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Gustavsson L, Peng B, Plamont R, Ikkala O. Propulsion of zwitterionic surfactant-stabilized water-in-oil droplets by low electric fields. Chem Commun (Camb) 2024; 60:4467-4470. [PMID: 38563781 PMCID: PMC11025442 DOI: 10.1039/d3cc05464k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 03/15/2024] [Indexed: 04/04/2024]
Abstract
We show directional and controllable propulsion of zwitterionic surfactant-stabilized water-in-oil droplets driven by low electric fields. Our results suggest that the propulsion mechanism is based on stimulus-responsive on-demand interfacial phenomena.
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Affiliation(s)
- Lotta Gustavsson
- Department of Applied Physics, Aalto University, Espoo FI-02150, Finland.
- Center of Excellence in Life Inspired Hybrid Materials (LIBER), Finland
| | - Bo Peng
- Department of Applied Physics, Aalto University, Espoo FI-02150, Finland.
- Center of Excellence in Life Inspired Hybrid Materials (LIBER), Finland
| | - Rémi Plamont
- Department of Applied Physics, Aalto University, Espoo FI-02150, Finland.
- Center of Excellence in Life Inspired Hybrid Materials (LIBER), Finland
- Institut Charles Sadron - CNRS - UPR22, BP 84047, Strasbourg 67034 Cedex 2, France.
| | - Olli Ikkala
- Department of Applied Physics, Aalto University, Espoo FI-02150, Finland.
- Center of Excellence in Life Inspired Hybrid Materials (LIBER), Finland
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Colón-Quintana G, Dick JE. Voltage-driven ion flux promotes emulsification at the water|oil interface. MATERIALS HORIZONS 2023; 10:4986-4991. [PMID: 37622282 PMCID: PMC10914326 DOI: 10.1039/d3mh00334e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Emulsions are critical across a vast range of industries. Generally, emulsion synthesis is a complicated chemical process, requiring many mixed-phase systems. Here, we demonstrate that the flux of ions across the oil|water interface induces emulsification. Ion flux is achieved by a voltage-driven process, where an anode and a cathode are placed in each phase. When a current density of 2 mA cm-2 is reached across the interface, emulsification occurs. We demonstrate that emulsification can be tuned to occur in both phases, depending on the ions present. Droplet sizes are on the order of hundreds of nm and are stable for over an hour even without purposefully added surfactant. We demonstrate qualitative control over droplet size and charge based on salt content, current densities, and polarity of the interface. The process is 1000 times less energetic than ultrasonication. Our results introduce a robust and low-energy means of nanodroplet dispersion without the use of more than two phases and complex phase-transfer agents.
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Affiliation(s)
| | - Jeffrey E Dick
- Department of Chemistry, Purdue University, West Lafayette, IN, 47906, USA.
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, 47907, USA
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Ullmann K, Fachet L, Nirschl H, Leneweit G. Monolayer/Bilayer Equilibrium of Phospholipids in Gel or Liquid States: Interfacial Adsorption via Monomer or Liposome Diffusion? Gels 2023; 9:803. [PMID: 37888376 PMCID: PMC10606027 DOI: 10.3390/gels9100803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 09/25/2023] [Accepted: 09/30/2023] [Indexed: 10/28/2023] Open
Abstract
Phospholipids (PLs) are widely used in the pharma industry and a better understanding of their behavior under different conditions is helpful for applications such as their use as medical transporters. The transition temperature Tm affects the lipid conformation and the interfacial tension between perfluoroperhydrophenanthrene (PFP) and an aqueous suspension of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), 1,2-distearoyl-sn-glycero-3-phosphatidylcholine (DSPC), as well as a mixture of these PLs with cholesterol. Interfacial tensions were measured with the Du Noüy ring at quasi-equilibrium; the area per molecule was calculated according to the Gibbsian approach and a time-dependent tension gradient. Results show that the time tε to reach quasi-equilibrium was shorter when the temperature was above Tm, indicating a faster adsorption process (tε,DPPC,36 °C = 48 h, tε,DPPC,48 °C = 24 h) for PL in the liquid crystalline state than in the gel state (T < Tm). In addition, concentration-dependent results of the interfacial tension revealed that above the respective Tm and at all concentrations c > 0.1 mM, the average minimum interfacial tension for DPPC and DSPC (14.1 mN/m and 15.3 mN/m) does not differ significantly between those two lipids. Equilibrium between monolayers and bilayers shows that for T < Tm, surface pressures ∏ ≈ 31 mN/m are reached while for T > Tm, ∏ ≈ 41 mN/m. Mixtures with cholesterol only reach ∏ ≤ 31 mN/m Tm, with no significant difference between the two PLs. The higher interfacial tension of the mixture indicates stabilization of the liposomal conformation in the aqueous phase by the addition of cholesterol. The high diffusion coefficients show that adsorption is mainly based on liposomes.
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Affiliation(s)
- Kirsten Ullmann
- Karlsruhe Institute of Technology (KIT), Department of Mechanical Process Engineering and Mechanics, Straße am Forum 8, 76131 Karlsruhe, Germany;
| | - Lea Fachet
- Independent Researcher, 76131 Karlsruhe, Germany
| | - Hermann Nirschl
- Karlsruhe Institute of Technology (KIT), Department of Mechanical Process Engineering and Mechanics, Straße am Forum 8, 76131 Karlsruhe, Germany;
| | - Gero Leneweit
- Carl Gustav Carus-Institute, Association for the Promotion of Cancer Therapy, Allmendstr. 55, 75223 Niefern-Oeschelbronn, Germany
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Langmuir-Blodgett transfer from the oil-water interface. J Colloid Interface Sci 2023; 630:21-27. [DOI: 10.1016/j.jcis.2022.10.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 09/23/2022] [Accepted: 10/14/2022] [Indexed: 11/21/2022]
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Hildebrandt E, Sommerling JH, Guthausen G, Zick K, Stürmer J, Nirschl H, Leneweit G. Phospholipid adsorption at oil in water versus water in oil interfaces: Implications for interfacial densities and bulk solubilities. Colloids Surf A Physicochem Eng Asp 2016. [DOI: 10.1016/j.colsurfa.2015.12.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Hazell G, Gee AP, Arnold T, Edler KJ, Lewis SE. Langmuir monolayers composed of single and double tail sulfobetaine lipids. J Colloid Interface Sci 2016; 474:190-8. [DOI: 10.1016/j.jcis.2016.04.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/13/2016] [Accepted: 04/14/2016] [Indexed: 11/16/2022]
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Eftimov P, Yokoi N, Tonchev V, Nencheva Y, Georgiev GA. Surface properties and exponential stress relaxations of mammalian meibum films. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2016; 46:129-140. [DOI: 10.1007/s00249-016-1146-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 05/25/2016] [Accepted: 06/01/2016] [Indexed: 02/06/2023]
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Hildebrandt E, Dessy A, Sommerling JH, Guthausen G, Nirschl H, Leneweit G. Interactions between Phospholipids and Organic Phases: Insights into Lipoproteins and Nanoemulsions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:5821-5829. [PMID: 27159619 DOI: 10.1021/acs.langmuir.6b00978] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The adsorption of phosphatidylcholines (PCs), dissolved in squalene or squalane as an organic phase, was studied at the interface with water. Using profile analysis tensiometry, the equilibrium adsorption isotherms, minimum molecular interfacial areas, and solubility limits were derived. For squalene, differences in PC solubility and interfacial adsorption were found, depending on PC saturation. Compared to saturated PCs, unsaturated PCs showed a 3-fold-lower interfacial density but up to a 28-fold-higher critical aggregation concentration (CAC). In addition, the solubility limit of unsaturated PC in squalene and in its saturated form squalane diverged by a factor of 739. These findings provided evidence for steric repulsion or π-π interactions of π bonds in both solvent and solute or both effects acting complementarily. In squalane, low solubilities but high interfacial densities were found for all investigated PCs. Changes in fatty acid chain lengths showed that the influence of the increases in entropy and enthalpy on solubility is much smaller than solvent/solute interactions. Oxidation products of squalene lowered the interfacial tension, but increasing concentrations of PC expelled them from the interface. The CAC of saturated PC was increased by oxidation products of squalene whereas that of unsaturated PCs was not. Our findings indicate that the oxidation of triglycerides in lipoprotein cores can lead to increased solubility of saturated phospholipids covering the lipoproteins, contributing to destabilization, coalescence, and terminally the formation of atherosclerotic plaques. The consideration of solvent/solute interactions in molecular modeling may contribute to the interfacial tension and the corresponding kinetic or thermodynamic stability of lipoproteins. Measured areas per molecule prove that PCs form monolayers of different interfacial densities at the squalene/water interface but multilayers at the squalane/water interface. These findings showed that combinations of solvent or solute saturation affect the outcome for nanoemulsions forming either expanded or condensed monolayers or multilayers.
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Affiliation(s)
- Ellen Hildebrandt
- Karlsruhe Institute of Technology (KIT), Institute of Mechanical Process Engineering and Mechanics , 76131 Karlsruhe, Germany
- Abnoba GmbH, 75177 Pforzheim, Germany
| | | | - Jan-Hendrik Sommerling
- Karlsruhe Institute of Technology (KIT), Institute of Mechanical Process Engineering and Mechanics , 76131 Karlsruhe, Germany
- Abnoba GmbH, 75177 Pforzheim, Germany
| | - Gisela Guthausen
- Karlsruhe Institute of Technology (KIT), Institute of Mechanical Process Engineering and Mechanics , 76131 Karlsruhe, Germany
| | - Hermann Nirschl
- Karlsruhe Institute of Technology (KIT), Institute of Mechanical Process Engineering and Mechanics , 76131 Karlsruhe, Germany
| | - Gero Leneweit
- Abnoba GmbH, 75177 Pforzheim, Germany
- Carl Gustav Carus-Institute, Association for the Promotion of Cancer Therapy , 75223 Niefern-Oeschelbronn, Germany
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Venkatesan GA, Sarles SA. Droplet immobilization within a polymeric organogel improves lipid bilayer durability and portability. LAB ON A CHIP 2016; 16:2116-2125. [PMID: 27164314 DOI: 10.1039/c6lc00391e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The droplet interface bilayer (DIB) is a promising technique for assembling lipid membrane-based materials and devices using water droplets in oil, but it has largely been limited to laboratory environments due to its liquid construction. With a vision to transform this lab-based technique into a more-durable embodiment, we investigate the use of a polymer-based organogel to encapsulate DIBs within a more-solid material matrix to improve their handling and portability. Specifically, a temperature-sensitive organogel formed from hexadecane and poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) triblock copolymer is used to replace the liquid solvent that surrounds the lipid-coated droplets to establish a novel liquid-in-gel DIB system. Through specific capacitance measurements and single-channel recordings of the pore forming peptide alamethicin, we verify that the structural and functional membrane properties are retained when DIBs are assembled within SEBS organogel. In addition, we demonstrate that organogel encapsulation offers improved handling of droplets and yields DIBs with a near 3× higher bilayer durability, as quantified by the lateral acceleration required to rupture the membrane, compared to liquid-in-liquid DIBs in oil. This encapsulated DIB system provides a barrier against contamination from the environment and offers a new material platform for supporting multilayered DIB-based devices as well as other digital microfluidic systems that feature water droplets in oil.
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Affiliation(s)
- Guru A Venkatesan
- Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee, 1512 Middle Drive, 414 Dougherty Engineering Building, Knoxville, TN 37996, USA.
| | - Stephen A Sarles
- Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee, 1512 Middle Drive, 414 Dougherty Engineering Building, Knoxville, TN 37996, USA.
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Venkatesan GA, Lee J, Farimani AB, Heiranian M, Collier CP, Aluru NR, Sarles SA. Adsorption Kinetics Dictate Monolayer Self-Assembly for Both Lipid-In and Lipid-Out Approaches to Droplet Interface Bilayer Formation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:12883-12893. [PMID: 26556227 DOI: 10.1021/acs.langmuir.5b02293] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The droplet interface bilayer (DIB)--a method to assemble planar lipid bilayer membranes between lipid-coated aqueous droplets--has gained popularity among researchers in many fields. Well-packed lipid monolayer on aqueous droplet-oil interfaces is a prerequisite for successfully assembling DIBs. Such monolayers can be achieved by two different techniques: "lipid-in", in which phospholipids in the form of liposomes are placed in water, and "lipid-out", in which phospholipids are placed in oil as inverse micelles. While both approaches are capable of monolayer assembly needed for bilayer formation, droplet pairs assembled with these two techniques require significantly different incubation periods and exhibit different success rates for bilayer formation. In this study, we combine experimental interfacial tension measurements with molecular dynamics simulations of phospholipids (DPhPC and DOPC) assembled from water and oil origins to understand the differences in kinetics of monolayer formation. With the results from simulations and by using a simplified model to analyze dynamic interfacial tensions, we conclude that, at high lipid concentrations common to DIBs, monolayer formation is simple adsorption controlled for lipid-in technique, whereas it is predominantly adsorption-barrier controlled for the lipid-out technique due to the interaction of interface-bound lipids with lipid structures in the subsurface. The adsorption barrier established in lipid-out technique leads to a prolonged incubation time and lower bilayer formation success rate, proving a good correlation between interfacial tension measurements and bilayer formation. We also clarify that advective flow expedites monolayer formation and improves bilayer formation success rate by disrupting lipid structures, rather than enhancing diffusion, in the subsurface and at the interface for lipid-out technique. Additionally, electrical properties of DIBs formed with varying lipid placement and type are characterized.
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Affiliation(s)
- Guru A Venkatesan
- Department of Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee , Knoxville, Tennessee 37996, United States
| | - Joonho Lee
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Amir Barati Farimani
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Mohammad Heiranian
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - C Patrick Collier
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Narayana R Aluru
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Stephen A Sarles
- Department of Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee , Knoxville, Tennessee 37996, United States
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Murashova NM, Yurtov EV. Lecithin organogels as prospective functional nanomaterial. ACTA ACUST UNITED AC 2015. [DOI: 10.1134/s199507801504014x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Georgiev GA, Yokoi N, Ivanova S, Tonchev V, Nencheva Y, Krastev R. Surface relaxations as a tool to distinguish the dynamic interfacial properties of films formed by normal and diseased meibomian lipids. SOFT MATTER 2014; 10:5579-88. [PMID: 24959988 DOI: 10.1039/c4sm00758a] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The surface properties of human meibomian lipids (MGS), the major constituent of the tear film (TF) lipid layer, are of key importance for TF stability. The dynamic interfacial properties of films by MGS from normal eyes (nMGS) and eyes with meibomian gland dysfunction (dMGS) were studied using a Langmuir surface balance. The behavior of the samples during dynamic area changes was evaluated by surface pressure-area isotherms and isocycles. The surface dilatational rheology of the films was examined in the frequency range 10(-5) to 1 Hz by the stress-relaxation method. A significant difference was found, with dMGS showing slow viscosity-dominated relaxation at 10(-4) to 10(-3) Hz, whereas nMGS remained predominantly elastic over the whole range. A Cole-Cole plot revealed two characteristic processes contributing to the relaxation, fast (on the scale of characteristic time τ < 5 s) and slow (τ > 100 s), the latter prevailing in dMGS films. Brewster angle microscopy revealed better spreading of nMGS at the air-water interface, whereas dMGS layers were non-uniform and patchy. The distinctions in the interfacial properties of the films in vitro correlated with the accelerated degradation of meibum layer pattern at the air-tear interface and with the decreased stability of TF in vivo. These results, and also recent findings on the modest capability of meibum to suppress the evaporation of the aqueous subphase, suggest the need for a re-evaluation of the role of MGS. The probable key function of meibomian lipids might be to form viscoelastic films capable of opposing dilation of the air-tear interface. The impact of temperature on the meibum surface properties is discussed in terms of its possible effect on the normal structure of the film.
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Affiliation(s)
- Georgi As Georgiev
- Department of Biochemistry, Faculty of Biology, University of Sofia, Sofia, Bulgaria.
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Phospholipids at the interface: current trends and challenges. Int J Mol Sci 2013; 14:11767-94. [PMID: 23736688 PMCID: PMC3709755 DOI: 10.3390/ijms140611767] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 05/03/2013] [Accepted: 05/28/2013] [Indexed: 11/30/2022] Open
Abstract
Phospholipids are one of the major structural elements of biological membranes. Due to their amphiphilic character, they can adopt various molecular assemblies when dispersed in water, such as bilayer vesicles or micelles, which give them unique interfacial properties and render them very attractive in terms of foam or emulsion stabilization. This article aims at reviewing the properties of phospholipids at the air/water and oil/water interfaces, as well as the recent advances in using these natural components as stabilizers, alone or in combination with other compounds such as proteins. A discussion regarding the challenges and opportunities offered by phospholipids-stabilized structure concludes the review.
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Crystalline titania nanoparticles synthesized in nonpolar Lα lecithin liquid-crystalline media in one stage at ambient conditions. Colloids Surf B Biointerfaces 2011; 87:203-8. [PMID: 21700435 DOI: 10.1016/j.colsurfb.2011.04.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2011] [Accepted: 04/30/2011] [Indexed: 11/20/2022]
Abstract
High-temperature modification of titania in the form of nanoplatelets is synthesized fast in one step at ambient conditions without any additional treatment like aging or calcination. Lecithin, which is the main component of lipid matrix of biological membranes, is first used as a structure-driven template. It is demonstrated that this natural surfactant can self-organize into lamellar L(α) mesophase when small amounts of water are admixed in its solution in nonpolar solvent. The water locating mainly in lecithin polar region as hydration shell at this concentration triggers the hydrolysis-condensation reactions after the precursor addition that results in instantaneous titania formation in the form of crystalline nanoparticles. Planar lamellar sheets serve as the template specifying its crystallinity.
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Interfacial properties of oleosins and phospholipids from rapeseed for the stability of oil bodies in aqueous medium. Colloids Surf B Biointerfaces 2010; 80:125-32. [DOI: 10.1016/j.colsurfb.2010.05.036] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 04/19/2010] [Accepted: 05/25/2010] [Indexed: 11/20/2022]
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Takhistov P, Paul S. Formation of Oil/Water Emulsions due to Electrochemical Instability at the Liquid/Liquid Interface. FOOD BIOPHYS 2006. [DOI: 10.1007/s11483-006-9011-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Bateni A, Laughton S, Tavana H, Susnar SS, Amirfazli A, Neumann AW. Effect of electric fields on contact angle and surface tension of drops. J Colloid Interface Sci 2005; 283:215-22. [PMID: 15694441 DOI: 10.1016/j.jcis.2004.08.134] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2004] [Accepted: 08/18/2004] [Indexed: 11/20/2022]
Abstract
Contact angles of sessile drops were experimentally investigated in the electric field. The experimental setup was designed such that the electric field was applied to all three interfaces. The advanced Automated Polynomial Fitting (APF) methodology was employed to measure contact angles with high accuracy. The significance of the observations and trends was examined by conducting statistical tests of hypothesis. It was found that contact angles of polar liquids such as alcohols increase in the electric field. However, no significant trend was observed for nonpolar liquids such as alkanes. The change in the contact angle was found to be stronger for liquids with longer molecules. It was shown that the polarity of the electric field is not an underlying factor in the observed trends. Using the equation of state for interfacial tensions, the observed shift in contact angles was translated into a corresponding change in surface tension of the liquids. The results suggest that the surface tension of alcohols increases by one to two percent (depending on the size of molecules) when an electric field of the order of magnitude of 10(6) V/m is applied.
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Affiliation(s)
- A Bateni
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8, Canada
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Bateni A, Susnar SS, Amirfazli A, Neumann AW. Development of a new methodology to study drop shape and surface tension in electric fields. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:7589-7597. [PMID: 15323506 DOI: 10.1021/la0494167] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Development of a new methodology for the study of both shape and surface tension of conducting drops in an electric field is presented. This methodology, called axisymmetric drop shape analysis-electric fields (ADSA-EF), generates numerical drop profiles in an electrostatic field, for a given surface tension. Then, it calculates the true value of the surface tension by matching theoretical profiles to the shape of experimental drops, using the surface tension as an adjustable parameter. ADSA-EF can be employed to simulate and study drop shapes in the electric field and to determine its effect on liquid surface tension. The method can also be used to measure surface tension in microgravity, where current drop-shape techniques are not applicable. The axisymmetric shape of the drop is the only assumption made in the development of ADSA-EF. The new scheme is applicable when both gravity and electrostatic forces are present. Preliminary measurements using ADSA-EF suggest that the surface tension of water increases by about 2% when an electric field with the magnitude of 10(6) V/m is applied.
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Affiliation(s)
- A Bateni
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
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Bateni A, Susnar S, Amirfazli A, Neumann A. A high-accuracy polynomial fitting approach to determine contact angles. Colloids Surf A Physicochem Eng Asp 2003. [DOI: 10.1016/s0927-7757(03)00053-0] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Combined scanning electrochemical microscopy–Langmuir trough technique for investigating phase transfer kinetics across liquid/liquid interfaces modified by a molecular monolayer. Electrochem commun 2003. [DOI: 10.1016/s1388-2481(02)00544-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Shchipunov YA, Mezzasalma SA, Koper GJM, Hoffmann H. Lecithin Organogel with New Rheological and Scaling Behavior. J Phys Chem B 2001. [DOI: 10.1021/jp010874n] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yu. A. Shchipunov
- Institute of Chemistry, Far East Department, Russian Academy of Sciences, 690022 Vladivostok, Russia, Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, PO Box 9502, 2300 RA Leiden, The Netherlands, Laboratory of Physical Chemistry, Delft University of Technology, Julianalaan, 136, 2628 BL Delft, The Netherlands, and Physical Chemistry I, Bayreuth University, 95440 Bayreuth, Germany
| | - S. A. Mezzasalma
- Institute of Chemistry, Far East Department, Russian Academy of Sciences, 690022 Vladivostok, Russia, Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, PO Box 9502, 2300 RA Leiden, The Netherlands, Laboratory of Physical Chemistry, Delft University of Technology, Julianalaan, 136, 2628 BL Delft, The Netherlands, and Physical Chemistry I, Bayreuth University, 95440 Bayreuth, Germany
| | - G. J. M. Koper
- Institute of Chemistry, Far East Department, Russian Academy of Sciences, 690022 Vladivostok, Russia, Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, PO Box 9502, 2300 RA Leiden, The Netherlands, Laboratory of Physical Chemistry, Delft University of Technology, Julianalaan, 136, 2628 BL Delft, The Netherlands, and Physical Chemistry I, Bayreuth University, 95440 Bayreuth, Germany
| | - H. Hoffmann
- Institute of Chemistry, Far East Department, Russian Academy of Sciences, 690022 Vladivostok, Russia, Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, PO Box 9502, 2300 RA Leiden, The Netherlands, Laboratory of Physical Chemistry, Delft University of Technology, Julianalaan, 136, 2628 BL Delft, The Netherlands, and Physical Chemistry I, Bayreuth University, 95440 Bayreuth, Germany
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Abstract
The molecular-level organization of mixed and pure saturated symmetric chain 1,2-diacyl-sn-glycero-3-phosphocholines (PCs) adsorbed at a carbon tetrachloride-aqueous interface is explored by probing the hydrocarbon chain conformation within the adsorbed layer. PCs of the chain lengths found most frequently in biological systems, which in pure form are seen to form either very well-ordered or disordered layers, are observed in these studies to assemble into interfacial layers ranging from disordered to ordered states when mixed in various proportions. Independently, while C(16) and shorter chain PCs tend to form disordered layers, a strong increase in ordering is observed for C(18) and longer chain PCs in which the hydrocarbon chains are found to be primarily in an all trans conformation. Pure C(17)-PCs adsorbed at the interface produce layers with an intermediate degree of chain ordering. The ability to tune interfacial layer properties in mixed systems as a function of molecular composition, including PC chain length as demonstrated here, is an important mechanism by which surface characteristics of oil-water emulsion systems can be controlled both in vivo and in numerous commercial applications.
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Affiliation(s)
- B L Smiley
- Department of Chemistry, University of Oregon, Eugene, Oregon 97403, USA
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Manzanares JA, Allen RM, Kontturi K. Enhanced ion transfer rate due to the presence of zwitterionic phospholipid monolayers at the ITIES. J Electroanal Chem (Lausanne) 2000. [DOI: 10.1016/s0022-0728(00)00032-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Shchipunov YA, Dürrschmidt T, Hoffmann H. Electrorheological Effects in Lecithin Organogels with Water and Glycerol. J Colloid Interface Sci 1999; 212:390-401. [PMID: 10092369 DOI: 10.1006/jcis.1998.6046] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of an external electric field on ternary mixtures consisting of lecithin, n-decane, and small amounts of polar additives (water or glycerol) has been studied by oscillating rheology, polarizing microscopy, and electric birefringence. It is shown that an electric field that is applied induces a so-called electrorheological (ER) effect, i.e., an increase in the viscosity and dynamic shear moduli of all the examined mixtures. The ER effect is absent in solutions of nonoverlapping micelles. The electric field causes the formation of fiber-like structures in the interelectrode gap. The ER effect becomes evident at a critical field of about 40 and 100 V/mm for water- and glycerol-containing organogels, respectively. In the latter case, a region of the reproducible and stable ER effect is extended up to 1700 V/mm, which is 3-4 times greater than that observed in the jelly-like phases with water. The buildup, as followed from birefringent measurements, includes fast and slow processes. Those correspond to both the local motions of parts of micellar chains and the restructuring of the whole network under the action of an external electric field. The ER response depends on the molar ratio of the polar additives to lecithin. Diagrams describing the behavior of ternary mixtures under the electric field have been constructed. They differ for water- and glycerol-containing organogels. The dependence of the stable ER effects on the molar ratio of glycerol to lecithin has a maximum in the vicinity of the phase separation of the homogeneous organogel, whereas for water-containing systems there is a gradual increase up to and including mixtures with the solid precipitate. A new rheological regime has been first established for solutions of polymer-like micelles. This feature is the square-root scaling of the dynamic moduli with the frequency. Such a scaling is inherent in polymers. A possible mechanism is considered, basing on the ordering of cylindrical micelles under the action of an external electric field. Copyright 1999 Academic Press.
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Affiliation(s)
- YA Shchipunov
- Far East Department, Russian Academy of Sciences, Vladivostok, 690022, Russia
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Shchipunov YA, Shumilina EV, Ulbricht W, Hoffmann H. The Branching of Reversed Polymer-like Micelles of Lecithin by Sugar-Containing Surfactants. J Colloid Interface Sci 1999; 211:81-88. [PMID: 9929437 DOI: 10.1006/jcis.1998.5927] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of n-dodecyl-beta-D-glucopyranoside and n-dodecyl-beta-D-lactobionamide on the formation and rheological behavior of lecithin organogels consisting of reverse long cylindrical (polymer-like) micelles were studied by oscillating rheology. The alkylglucoside addition results in a decrease of the zero shear viscosity and plateau modulus of the organogel, whereas the lactobionamide derivative causes an increase of these parameters. Despite their different effects, both the sugar-containing surfactants change the scaling exponents of the zero shear viscosity, plateau modulus, and terminal relaxation time in a similar way. Before their addition, the scaling behavior is in a satisfactory agreement with that expected from a model by Cates who considered polymer-like micelles as linear and flexible. In mixtures of lecithin with n-dodecyl-beta-D-glucopyranoside or n-dodecyl-beta-D-lactobionamide, the power law exponents are close to the theoretical predictions that follow from a model for branched (connected) cylindrical micelles. It was concluded that both the sugar-containing surfactants bring about a change in the growing mechanism of the lecithin micelles in nonpolar media. A molecular model is considered. This takes into account the formation of hydrogen bonds between amphiphile molecules, occurrence of packing constraints, and a change of excess free energy of the micellar endings. Copyright 1999 Academic Press.
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Smiley BL, Richmond GL. Alkyl Chain Ordering of Asymmetric Phosphatidylcholines Adsorbed at a Liquid−Liquid Interface. J Phys Chem B 1999. [DOI: 10.1021/jp982008p] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- B. L. Smiley
- Department of Chemistry, University of Oregon, Eugene, Oregon 97403
| | - G. L. Richmond
- Department of Chemistry, University of Oregon, Eugene, Oregon 97403
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KUZMIN MG, SOBOLEVA IV, KOTOV NA. Kinetics of Photoinduced Charge Transfer at Microscopic and Macroscopic Interfaces. ANAL SCI 1999. [DOI: 10.2116/analsci.15.3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Li J, Miller R, Möhwald H. Characterisation of phospholipid layers at liquid interfaces. 1. Dynamics of adsorption of phospholipids at the chloroform/water interface. Colloids Surf A Physicochem Eng Asp 1996. [DOI: 10.1016/0927-7757(96)03521-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Li J, Miller R, Möhwald H. Characterisation of phospholipid layers at liquid interfaces 2. Comparison of isotherms of insoluble and soluble films of phospholipids at different fluid/water interfaces. Colloids Surf A Physicochem Eng Asp 1996. [DOI: 10.1016/0927-7757(96)03522-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Shchipunov YA, Shumilina EV. Lecithin bridging by hydrogen bonds in the organogel. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 1995. [DOI: 10.1016/0928-4931(95)00102-6] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Schweighofer KJ, Benjamin I. Electric field effects on the structure and dynamics at a liquid | liquid interface. J Electroanal Chem (Lausanne) 1995. [DOI: 10.1016/0022-0728(95)03929-b] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Shchipunov YA, Kolpakov AF. Unusual processes of phospholipid dispersion formation by the action of an external electric field. Colloids Surf A Physicochem Eng Asp 1993. [DOI: 10.1016/0927-7757(93)80056-k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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