54. [PMID: 16471766 DOI: 10.1021/jp056359x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The phase behavior in the system of cationic modified poly(vinyl alcohol) (CPVA)-sodium dodecylsulfate (SDS)-water has been investigated. Samples were found phase separated near electroneutral mixing at CPVA concentrations < or =6%, while in a medium CPVA concentration of 7-12%, the phase separation disappeared and the system transformed into bluish homogeneous solution. At > or =13% CPVA concentrations, the mixed systems became colorless homogeneous. Preclouding phenomenon was observed in 5-8% CPVA-SDS mixed systems at an electroneutral mixing ratio. The addition of inorganic salts, such as Na2SO4, NaCl, NaBr, and NaSCN, could exclude the bluish and phase separation phenomenon that was found to be caused by the increase of clouding point in these systems. The clouding phenomenon was proven to be the origin of the phase separation in the CPVA-SDS mixed system. The ability for the inorganic salts to increase the clouding point follows the order of the Hofmeister series.
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Affiliation(s)
- Yun Yan
- Bayreuther Zentrum für Kolloid und Grenzflächen, Universität Bayreuth, Gottlieb-keim Strasse 60, 95448, Germany.
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Peng S, An X, Shen W. Critical phenomenon of nonaqueous microemulsion (AOT/DMA/decane). J Colloid Interface Sci 2005; 287:141-5. [PMID: 15914158 DOI: 10.1016/j.jcis.2005.01.082] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2004] [Revised: 01/21/2005] [Accepted: 01/24/2005] [Indexed: 11/19/2022]
Abstract
The critical phenomenon of nonaqueous microemulsion was studied for the first time. The coexistence curves of (T,n), (T,phi), and (T,psi) (n and phi are refractive index and volume fraction, respectively; psi is defined as psi=phi/[phi+phi(c)(1-phi)/(1-phi(c))]) for a ternary microemulsion [phi (AOT-DMA)+(1-phi) decane] at constant pressure and a constant molar ratio (omega=2.86) of DMA to AOT have been determined within about 7 K from the critical temperature T(c) by measurements of refractive index. The critical exponent beta has been deduced from (T,n), (T,phi), and (T,psi) coexistence curves within 1 K below T(c). They all were 0.329+/-0.005 and were consistent with the 3D Ising value. The experimental results in a temperature range of (T(c)-T)<7 K also have been analyzed to obtain critical amplitudes and the Wegner correction terms, to examine the diameters of the coexistence curves.
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Affiliation(s)
- S Peng
- Department of Chemistry, Lanzhou University, Lanzhou, Gansu 730000, China
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Monroy F, Muñoz MG, Rubio JEF, Ortega F, Rubio RG. Capillary Waves in Ionic Surfactant Solutions: Effects of the Electrostatic Adsorption Barrier and Analysis in Terms of a New Dispersion Equation. J Phys Chem B 2002. [DOI: 10.1021/jp012044f] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Francisco Monroy
- Department Química Física I, Facultad de Química, Universidad Complutense, E28040-Madrid, Spain
| | - Mercedes G. Muñoz
- Department Química Física I, Facultad de Química, Universidad Complutense, E28040-Madrid, Spain
| | - José E. F. Rubio
- Department Química Física I, Facultad de Química, Universidad Complutense, E28040-Madrid, Spain
| | - Francisco Ortega
- Department Química Física I, Facultad de Química, Universidad Complutense, E28040-Madrid, Spain
| | - Ramón G. Rubio
- Department Química Física I, Facultad de Química, Universidad Complutense, E28040-Madrid, Spain
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Oleinikova A, Weingärtner H. Isotope effect on the coexistence curve and crossover behavior of water+tetrahydrofuran. Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(00)00086-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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17 Ionic fluids near critical points and at high temperatures. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s1874-5644(00)80007-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Koulinskii VL, Malomuzh NP, Tolpekin VA. Influence of charge fluctuations on the critical behavior of electrolyte solutions. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1999; 60:6897-905. [PMID: 11970628 DOI: 10.1103/physreve.60.6897] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/1998] [Revised: 06/16/1999] [Indexed: 04/18/2023]
Abstract
The effective Hamiltonian of electrolyte solution near its critical point is constructed. The vapor-liquid critical point is investigated in detail. The strong dependence of the Landau-Ginsburg number on the concentration of electrolyte is demonstrated. It is shown that the charge fluctuations in electrolytes essentially suppress the fluctuation of the order parameter and broaden the region of classical behavior.
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Affiliation(s)
- V L Koulinskii
- Department of Theoretical Physics, Odessa State University, 2 Petra Velikogo, 270100 Odessa, Ukraine
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Compostizo A, Martín C, Rubio R, Crespo Colin A. Temperature dependence of the density of an ionic micellar system near the critical point. Chem Phys 1996. [DOI: 10.1016/s0301-0104(96)00234-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Martín A, Ortega F, Rubio RG. Double-exponential relaxation near the critical point of an ionic micellar system. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 54:5302-5308. [PMID: 9965715 DOI: 10.1103/physreve.54.5302] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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An X, Feng J, Shen W. Critical Behavior of a Pseudobinary System for a Three-Component Microemulsion. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp961287i] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xueqin An
- Department of Chemistry, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China
| | - Jiao Feng
- Department of Chemistry, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China
| | - Weiguo Shen
- Department of Chemistry, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China
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Kenkare PU, Hall CK, Caccamo C. Phase instabilities in charged hard‐sphere mixtures. II. Binary mixtures of salts. J Chem Phys 1995. [DOI: 10.1063/1.470175] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Martín A, Ortega F, Rubio RG. Critical behavior of a cationic-surfactant-water-salt system near and far from the Krafft temperature. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1995; 52:1871-1876. [PMID: 9963606 DOI: 10.1103/physreve.52.1871] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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