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González-Barramuño B, Cea-Klapp E, Polishuk I, Quinteros-Lama H, Piñeiro MM, Garrido JM. Molecular Insights into the Wettability and Adsorption of Acid Gas-Water Mixture. J Phys Chem B 2024; 128:3764-3774. [PMID: 38576228 DOI: 10.1021/acs.jpcb.4c00592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Sequestration of acid gas in geological formations is a disposal method with potential economic and environmental benefits. The process is governed by variables such as gas-water interfacial tension, wetting transition, and gas adsorption into water, among other things. However, the influence of the pressure and temperature on these parameters is poorly understood. This study investigates these parameters using coarse-grained molecular dynamics (CG-MD) simulations and density gradient theory (DGT). Simulations were carried out at 313.15 K and a pressure range of 0-15 MPa. A comparison was made against H2S-water systems to clarify the effects of adsorption on interfacial tension due to vapor-liquid-liquid equilibrium. The predicted H2S-water interfacial tension and phase densities by CG-MD and DGT matched the experimental values well. The adsorption can be quantified via the Gibbs Adsorption function Γ12, which correlated well with the three-phase transition. On the one hand, pressure increments below the three-phase transition revealed a significant adsorption of H2S. On the other hand, above the three-phase transition, the Gibbs Adsorption capacity remained constant, which indicated a saturation of H2S at the water surface due to liquid-liquid equilibrium. Finally, H2S behaves markedly differently in wetting transition, rather than the involved for CO2 to different molecular layers beneath the surface of aqueous solutions. In this respect, H2S is represented by a first-order wetting transition while CO2 presents a critical wetting. Finally, it has also been found that the preferential adsorption of H2S over the H2O interface is greater if compared to that of CO2, due to its strong interaction with water. In fact, we have also demonstrated that CO2 under triphasic conditions strongly influences the wetting of the ternary system.
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Affiliation(s)
| | - Esteban Cea-Klapp
- Departamento de Ingeniería Química, Universidad de Concepción, 4070386 Concepción, Chile
| | - Ilya Polishuk
- Department of Chemical Engineering, Ariel University, 40700 Ariel, Israel
| | - Héctor Quinteros-Lama
- Departamento de Tecnologías Industriales, Universidad de Talca, Merced, 437 Curicó, Chile
| | - Manuel M Piñeiro
- Departamento de Física Aplicada, Universidade de Vigo, E36310 Vigo, España
| | - José Matías Garrido
- Departamento de Ingeniería Química, Universidad de Concepción, 4070386 Concepción, Chile
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2
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Hrahsheh F, Wilemski G. Effects of molecular size and orientation on the interfacial properties and wetting behavior of water/ n-alkane systems: a molecular-dynamics study. Phys Chem Chem Phys 2023; 25:5808-5816. [PMID: 36744733 DOI: 10.1039/d2cp05735b] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Molecular dynamics simulations (MD) are performed to study the interfacial structure/tension and wetting behavior of water/n-alkane systems (water/nC5 to water/nC16 where nCx = CxH(2x + 2)). In particular, we study complete-to-partial wetting transitions by changing the n-alkane chain length (NC) at a constant temperature, T = 295 K. Simulations are carried out with a united-atom TraPPE model for n-alkanes and the TIP4P-2005 model of water. Simulation results are in excellent agreement with the initial spreading coefficients and contact angles calculated using experimental values of the surface and interfacial tensions. In addition, it has been determined that water/(nC5-nC7) and water/(nC8-nC16), respectively, exhibit complete and partial initial wetting modes. Simulations show that the interfacial structures of water/(nC5-nC7) are different from water/(nC8-nC16) systems. In the latter, water preferentially orients near the interface to increase the number of hydrogen bonds and the charge and mass densities. Moreover, the orientation of n-alkane molecules at water/(nC8-nC16) interfaces has a long-range persistence, resulting in layered structures that increase with NC. In addition, simulation results of the orientational order parameter Sz show alignment behavior of the n-alkane molecules with respect to the interfaces. Simulations predict that the central segments of n-alkane are strongly packed in the interfaces while the end segments (methyl groups) form smaller peaks in the outer edge of the layer. This observation confirms the "horseshoe" or "C-shaped" structure of n-alkane molecules in the water/n-alkane interfaces. At constant temperature, the interface widths of both water and the n-alkanes decrease with increasing n-alkane molecular length. These results suggest that increasing the n-alkane chain length affects the water/n-alkane interfacial properties in a manner similar to that of cooling.
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Affiliation(s)
- Fawaz Hrahsheh
- Higher Colleges of Technology, ETS, MZWC, Abu Dhabi, 58855, United Arab Emirates.
| | - Gerald Wilemski
- Department of Physics, Missouri University of Science and Technology, Rolla, MO 65409, USA.
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Neupane P, Wilemski G. Molecular dynamics study of wetting of alkanes on water: from high temperature to the supercooled region and the influence of second inflection points of interfacial tensions. Phys Chem Chem Phys 2021; 23:14465-14476. [PMID: 34184020 DOI: 10.1039/d1cp01108a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To explore the wetting behavior of alkanes on bulk water interfaces, molecular dynamics (MD) simulations were carried out for united-atom PYS alkane models, and for SPC/E and TIP4P/2005 water models over a wide temperature range. The MD results at each temperature were used to find (1) the surface tension of the alkanes (octane, nonane) and water, and (2) the interfacial tensions of the alkane-water systems. These quantities were then used to calculate the spreading coefficient (S) and contact angle (θc) for each alkane on water. At higher temperatures, the contact angle of octane and nonane on water is found to behave in accord with conventional expectations, i.e., it decreases with increasing temperature for both water models as each system approaches the usual high-temperature transition to perfect wetting. At lower temperatures, we found an unusual temperature dependence of S and θc for each PYS alkane on SPC/E water. In contrast to conventional expectations, θc decreases with a decrease in the temperature. For octane-SPC/E water, this unusual behavior of θc occurs due to the presence of second inflection points (SIP) in the vapor-water and the octane-water interfacial tensions, whereas the SIP effect is much less important for the nonane-water system. The unusual temperature dependence of θc observed for nonane on SPC/E water is also found for nonane on TIP4P/2005 water. On the other hand, such unusual wetting behavior has not been observed in the PYS octane-TIP4P/2005 water system, except possibly for the two lowest temperatures studied.
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Affiliation(s)
- Pauf Neupane
- Department of Physics, Missouri University of Science and Technology, Rolla, MO 65409, USA.
| | - Gerald Wilemski
- Department of Physics, Missouri University of Science and Technology, Rolla, MO 65409, USA.
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4
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Alonso G, Chaparro G, Cartes M, Müller EA, Mejía A. Probing the Interfacial Behavior of Type IIIa Binary Mixtures Along the Three-Phase Line Employing Molecular Thermodynamics. Molecules 2020; 25:molecules25071499. [PMID: 32218362 PMCID: PMC7180757 DOI: 10.3390/molecules25071499] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 03/18/2020] [Accepted: 03/20/2020] [Indexed: 11/16/2022] Open
Abstract
Interfacial properties such as interfacial profiles, surface activity, wetting transitions, and interfacial tensions along the three-phase line are described for a Type IIIa binary mixture. The methodological approach combines the square gradient theory coupled to the statistical associating fluid theory for Mie potentials of variable range, and coarse-grained molecular dynamics simulations using the same underlying potential. The water + n-hexane mixture at three-phase equilibrium is chosen as a benchmark test case. The results show that the use of the same molecular representation for both the theory and the simulations provides a complementary picture of the aforementioned mixture, with an excellent agreement between the molecular models and the available experimental data. Interfacial tension calculations are extended to temperatures where experimental data are not available. From these extrapolations, it is possible to infer a first order wetting transition at 347.2 K, where hexane starts to completely wet the water/vapor interface. Similarly, the upper critical end point is estimated at 486.3 K. Both results show a very good agreement to the available experimental information. The concentration profiles confirm the wetting behavior of n-hexane along with a strong positive surface activity that increases with temperature, contrasting the weak positive surface activity of water that decreases with temperature.
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Affiliation(s)
- Gerard Alonso
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain;
| | - Gustavo Chaparro
- Departamento de Ingeniería Química, Universidad de Concepción POB 160–C, Concepción, Chile; (G.C.); (M.C.)
| | - Marcela Cartes
- Departamento de Ingeniería Química, Universidad de Concepción POB 160–C, Concepción, Chile; (G.C.); (M.C.)
| | - Erich A. Müller
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK;
| | - Andrés Mejía
- Departamento de Ingeniería Química, Universidad de Concepción POB 160–C, Concepción, Chile; (G.C.); (M.C.)
- Correspondence: ; Tel.: +56-412-203-897
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Feldman S, Raz E, Lipson SG. Phase-retrieval method for measuring small contact angles of pentane on water. APPLIED OPTICS 2019; 58:8577-8582. [PMID: 31873342 DOI: 10.1364/ao.58.008577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 10/08/2019] [Indexed: 06/10/2023]
Abstract
Pentane drops on a water surface are predicted to have contact angles of the order of 1 degree or less in the phase of frustrated complete wetting. We have developed an optical method of measuring such small contact angles, applicable to cases where the refractive indices of the substrate and adsorbate are very similar and the fluid dynamics do not allow delay between image acquisitions, by using phase retrieval to map the surface profile of the drops. It is empirically shown that, with our method, a difference of nanometer order can be achieved for the phase-retrieved dimensions relative to their expected value. Results agree with numerical predictions by Weiss and Widom [Physica A292, 137 (2001)PHYADX0378-437110.1016/S0378-4371(00)00619-1].
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Benet J, Llombart P, Sanz E, MacDowell LG. Structure and fluctuations of the premelted liquid film of ice at the triple point. Mol Phys 2019. [DOI: 10.1080/00268976.2019.1583388] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Jorge Benet
- Departamento de Química-Física (Unidad Asociada de I+D+i al CSIC), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid, Spain
| | - Pablo Llombart
- Departamento de Química-Física (Unidad Asociada de I+D+i al CSIC), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid, Spain
- Instituto de Química Física Rocasolano, CSIC, Madrid, Spain
| | - Eduardo Sanz
- Departamento de Química-Física (Unidad Asociada de I+D+i al CSIC), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid, Spain
| | - Luis G. MacDowell
- Departamento de Química-Física (Unidad Asociada de I+D+i al CSIC), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid, Spain
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7
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Effect of Lubricating Phase on Microstructure and Properties of Cu⁻Fe Friction Materials. MATERIALS 2019; 12:ma12020313. [PMID: 30669510 PMCID: PMC6356597 DOI: 10.3390/ma12020313] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/11/2019] [Accepted: 01/15/2019] [Indexed: 11/20/2022]
Abstract
Cu–Fe-based friction materials with flake graphite, granulated carbon black, and high-strength graphite as lubricating phase were prepared by the powder metallurgy method. The effects of different types and mass fraction of lubricating phase on the microstructure, mechanical properties, and tribological properties were investigated. The results show that when the mass fraction of granulated carbon black is 5 wt%, it is easy to form a good interface with the matrix, but the interface is prone to pores and cracks when its mass fraction is 10 wt%. The bending strength and compressive strength properties of the composites increased with increasing in the mass fraction of granulated carbon black and reached the maximum of 40 MPa and 70 MPa at 5 wt% granulated carbon black, after which bending strength and compressive strength all decreased. The friction coefficient and the wear loss of the materials initially decreased as the mass fraction of granulated carbon black increased and obtained minimum of 0.436 and 0.145 mm when the mass fraction of granulated carbon black was 5 wt%, then ascended. Compared with the sample with 5 wt% high-strength graphite as lubricating phase, the sample with 5 wt% granulated carbon black as lubricating phase had better sintering performance, mechanical properties, and tribological properties.
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8
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Diaz ME, Savage MD, Cerro RL. The effect of temperature on contact angles and wetting transitions for n -alkanes on PTFE. J Colloid Interface Sci 2017; 503:159-167. [DOI: 10.1016/j.jcis.2017.05.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/02/2017] [Accepted: 05/02/2017] [Indexed: 11/30/2022]
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9
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The interaction between stearic acid monolayers and butane under elevated pressures. Colloids Surf A Physicochem Eng Asp 2016. [DOI: 10.1016/j.colsurfa.2016.05.067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Müller EA, Mejía A. Resolving Discrepancies in the Measurements of the Interfacial Tension for the CO2 + H2O Mixture by Computer Simulation. J Phys Chem Lett 2014; 5:1267-71. [PMID: 26274482 DOI: 10.1021/jz500417w] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Literature values regarding the pressure dependence of the interfacial tension of the system of carbon dioxide (CO2) + water (H2O) show an unexplained divergence and scatter at the transition between low-pressure gas-liquid equilibrium and the high-pressure liquid-liquid equilibrium. We employ the Statistical Associating Fluid Theory (SAFT) and canonical molecular dynamics simulations based on the corresponding coarse grained force field to map out the phase diagram of the mixture and the interfacial tension for this system. We showcase how at ambient temperatures a triple point (gas-liquid-liquid) is expected and detail the implications that the appearance of the third phase has on the interfacial tensions of the system.
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Affiliation(s)
- Erich A Müller
- †Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Andrés Mejía
- ‡Departamento de Ingeniería Química, Universidad de Concepción, POB 160-C, Correo 3, Concepción, Chile
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11
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Matsubara H, Ushijima B, Law BM, Takiue T, Aratono M. Line tension of alkane lenses on aqueous surfactant solutions at phase transitions of coexisting interfaces. Adv Colloid Interface Sci 2014; 206:186-94. [PMID: 24007861 DOI: 10.1016/j.cis.2013.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 07/01/2013] [Accepted: 07/01/2013] [Indexed: 10/26/2022]
Abstract
Alkane droplets on aqueous solutions of surfactants exhibit a first-order wetting transition as the concentration of surfactant is increased. The low-concentration or "partial wetting" state corresponds to an oil lens in equilibrium with a two-dimensional dilute gas of oil and surfactant molecules. The high-concentration or "pseudo-partial wetting" state consists of an oil lens in equilibrium with a mixed monolayer of surfactant and oil. Depending on the combination of surfactant and oil, these mixed monolayers undergo a thermal phase transition upon cooling, either to a frozen mixed monolayer or to an unusual bilayer structure in which the upper leaflet is a solid layer of pure alkane with hexagonal packing and upright chains while the lower leaflet remains a disordered liquid-like mixed monolayer. Additionally, certain long-chain alkanes exhibit a surface freezing transition at the air-oil interface where the top monolayer of oil freezes above its melting point. In this review, we summarize our previous studies and discuss how these wetting and surface freezing transitions influence the line tension of oil lenses from both an experimental and theoretical perspective.
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12
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Jose BM, Cubaud T. Formation and dynamics of partially wetting droplets in square microchannels. RSC Adv 2014. [DOI: 10.1039/c4ra00654b] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Droplet motion and dynamic wetting transitions are experimentally investigated over a wide range of viscosities and flow rates in square microchannels
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Affiliation(s)
- Bibin M. Jose
- Department of Mechanical Engineering
- Stony Brook University
- , 11794 USA
| | - Thomas Cubaud
- Department of Mechanical Engineering
- Stony Brook University
- , 11794 USA
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13
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Abstract
The thin layers of a second phase (also called complexions) in grain boundaries (GB) and triple junctions (TJs) are more and more frequently observed in polycrystals. The prewetting (or premelting) phase transitions were the first phenomena proposed to explain their existence. The deficit of the wetting phase in case of complete wetting can also lead to the formation of thin GB and TJ phases. However, only the phenomenon of pseudopartial (or pseudoincomplete, or constrained complete) wetting permitted to explain, how the thin GB film can exist in the equilibrium with GB lenses of a second phase with non-zero contact angle.
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14
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Yi T, Wang Q, Lichter S. Conformations of a dipolar solute in a Stockmayer solvent channel. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15286-15293. [PMID: 23050989 DOI: 10.1021/la303252c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A wide range of molecules, from inorganic to biological, self-assemble on surfaces. Previous studies have elucidated many features of solute reorganization on surfaces using coarse-grained modeling, implicit solvents, and constraints such as chemically bonding the solute to the surface. Using molecular dynamics simulations under various combinations of interaction parameters, solute fractions, and solute dipole moment, we study the redistribution of freely-rotating dipolar solute molecules solvated by a water-like Stockmayer solvent initially adhered to a face-centered cubic substrate. The balance of attractive and repulsive forces is essential for acquiring a particular stable conformation. Here we show that the adsorbed molecules redistribute into different conformations--wetting film, nonwetting, partial wetting, and pseudopartial wetting drops--depending on the parameter values. We observe that the pseudopartial wetting drop is transient and its rate of spreading fluctuates, slowing to nearly zero as it passes through particular conformations before reaching an equilibrium thin film. Strong attraction between solute molecules yields a droplet with a net dipole moment. A high solute fraction leads to a pancake-like conformation arising from a balance of surface tension and van der Waals forces. This study augments our understanding of the evolution of aggregates in biological systems and also the design of polymers for self-assembled monolayers for industrial applications.
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Affiliation(s)
- Taeil Yi
- Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208, United States.
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Miqueu C, Míguez JM, Piñeiro MM, Lafitte T, Mendiboure B. Simultaneous Application of the Gradient Theory and Monte Carlo Molecular Simulation for the Investigation of Methane/Water Interfacial Properties. J Phys Chem B 2011; 115:9618-25. [DOI: 10.1021/jp202276k] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Christelle Miqueu
- Laboratoire des Fluides Complexes et leurs Réservoirs, UMR5150, Université de Pau et des Pays de L’Adour, B.P. 1155, Pau, Cedex 64013, France
| | - José M. Míguez
- Departamento de Física Aplicada, Facultade de Ciencias, Universidade de Vigo, 36310 Vigo, Spain
| | - Manuel M. Piñeiro
- Departamento de Física Aplicada, Facultade de Ciencias, Universidade de Vigo, 36310 Vigo, Spain
| | - Thomas Lafitte
- Laboratoire des Fluides Complexes et leurs Réservoirs, UMR5150, Université de Pau et des Pays de L’Adour, B.P. 1155, Pau, Cedex 64013, France
| | - Bruno Mendiboure
- Laboratoire des Fluides Complexes et leurs Réservoirs, UMR5150, Université de Pau et des Pays de L’Adour, B.P. 1155, Pau, Cedex 64013, France
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Biscay F, Ghoufi A, Malfreyt P. Adsorption of n-alkane vapours at the water surface. Phys Chem Chem Phys 2011; 13:11308-16. [DOI: 10.1039/c0cp02511a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Lafitte T, Mendiboure B, Piñeiro MM, Bessières D, Miqueu C. Interfacial Properties of Water/CO2: A Comprehensive Description through a Gradient Theory−SAFT-VR Mie Approach. J Phys Chem B 2010; 114:11110-6. [DOI: 10.1021/jp103292e] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Thomas Lafitte
- UMR 5150 - Laboratoire des Fluides Complexes, Université de Pau et des Pays de L’Adour, B.P. 1155, Pau, Cedex 64013, France, and Departamento de Física Aplicada, Facultade de Ciencias, Universidade de Vigo, 36310 Vigo, Spain
| | - Bruno Mendiboure
- UMR 5150 - Laboratoire des Fluides Complexes, Université de Pau et des Pays de L’Adour, B.P. 1155, Pau, Cedex 64013, France, and Departamento de Física Aplicada, Facultade de Ciencias, Universidade de Vigo, 36310 Vigo, Spain
| | - Manuel M. Piñeiro
- UMR 5150 - Laboratoire des Fluides Complexes, Université de Pau et des Pays de L’Adour, B.P. 1155, Pau, Cedex 64013, France, and Departamento de Física Aplicada, Facultade de Ciencias, Universidade de Vigo, 36310 Vigo, Spain
| | - David Bessières
- UMR 5150 - Laboratoire des Fluides Complexes, Université de Pau et des Pays de L’Adour, B.P. 1155, Pau, Cedex 64013, France, and Departamento de Física Aplicada, Facultade de Ciencias, Universidade de Vigo, 36310 Vigo, Spain
| | - Christelle Miqueu
- UMR 5150 - Laboratoire des Fluides Complexes, Université de Pau et des Pays de L’Adour, B.P. 1155, Pau, Cedex 64013, France, and Departamento de Física Aplicada, Facultade de Ciencias, Universidade de Vigo, 36310 Vigo, Spain
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20
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Matsubara H, Ohtomi E, Aratono M, Bain CD. Wetting and Freezing of Hexadecane on an Aqueous Surfactant Solution: Triple Point in a 2-D film. J Phys Chem B 2008; 112:11664-8. [DOI: 10.1021/jp802108v] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- H. Matsubara
- Department of Chemistry, University of Durham, South Road, Durham, DH1 3LE, United Kingdom and Department of Chemistry, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
| | - E. Ohtomi
- Department of Chemistry, University of Durham, South Road, Durham, DH1 3LE, United Kingdom and Department of Chemistry, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
| | - M. Aratono
- Department of Chemistry, University of Durham, South Road, Durham, DH1 3LE, United Kingdom and Department of Chemistry, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
| | - Colin D. Bain
- Department of Chemistry, University of Durham, South Road, Durham, DH1 3LE, United Kingdom and Department of Chemistry, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
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21
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Paulus M, Gutt C, Tolan M. The structure of the water–propane interface investigated by x-ray reflectivity measurements. SURF INTERFACE ANAL 2008. [DOI: 10.1002/sia.2851] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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22
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23
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Shah V, Broseta D. Predicting interfacial tension between water and nonpolar fluids from a Cahn-type theory. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:12598-12605. [PMID: 17973408 DOI: 10.1021/la701893z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We propose an accurate method to predict interfacial tension between water and nonpolar fluids by using Cahn gradient theory. The only necessary elements are (i) a water contact energy function and (ii) an equation of state (EoS) for the nonpolar fluid, chosen here as the Peng-Robinson EoS. The contact energy, a function of the fluid (adsorbate) surface density, is related to interfacial tension (IFT) by means of the Gibbs adsorption equation. Examining a large number of IFT data, we observe that the water contact energy is a universal function of adsorbate's surface density when proper scaling variables are used: it depends neither on adsorbate nor on temperature. A corresponding-states principle appears to govern the interfacial behavior between water and any nonpolar compound that is sparingly soluble in water. A predictive method (without any adjustable parameter) is therefore available for estimating IFT between water and any nonpolar fluid, whether the fluid is in supercritical or in subcritical states. The method performs well when the adsorbate is sparingly soluble in water, but slightly overestimates IFTs when the adsorbate's solubility in water is significant (e.g., CO2 and H2S). A similar behavior should also hold for interfaces involving a solid substrate.
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Affiliation(s)
- Virenkumar Shah
- Laboratoire des Fluides Complexes, UMR 5150, Université de Pau et des Pays de l'Adour, BP1155, 64013, Pau Cedex, France
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Kwon OS, Jing H, Shin K, Wang X, Satija SK. Formation of n-alkane layers at the vapor/water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:12249-12253. [PMID: 17956139 DOI: 10.1021/la702084e] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We present a study on the initial wetting behaviors of two low molecular weight alkanes, heptane and octane, at the vapor/water interface using both neutron and X-ray reflectometry. Combined X-ray and neutron reflectivity studies data showed that a uniform film, which has never been reported, was formed continuously at 25 degrees C. As the adsorptive deposition continued, each adsorbed film was saturated at a specific equilibrium thickness: 48 and 36 A for deuterated heptane and octane, respectively, and 21 A for hydrogenated octane. The thickness of the adsorbed layer measured by neutron reflectivity is in agreement with that measured using X-ray reflectivity. Our observations of continuous and saturated adsorption behaviors are analyzed qualitatively using a kinetic adsorption model.
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Affiliation(s)
- Oh-Sun Kwon
- Department of Chemistry and Program of Integrated Biotechnology, Sogang University, Shinsoo, Mapogu, Seoul, Korea
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25
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Weiss VC, Bertrand E, Rafaï S, Indekeu JO, Bonn D. Effective exponents in the long-range critical wetting of alkanes on aqueous substrates. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 76:051602. [PMID: 18233664 DOI: 10.1103/physreve.76.051602] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Indexed: 05/25/2023]
Abstract
Alkanes on water show a two-stage wetting transition. Upon raising the temperature, a first-order transition from a molecularly thin to a mesoscopically thick liquid film is followed by a continuous divergence of the film thickness. This second transition is brought about by long-range interactions between adsorbate and substrate and is, therefore, referred to as long-range critical wetting. The divergence of the film thickness is theoretically expected to occur according to the asymptotic power law l approximately (Tw,c-T)betas, with betas=-1. This value has indeed been found for pentane on pure water; however, for hexane on salt solutions of different concentrations, betas=-0.73 was found for a 1.5M solution of NaCl and betas=-0.57 for a 2.5M salt solution. In addition, for hexane on a 2.5M solution of NaCl, an exponent of alphas=0.1 was found from contact-angle measurements, differing greatly from the theoretically expected value of alphas=-1. Using Dzyaloshinskii-Lifshitz-Pitaevskii theory, we calculate effective local exponents in order to explain the experimental findings. Taking into account the uncertainty of the exponents derived from experiments as well as the temperature range in which the measurements were carried out, a reasonable agreement between theory and experiment is found, thereby providing a consistent approach to resolving the apparently anomalous behavior of hexane on brine. The experimentally observed exponents betas=-0.57 and alphas=0.1 are also compatible with a long-range tricritical wetting transition, which is characterized by betas=-1/2 and alphas=0; this alternative explanation of the experimental findings is neither supported nor completely ruled out by our calculations.
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Affiliation(s)
- Volker C Weiss
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, Petersenstrasse 20, 64287 Darmstadt, Germany.
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26
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Yi T, Wong H. Theory of slope-dependent disjoining pressure with application to Lennard–Jones liquid films. J Colloid Interface Sci 2007; 313:579-91. [PMID: 17570389 DOI: 10.1016/j.jcis.2007.05.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Revised: 04/22/2007] [Accepted: 05/04/2007] [Indexed: 11/27/2022]
Abstract
A liquid film of thickness h<100 nm is subject to additional intermolecular forces, which are collectively called disjoining pressure Pi. Since Pi dominates at small film thicknesses, it determines the stability and wettability of thin films. Current theory derived for uniform films gives Pi=Pi(h). This solution has been applied recently to non-uniform films and becomes unbounded near a contact line as h-->0. Consequently, many different effects have been considered to eliminate or circumvent this singularity. We present a mean-field theory of Pi that depends on the slope h(x) as well as the height h of the film. When this theory is implemented for Lennard-Jones liquid films, the new Pi=Pi(h,h(x)) is bounded near a contact line as h-->0. Thus, the singularity in Pi(h) is artificial because it results from extending a theory beyond its range of validity. We also show that the new Pi can capture all three regimes of drop behavior (complete wetting, partial wetting, and pseudo-partial wetting) without altering the signs of the long and short-range interactions. We find that a drop with a precursor film is linearly stable.
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Affiliation(s)
- Taeil Yi
- Department of Mechanical Engineering, Louisiana State University, Baton Rouge, LA 70803, USA
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27
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Macdowell LG, Müller M. Adsorption of polymers on a brush: Tuning the order of the wetting phase transition. J Chem Phys 2007; 124:084907. [PMID: 16512742 DOI: 10.1063/1.2172597] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We develop a computational methodology for the direct measurement of a wetting transition and its order via the effective interface potential. The method also allows to estimate contact angles in the nonwet state and to study adsorption isotherms. The proposed methodology is employed in order to study the wetting behavior of polymers on top of a brush consisting of identical polymers. In the absence of long-range forces, the system shows a sequence of nonwet, wet, and nonwet states as the brush density is increased. Including attractive long-range interactions we can make the polymer liquid wet the bush at all grafting densities, and both first- and second-order wetting transitions are observed. The latter case is limited to a small interval of grafting densities where the melt wets the brush in the absence of long-range interactions. Second-order wetting transitions are preceded by a first-order surface transition from a thin to a thick adsorbed layer. The interval of second-order wetting transitions is limited at low grafting densities by a surface critical end point and at high grafting densities by a tricritical wetting point. Our study highlights the rich wetting behavior that results when competing adsorbent-substrate interactions of different scales are tuned over a broad range.
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Affiliation(s)
- Luis G Macdowell
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain.
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28
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Cheng Y, Ye X, Huang XD, Ma HR. Reentrant wetting transition on surfactant solution surfaces. J Chem Phys 2006; 125:164709. [PMID: 17092122 DOI: 10.1063/1.2360941] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The wetting of polydimethylsiloxane oil drops on the surfaces of anionic surfactant sodium dodecylsulfate solutions is studied systematically by changing the bulk surfactant concentration. The wetting state changes from complete wetting to pseudopartial wetting at 0.3 cmc (critical micelle concentration) surfactant concentration and there is a reentrant transition back to complete wetting at 1.4 cmc. The measured free energy is consistent with the prediction of the wetting theory. The interaction potential minimum of the two surfaces of the oil film disappears at the reentrant point, which is speculated to be an effect of micelle formation in the solution.
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Affiliation(s)
- Y Cheng
- Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, China
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29
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Weiss VC. Theoretical description of the adsorption and the wetting behavior of alkanes on water. J Chem Phys 2006; 125:084718. [PMID: 16965050 DOI: 10.1063/1.2338806] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The wetting behavior of alkanes of medium chain length (e.g., pentane, hexane, and heptane) on water is more complex than the usually observed first-order wetting transition from partial to complete wetting by showing a sequence of two transitions. In this sequential-wetting scenario, a first-order transition from a microscopically thin to a mesoscopically thick layer of liquid on the substrate surface is followed by a continuous divergence of the film thickness upon increase of the temperature. This critical transition to complete wetting at T(w,c) is solely determined by long-range interactions between substrate and adsorbate, which are well-described by Dzyaloshinskii-Lifshitz-Pitaevskii [Adv. Phys. 10, 165 (1961)] theory in terms of the static dielectric constants and the refractive indices of the media involved. The first-order thin-thick transition, however, which occurs at a lower temperature T(w,1), results from an interplay of short-range and long-range forces and is notoriously more difficult to describe because a satisfactory theory of the short-range interactions between substrate and adsorbate is still missing. The approach presented in this paper attempts to account for the short-range interactions in an effective way: Within a Cahn-type [J. Chem. Phys. 66, 3667 (1977)] theory that has been augmented for long-range interactions and modified to treat the first layer of adsorbed molecules in a lattice-gas approach, the contact energy is deduced from the surface pressure, which in turn is calculated using a two-dimensional van der Waals equation of state and an expression for the Henry's law constant that was derived by Hirasaki [J. Adhes. Sci. Technol. 7, 285 (1993)]. The method uses only the dielectric properties of the isolated bulk media and simple assumptions on the size and the shape of the adsorbed alkane molecules and leads to satisfactory results for the transition temperatures T(w,1) and T(w,c).
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Affiliation(s)
- Volker C Weiss
- School of Engineering and Science, International University Bremen, P.O. Box 750561, 28725 Bremen, Germany.
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30
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Wilkinson KM, Bain CD, Matsubara H, Aratono M. Wetting of surfactant solutions by alkanes. Chemphyschem 2006; 6:547-55. [PMID: 15799482 DOI: 10.1002/cphc.200400514] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Ellipsometry, surface tensiometry, and contact-angle measurement have been used to study the transition between partial wetting and pseudo-partial wetting of surfactant solutions by alkanes. In the partial wetting regime, the air-water surface tension is the same with and without alkane. In the pseudo-partial wetting regime, the air-water surface tension is lowered by the presence of alkane, showing that oil is solubilised into the surfactant monolayer. A discontinuous change in the coefficient of ellipticity with increasing surfactant concentration provides unequivocal evidence for the first-order nature of the wetting transitions. Ellipsometry has been used to explore the generality of wetting transitions of alkanes (dodecane, hexadecane, and squalane) on surfactant solutions [dodecyltrimethylammonium bromide, tetredecyltrimethylammonium bromide, dibucaine hydrochloride, and Aerosol OT (AOT)]. Of the systems studied, only hexadecane on AOT solutions did not show a wetting transition. Excess alkane remains as a lens on the surface of the surfactant solutions at all concentrations, but the contact angle is a minimum at the wetting transition. A semiquantitative model for the variation of the contact angle with surfactant concentration is provided.
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Affiliation(s)
- Katherine M Wilkinson
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, United Kingdom
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31
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Wu CK, Chen LJ. The Pressure- and Temperature-Induced Wetting Transitions in the Binary Water + Ethylene Glycol Monoisobutyl Ether Mixture. J Phys Chem B 2006; 110:11907-11. [PMID: 16800493 DOI: 10.1021/jp061093v] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A homemade pendent drop/bubble tensiometer is applied to perform the surface/interfacial tension measurements for the binary water + ethylene glycol monoisobutyl ether (iso-C4E1) mixture over the temperature range from 25 to 150 degrees C and over the pressure range up to 100 bar. The symbol C(i)E(j) is the abbreviation of a nonionic polyoxyethylene alcohol C(i)H(2i+1)(OCH2CH2)(j)OH. The wetting behavior of the iso-C4E1-rich phase at the surface of the aqueous phase is systematically examined according to the wetting coefficient determined from the experimental results of surface/interfacial tensions. It is found that the iso-C4E1-rich phase exhibits a sequence of wetting transitions, nonwetting --> partial wetting --> complete wetting, at the water surface in the water + iso-C4E1 system along with increasing temperature. On the other hand, the iso-C4E1-rich phase undergoes a wetting transition from partial wetting to nonwetting at the surface of the aqueous phase by increasing the system pressure at a fixed temperature near the lower critical solution temperature (LCST) of the closed-loop miscibility gap in the water + iso-C4E1 system.
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Affiliation(s)
- Chih-Kang Wu
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
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32
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Forsman J, Woodward CE. Surface transition in athermal polymer solutions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 73:051803. [PMID: 16802959 DOI: 10.1103/physreve.73.051803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Indexed: 05/10/2023]
Abstract
According to a recently developed density functional theory, athermal polymer solutions, in which the solvent particles are smaller than the monomers, may undergo a bulk fluid-fluid phase separation, driven by excluded volume effects. In recent work, we showed that an inert surface immersed in the dilute polymer phase can, in principle, be wetted by the condensed phase. However, we show here that the "prewetting transition" we assumed in our earlier studies is in fact a different type of surface transition. Rather than completely wet the surface at coexistence, the condensed phase layer which forms in the presence of the dilute bulk remains globally stable (and is finite in width) even as the bulk coexistence conditions are approached. Hence, the adsorbed phase inhibits complete wetting of the surface by the dilute phase. The surface transition is first order for the systems we study here and, for longer polymers, the surface phase coexistence line meets the bulk coexistence curve nontangentially to give rise to a lower transition point. For short polymers, we find that the surface transition can occur for a supercritical bulk. We develop a simple one-component thermal model, which displays analogous behavior at an adsorbing surface and provides us with some insight into the qualitative mechanisms responsible.
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Affiliation(s)
- Jan Forsman
- Theoretical Chemistry, P.O. Box 124, 221 00 Lund, Sweden.
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33
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Chen CM, Yeh MC, Chen LJ. Bulk and Interfacial Wetting Behavior of Binary Mixtures Induced by Associating between Unlike-Pair Molecules. J Phys Chem B 2006; 110:3294-301. [PMID: 16494343 DOI: 10.1021/jp056314w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The statistical associating fluid theory of Wertheim is applied to describe binary mixtures with associating between unlike-pair molecules. The phase behavior of this binary mixture would fall into five different types (I, II, III, V, and VI) of the classification scheme of van Konynenburg and Scott by varying the associating strength and the energy parameters. Both interfacial wetting behavior and wetting transitions are carefully examined in all the vapor-liquid-liquid (gamma-beta-alpha) three-phase-coexisting regions of the binary mixtures. The global wetting behavior and wetting transitions are delineated by scanning the parameter space. In certain regions, the middle beta phase exhibits interfacial phase transitions sequentially, nonwetting --> partial-wetting --> nonwetting, at the interface separating lower alpha and upper gamma phases along with increasing temperature.
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Affiliation(s)
- Chia-Ming Chen
- Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan 10617, Republic of China
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34
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Matsubara H, Aratono M, Wilkinson KM, Bain CD. Lattice model for the wetting transition of alkanes on aqueous surfactant solutions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:982-8. [PMID: 16430257 DOI: 10.1021/la052632a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Droplets of alkanes on aqueous solutions of the cationic surfactants C(n)TAB (CH3(CH2)(n-1)N+ (CH3)3Br-) exhibit a first-order wetting transition as the concentration of the surfactant is increased. A theoretical model is presented in which the surface free energy is broken down into a long-range dispersion interaction and a short-range interaction described by a 2D lattice gas, taking into account the interaction between oil and surfactant molecules. The model provides quantitative agreement with the observed wetting transitions and the variation in composition of the wetting film with bulk surfactant concentration. The behavior of oil drops on large reservoirs of dilute surfactant is discussed.
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Affiliation(s)
- H Matsubara
- Department of Chemistry, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
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35
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Wu J. Density functional theory for chemical engineering: From capillarity to soft materials. AIChE J 2006. [DOI: 10.1002/aic.10713] [Citation(s) in RCA: 299] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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36
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McNamee CE, Jaumann M, Möller M, Ding A, Hemeltjen S, Ebert S, Baumann W, Goedel WA. Formation of a freely suspended membrane via a combination of interfacial reaction and wetting. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:10475-80. [PMID: 16262308 DOI: 10.1021/la0509089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Applying poly(ethoxysiloxane) (a liquid non-water-soluble polymer that can be hydrolyzed and cross-linked by diluted acids) to an air/pH 1 water interface gave rise to thin homogeneous solid layers. These layers were strong enough to be transferable to electron microscopy grids with holes of dimensions up to 150 microm and covered the holes as freely suspended membranes. No homogeneous layers were formed at an air/pH 5 water interface. Brewster angle microscopy images show that the poly(ethoxysiloxane) is not spontaneously forming a wetting layer on water. It initially forms lenses, which slowly spread out within several hours. We conclude that the spreading occurs simultaneously with the hydrolysis and cross-linking of the poly(ethoxysiloxane) and that the reaction products finally assist the complete wetting of the water surface.
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Affiliation(s)
- Cathy E McNamee
- Organic and Macromolecular Chemistry, OC3, The University of Ulm
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37
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Wu CK, Chen LJ. Wetting behavior of mixtures of water and nonionic polyoxyethylene alcohol. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:6883-90. [PMID: 16008400 DOI: 10.1021/la050691i] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Five binary water + C4Ej mixtures, water + n-C4E0, water + 2-C4E0, water + iso-C4E0, water + n-C4E1, and water + iso-C4E1, were chosen to perform the surface/interfacial tension measurements over the experimental temperature range from 10 to 85 degrees C at the normal pressure by using a homemade pendent drop/bubble tensiometer. The symbol CiEj is the abbreviation of a nonionic polyoxyethylene alcohol CiH(2i+1)(OCH2CH2)jOH. The wetting behavior of the CiEj-rich phase at the interface separating gas and the aqueous phase is systematically examined according to the wetting coefficient resulting from the experimental data of surface/interfacial tensions measurements. For those systems with a lower critical solution temperature, for example, water + n-C6E2, water + n-C4E1, and water + iso-C4E1, a wetting transition from partial wetting to nonwetting is always observed when the system is brought to close to its lower critical solution temperature. On the other hand, to start with a partial wetting CiEj-rich phase, a wetting transition from partial wetting to complete wetting is always observed when the system is driven to approach its upper critical solution temperature. The effect of hydrophobicity of CiEj on the wetting behavior of the CiEj-rich phase at the interface separating gas and the aqueous phase was carefully investigated by using five sets of mixtures: (1) water + n-C4E0, water + n-C5E0, and water + n-C6E0; (2) water + 2-C4E0 and water + 2-C5E0; (3) water + 2-C4E0 and water + n-C4E0; (4) water + n-C4E1, water + n-C5E1, and water + n-C6E1; (5) water + n-C4E0 and water + n-C4E1. The CiEj-rich phase would tend to drive away from complete wetting (or nonwetting) to partial wetting with an increase in the hydrophobicity of CiEj in the binary water + CiEj system. All the wetting behavior observed in the water + CiEj mixtures is consistent with the prediction of the critical point wetting theory of Cahn.
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Affiliation(s)
- Chih-Kang Wu
- Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan 10617, Republic of China
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38
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Bonn D, Meunier J, Indekeu J. Comment on pseudopartial wetting and precursor film growth in immiscible metal systems. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:3722-3724. [PMID: 15807625 DOI: 10.1021/la040104d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Affiliation(s)
- Daniel Bonn
- Laboratoire de Physique Statistique de l'ENS, UMR 8550 du CNRS, associe aux Universites Paris VI et Paris VII, 24 rue Lhomond, 75231 Paris Cedex 05, France
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39
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Rafaï S, Bonn D, Bertrand E, Meunier J, Weiss VC, Indekeu JO. Long-range critical wetting: observation of a critical end point. PHYSICAL REVIEW LETTERS 2004; 92:245701. [PMID: 15245104 DOI: 10.1103/physrevlett.92.245701] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2004] [Indexed: 05/24/2023]
Abstract
Alkanes deposited on aqueous substrates exhibit two different types of wetting behavior: alternatively to the usual first-order wetting transition, a sequential-wetting scenario of a long-range critical wetting transition preceded by a first-order thin-thick transition may be observed. Here, we present the first successful experimental attempt to locate the transition point between the standard first-order wetting and the long-range critical wetting: a critical end point, observed in a mixture of pentane and hexane which is deposited on an aqueous solution of glucose. Furthermore, we present the first direct measurement of the contact angle in the intermediate wetting state (frustrated-complete wetting) in the sequential-wetting scenario of hexane on brine and compare to theoretical predictions.
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Affiliation(s)
- Salima Rafaï
- Laboratoire de Physique Statistique, 24 rue Lhomond, 75231 Paris Cedex 05, France
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40
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Weiss VC, Indekeu JO. Effect of ion hydration on the first-order transition in the sequential wetting of hexane on brine. J Chem Phys 2003. [DOI: 10.1063/1.1573172] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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41
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Yeh MC, Chen LJ. Density functional approach on wetting behavior of binary associating mixtures. J Chem Phys 2003. [DOI: 10.1063/1.1565327] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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42
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Schilling T, Gompper G. Wetting in ternary mixtures—with and without amphiphiles. J Chem Phys 2002. [DOI: 10.1063/1.1502242] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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43
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Wetting of hydrocarbon liquid surfaces by fluorocarbon vapor: a microscopic study. Colloids Surf A Physicochem Eng Asp 2002. [DOI: 10.1016/s0927-7757(02)00087-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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44
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Müller M, MacDowell LG, Müller-Buschbaum P, Wunnike O, Stamm M. Nano-dewetting: Interplay between van der Waals- and short-ranged interactions. J Chem Phys 2001. [DOI: 10.1063/1.1413985] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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45
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Yeh MC, Chen LJ. Wetting transitions at the air–liquid interface of water+tetradecane+C6E2 mixtures. J Chem Phys 2001. [DOI: 10.1063/1.1410898] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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46
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Shahidzadeh N, Bonn D, Meunier J, Mavon A. Wetting of biological lipids on aqueous substrates. PHYSICAL REVIEW E 2001; 64:021911. [PMID: 11497624 DOI: 10.1103/physreve.64.021911] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2000] [Revised: 03/28/2001] [Indexed: 11/07/2022]
Abstract
We study the dynamics and final wetting state of skin lipids on water and brine by fluorescence microscopy and ellipsometry. When a lipid droplet is brought into contact with the water surface, a lipid wetting film spreads out rapidly by a Marangoni effect. Subsequently, this film undergoes a dewetting instability. However, the final equilibrium is not partial wetting. The film breaks up into droplets with a mesoscopic (approximately 50 A) film in between. These observations result from a subtle interplay between short- and long-range forces: surfactants naturally present in the lipids favor wetting, while the van der Waals forces oppose it. In addition, this reveals the likely organization of the hydrolipid film that covers and protects the skin.
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Affiliation(s)
- N Shahidzadeh
- Laboratoire de Physique Statistique de l'Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France
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47
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Schulz J, Bowers J, Findenegg GH. Crossover from Preferential Adsorption to Depletion: Aqueous Systems of Short-Chain CnEm Amphiphiles at Liquid/Liquid Interfaces. J Phys Chem B 2001. [DOI: 10.1021/jp010616q] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jens Schulz
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Technische Universität Berlin, Strasse des 17. Juni 112, D-10623 Berlin, Germany
| | - James Bowers
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Technische Universität Berlin, Strasse des 17. Juni 112, D-10623 Berlin, Germany
| | - Gerhard H. Findenegg
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Technische Universität Berlin, Strasse des 17. Juni 112, D-10623 Berlin, Germany
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Bertrand E, Bonn D, Meunier J, Segal D. Wetting of alkanes on water. PHYSICAL REVIEW LETTERS 2001; 86:3208. [PMID: 11290147 DOI: 10.1103/physrevlett.86.3208] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2000] [Indexed: 05/23/2023]
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Ross D, Bonn D, Meunier J. Wetting of methanol on the n-alkanes: Observation of short-range critical wetting. J Chem Phys 2001. [DOI: 10.1063/1.1338124] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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