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Fallah-Totkar H, Bagheri A, Maddah M. The correlation between the micelle morphology of surface-active ionic liquids with self-assembly and thermodynamic characteristics: coarse-grained MD simulation and experiment. Phys Chem Chem Phys 2023; 25:23164-23176. [PMID: 37605522 DOI: 10.1039/d3cp02126b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Surface-active ionic liquids (SAILs) show great promise as novel green solvents due to their low vapor pressure, high thermal stability, high electrical conductivity, and bio-friendly nature to replace traditional volatile organic solvents in industrial processes. In the present work, the combination of coarse-grained (CG) molecular dynamics (MD) simulations with conductivity measurements was employed to explain the correlation between the micelle morphology and physicochemical and thermodynamic properties of self-assembly. A homologous series of SAIL molecules, 1-n-alkyl-3-methylimidazolium bromide [Cnmim][Br] (n = 4, 6, 8, 10, and 12), were chosen at various concentrations to shed light on this issue. Simultaneously two factors of concentration and alkyl chain length affected the morphology to control the physical and thermodynamic features. Moreover, the nature of the headgroup for two SAILs with the longest alkyl chain was assessed by shifting from imidazolium into ammonium. First, the critical micelle concentration (CMC), the degree of counterion dissociation of micelles, and the standard Gibbs energy of micellization of SAILs were determined using conductivity data. The micelle morphology such as the aggregation number, micelle radius, and moment of inertia was computed before, around, and after the CMC by MD simulation. Simulated results in accordance with the experimental measurements provide a quantitative understanding of the micellar properties. Increasing the alkyl chain length was associated with a non-spherical bigger micelle while the ammonium-based surfactant with a lower repulsion between neighboring monomers in micelles induced bigger and more spherical aggregates. Raising the SAIL concentration did not considerably influence the sphericity of the micelle except for the SAIL with the longest tail. The umbrella sampling method calculated the potential of mean force (PMF) for pulling a monomer of SAIL from a pre-assembled micelle into the solution. The dissociation energy of a SAIL monomer from a micelle increased with the tail length or with shifting into the ammonium head group and was substantially influenced by micelle morphology. Comparison between a sphere micelle with an oval one demonstrated that the dissociation of a SAIL monomer from a non-spherical shape needed a higher amount of energy. An improved understanding of how the shape of the SAIL micelles controls the physicochemical properties and stability helps to extend their application to different chemical processes.
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Affiliation(s)
- Hajar Fallah-Totkar
- Department of Chemistry, Semnan University, P.O. Box 35131-19111, Semnan, Iran.
| | - Ahmad Bagheri
- Department of Chemistry, Semnan University, P.O. Box 35131-19111, Semnan, Iran.
| | - Mina Maddah
- Researcher of Semnan University, Semnan, 35131-19111, Iran
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2
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Hussain S, Hung SH, Tsay RY, Lin SY. On the determination of critical micelle concentration of partially dissociated ionic surfactants using contact angle data. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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3
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Surfactant Induced Synthesis of LiAlH4 and NaAlH4 Nanoparticles for Hydrogen Storage. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12094742] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
LiAlH4 and NaAlH4 are considered to be promising hydrogen storage materials due to their high hydrogen density. However, their practical use is hampered by the lack of hydrogen reversibility along with poor kinetics. Nanosizing is an effective strategy to enable hydrogen reversibility under practical conditions. However, this has remained elusive as the synthesis of alanate nanoparticles has not been explored. Herein, a simple solvent evaporation method is demonstrated to assemble alanate nanoparticles with the use of surfactants as a stabilizer. More importantly, the roles of the surfactants in enabling control over particle size and morphology was determined. Surfactants with long linear carbon chains and matching the hard character of alanates are more prone to lead to the formation of small particles of ~10 nm due to steric hindrance. This can result in significant shifts in the temperature for hydrogen release.
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4
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Queirós MVA, Loh W. From Associative to Segregative Phase Separation: The Phase Behavior of Poly(acrylate)/Dodecyltrimethylammonium Complex Salts in the Presence of NaBr and NaCl. J Phys Chem B 2021; 125:2968-2975. [PMID: 33720730 DOI: 10.1021/acs.jpcb.0c11245] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report here a systematic study on the phase behavior of dodecyltrimethylammonium-poly(acrylate) (C12TAPA) complex salts upon addition of simple salts (NaBr and NaCl). Complex salts of poly(acrylate) of two molar masses were employed (2000 and 450,000 g mol-1). Systems containing different surfactant mesophases were observed, whose structures were elucidated by small-angle X-ray scattering analyses. Overall, we observe a transition from associative to segregative phase separation intercalated with monophasic regions. In terms of surfactant association, a transition from micellar cubic phases to an isotropic micellar solution was observed, where these two phases occur in equilibrium with a dilute phase as a consequence of associative phase separation. However, as the salt concentration increases, segregative phase separation is observed, and scattering analyses of the surfactant-rich phase indicate the growth of micellar aggregates. These results are discussed in terms of the electrolyte effect screening the interactions between the oppositely charged surfactant and polymer and as a result of salting-out effects of the different electrolytes that prevail at higher concentrations.
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Affiliation(s)
| | - Watson Loh
- Institute of Chemistry, University of Campinas (UNICAMP), P.O. Box 6154, 13083-970 Campinas, São Paulo, Brazil
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5
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Das S, Patra N, Banerjee A, Das B, Ghosh S. Studies on the self-aggregation, interfacial and thermodynamic properties of a surface active imidazolium-based ionic liquid in aqueous solution: Effects of salt and temperature. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.114497] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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6
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DTAB micelle formation in ionic liquid/water mixtures is determined by ionic liquid cation structure. J Colloid Interface Sci 2019; 552:597-603. [DOI: 10.1016/j.jcis.2019.05.082] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/24/2019] [Accepted: 05/25/2019] [Indexed: 11/21/2022]
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7
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Wasiak M. Two-point scaling analysis of the isobaric heat capacity of dodecyltrimethylammonium bromide aqueous solutions in the presence of the n-hexan-1-ol as a co-surfactant. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.04.056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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8
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Investigating Two-Photon-Induced Fluorescence in Rhodamine-6G in Presence of Cetyl-Trimethyl-Ammonium-Bromide. J Fluoresc 2016; 26:1573-7. [PMID: 27324955 DOI: 10.1007/s10895-016-1841-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 05/30/2016] [Indexed: 10/21/2022]
Abstract
We investigate the effect of cetyl-trimethyl-ammonium-bromides (CTAB) concentration on the fluorescence of Rhodamine-6G in water. This spectroscopic study of Rhodamine-6G in presence of CTAB was performed using two-photon-induced-fluorescence at 780 nm wavelength using high repetition rate femtosecond laser pulses. We report an increment of ∼10 % in the fluorescence in accordance with ∼12 % enhancement in the absorption intensity of the dye molecule around the critical micellar concentration. We discuss the possible mechanism for the enhancement in the two-photon fluorescence intensity and the importance of critical micellar concentration.
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9
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Lima FS, Cuccovia IM, Buchner R, Antunes FE, Lindman B, Miguel MG, Horinek D, Chaimovich H. Sodium triflate decreases interaggregate repulsion and induces phase separation in cationic micelles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:2609-2614. [PMID: 25689018 DOI: 10.1021/la5049216] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Dodecyltrimethylammonium triflate (DTATf) micelles possess lower degree of counterion dissociation (α), lower hydration, and higher packing of monomers than other micelles of similar structure. Addition of sodium triflate ([NaTf] > 0.05 M) to DTATf solutions promotes phase separation. This phenomenon is commonly observed in oppositely charged surfactant mixtures, but it is rare for ionic surfactants and relatively simple counterions. While the properties of DTATf have already been reported, the driving forces for the observed phase separation with added salt remain unclear. Thus, we propose an interpretation for the observed phase separation in cationic surfactant solutions. Addition of up to 0.03 M NaTf to micellar DTATf solutions led to a limited increase of the aggregation number, to interface dehydration, and to a progressive decrease in α. The viscosity of DTATf solutions of higher concentration ([DTATf] ≥ 0.06 M) reached a maximum with increasing [NaTf], though the aggregation number slightly increased, and no shape change occurred. We hypothesize that this maximum results from a decrease in interaggregate repulsion, as a consequence of increased ion binding. This reduction in micellar repulsion without simultaneous infinite micellar growth is, probably, the major driving force for phase separation at higher [NaTf].
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Affiliation(s)
- Filipe S Lima
- Instituto de Química, Universidade de São Paulo , São Paulo, Brazil
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10
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Lin F, Meng X, Kukueva E, Mertens M, Van Doorslaer S, Bals S, Cool P. New insights into the mesophase transformation of ethane-bridged PMOs by the influence of different counterions under basic conditions. RSC Adv 2015. [DOI: 10.1039/c4ra15849k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The counterions are of crucial importance in determining the mesostructure and morphology of ethane-bridged PMO materials synthesized under basic conditions.
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Affiliation(s)
- Feng Lin
- Laboratory of Adsorption and Catalysis
- Department of Chemistry
- University of Antwerp
- Wilrijk
- Belgium
| | - Xiangyan Meng
- Laboratory of Adsorption and Catalysis
- Department of Chemistry
- University of Antwerp
- Wilrijk
- Belgium
| | - Elena Kukueva
- EMAT
- Department of Physics
- University of Antwerp
- B-2020 Antwerpen
- Belgium
| | - Myrjam Mertens
- Flemish Institute for Technological Research
- VITO
- Mol
- Belgium
| | | | - Sara Bals
- EMAT
- Department of Physics
- University of Antwerp
- B-2020 Antwerpen
- Belgium
| | - Pegie Cool
- Laboratory of Adsorption and Catalysis
- Department of Chemistry
- University of Antwerp
- Wilrijk
- Belgium
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11
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Akram M, Yousuf S, Sarwar T, Kabir-ud-Din. Micellization and interfacial behavior of 16-E2-16 in presence of inorganic and organic salt counterions. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2013.09.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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12
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Lima FS, Cuccovia IM, Horinek D, Amaral LQ, Riske KA, Schreier S, Salinas RK, Bastos EL, Pires PAR, Bozelli JC, Favaro DC, Rodrigues ACB, Dias LG, El Seoud OA, Chaimovich H. Effect of counterions on the shape, hydration, and degree of order at the interface of cationic micelles: the triflate case. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:4193-4203. [PMID: 23473070 DOI: 10.1021/la304658e] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Specific ion effects in surfactant solutions affect the properties of micelles. Dodecyltrimethylammonium chloride (DTAC), bromide (DTAB), and methanesulfonate (DTAMs) micelles are typically spherical, but some organic anions can induce shape or phase transitions in DTA(+) micelles. Above a defined concentration, sodium triflate (NaTf) induces a phase separation in dodecyltrimethylammonium triflate (DTATf) micelles, a phenomenon rarely observed in cationic micelles. This unexpected behavior of the DTATf/NaTf system suggests that DTATf aggregates have unusual properties. The structural properties of DTATf micelles were analyzed by time-resolved fluorescence quenching, small-angle X-ray scattering, nuclear magnetic resonance, and electron paramagnetic resonance and compared with those of DTAC, DTAB, and DTAMs micelles. Compared to the other micelle types, the DTATf micelles had a higher average number of monomers per aggregate, an uncommon disk-like shape, smaller interfacial hydration, and restricted monomer chain mobility. Molecular dynamic simulations supported these observations. Even small water-soluble salts can profoundly affect micellar properties; our data demonstrate that the -CF3 group in Tf(-) was directly responsible for the observed shape changes by decreasing interfacial hydration and increasing the degree of order of the surfactant chains in the DTATf micelles.
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Affiliation(s)
- Filipe S Lima
- Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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13
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Pérez-Sánchez G, Gomes JRB, Jorge M. Modeling self-assembly of silica/surfactant mesostructures in the templated synthesis of nanoporous solids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:2387-96. [PMID: 23343439 DOI: 10.1021/la3046274] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
A novel coarse-grained (CG) model to study the self-assembly of silica/surfactant mesostructures during the synthesis of periodic mesoporous silica is reported. Molecular dynamics simulations of hexadecyltrimethylammonium bromide (also called cetyltrimethylammonium bromide, or CTAB) surfactants in water and in aqueous silicate solutions have been performed to understand micelle formation, micelle growth, and their size evolution during the synthesis of surfactant-templated mesoporous materials. Direct comparison of density profiles obtained for preassembled micelles employing an all-atom description, AA, with those calculated with the CG model has been carried out for checking the validity of the latter model. Good agreement between AA and CG approaches was found, demonstrating the potential of the CG approximation for modeling these highly complex systems. The micelle formation and micelle fusion/fission processes were analyzed after performing long CG simulations for surfactant and ionized silica-surfactant aqueous solutions. We observed the formation of rodlike micelles in the case of silica-surfactant solutions, while spherical micelles were stable under the same conditions for the CTAB+H(2)O system. This demonstrates that the interaction of anionic silicates with cationic surfactants promotes a sphere-to-rod transition in surfactant solutions, a key step in the synthesis of nanoporous silica materials.
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Affiliation(s)
- Germán Pérez-Sánchez
- LSRE-Laboratory of Separation and Reaction Engineering-Associate Laboratory LSRE/LCM, Faculdade de Engenharia, Universidade do Porto, Porto, Portugal
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14
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Yang Y, Dong J, Li X. Micelle to vesicle transitions of N-dodecyl-1, ω-diaminoalkanes: Effects of pH, temperature and salt. J Colloid Interface Sci 2012; 380:83-9. [DOI: 10.1016/j.jcis.2012.04.068] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2012] [Revised: 04/19/2012] [Accepted: 04/24/2012] [Indexed: 11/30/2022]
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15
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Lima FS, Maximiano FA, Cuccovia IM, Chaimovich H. Surface activity of the triflate ion at the air/water interface and properties of N,N,N-trimethyl-N-dodecylammonium triflate aqueous solutions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:4319-4323. [PMID: 21413729 DOI: 10.1021/la2004613] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The surface activity of salts added to water is orders of magnitude lower than that of surfactants. Sodium trifluoromethanesulfonate (NaTf) produced a change in surface tension with concentration, Δγ/Δc, of -13.2 mN·L/m·mol. This value is ca. 4-fold larger than those of simple salts and that of methanesulfonate. This unexpected surface effect suggested that positively charged micelles containing Tf could exhibit interesting properties. Dodecyltrimethylammonium triflate (DTATf) had a higher Kraft temperature (37 °C) and a lower cmc (5 × 10(-3) M) and degree of dissociation (0.11) than the chloride and bromide salts of DTA. Above the Kraft temperature, at a characteristic temperature t(1), the addition of NaTf above 0.05 M to a DTATf solution induced phase separation. By increasing the temperature of the two-phase system to above t(1), a homogeneous, transparent solution was obtained at a characteristic temperature t(2). These results, together with well-known triflate properties, led us to suggest that the Tf ion pairs with DTA and that the -CF(3) group may be dehydrated in the interfacial region, resulting in new and interesting self-aggregated structures.
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Affiliation(s)
- F S Lima
- Instituto de Química, Universidade de São Paulo, SP, Brazil
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16
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Xu Y, Malkovskiy A, Wang Q, Pang Y. Molecular assembly of a squaraine dye with cationic surfactant and nucleotides: its impact on aggregation and fluorescence response. Org Biomol Chem 2011; 9:2878-84. [PMID: 21373660 DOI: 10.1039/c0ob01061h] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel fluorescent system has been assembled by using ATP, surfactant, and a squaraine dye in an aqueous buffer solution. In the system, a cationic surfactant such as cetyl trimethyl ammonium bromide (CTAB) forms a sphere-like micelle, whose positive charge at the surface of the micelle attracts the negatively charged ATP to form a unique organized nanostructure. Such an organized system is shown to interact with the squaraine dye (SQ) to perturb its aggregate structure, thereby generating the optical response. The nanostructure of the assembly has been characterized by dynamic light-scattering (DLS) and atomic force microscopy (AFM). The unique feature of the developed sensing system is that the analytes ATP form part of the assembly structure. The system utilizes forces such as electrostatic interaction and π-π stacking of the aromatic segment of ATP and SQ to achieve the selective detection of ATP.
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Affiliation(s)
- Yongqian Xu
- Department of Chemistry & Maurice Morton Institute of Polymer Science, The University of Akron, Akron, OH 44325, USA
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17
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Concentrated Gas-in-Liquid Emulsions in Artificial Media. II. Characterization by Photon Correlation Spectroscopy. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/b978-0-444-53798-0.00012-2] [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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18
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Ruiz MO, Benito JM, Barriuso B, Cabezas JL, Escudero I. Equilibrium Distribution Model of Betaine between Surfactant Micelles and Water: Application to a Micellar-Enhanced Ultrafiltration Process. Ind Eng Chem Res 2010. [DOI: 10.1021/ie100485w] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- María O. Ruiz
- Department of Chemical Engineering, University of Burgos, Plaza Misael Bañuelos s/n. 09001 Burgos, Spain
| | - José M. Benito
- Department of Chemical Engineering, University of Burgos, Plaza Misael Bañuelos s/n. 09001 Burgos, Spain
| | - Beatriz Barriuso
- Department of Chemical Engineering, University of Burgos, Plaza Misael Bañuelos s/n. 09001 Burgos, Spain
| | - José L. Cabezas
- Department of Chemical Engineering, University of Burgos, Plaza Misael Bañuelos s/n. 09001 Burgos, Spain
| | - Isabel Escudero
- Department of Chemical Engineering, University of Burgos, Plaza Misael Bañuelos s/n. 09001 Burgos, Spain
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19
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Ferreira TL, Sato BM, El Seoud OA, Bertotti M. Application of Microelectrode Voltammetry to Study the Properties of Surfactant Solutions: Alkyltrimethylammonium Bromides. J Phys Chem B 2009; 114:857-62. [DOI: 10.1021/jp909655y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tiago L. Ferreira
- Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, São Paulo, SP, Brazil, and Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Bruno M. Sato
- Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, São Paulo, SP, Brazil, and Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Omar A. El Seoud
- Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, São Paulo, SP, Brazil, and Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Mauro Bertotti
- Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, São Paulo, SP, Brazil, and Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
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20
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Vlachy N, Drechsler M, Touraud D, Kunz W. Anion specificity influencing morphology in catanionic surfactant mixtures with an excess of cationic surfactant. CR CHIM 2009. [DOI: 10.1016/j.crci.2008.10.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Diehl A, Kuhn PS. Effect of monovalent salt on the conformation of polyelectrolyte-surfactant complexes. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 79:011805. [PMID: 19257062 DOI: 10.1103/physreve.79.011805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Indexed: 05/27/2023]
Abstract
We study the conformation of polyelectrolyte-surfactant complexes in the presence of monovalent salt. A simple model for the formation of these structures is presented in the framework of the Debye-Hückel-Bjerrum-Manning and Flory theories, with the hydrophobic interactions between the hydrocarbon tails of surfactant molecules treated in the spirit of van der Waals theory as an effective attraction. The extension of the polyelectrolyte-surfactant complexes is analyzed as a function of the salt concentration and a discrete conformational transition between a compact globule and an elongated coil is found, in agreement with experimental results for the unfolding transition of a DNA-cationic surfactant complex.
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Affiliation(s)
- A Diehl
- Departamento de Física, Instituto de Física e Matemática, Universidade Federal de Pelotas, Caixa Postal 354, CEP 96010-900, Pelotas, RS, Brazil.
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22
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Sakai K, Wada M, Matsuda W, Tsuchiya K, Takamatsu Y, Tsubone K, Endo T, Torigoe K, Sakai H, Abe M. Polymerizable Anionic Gemini Surfactants: Physicochemical Properties in Aqueous Solution and Polymerization Behavior. J Oleo Sci 2009; 58:403-13. [DOI: 10.5650/jos.58.403] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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23
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Drach M, Andrzejewska A, Ciesla J, Narkiewicz-Michałek J. Theoretical description of aggregation of cationic gemini surfactants in the bulk solution and on the silica surface. ADSORPTION 2008. [DOI: 10.1007/s10450-008-9127-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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24
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Zhang J, Ge Z, Jiang X, Hassan PA, Liu S. Stopped-flow kinetic studies of sphere-to-rod transitions of sodium alkyl sulfate micelles induced by hydrotropic salt. J Colloid Interface Sci 2007; 316:796-802. [PMID: 17904570 DOI: 10.1016/j.jcis.2007.08.067] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Revised: 08/24/2007] [Accepted: 08/30/2007] [Indexed: 10/22/2022]
Abstract
The kinetics and mechanism of sphere-to-rod transitions of sodium alkyl sulfate micelles induced by hydrotropic salt, p-toluidine hydrochloride (PTHC), were investigated by stopped-flow with light scattering detection. Spherical sodium dodecyl sulfate (SDS) micelles transform into short ellipsoidal shapes at low salt concentrations ([PTHC]/[SDS], chi(PTHC)=0.3 and 0.4). Upon stopped-flow mixing aqueous solutions of spherical SDS micelles with PTHC, the scattered light intensity gradually increases with time. Single exponential fitting of the dynamic traces leads to characteristic relaxation time, tau(g), for the growth process from spherical to ellipsoidal micelles, and it increases with increasing SDS concentrations. This suggests that ellipsoidal micelles might be produced by successive insertion of unimers into spherical micelles, similar to the case of formation of spherical micelles as suggested by Aniansson-Wall (A-W) theory. At chi(PTHC) > or = 0.5, rod-like micelles with much higher axial ratio form. The scattered light intensity exhibits an initially abrupt increase and then levels off. The dynamic curves can be well fitted with single exponential functions, and the obtained tau(g) decreases with increasing SDS concentration. Thus, the growth from spherical to rod-like micelles might proceed via fusion of spherical micelles, in agreement with mechanism proposed by Ikeda et al. At chi(PTHC)=0.3 and 0.6, the apparent activation energies obtained from temperature dependent kinetic studies for the micellar growth are 40.4 and 3.6 kJ/mol, respectively. The large differences between activation energies for the growth from spherical to ellipsoidal micelles at low chi(PTHC) and the sphere-to-rod transition at high chi(PTHC) further indicate that they should follow different mechanisms. Moreover, the sphere-to-rod transition kinetics of sodium alkyl sulfate with varying hydrophobic chain lengths (n=10, 12, 14, and 16) are also studied. The longer the carbon chain lengths, the slower the sphere-to-rod transition.
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Affiliation(s)
- Jingyan Zhang
- Department of Polymer Science and Engineering, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
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25
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Koniari A, Avranas A. Condensed film formation of binary mixtures of cetyltrimethylammonium bromide and cetyldimethylbenzylammonium chloride in a wide potential region at the mercury/electrolyte interface. J Colloid Interface Sci 2006; 304:172-9. [PMID: 16989847 DOI: 10.1016/j.jcis.2006.08.043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2006] [Revised: 08/22/2006] [Accepted: 08/22/2006] [Indexed: 11/26/2022]
Abstract
The adsorption of binary mixtures of cetyltrimethylammonium bromide (CTAB) and cetyldimethylbenzylammonium chloride (CDBACl) at the mercury/electrolyte interface was studied in various electrolyte systems. The optimum surfactant concentration and electrolyte ratio was searched for, to obtain the formation of a condensed film at as wide a potential range as possible at the highest temperature possible. The optimum conditions found were 2 x 10(-4) M CTAB and 2 x 10(-4) M CDBACl in 0.07 M KF and 0.03 M KBr at 2 degrees C. The capacitances vs time curves were used for the reconstruction of isochronous capacitance vs potential curves. These curves showed that in that system the condensed film was formed in the potential range from -0.4 to -1.9 V vs Ag/AgCl in less than 220 s. The stability of this film, following the removal of the mercury drop from the solution, was also studied.
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Affiliation(s)
- Argiro Koniari
- Laboratory of Physical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
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26
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Pisárcik M, Polakovicová M, Devínsky F, Lacko I. Dynamic light scattering, interfacial properties, and conformational analysis of biodegradable quarternary ammonium surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:9160-8. [PMID: 17042524 DOI: 10.1021/la0613934] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Aggregation properties of biodegradable ammonium surfactants containing amide and ester groups in the bulk and at the air-water interface were investigated as a function of surfactant tail length m using dynamic light scattering and surface tension experimental methods. The results indicate that surfactants containing an ester group in the structure display higher aggregation ability in the volume and form more densely packed layer of molecules at the air-water interface than those with an amide group. The results of physical measurements were correlated with 3D models of respective surfactant molecules. As the results indicate, a surfactant molecule headgroup containing an ester group shows higher flexibility than that with an amide group in its structure, which is documented by somewhat smaller headgroup size and denser packing at the air-water interface.
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Affiliation(s)
- Martin Pisárcik
- Department of Chemical Theory of Drugs, Faculty of Pharmacy, Comenius University, Kalinciakova 8, SK-83232 Bratislava, Slovakia.
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27
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Andreev VA, Victorov AI. Molecular thermodynamics for micellar branching in solutions of ionic surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:8298-310. [PMID: 16981741 DOI: 10.1021/la061087q] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We develop an analytical molecular-thermodynamic model for the aggregation free energy of branching portions of wormlike ionic micelles in 1:1 salt solution. The junction of three cylindrical aggregates is represented by a combination of pieces of the torus and bilayer. A geometry-dependent analytical solution is obtained for the linearized Poisson-Boltzmann equation. This analytical solution is applicable to saddle-like structures and reduces to the solutions known previously for planar, cylindrical, and spherical aggregates. For micellar junctions, our new analytical solution is in excellent agreement with numerical results over the range of parameters typical of ionic surfactant systems with branching micelles. Our model correctly predicts the sequence of stable aggregate morphologies, including a narrow bicontinuous zone, in dependence of hydrocarbon tail length, head size, and solution salinity. For predicting properties of a spatial network of wormlike micelles, our aggregation free energy is used in the Zilman-Safran theory. Our predictions are compared with experimental data for branching micelles of ionic surfactants.
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Affiliation(s)
- Vasily A Andreev
- Department of Chemistry, St. Petersburg State University, Universitetsky prospect 26, 198504, St. Petersburg, Russia
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28
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Mata JP, Aswal VK, Hassan PA, Bahadur P. A phenol-induced structural transition in aqueous cetyltrimethylammonium bromide solution. J Colloid Interface Sci 2006; 299:910-5. [PMID: 16529765 DOI: 10.1016/j.jcis.2006.02.032] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2005] [Revised: 02/15/2006] [Accepted: 02/15/2006] [Indexed: 10/24/2022]
Abstract
The effect of phenol on the structure of micellar solution of a cationic surfactant, cetyltrimethylammonium bromide (CTAB) was investigated using viscosity, dynamic light scattering (DLS), small angle neutron scattering (SANS) and nuclear magnetic resonance (NMR) techniques. The relative viscosity and apparent hydrodynamic diameters of the micelles in CTAB solution increase initially and then decrease with addition of phenol. SANS studies indicate a prolate ellipsoidal structure of the micelles. The axial ratio of the prolate ellipsoidal micelles increases and then decreases with addition of phenol, consistently with DLS and viscosity measurements. NMR studies confirm the solubilization of phenol to the palisade layer and growth of the micelles at high concentration of phenol as revealed from the broadening of peaks.
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Affiliation(s)
- J P Mata
- Department of Chemistry, VNSG University, Surat 395007, India.
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29
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Geng Y, Romsted LS, Menger F. Specific Ion Pairing and Interfacial Hydration as Controlling Factors in Gemini Micelle Morphology. Chemical Trapping Studies. J Am Chem Soc 2005; 128:492-501. [PMID: 16402836 DOI: 10.1021/ja056807e] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Results from chemical trapping experiments in micellar solutions containing 1.5-5 mM aqueous solutions of three didodecyl dicationic dibromide gemini surfactants with different methylene spacer lengths (12-n-12 2Br where n = 2-4 CH(2) groups) gave quantitative estimates of the molarities of interfacial bromide (Br(m)) and water (H(2)O(m)), the fractions of free and paired headgroups and counterions, and the net headgroup charge. These results are one of the most detailed compositional studies of an association colloid interface to date. Br(m) increases and H(2)O(m) decreases as n decreases and the two cationic charges are closer together. The 12-2-12 2Br gemini (the only one of the three geminis known to form threadlike micelles) shows a marked increase in Br(m) (from 2.3 to 3.6 M) and a decrease in H(2)O(m) (from 35 to 17 M) at the exceptionally low surfactant concentration in the vicinity of the previously reported sphere-to-rod transition or second cmc concentration. Rod formation occurs because of an increase in headgroup-counterion association and dehydration at the micelle surface that depend on both the free energies of hydration and specific ion interactions and surfactant and counterion concentrations. These and other recent chemical trapping results support a new model for the balance of forces controlling morphological transitions of association colloids. The hydrophobic effect drives the formation of headgroup-counterion pairs, which have a lower demand for water of hydration. Release of water permits tighter packing and formation of cylindrical aggregates.
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Affiliation(s)
- Yan Geng
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, 19104, USA
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30
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Geng Y, Romsted LS. Ion Pair Formation in Water. Association Constants of Bolaform, Bisquaternary Ammonium, Electrolytes by Chemical Trapping. J Phys Chem B 2005; 109:23629-37. [PMID: 16375341 DOI: 10.1021/jp0546195] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The first and second association constants, K1 and K2, for ion pair formation in aqueous 0.02-3.5 M solutions of bis(trimethyl)-alpha,omega-alkanediammonium halides with variable spacer lengths, 1-n-1 2X (n = 2-4, X = Cl, Br) and bolaform salts and for tetramethylammonium halides (TMAX, X = Cl, Br), K(TMAX), were determined by the chemical trapping method. Values for K(TMAX) are small, K(TMABr) = 0.83 M(-1) and K(TMACl) = 0.29 M(-1), in agreement with literature values. For the bolaform salts, K1 depends on spacer length and counterion type, ranges from 0.4 to 17 M(-1), is 2-10 times larger than K2, is larger for Br- than Cl-, and decreases by a factor of approximately 3 for Cl- and approximately 10 for Br- as n increases from 2 to 4. K2, for the formation of bolaform dihalide pair, is essentially the same as that for ion pair formation in TMAX solutions, i.e., K2 approximately K(TMAX). Values of K1 and K(TMABr) obtained from changes in 79Br line widths are in good agreement with those obtained by chemical trapping. The results are consistent with a thermodynamic model in which the ion association depends on the balance of the ion specific hydration free energies of cations and anions and their ion specific and hydration interactions in ion pairs. Spacer length dependent ion pairing by bolaform electrolytes, which are analogues of the headgroups and counterions of gemini amphiphiles, suggests a new model for the spacer length dependent sphere-to-rod transitions of gemini micelles. Neutral, but polar, headgroup-counterion pairs have a lower demand for hydration that free headgroups and counterions, and headgroup-counterion pair formation releases interfacial water into the bulk aqueous phase, permitting tighter amphiphile packing in rodlike micelles.
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Affiliation(s)
- Yan Geng
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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31
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Hsu WL, Chen HL, Liou W, Lin HK, Liu WL. Mesomorphic complexes of DNA with the mixtures of a cationic surfactant and a neutral lipid. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:9426-31. [PMID: 16207017 DOI: 10.1021/la051863e] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Polyanionic DNA binds to cationic lipids to form electrostatic complexes exhibiting rich self-assembled structures. These types of complexes have been considered as a nonviral carrier in gene therapy and as a template for nanostructure construction. For the latter application where biocompatibility is not the key issue, replacement of cationic lipid by cationic surfactant is advantageous due to the wide availability of surfactant. Here we report the self-assembly behavior of the complexes of DNA with a cationic surfactant, dodecyltrimethylammonium bromide (DTAB), mixed with a neutral lipid, dioleoylphosphatidylethanolamine (DOPE), in fully hydrated state as a function of DTAB-to-DNA base pair molar ratio (x), DOPE-to-DTAB molar ratio (m) and temperature. The binary complexes of DNA with DTAB microphase separated to form hydrophilic and hydrophobic domains without long-range order. Incorporating DOPE into the complexes effectively strengthened the hydrophobic interaction and hence promoted the formations of long-range ordered mesophases, including a condensed multilamellar phase (L(alpha)(c)) at small to intermediate m (m </= approximately 4) and an inverted hexagonal phase (H(II)(c)) at large m (m > approximately 6). The lyotropic mesophase transition with respect to the change of m was properly predicted by a formula for calculating the packing parameter of amphiphile mixture. In addition to the lyotropic transition, an unusual thermotropic order-order transition (OOT) between L(alpha)(c) and H(II)(c) phases was revealed for the isoelectric complex with m = 3. This OOT was thermally reversible and was postulated to be driven by the reduction of the effective headgroup area due to the release of trapped water molecules.
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Affiliation(s)
- Wei-Long Hsu
- Department of Chemical Engineering, National Tsing Hua University, Hsin-Chu 30013, Taiwan
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32
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Abstract
A thermodynamic analysis is presented for electrically charged mixed micelles in water on the basis of the Gibbs-Duhem relation proposed by Hall in combination with the information on the degree of counterion binding. The proposed analyses are shown to work well for both ionic/nonionic mixed micelles and those consisting of ionic surfactants of like charges. Conclusions for ionic/nonionic mixed micelles are as follows. (1) The contribution from counterions is significant. (2) In media of low ionic strengths, the counterion concentration varies with the micellar mole fraction of the ionic species x. The dependency of the activity coefficients and the excess free energy on x is significantly influenced by this effect, but it can be corrected to a large extent in terms of the Corrin-Harkins relation. (3) The regular solution theory (RST) is not always valid even when the excess free energy is described well with the RST expression unless the observed range of the micelle composition is wide enough. (4) The RST overestimates x and underestimates the activity coefficient of the ionic species when applied to the mixed micelles to which it is inapplicable. For the ionic mixed micelles consisting of surfactants of like charges, the Lange-Shinoda approach is shown to be consistent with the present analysis in terms of the Gibbs-Duhem relation, but Motomura's approach is found to be not exact but approximate.
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Affiliation(s)
- Hiroshi Maeda
- Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka 812-8581, Japan.
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33
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Molina-Bolívar JA, Aguiar J, Peula-García JM, Ruiz CC. Surface Activity, Micelle Formation, and Growth of n-Octyl-β-d-Thioglucopyranoside in Aqueous Solutions at Different Temperatures. J Phys Chem B 2004. [DOI: 10.1021/jp0480551] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- J. A. Molina-Bolívar
- Departamento de Física Aplicada II, Escuela Universitaria Politécnica, Universidad de Málaga, Campus de El Ejido, s/n, 29013 - Málaga, Spain
| | - J. Aguiar
- Departamento de Física Aplicada II, Escuela Universitaria Politécnica, Universidad de Málaga, Campus de El Ejido, s/n, 29013 - Málaga, Spain
| | - J. M. Peula-García
- Departamento de Física Aplicada II, Escuela Universitaria Politécnica, Universidad de Málaga, Campus de El Ejido, s/n, 29013 - Málaga, Spain
| | - C. Carnero Ruiz
- Departamento de Física Aplicada II, Escuela Universitaria Politécnica, Universidad de Málaga, Campus de El Ejido, s/n, 29013 - Málaga, Spain
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34
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Matsumoto K, Mazaki H, Matsuoka H. Fluorinated Amphiphilic Vinyl Ether Block Copolymers: Synthesis and Characteristics of Their Micelles in Water. Macromolecules 2004. [DOI: 10.1021/ma021166i] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kozo Matsumoto
- Department of Polymer Chemistry, Kyoto University, Kyoto 615-8510, Japan
| | - Hiroaki Mazaki
- Department of Polymer Chemistry, Kyoto University, Kyoto 615-8510, Japan
| | - Hideki Matsuoka
- Department of Polymer Chemistry, Kyoto University, Kyoto 615-8510, Japan
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35
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Leonard MJ, Strey HH. Phase Diagrams of Stoichiometric Polyelectrolyte−Surfactant Complexes. Macromolecules 2003. [DOI: 10.1021/ma034352c] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michael J. Leonard
- Department of Polymer Science and Engineering, Box 34530, University of Massachusetts, Amherst, Massachusetts 01003
| | - Helmut H. Strey
- Department of Polymer Science and Engineering, Box 34530, University of Massachusetts, Amherst, Massachusetts 01003
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36
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Che S, Lim S, Kaneda M, Yoshitake H, Terasaki O, Tatsumi T. The effect of the counteranion on the formation of mesoporous materials under the acidic synthesis process. J Am Chem Soc 2002; 124:13962-3. [PMID: 12440872 DOI: 10.1021/ja020854e] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The presence of various counteranions at the interfacial region of the silicate-surfactant mesophase introduces opportunities for manipulation of the phase structure. Well-ordered 3D-hexagonal P63/mmc, cubic Pmn, 2D-hexagonal p6mm, and cubic Iad mesoporous materials have been synthesized with the same surfactant, cetyltriethylammonium bromide, in the presence of various acids. The counteranions of acidic media have resulted in increasing the surfactant packing parameter g in the order SO42- < Cl- < Br- < NO3-, which leads to the different time course of formation of mesostructures. The effect of counteranions on the formation of mesostructures is explained in terms of not only the adsorption strength on the headgroups of the surfactant micelle but also the rate of silica condensation affecting the charge density matching between the surfactant and silica. It has been found that the mesophase is always transformed from the larger g parameter into the smaller one. The distinct morphologies of the 3D-hexagonal P63/mmc mesophases have been rationally explained by supposing this particular mesostructure. The cubic Iad phase has been first synthesized under acidic conditions.
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Affiliation(s)
- Shunai Che
- Division of Materials Science & Chemical Engineering, Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogayaku, Yokohama 240-8501, Japan
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37
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Pisárčik M, Imae T, Devı́nsky F, Lacko I. Aggregates of sodium hyaluronate with cationic and aminoxide surfactants in aqueous solution — light scattering study. Colloids Surf A Physicochem Eng Asp 2001. [DOI: 10.1016/s0927-7757(01)00512-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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38
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Zielinski R. Effect of Temperature on Micelle Formation in Aqueous NaBr Solutions of Octyltrimethylammonium Bromide. J Colloid Interface Sci 2001; 235:201-209. [PMID: 11254292 DOI: 10.1006/jcis.2000.7364] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Association processes in aqueous solutions of octyltrimethylammonium bromide, C(8)TAB, have been studied in aqueous NaBr solutions at temperatures from 20 to 55 degrees C. The values of the critical micelle concentration, CMC, were determined from the intersections of two straight line portions of the plots of the relationship between adiabatic compressibility of the solutions and surfactant concentration. The value of the CMC thus determined exhibits minima at a certain temperature, T(min). The value of T(min) shifts toward a lower temperature with increasing NaBr concentration. Based on the most probable micelle size model, the values of thermodynamic functions of micelle formation have been estimated at various temperatures. Copyright 2001 Academic Press.
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Affiliation(s)
- Ryszard Zielinski
- Department of Technology and Environmental Protection, Faculty of Commodity Science, Poznan University of Economics, Aleja Niepodleglosci 10, Poznan, 60-967, Poland
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39
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Nomura H, Koda S, Matsuoka T, Hiyama T, Shibata R, Kato S. Study of Salt Effects on the Micelle-Monomer Exchange Process of Octyl-, Decyl-, and Dodecyltrimethylammonium Bromide in Aqueous Solutions by Means of Ultrasonic Relaxation Spectroscopy. J Colloid Interface Sci 2000; 230:22-28. [PMID: 10998284 DOI: 10.1006/jcis.2000.7067] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of added salt on the micelle-monomer exchange process of octyl- and decyltrimethylammonium bromide were investigated by means of ultrasonic relaxation techniques. Using the Aniansson-Wall model, the micellar distribution width sigma and the dissociation rate constant k(-1) of the micelle-monomer exchange process were determined as functions of carbon number and of added salt concentration in aqueous solutions of a series of tetraalkylammonium bromide-NaBr systems and discussed on the basis of the Aniansson-Wall-Teubner model. From the rate constant of the micelle-monomer exchange process, the total energy change for the transfer of the alkyl chain of the surfactant ion from the interior of the micelle to a position where its terminal methyl groups is at the surface of the micelles was estimated and compared with those calculated by the Gouy-Chapmann model of the electric double-layer theory. Copyright 2000 Academic Press.
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Affiliation(s)
- H Nomura
- Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Nagoya, 464-8603, Japan
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40
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Aggregation number of alkanediyl-α,ω-bis(dimethylalkylammonium bromide) surfactants determined by static light scattering. Colloids Surf A Physicochem Eng Asp 2000. [DOI: 10.1016/s0927-7757(00)00589-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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41
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Hansson P, Jönsson B, Ström C, Söderman O. Determination of Micellar Aggregation Numbers in Dilute Surfactant Systems with the Fluorescence Quenching Method. J Phys Chem B 2000. [DOI: 10.1021/jp992444r] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Per Hansson
- Department of Physical Chemistry, Uppsala University, Box 532, S-751 21 Uppsala, Sweden and Department of Physical Chemistry, Center for Chemistry and Chemical Engineering, Lund University, P. O. Box 124, S-221 00 Lund, Sweden
| | - Bengt Jönsson
- Department of Physical Chemistry, Uppsala University, Box 532, S-751 21 Uppsala, Sweden and Department of Physical Chemistry, Center for Chemistry and Chemical Engineering, Lund University, P. O. Box 124, S-221 00 Lund, Sweden
| | - Cecilia Ström
- Department of Physical Chemistry, Uppsala University, Box 532, S-751 21 Uppsala, Sweden and Department of Physical Chemistry, Center for Chemistry and Chemical Engineering, Lund University, P. O. Box 124, S-221 00 Lund, Sweden
| | - Olle Söderman
- Department of Physical Chemistry, Uppsala University, Box 532, S-751 21 Uppsala, Sweden and Department of Physical Chemistry, Center for Chemistry and Chemical Engineering, Lund University, P. O. Box 124, S-221 00 Lund, Sweden
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42
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Hansson P, Almgren M. Reliable Aggregation Numbers Are Obtained for Polyelectrolyte Bound Cationic Micelles Using Fluorescence Quenching with a Cationic Surfactant Quencher. J Phys Chem B 2000. [DOI: 10.1021/jp9923217] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Per Hansson
- Department of Physical Chemistry, Uppsala University, Box 532, S-75121 Uppsala, Sweden
| | - Mats Almgren
- Department of Physical Chemistry, Uppsala University, Box 532, S-75121 Uppsala, Sweden
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43
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Roy BK, Moulik SP. BULK AND INTERFACIAL BEHAVIORS OF MIXED SYSTEM OF HEXADECYLPYRIDINIUM CHLORIDE AND Na+2-HYDROXY BENZOATE−. J DISPER SCI TECHNOL 2000. [DOI: 10.1080/01932690008913256] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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44
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Gaillon L, Lelièvre J, Gaboriaud R. Counterion Effects in Aqueous Solutions of Cationic Surfactants: Electromotive Force Measurements and Thermodynamic Model. J Colloid Interface Sci 1999; 213:287-297. [PMID: 10222068 DOI: 10.1006/jcis.1999.6141] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
EMF measurements have been performed to study the influence of counterions in aqueous solutions of ionic surfactants in which the amphiphile is an n-alkyltrimethylammonium cation. General rules of variation were observed for the activities of the amphiphilic ion and the counterion, as a function of the global concentration of the surfactant salt. This study also allows us to have access to the degree of counterion binding beta over a wide range of counterions (bromide, chloride, fluoride, hydroxide, nitrate, acetate, benzoate). A systematic correlation between the concentrations of an amphiphilic cation and a counterion in solution has been established when the micellization process occurs. This correlation is also verified when a background electrolyte with a common anion is added to the surfactant solution. The mathematical relation translating the real link between concentrations of both ions of the micellar salt, deduced from this correlation, emphasizes the existence of a condition of micellization, in the form of a micellization product. A new thermodynamic model based on the electrochemical equilibrium of a dispersed phase (pseudo-phase) is developed, and we justify the existence of this condition of micellization or micellization product. Furthermore, this model is shown to be well adapted for the description of the whole phenomena observed in micellar solutions. Copyright 1999 Academic Press.
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Affiliation(s)
- L Gaillon
- Laboratoire Energétique et Réactivité aux Interfaces, Université Pierre et Marie Curie, 4, place Jussieu, bat F boite 39, Paris cedex 05, 75252, France
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45
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Pisárèik M, Soldán M, Bakoš D, Devı́nsky F, Lacko I. Viscometric study of the sodium hyaluronate-sodium chloride-alkyl-(n)-ammonium surfactant system. Colloids Surf A Physicochem Eng Asp 1999. [DOI: 10.1016/s0927-7757(98)00837-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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46
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Dynamic light scattering and electrokinetic potential of bis(quarternary ammonium bromide) surfactant micelles as the function of the alkyl chain length. Colloids Surf A Physicochem Eng Asp 1998. [DOI: 10.1016/s0927-7757(98)00497-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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47
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Bijma K, Rank E, Engberts JBFN. Effect of Counterion Structure on Micellar Growth of Alkylpyridinium Surfactants in Aqueous Solution. J Colloid Interface Sci 1998; 205:245-256. [PMID: 9735187 DOI: 10.1006/jcis.1998.5687] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This paper describes the influence of counterions on the unidirectional growth of micelles formed by alkylpyridinium surfactants in aqueous solution. It is shown that the growth of spherical micelles to form wormlike micelles is strongly dependent on counterion structure. More hydrophobic counterions induce the formation of wormlike micelles at lower surfactant concentrations. Next to hydrophobicity and the type of substituent, the substitution pattern of the aromatic ring plays the most important role in micellar growth. The formation of a network of entangled, elongated wormlike micelles by alkylpyridinium surfactants with o-hydroxybenzoate and p-chlorobenzoate counterions is discussed in terms of surfactant structure. It is concluded that, next to counterion structure, the microenvironment of the counterion (substituent) in the Stern region and the structure of the surfactant monomer (i.e., the surfactant cation) play the most important role in the formation of these elongated wormlike micelles. Headgroup effects are proposed to be the main driving force for this phenomenon. Copyright 1998 Academic Press.
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Affiliation(s)
- K Bijma
- Department of Organic and Molecular Inorganic Chemistry, University of Groningen, Nijenborgh 4, Groningen, 9747 AG, The Netherlands
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48
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Hassan PA, Manohar C. Diffusion of Probe Particles in Surfactant Gels: Dynamic Light Scattering Study. J Phys Chem B 1998. [DOI: 10.1021/jp981639g] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- P. A. Hassan
- Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085, India
| | - C. Manohar
- Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085, India
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Király Z, Findenegg GH. Calorimetric Evidence of the Formation of Half-Cylindrical Aggregates of a Cationic Surfactant at the Graphite/Water Interface. J Phys Chem B 1998. [DOI: 10.1021/jp972218m] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Z. Király
- Technische Universität Berlin, Iwan-N.-Stranski-Institute für Physikalische und Theoretische Chemie, Strasse des 17. Juni 112, 10623 Berlin, Germany
| | - G. H. Findenegg
- Technische Universität Berlin, Iwan-N.-Stranski-Institute für Physikalische und Theoretische Chemie, Strasse des 17. Juni 112, 10623 Berlin, Germany
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Fujio K. The Salt-Induced Sphere–Rod Transition of Micelles of 1-Tetradecylpyridinium Bromide in Aqueous NaBr Solutions. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1998. [DOI: 10.1246/bcsj.71.83] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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