201
|
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].
Collapse
Affiliation(s)
- Filipe S Lima
- Instituto de Química, Universidade de São Paulo , São Paulo, Brazil
| | | | | | | | | | | | | | | |
Collapse
|
202
|
Lunkenheimer K, Prescher D, Hirte R, Geggel K. Adsorption properties of surface chemically pure sodium perfluoro-n-alkanoates at the air/water interface: counterion effects within homologous series of 1:1 ionic surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:970-81. [PMID: 25540840 DOI: 10.1021/la503450k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The unusual behavior of saturation adsorption calculated from experimental equilibrium surface tension (σ(e)) versus logarithm of concentration (c) isotherms within the homologous series of aqueous sodium perfluoro-n-alkanoate solutions represents a particular problem in the adsorption of homologous ionic 1:1 amphiphiles at fluid interfaces. Special precautions were taken to guarantee surface-chemical purity for all solutions, avoiding falsifying effects by surface-active trace impurities. Surprisingly, all homologues' adsorption isotherms reveal ideal surface behavior. The minimal surface area demand per molecule adsorbed for shorter-chain homologues slightly decreases with increasing chain lengths but then goes up steeply after having passed a minimum. A similar feature has been observed with the chemically quite different homologous series of the hydrocarbon surfactants of sodium-n-alkylsulfates. Comparing the corresponding 3D saturation concentrations in the boundary layer and in the bulk, it becomes evident that at high bulk concentrations when boundary layer and bulk concentrations are of the same order of magnitude the adsorption behavior may be treated as that of a pseudononionic surfactant. However, under conditions of the homologues' strongest surface activity, adsorption seems to become increasingly governed by electrostatic repulsion, resulting in increasingly greater cross-sectional areas. Deviation from pseudononionic behavior sets in when the Debye length becomes distinctly greater than the adsorbent's diameter at saturation. Formerly available theories on ionic amphiphiles' adsorption deal either with electrical conditions of surfactant ions and counterions in the adsorption boundary layer or alternatively with pseudononionic behavior neglecting the former theories completely. Warszynski et al.'s novel theoretical model of the "surface quasi-two-dimensional electrolyte" seems to be capable of describing the adsorption of ionic amphiphiles at fluid interfaces in general. We conclude that the conditions of the two alternative approaches may be met within homologous series of ionic amphiphiles as limiting cases only.
Collapse
Affiliation(s)
- Klaus Lunkenheimer
- Max-Planck-Institut für Kolloid- und Grenzflächenforschung , Department Adsorption Layers, Am Mühlenberg 1, D-16321 Potsdam, Germany
| | | | | | | |
Collapse
|
203
|
Hostnik G, Vlachy V, Bondarev D, Vohlídal J, Cerar J. Salt-specific effects observed in calorimetric studies of alkali and tetraalkylammonium salt solutions of poly(thiophen-3-ylacetic acid). Phys Chem Chem Phys 2015; 17:2475-83. [DOI: 10.1039/c4cp04710a] [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]
Abstract
Differences in hydration of counterions are blamed for strong salt-specific effects produced upon dilution and mixing of poly(thiophene-3-ylacetic acid) salts with simple salts.
Collapse
Affiliation(s)
- Gregor Hostnik
- Faculty of Chemistry and Chemical Technology
- University of Ljubljana
- SI–1000 Ljubljana
- Slovenia
| | - Vojko Vlachy
- Faculty of Chemistry and Chemical Technology
- University of Ljubljana
- SI–1000 Ljubljana
- Slovenia
| | - Dmitrij Bondarev
- University Institute
- Tomas Bata University in Zlín
- Zlín
- Czech Republic
| | - Jir̆í Vohlídal
- Faculty of Science
- Charles University in Prague
- CZ-12840 Prague 2
- Czech Republic
| | - Janez Cerar
- Faculty of Chemistry and Chemical Technology
- University of Ljubljana
- SI–1000 Ljubljana
- Slovenia
| |
Collapse
|
204
|
Interpretation of different molecular packing in the micelles of lyotropic nematic and cholesteric phases via mass density measurements. J Mol Liq 2014. [DOI: 10.1016/j.molliq.2014.11.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
205
|
Recycling metals by controlled transfer of ionic species between complex fluids: en route to “ienaics”. Colloid Polym Sci 2014. [DOI: 10.1007/s00396-014-3447-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
206
|
Lee HS, Adhimoolam Arunagirinathan M, Vagias A, Lee S, Bellare JR, Davis HT, Kaler EW, McCormick AV, Bates FS. Almost fooled again: new insights into cesium dodecyl sulfate micelle structures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:12743-12747. [PMID: 25285478 DOI: 10.1021/la502809y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Replacing sodium with cesium as the counterion for dodecyl sulfate in aqueous solution results in stronger complexation and charge shielding, which should lead to larger micelles and ultimately to a cylindrical structure (cf. spheres for sodium dodecyl sulfate), but small angle X-ray scattering (SAXS) and small angle neutron scattering patterns previously have been interpreted with ellipsoidal micelle models. We directly image CsDS micelles via cryo-transmission electron microscopy and report large core-shell spherical micelles at low concentrations (≤2 wt %) and cylindrical micelles at higher concentrations (5.0 and 8.1 wt %). These structures are shown to be consistent with SAXS patterns modeled using established form factors. These findings highlight the importance of combining real and reciprocal space imaging techniques in the characterization of self-assembled soft materials.
Collapse
Affiliation(s)
- Han Seung Lee
- Department of Chemical Engineering and Materials Science, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | | | | | | | | | | | | | | | | |
Collapse
|
207
|
Binding of phenol red to cetylpyridinium chloride at air–solution and micelle–solution interfaces in aqueous ethylene glycol media. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2014.08.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
208
|
Impact of seawater salts on the viscoelastic behavior of flocculated mineral suspensions. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2014.08.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
209
|
Effect of choline carboxylate ionic liquids on biological membranes. Colloids Surf B Biointerfaces 2014; 123:575-81. [PMID: 25444662 DOI: 10.1016/j.colsurfb.2014.09.057] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 09/11/2014] [Accepted: 09/28/2014] [Indexed: 11/20/2022]
Abstract
Choline carboxylates, ChCm, with m=2-10 and choline oleate are known as biocompatible substances, yet their influence on biological membranes is not well-known, and the effect on human skin has not previously been investigated. The short chain choline carboxylates ChCm with m=2, 4, 6 act as hydrotropes, solubilizing hydrophobic compounds in aqueous solution, while the longer chain choline carboxylates ChCm with m=8, 10 and oleate are able to form micelles. In the present study, the cytotoxicity of choline carboxylates was tested using HeLa and SK-MEL-28 cells. The influence of these substances on liposomes prepared from dipalmitoylphosphatidylcholine (DPPC) was also evaluated to provide insights on membrane interactions. It was observed that the choline carboxylates with a chain length of m>8 distinctly influence the bilayer, while the shorter ones had minimal interaction with the liposomes.
Collapse
|
210
|
Effects of counterion structure on the surface activities of anionic fluorinated surfactants whose counterions are organic ammonium ions. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2014.06.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
211
|
Przybyło M, Drabik D, Łukawski M, Langner M. Effect of Monovalent Anions on Water Transmembrane Transport. J Phys Chem B 2014; 118:11470-9. [DOI: 10.1021/jp505687d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Magda Przybyło
- Laboratory for Biophysics of Macromolecular Aggregates,
Institute of Biomedical Engineering and Instrumentation, Wroclaw University of Technology, Pl. Grunwaldzki 13, 50-370 Wroclaw, Poland
| | - Dominik Drabik
- Laboratory for Biophysics of Macromolecular Aggregates,
Institute of Biomedical Engineering and Instrumentation, Wroclaw University of Technology, Pl. Grunwaldzki 13, 50-370 Wroclaw, Poland
| | - Maciej Łukawski
- Laboratory for Biophysics of Macromolecular Aggregates,
Institute of Biomedical Engineering and Instrumentation, Wroclaw University of Technology, Pl. Grunwaldzki 13, 50-370 Wroclaw, Poland
| | - Marek Langner
- Laboratory for Biophysics of Macromolecular Aggregates,
Institute of Biomedical Engineering and Instrumentation, Wroclaw University of Technology, Pl. Grunwaldzki 13, 50-370 Wroclaw, Poland
| |
Collapse
|
212
|
|
213
|
Déjugnat C, Berthon L, Dubois V, Meridiano Y, Dourdain S, Guillaumont D, Pellet-Rostaing S, Zemb T. Liquid-Liquid Extraction of Acids and Water by a Malonamide: I-Anion Specific Effects on the Polar Core Microstructure of the Aggregated Malonamide. SOLVENT EXTRACTION AND ION EXCHANGE 2014. [DOI: 10.1080/07366299.2014.940229] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
214
|
Salis A, Ninham BW. Models and mechanisms of Hofmeister effects in electrolyte solutions, and colloid and protein systems revisited. Chem Soc Rev 2014; 43:7358-77. [PMID: 25099516 DOI: 10.1039/c4cs00144c] [Citation(s) in RCA: 365] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Specific effects of electrolytes have posed a challenge since the 1880's. The pioneering work was that of Franz Hofmeister who studied specific salt induced protein precipitation. These effects are the rule rather the exception and are ubiquitous in chemistry and biology. Conventional electrostatic theories (Debye-Hückel, DLVO, etc.) cannot explain such effects. Over the past decades it has been recognised that additional quantum mechanical dispersion forces with associated hydration effects acting on ions are missing from theory. In parallel Collins has proposed a phenomenological set of rules (the law of matching water affinities, LMWA) which explain and bring to order the order of ion-ion and ion-surface site interactions at a qualitative level. The two approaches appear to conflict. Although the need for inclusion of quantum dispersion forces in one form or another is not questioned, the modelling has often been misleading and inappropriate. It does not properly describe the chemical nature (kosmotropic/chaotropic or hard/soft) of the interacting species. The success of the LMWA rules lies in the fact that they do. Here we point to the way that the two apparently opposing approaches might be reconciled. Notwithstanding, there are more challenges, which deal with the effect of dissolved gas and its connection to 'hydrophobic' interactions, the problem of water at different temperatures and 'water structure' in the presence of solutes. They take us to another dimension that requires the rebuilding of theoretical foundations.
Collapse
Affiliation(s)
- Andrea Salis
- Department of Chemical and Geological Science, University of Cagliari, Italy and CSGI.
| | | |
Collapse
|
215
|
Bickel KR, Timm AE, Nattland D, Schuster R. Microcalorimetric determination of the entropy change upon the electrochemically driven surface aggregation of dodecyl sulfate. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:9085-9090. [PMID: 24494729 DOI: 10.1021/la404692u] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The aggregation of amphiphilic molecules (e.g., the formation of micelles or membranes) is usually entropy-driven. We use electrochemical microcalorimetry to directly determine the entropy change a dodecyl sulfate molecule experiences upon potential-induced adsorption from aqueous solution into a surface aggregate. From measurements of the heat, which is reversibly exchanged during the adsorption or desorption process, we determined a value of 37 ± 9 J/(mol K) for the aggregation entropy. This value is in accordance with entropies of micellization of dodecyl sulfate in solution. A comparison with estimates of the entropy of aggregation of dodecane in aqueous solutions reveals that the aggregation is driven by the entropic contribution of the hydrophobic hydrocarbon tail, in accordance with general models for the aggregation of amphiphilic molecules.
Collapse
Affiliation(s)
- Katrin R Bickel
- Institute of Physical Chemistry, Karlsruhe Institute of Technology , D-76131 Karlsruhe, Germany
| | | | | | | |
Collapse
|
216
|
Koroleva SV, Victorov AI. The strong specific effect of coions on micellar growth from molecular-thermodynamic theory. Phys Chem Chem Phys 2014; 16:17422-5. [DOI: 10.1039/c4cp02178a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
217
|
Dourdain S, Déjugnat C, Berthon L, Dubois V, Pellet-Rostaing S, Dufrêche JF, Zemb T. Liquid-Liquid Extraction of Acids by a Malonamide: II-Anion Specific Effects in the Aggregate-Enhanced Extraction Isotherms. SOLVENT EXTRACTION AND ION EXCHANGE 2014. [DOI: 10.1080/07366299.2014.924311] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
218
|
Shao Q, Jiang S. Influence of Charged Groups on the Properties of Zwitterionic Moieties: A Molecular Simulation Study. J Phys Chem B 2014; 118:7630-7637. [DOI: 10.1021/jp5027114] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Qing Shao
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Shaoyi Jiang
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States
| |
Collapse
|
219
|
Affiliation(s)
- Yun Xu
- Department of Chemical Physics,
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, P. R. China 230026
| | - Guangming Liu
- Department of Chemical Physics,
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, P. R. China 230026
| |
Collapse
|
220
|
Asciutto EK, Gaborek T, Madura JD. Sodium versus potassium effects on the glutamic acid side-chains interaction on a heptapeptide. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2014. [DOI: 10.1142/s0219633614400045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Equilibrium peptide conformations in solution, especially in the presence of salts, has been of interest for several decades. The fundamental interactions that determine the dominant peptide conformations in solution have been experimentally and computationally probed; however, a unified understanding has not yet emerged. In a previous study, we performed metadynamics simulations on the heptapeptide AEAAAEA in Sodium Chloride ( NaCl ) and Potassium Chloride ( KCl ) solutions at concentrations ranging from 0.5–2.0 M. Using a three-dimensional collective variable coordinate system, we computed the free energy landscapes in each saline environment as well as in pure water. We found that the presence of Na + and K + ions induces some changes in the stability of the conformers that define the state space, but does not alter the overall energetics between conformers and does not favor helical conformations. We investigate here, how the presence of salts ( NaCl and KCl ) affects the glutamic–glutamic interaction and its consequences on the stability of each equilibrium conformation. We perform this study through fixed backbone simulations for the most populated conformations identified in our previous work: the α-helix, 310-helix, π-helix, the extended polyproline II (PPII) and 2.51-helix conformations. It was found that for each conformation, there exists stable substates determined by the glutamic acid side-chains distance and orientation, and that Na + and K + cations (de)stabilize preferentially each conformation. It was also found that intramolecular single water mediated hydrogen bonds play a crucial role in the observed (de) stabilization of each equilibrium conformation.
Collapse
Affiliation(s)
- Eliana K. Asciutto
- Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Ave., Pittsburgh, PA 15219, USA
| | - Timothy Gaborek
- Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Ave., Pittsburgh, PA 15219, USA
| | - Jeffry D. Madura
- Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Ave., Pittsburgh, PA 15219, USA
| |
Collapse
|
221
|
Fameau AL, Zemb T. Self-assembly of fatty acids in the presence of amines and cationic components. Adv Colloid Interface Sci 2014; 207:43-64. [PMID: 24345730 DOI: 10.1016/j.cis.2013.11.017] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 11/18/2013] [Accepted: 11/21/2013] [Indexed: 11/27/2022]
Abstract
Fatty acids can self-assemble under various shapes in the presence of amines or cationic components. We assemble and compare these types of self-assembly leading toward a catanionic system either with a cationic surfactant or with an amine component playing the role of counter-ion. First, we focus on the molar ratio as a key driving parameter. Known and yet un-known values from other quantities governing the colloidal properties of these systems such as structural surface charge, osmotic pressure, molecular segregation, rigidity, in plane colloidal interactions and melting transition are discussed. We include also recent results obtained on the interfacial and foaming properties of these systems. We will highlight the specificity of these self-assemblies leading to unusual macroscopic properties rich of robust applications.
Collapse
|
222
|
England AH, Clare TL. Synthesis and Characterization of Flexible Hydrogel Electrodes for Electrochemical Impedance Measurements of Protective Coatings on Metal Sculptures. ELECTROANAL 2014. [DOI: 10.1002/elan.201300653] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
223
|
Danov KD, Kralchevsky PA, Ananthapadmanabhan KP. Micelle-monomer equilibria in solutions of ionic surfactants and in ionic-nonionic mixtures: a generalized phase separation model. Adv Colloid Interface Sci 2014; 206:17-45. [PMID: 23558017 DOI: 10.1016/j.cis.2013.02.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 02/16/2013] [Accepted: 02/19/2013] [Indexed: 12/01/2022]
Abstract
On the basis of a detailed physicochemical model, a complete system of equations is formulated that describes the equilibrium between micelles and monomers in solutions of ionic surfactants and their mixtures with nonionic surfactants. The equations of the system express mass balances, chemical and mechanical equilibria. Each nonionic surfactant is characterized by a single thermodynamic parameter--its micellization constant. Each ionic surfactant is characterized by three parameters, including the Stern constant that quantifies the counterion binding. In the case of mixed micelles, each pair of surfactants is characterized with an interaction parameter, β, in terms of the regular solution theory. The comparison of the model with experimental data for surfactant binary mixtures shows that β is constant--independent of the micelle composition and electrolyte concentration. The solution of the system of equations gives the concentrations of all monomeric species, the micelle composition, ionization degree, surface potential and mean area per head group. Upon additional assumptions for the micelle shape, the mean aggregation number can be also estimated. The model gives quantitative theoretical interpretation of the dependence of the critical micellization concentration (CMC) of ionic surfactants on the ionic strength; of the CMC of mixed surfactant solutions, and of the electrolytic conductivity of micellar solutions. It turns out, that in the absence of added salt the conductivity is completely dominated by the contribution of the small ions: monomers and counterions. The theoretical predictions are in good agreement with experimental data.
Collapse
Affiliation(s)
- Krassimir D Danov
- Department of Chemical Engineering, Faculty of Chemistry and Pharmacy, Sofia University, Sofia 1164, Bulgaria
| | - Peter A Kralchevsky
- Department of Chemical Engineering, Faculty of Chemistry and Pharmacy, Sofia University, Sofia 1164, Bulgaria.
| | | |
Collapse
|
224
|
Koroleva SV, Victorov AI. Modeling of the effects of ion specificity on the onset and growth of ionic micelles in a solution of simple salts. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:3387-3396. [PMID: 24601813 DOI: 10.1021/la404845y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A new version of the molecular thermodynamic model has been developed that takes into account the effect of ion specificity on the free energy of aggregation. The specificity of salt is reflected by differences in the bare ionic sizes and polarizabilities leading to the difference in the dispersion interaction of ions with the aggregate. The model also contains parameters that characterize the compactness of ionic pairs formed between a mobile ion and surfactant's headgroup. The values of these parameters show that more chaotropic heads form tighter pairs with chaotropic ions whereas more cosmotropic heads form more compact pairs with cosmotropic ions. The formation of compact pairs in the micelle corona diminishes the preferable curvature of the aggregates and promotes their growth. The model has been applied to aqueous solutions of cationic (alkyltrimethylammonium, alkyldimethylammonium, and alkylpyridinium) and anionic (alkylsulfate and alkylcarboxylate) surfactants in the presence of simple 1:1 salts. With a single set of parameter values, the model reproduces the critical micelle concentration-salinity curves and the sphere-to-rod transitions or the absence of thereof and describes the aggregate growth for different simple salts, in good agreement with experiment.
Collapse
Affiliation(s)
- Sofia V Koroleva
- Department of Chemistry, St. Petersburg State University , Universitetsky Prospect 26, 198504 St. Petersburg, Russia
| | | |
Collapse
|
225
|
Zahn R, Bickel KR, Zambelli T, Reichenbach J, Kuhn FM, Vörös J, Schuster R. The entropy of water in swelling PGA/PAH polyelectrolyte multilayers. SOFT MATTER 2014; 10:688-693. [PMID: 24835977 DOI: 10.1039/c3sm52489b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We investigated the thermodynamical properties of water exchanged in poly(l-glutamic acid)/poly(allylamine)hydrochloride (PGA/PAH) polyelectrolyte multilayers containing ferrocyanide. Oxidation/reduction of the ferrocyanide in the multilayer caused a reversible swelling/contraction of the film due to the uptake/release of counter ions and water. We used electrochemical quartz crystal microbalance and electrochemical microcalorimetry to correlate the amount of water with the accompanying entropy changes during electrochemical swelling of the multilayer for a series of different anions at different concentrations. The number of exchanged water molecules was highly dependent on the ionic strength and the type of anion in the buffer solution. However, the entropy change per exchanged water molecule was found to be independent of these two parameters. The water molecules in the polyelectrolyte multilayer have reduced the entropy compared to that of bulk water (≈-1 J mol(-1) K(-1)). A comparison of hydration entropies for free polyelectrolytes and PGA/PAH multilayers suggests that such systems are mainly stabilized by water release during multilayer construction.
Collapse
Affiliation(s)
- Raphael Zahn
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, Switzerland.
| | | | | | | | | | | | | |
Collapse
|
226
|
Bauduin P, Zemb T. Perpendicular and lateral equations of state in layered systems of amphiphiles. Curr Opin Colloid Interface Sci 2014. [DOI: 10.1016/j.cocis.2014.02.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
227
|
The ion–lipid battle for hydration water and interfacial sites at soft-matter interfaces. Curr Opin Colloid Interface Sci 2014. [DOI: 10.1016/j.cocis.2014.02.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
228
|
Wang L, Guo Y, Li P, Song Y. Anion-Specific Effects on the Assembly of Collagen Layers Mediated by Magnesium Ion on Mica Surface. J Phys Chem B 2014; 118:511-8. [DOI: 10.1021/jp405035x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Li Wang
- Key Laboratory
of Functional
Small Organic Molecule, Ministry of Education, College of Chemistry
and Chemical Engineering, Jiangxi Normal University, 99 Ziyang
Road, Nanchang 330022, China
| | - Yan Guo
- Key Laboratory
of Functional
Small Organic Molecule, Ministry of Education, College of Chemistry
and Chemical Engineering, Jiangxi Normal University, 99 Ziyang
Road, Nanchang 330022, China
| | - Pengcheng Li
- Key Laboratory
of Functional
Small Organic Molecule, Ministry of Education, College of Chemistry
and Chemical Engineering, Jiangxi Normal University, 99 Ziyang
Road, Nanchang 330022, China
| | - Yonghai Song
- Key Laboratory
of Functional
Small Organic Molecule, Ministry of Education, College of Chemistry
and Chemical Engineering, Jiangxi Normal University, 99 Ziyang
Road, Nanchang 330022, China
| |
Collapse
|
229
|
Déjugnat C, Dourdain S, Dubois V, Berthon L, Pellet-Rostaing S, Dufrêche JF, Zemb T. Reverse aggregate nucleation induced by acids in liquid–liquid extraction processes. Phys Chem Chem Phys 2014; 16:7339-49. [DOI: 10.1039/c4cp00073k] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
230
|
Arends F, Baumgärtel R, Lieleg O. Ion-specific effects modulate the diffusive mobility of colloids in an extracellular matrix gel. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:15965-15973. [PMID: 24320773 DOI: 10.1021/la404016y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The diffusion of colloids in complex biological hydrogels is regulated by a broad range of factors including geometric constraints and different types of physical interactions between the particles and the hydrogel constituents. As a consequence, the particle mobility depends not only on the hydrogel microarchitecture but also on the detailed chemical composition of the hydrogel solvent. Here, we employ single particle tracking techniques to quantify the diffusion behavior of submicrometer-sized particles in such a biological hydrogel. We observe three states of colloid mobility: free diffusion, tightly and weakly bound particles, and transitions between those states. Finally, by comparing the efficiency of particle trapping in Matrigel as a function of the ionic strength of the hydrogel buffer, we show that ion-specific effects regulate the efficiency of this trapping process.
Collapse
Affiliation(s)
- Fabienna Arends
- Zentralinstitut für Medizintechnik, Technische Universität München , Boltzmannstrasse 11, 85748 Garching, Germany
| | | | | |
Collapse
|
231
|
Huang Z, Hua W, Verreault D, Allen HC. Influence of Salt Purity on Na+ and Palmitic Acid Interactions. J Phys Chem A 2013; 117:13412-8. [PMID: 24041145 DOI: 10.1021/jp406690p] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Zishuai Huang
- Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Wei Hua
- Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Dominique Verreault
- Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Heather C. Allen
- Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| |
Collapse
|
232
|
Marcus J, Touraud D, Kunz W. Formulation and stability of a soap microemulsion and the apparent pKA herein. J Colloid Interface Sci 2013; 407:382-9. [DOI: 10.1016/j.jcis.2013.06.052] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2013] [Revised: 06/17/2013] [Accepted: 06/19/2013] [Indexed: 11/16/2022]
|
233
|
Khan MN, Yusof NSM, Razak NA. Semi-empirical spectrophotometric (SESp) method for the indirect determination of the ratio of cationic micellar binding constants of counterions X⁻ and Br⁻(K(X)/K(Br)). J Oleo Sci 2013; 62:695-708. [PMID: 24005014 DOI: 10.5650/jos.62.695] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The semi-empirical spectrophotometric (SESp) method, for the indirect determination of ion exchange constants (K(X)(Br)) of ion exchange processes occurring between counterions (X⁻ and Br⁻) at the cationic micellar surface, is described in this article. The method uses an anionic spectrophotometric probe molecule, N-(2-methoxyphenyl)phthalamate ion (1⁻), which measures the effects of varying concentrations of inert inorganic or organic salt (Na(v)X, v = 1, 2) on absorbance, (A(ob)) at 310 nm, of samples containing constant concentrations of 1⁻, NaOH and cationic micelles. The observed data fit satisfactorily to an empirical equation which gives the values of two empirical constants. These empirical constants lead to the determination of K(X)(Br) (= K(X)/K(Br) with K(X) and K(Br) representing cationic micellar binding constants of counterions X and Br⁻). This method gives values of K(X)(Br) for both moderately hydrophobic and hydrophilic X⁻. The values of K(X)(Br), obtained by using this method, are comparable with the corresponding values of K(X)(Br), obtained by the use of semi-empirical kinetic (SEK) method, for different moderately hydrophobic X. The values of K(X)(Br) for X = Cl⁻ and 2,6-Cl₂C6H₃CO₂⁻, obtained by the use of SESp and SEK methods, are similar to those obtained by the use of other different conventional methods.
Collapse
Affiliation(s)
- Mohammad Niyaz Khan
- Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.
| | | | | |
Collapse
|
234
|
Landázuri G, Macías E, Fernandez V, Escalante J, Pérez-Carrillo L, Álvarez J, Schulz P, Rharbi Y, Puig J, Soltero J. On the shear thickening behavior of micellar aqueous solutions of cetyltrimethylammonium fluorobenzoates: Effect of the fluor position. Colloids Surf A Physicochem Eng Asp 2013. [DOI: 10.1016/j.colsurfa.2013.05.076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
235
|
The influence of inorganic salts on the rheological properties of 1,3-propanediyl bis(dodecyl dimethylammonium bromide) and sodium dodecylsulfonate aqueous mixed system. Colloids Surf A Physicochem Eng Asp 2013. [DOI: 10.1016/j.colsurfa.2013.06.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
236
|
Tarafdar PK, Reddy ST, Swamy MJ. Effect of Hofmeister Series Anions on the Thermotropic Phase Behavior of Bioactive O-Acylcholines. J Phys Chem B 2013; 117:9900-9. [DOI: 10.1021/jp403964k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
| | | | - Musti J. Swamy
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
| |
Collapse
|
237
|
Lima FS, Chaimovich H, Cuccovia IM, Buchner R. Dielectric relaxation spectroscopy shows a sparingly hydrated interface and low counterion mobility in triflate micelles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:10037-10046. [PMID: 23899188 DOI: 10.1021/la401728g] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The properties of ionic micelles are affected by the nature of the counterion. Specific ion effects can be dramatic, inducing even shape and phase changes in micellar solutions, transitions apparently related to micellar hydration and counterion binding at the micellar interface. Thus, determining the hydration and dynamics of ions in micellar systems capable of undergoing such transitions is a crucial step in understanding shape and phase changes. For cationic micelles, such transitions are common with large organic anions as counterions. Interestingly, however, phase separation also occurs for dodecyltrimethylammonium triflate (DTATf) micelles in the presence of sodium triflate (NaTf). Specific ion effects for micellar solutions of dodecyltrimethylammonium chloride (DTAC), bromide (DTAB), methanesulfonate (DTAMs), and triflate (DTATf) were studied with dielectric relaxation spectroscopy (DRS), a technique capable of monitoring hydration and counterion dynamics of micellar aggregates. In comparison to DTAB, DTAC, and DTAMs, DTATf micelles were found to be considerably less hydrated and showed reduced counterion mobility at the micellar interface. The obtained DTATf and DTAMs data support the reported central role of the anion's -CF3 moiety with respect to the properties of DTATf micelles. The reduced hydration observed for DTATf micelles was rationalized in terms of the higher packing of this surfactant compared to that of other DTA-based systems. The decreased mobility of Tf(-) anions condensed at the DTATf interface strongly suggests the insertion of Tf(-) in the micellar interface, which is apparently driven by the strong hydrophobicity of -CF3.
Collapse
Affiliation(s)
- Filipe S Lima
- Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | | | | | | |
Collapse
|
238
|
Jiao J, Zhang Y, Fang L, Yu L, Sun L, Wang R, Cheng N. Electrolyte effect on the aggregation behavior of 1-butyl-3-methylimidazolium dodecylsulfate in aqueous solution. J Colloid Interface Sci 2013; 402:139-45. [DOI: 10.1016/j.jcis.2013.03.027] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 03/13/2013] [Accepted: 03/14/2013] [Indexed: 11/17/2022]
|
239
|
Di Michele A, Germani R, Pastori G, Spreti N, Brinchi L. Effects of temperature on micellar-assisted bimolecular reaction of methylnaphtalene-2-sulphonate with bromide and chloride ions. J Colloid Interface Sci 2013; 402:165-72. [PMID: 23660022 DOI: 10.1016/j.jcis.2013.03.048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 03/27/2013] [Accepted: 03/28/2013] [Indexed: 12/22/2022]
Affiliation(s)
- A Di Michele
- Dipartimento di Fisica, Università di Perugia, Perugia, Italy
| | | | | | | | | |
Collapse
|
240
|
Wang T, Wang X, Long Y, Liu G, Zhang G. Ion-specific conformational behavior of polyzwitterionic brushes: exploiting it for protein adsorption/desorption control. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:6588-96. [PMID: 23659322 DOI: 10.1021/la401069y] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The conformation of polyzwitterionic brushes plays a crucial role in the adsorption/desorption of proteins on solid surfaces. By use of quartz crystal microbalance with dissipation (QCM-D) and surface plasmon resonance (SPR), we have systematically investigated the conformational behavior of poly(sulfobetaine methacrylate) (PSBMA) brushes as a function of ionic strength in the presence of different ions. The frequency change demonstrates that the effectiveness of anions to weaken the inter/intrachain association and to enhance the hydration of the grafted chains increases from kosmotrope to chaotrope in the low ionic strength regime, but the ordering of anions is almost reversed at the high ionic strengths. The dissipation change indicates that some heterogeneous structures are formed inside the brushes in the presence of chaotropic anions with the increase of ionic strength. In SPR studies, the change of resonance unit (ΔRU) with ionic strength is determined by the balance between the increase of thickness and the decrease of refractive index of the brushes. No anion specificity is observed in the SPR measurements because ΔRU is insensitive to the coupled water molecules inside the brushes. For the control of protein adsorption/desorption, our studies show that the brushes can more effectively resist the protein adsorption in the presence of a more chaotropic anion and a more chaotropic anion can also more effectively induce the protein desorption from the surface of the brushes. In addition, no obvious cation specificity can be observed in the conformational change of the brushes in either QCM-D or SPR measurements.
Collapse
Affiliation(s)
- Tao Wang
- Department of Chemical Physics, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, P R China
| | | | | | | | | |
Collapse
|
241
|
Zhao J, Yang D, You Y. Effect of Bolaform Counterions on the Adsorption of Sodium Dodecyl Sulfonate at the Air/Water Interface. J SURFACTANTS DETERG 2013. [DOI: 10.1007/s11743-013-1486-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
242
|
Müller W, Déjugnat C, Diat O, Zemb T. Effects of Alkaline Cations on Self-assembly of Cetylpyridinium Surfactants. TENSIDE SURFACT DET 2013. [DOI: 10.3139/113.110102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Here we study the influence of alkaline cations on the self-assembly of cetylpyridinium chloride and cetylpyridinium nitrate. It is known that the anionic counterions have a strong influence on the solubility and self-assembly properties of cationic surfactants. However, in this paper we will show that monovalent cations have also an influence which is weaker but detectable. Scattering techniques (X-Ray, light) were used to obtain structural information about the aggregation as a function of the temperature and the ionic strength. The results are interpreted in terms of ion pair adsorption at the micellar interface, depending on the ionic strength.
Collapse
Affiliation(s)
- W. Müller
- ICSM – UMR 5257 (CEA, CNRS, UM2, ENSCM), Bagnols-sur-Cèze, France
| | - Ch. Déjugnat
- ICSM – UMR 5257 (CEA, CNRS, UM2, ENSCM), Bagnols-sur-Cèze, France
- IMRCP – UMR 5623, Université Paul Sabatier, Toulouse, France
| | - O. Diat
- ICSM – UMR 5257 (CEA, CNRS, UM2, ENSCM), Bagnols-sur-Cèze, France
| | - Th. Zemb
- ICSM – UMR 5257 (CEA, CNRS, UM2, ENSCM), Bagnols-sur-Cèze, France
| |
Collapse
|
243
|
Kumar S, Patel H, Patil SR. Test of Hofmeister-like series of anionic headgroups: clouding and micellar growth. Colloid Polym Sci 2013. [DOI: 10.1007/s00396-013-2942-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
244
|
Long Y, Wang T, Liu L, Liu G, Zhang G. Ion specificity at a low salt concentration in water-methanol mixtures exemplified by a growth of polyelectrolyte multilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:3645-3653. [PMID: 23425248 DOI: 10.1021/la400035e] [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
By use of a quartz crystal microbalance with dissipation (QCM-D), we have investigated the specific ion effect on the growth of poly(sodium 2-acrylamido-2-methylpropanesulfonate)/poly(diallyldimethylammonium chloride) multilayer at a salt concentration as low as 2.0 mM in water-methanol mixtures. QCM-D results demonstrate that specific ion effect can be observed in methanol and water-methanol mixtures though it is negligible in water. Moreover, the specific ion effect is amplified as the molar fraction of methanol (xM) increases from 0% to 75% but is weakened again with the further increase of xM from 75% to 100%. Nuclear magnetic resonance measurements reveal that the counterion-polyelectrolyte segment interactions may not account for the observed ion specificity. By extending the Collins' concept of matching water affinities to methanol and water-methanol mixtures, we suggest that the ion-solvent interactions and the resulted counterion-charged group interactions are responsible for the occurrence of the specific ion effect. The conductivity measurements indicate that water and methanol molecules may form complexes, and the change of relative proportion of complexes with the xM causes the amplification or weakening of the specific ion effect.
Collapse
Affiliation(s)
- Yunchao Long
- Department of Chemical Physics, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, PR China 230026
| | | | | | | | | |
Collapse
|
245
|
Aslam J, Siddiqui US, Ansari WH, Kabir-ud-Din. Micellization Studies of Dicationic Gemini Surfactants (m-2-m Type) in the Presence of Various Counter- and Co-Ions. J SURFACTANTS DETERG 2013. [DOI: 10.1007/s11743-013-1453-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
246
|
Schwierz N, Horinek D, Netz RR. Anionic and cationic Hofmeister effects on hydrophobic and hydrophilic surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:2602-14. [PMID: 23339330 DOI: 10.1021/la303924e] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Using a two-step modeling approach, we address the full spectrum of direct, reversed, and altered ionic sequences as the charge of the ion, the charge of the surface, and the surface polarity are varied. From solvent-explicit molecular dynamics simulations, we extract single-ion surface interaction potentials for halide and alkali ions at hydrophilic and hydrophobic surfaces. These are used within Poisson-Boltzmann theory to calculate ion density and electrostatic potential distributions at mixed polar/unpolar surfaces for varying surface charge. The resulting interfacial tension increments agree quantitatively with experimental data and capture the Hofmeister series, especially the anomaly of lithium, which is difficult to obtain using continuum theory. Phase diagrams that feature different Hofmeister series as a function of surface charge, salt concentration, and surface polarity are constructed from the long-range force between two surfaces interacting across electrolyte solutions. Large anions such as iodide have a high hydrophobic surface affinity and increase the effective charge magnitude on negatively charged unpolar surfaces. Large cations such as cesium also have a large hydrophobic surface affinity and thereby compensate an external negative charge surface charge most efficiently, which explains the well-known asymmetry between cations and anions. On the hydrophilic surface, the size-dependence of the ion surface affinity is reversed, explaining the Hofmeister series reversal when comparing hydrophobic with hydrophilic surfaces.
Collapse
Affiliation(s)
- Nadine Schwierz
- Fachbereich für Physik, Freie Universität Berlin, 141954 Berlin, Germany
| | | | | |
Collapse
|
247
|
Haramaki H, Shimomura T, Umecky T, Takamuku T. SANS, Infrared, and 7Li and 23Na NMR Studies on Phase Separation of Alkali Halide–Acetonitrile–Water Mixtures by Cooling. J Phys Chem B 2013; 117:2438-48. [DOI: 10.1021/jp309881v] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Hiroki Haramaki
- Department of Chemistry
and Applied Chemistry, Faculty
of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan
| | - Takuya Shimomura
- Department of Chemistry
and Applied Chemistry, Faculty
of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan
| | - Tatsuya Umecky
- Department of Chemistry
and Applied Chemistry, Faculty
of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan
| | - Toshiyuki Takamuku
- Department of Chemistry
and Applied Chemistry, Faculty
of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan
| |
Collapse
|
248
|
Liu L, Wang T, Liu C, Lin K, Ding Y, Liu G, Zhang G. Mechanistic Insights into Amplification of Specific Ion Effect in Water–Nonaqueous Solvent Mixtures. J Phys Chem B 2013; 117:2535-44. [DOI: 10.1021/jp311841m] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Lvdan Liu
- Department of Chemical Physics,
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei,
P. R. China 230026
| | - Tao Wang
- Department of Chemical Physics,
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei,
P. R. China 230026
| | - Chang Liu
- Department of Chemical Physics,
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei,
P. R. China 230026
| | - Ke Lin
- Department of Chemical Physics,
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei,
P. R. China 230026
| | - Yanwei Ding
- Department of Chemical Physics,
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei,
P. R. China 230026
| | - Guangming Liu
- Department of Chemical Physics,
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei,
P. R. China 230026
| | - Guangzhao Zhang
- Faculty
of Materials Science
and Engineering, South China University of Technology, Guangzhou, P. R. China 510640
| |
Collapse
|
249
|
Müller W, Déjugnat C, Zemb T, Dufrêche JF, Diat O. How Do Anions Affect Self-Assembly and Solubility of Cetylpyridinium Surfactants in Water. J Phys Chem B 2013; 117:1345-56. [DOI: 10.1021/jp3093622] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Wolfram Müller
- Institut de Chimie Séparative
de Marcoule (ICSM),
UMR 5257 (CEA/CNRS/UM2/ENSCM), Bagnols-sur-Cèze, France
| | - Christophe Déjugnat
- Institut de Chimie Séparative
de Marcoule (ICSM),
UMR 5257 (CEA/CNRS/UM2/ENSCM), Bagnols-sur-Cèze, France
| | - Thomas Zemb
- Institut de Chimie Séparative
de Marcoule (ICSM),
UMR 5257 (CEA/CNRS/UM2/ENSCM), Bagnols-sur-Cèze, France
| | - Jean-François Dufrêche
- Institut de Chimie Séparative
de Marcoule (ICSM),
UMR 5257 (CEA/CNRS/UM2/ENSCM), Bagnols-sur-Cèze, France
| | - Olivier Diat
- Institut de Chimie Séparative
de Marcoule (ICSM),
UMR 5257 (CEA/CNRS/UM2/ENSCM), Bagnols-sur-Cèze, France
| |
Collapse
|
250
|
Reif MM, Winger M, Oostenbrink C. Testing of the GROMOS Force-Field Parameter Set 54A8: Structural Properties of Electrolyte Solutions, Lipid Bilayers, and Proteins. J Chem Theory Comput 2013; 9:1247-1264. [PMID: 23418406 PMCID: PMC3572754 DOI: 10.1021/ct300874c] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Indexed: 11/28/2022]
Abstract
![]()
The GROMOS 54A8 force field [Reif et al. J. Chem.
Theory
Comput.2012, 8, 3705–3723]
is the first of its kind to contain nonbonded parameters for charged
amino acid side chains that are derived in a rigorously thermodynamic
fashion, namely a calibration against single-ion hydration free energies.
Considering charged moieties in solution, the most decisive signature
of the GROMOS 54A8 force field in comparison to its predecessor 54A7
can probably be found in the thermodynamic equilibrium between salt-bridged
ion pair formation and hydration. Possible shifts in this equilibrium
might crucially affect the properties of electrolyte solutions or/and
the stability of (bio)molecules. It is therefore important to investigate
the consequences of the altered description of charged oligoatomic
species in the GROMOS 54A8 force field. The present study focuses
on examining the ability of the GROMOS 54A8 force field to accurately
model the structural properties of electrolyte solutions, lipid bilayers,
and proteins. It is found that (i) aqueous electrolytes
involving oligoatomic species (sodium acetate, methylammonium chloride,
guanidinium chloride) reproduce experimental salt activity derivatives
for concentrations up to 1.0 m (1.0-molal) very well, and good agreement
between simulated and experimental data is also reached for sodium
acetate and methylammonium chloride at 2.0 m concentration, while
not even qualitative agreement is found for sodium chloride throughout
the whole range of examined concentrations, indicating a failure of
the GROMOS 54A7 and 54A8 force-field parameter sets to correctly account
for the balance between ion–ion and ion–water binding
propensities of sodium and chloride ions; (ii) the
GROMOS 54A8 force field reproduces the liquid crystalline-like phase
of a hydrated DPPC bilayer at a pressure of 1 bar and a temperature
of 323 K, the area per lipid being in agreement with experimental
data, whereas other structural properties (volume per lipid, bilayer
thickness) appear underestimated; (iii) the secondary
structure of a range of different proteins simulated with the GROMOS
54A8 force field at pH 7 is maintained and compatible with experimental
NMR data, while, as also observed for the GROMOS 54A7 force field,
α-helices are slightly overstabilized with respect to 310-helices; (iv) with the GROMOS 54A8 force
field, the side chains of arginine, lysine, aspartate, and glutamate
residues appear slightly more hydrated and present a slight excess
of oppositely-charged solution components in their vicinity, whereas
salt-bridge formation properties between charged residues at the protein
surface, as assessed by probability distributions of interionic distances,
are largely equivalent in the GROMOS 54A7 and 54A8 force-field parameter
sets.
Collapse
Affiliation(s)
- Maria M Reif
- Institute for Molecular Modeling and Simulation, University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | | | | |
Collapse
|