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Haverkamp R, Dahl M, Stank TJ, Hübner J, Strasser P, Wellert S, Hellweg T. Confined microemulsions: pore diameter induced change of the phase behavior. RSC Adv 2024; 14:12735-12741. [PMID: 38645522 PMCID: PMC11027042 DOI: 10.1039/d4ra01283f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 04/07/2024] [Indexed: 04/23/2024] Open
Abstract
In the present work, the temperature-dependent phase behavior of a C10E4 based microemulsion is studied in different meso-macroporous glasses, as a function of their pore diameter. The phase behavior in these pores is investigated by small-angle X-ray scattering (SAXS). The crucial parameter we discuss based on the SAXS results is the domain size of the bicontinuous phase. Using a simplified model to fit the scattering data, we can observe the microemulsion inside the pores. These experiments reveal a temperature-dependent change in domain sizes of the bicontinuous microemulsion only for large pores.
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Affiliation(s)
- René Haverkamp
- Department of Physical and Biophysical Chemistry, University of Bielefeld Universitätsstraße 25 Bielefeld 33615 Germany
| | - Margarethe Dahl
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Technical University of Berlin Straße des 17. Juni 124 Berlin 10623 Germany
| | - Tim Julian Stank
- Department of Physical and Biophysical Chemistry, University of Bielefeld Universitätsstraße 25 Bielefeld 33615 Germany
| | - Jessica Hübner
- Department of Chemistry, Chemical Engineering Division, Technical University of Berlin Straße des 17. Juni 124 Berlin 10623 Germany
| | - Peter Strasser
- Department of Chemistry, Chemical Engineering Division, Technical University of Berlin Straße des 17. Juni 124 Berlin 10623 Germany
| | - Stefan Wellert
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Technical University of Berlin Straße des 17. Juni 124 Berlin 10623 Germany
| | - Thomas Hellweg
- Department of Physical and Biophysical Chemistry, University of Bielefeld Universitätsstraße 25 Bielefeld 33615 Germany
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2
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Holderer O, Frielinghaus H, Zolnierczuk P, Ohl M, Monkenbusch M. Data reduction strategies at a time-of-flight NSE for a lamellar microemulsion. EPJ WEB OF CONFERENCES 2022. [DOI: 10.1051/epjconf/202227201007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neutron spin echo (NSE) spectroscopy provides the ultimate energy resolution in quasi-elastic thermal and cold neutron scattering spectroscopy. A peculiarity of the SNS-NSE, the only NSE spectrometer at a pulsed beam port at the moment, is that the wavelength spread δλ/λ can be chosen during evaluation with an appropriate time channel binning. The Q-resolution can be adjusted in certain limits a posteriori by choosing the appropriate detector binning (as on a continuous source) and time channel binning. This can be exploited for samples with a strongly varying scattering function S (Q, t), e.g. due to Bragg peaks in a crystal or lamellar ordering in microemulsions. The data reduction software DrSpine allows for appropriate slicing and masking for this task. In this contribution the correlation function of microemulsions, thermodynamically stable mixtures of oil, water and surfactant, is measured with NSE on length scales where structural correlations are important, and data reduction strategies varying the Q-resolution by pixel and time channel grouping are discussed. The typical ”de Gennes narrowing” or structural narrowing is observed with a relaxation time proportional to I(Q). In these regions of strongly varying intensity it is shown that a too coarse grouping has an influence on the data reduction, with a broadened in Q of the apparent slowing down.
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3
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Kyrey T, Ganeva M, Witte J, von Klitzing R, Wellert S, Holderer O. Understanding near-surface polymer dynamics by a combination of grazing-incidence neutron scattering and virtual experiments. J Appl Crystallogr 2021; 54:72-79. [PMID: 33833641 PMCID: PMC7941298 DOI: 10.1107/s1600576720014739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 11/06/2020] [Indexed: 11/10/2022] Open
Abstract
Neutron spin-echo spectroscopy is a unique experimental method for the investigation of polymer dynamics. The combination of neutron spin-echo spectroscopy with grazing-incidence geometry (GINSES) opens the possibility to probe the dynamics of soft-matter materials in the vicinity of the solid substrate in the time range up to 100 ns. However, the usage of the GINSES technique has some peculiarities and, due to the novelty of the method and complexity of the scattering geometry, difficulties in further data analysis occur. The current work discusses how virtual experiments within the distorted-wave Born approximation using the BornAgain software can improve GINSES data treatment and aid the understanding of polymer dynamics in the vicinity of the solid surface. With two examples, poly(N-isopropyl acrylamide) brushes and poly(ethylene glycol) microgels on Si surfaces, the simulation as well as the application of the simulation to the GINSES data analysis are presented. The approach allowed a deeper insight to be gained of the background effect and scattering contribution of different layers.
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Affiliation(s)
- Tetyana Kyrey
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Garching, Germany
| | - Marina Ganeva
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Garching, Germany
| | - Judith Witte
- Institute of Chemistry, Technical University Berlin, Berlin, Germany
| | | | - Stefan Wellert
- Institute of Chemistry, Technical University Berlin, Berlin, Germany
| | - Olaf Holderer
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Garching, Germany
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4
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Gvaramia M, Mangiapia G, Pipich V, Appavou MS, Jaksch S, Holderer O, Rukhadze MD, Frielinghaus H. Tunable viscosity modification with diluted particles: when particles decrease the viscosity of complex fluids. Colloid Polym Sci 2019. [DOI: 10.1007/s00396-019-04567-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Abstract
While spherical particles are the most studied viscosity modifiers, they are well known only to increase viscosities, in particular at low concentrations of approx. 1%. Extended studies and theories on non-spherical particles in simple fluids find a more complicated behavior, but still a steady increase with increasing concentration. Involving platelets in combination with complex fluids—in our case, a bicontinuous microemulsion—displays an even more complex scenario that we analyze experimentally and theoretically as a function of platelet diameter using small angle neutron scattering, rheology, and the theory of the lubrication effect, to find the underlying concepts. The clay particles effectively form membranes in the medium that itself may have lamellar aligned domains and surfactant films in the case of the microemulsion. The two-stage structure of clay and surfactant membranes explains the findings using the theory of the lubrication effect. This confirms that layered domain structures serve for lowest viscosities. Starting from these findings and transferring the condition for low viscosities to other complex fluids, namely crude oils, even lowered viscosities with respect to the pure crude oil were observed. This strengthens our belief that also here layered domains are formed as well. This apparent contradiction of a viscosity reduction by solid particles could lead to a wider range of applications where low viscosities are desired. The same concepts of two-stage layered structures also explain the observed conditions for extremely enhanced viscosities at particle concentrations of 1% that may be interesting for the food industry.
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Jaksch S, Gutberlet T, Müller-Buschbaum P. Grazing-incidence scattering—status and perspectives in soft matter and biophysics. Curr Opin Colloid Interface Sci 2019. [DOI: 10.1016/j.cocis.2019.04.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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6
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Lipfert F, Kerscher M, Mattauch S, Frielinghaus H. Stability of near-surface ordering of bicontinuous microemulsions in external shear-fields. J Colloid Interface Sci 2019; 534:31-36. [DOI: 10.1016/j.jcis.2018.09.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 09/04/2018] [Accepted: 09/04/2018] [Indexed: 11/27/2022]
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7
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A grazing incidence neutron spin echo study of near surface dynamics in p(MEO2MA-co-OEGMA) copolymer brushes. Colloid Polym Sci 2018. [DOI: 10.1007/s00396-018-4421-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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8
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Cristofolini L, Orsi D, Isa L. Characterization of the dynamics of interfaces and of interface-dominated systems via spectroscopy and microscopy techniques. Curr Opin Colloid Interface Sci 2018. [DOI: 10.1016/j.cocis.2018.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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9
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Gvaramia M, Mangiapia G, Falus P, Ohl M, Holderer O, Frielinghaus H. Capillary condensation and gelling of microemulsions with clay additives. J Colloid Interface Sci 2018; 525:161-165. [DOI: 10.1016/j.jcis.2018.04.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 04/06/2018] [Accepted: 04/06/2018] [Indexed: 11/30/2022]
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Oberdisse J, Hellweg T. Structure, interfacial film properties, and thermal fluctuations of microemulsions as seen by scattering experiments. Adv Colloid Interface Sci 2017; 247:354-362. [PMID: 28751064 DOI: 10.1016/j.cis.2017.07.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 07/12/2017] [Accepted: 07/12/2017] [Indexed: 10/19/2022]
Abstract
The physics of microemulsions and in particular Dominique Langevin's contributions to the understanding of microemulsion structure and bending properties using scattering techniques are reviewed. Among the many methods used by her and her co-workers, we particularly emphasize optical techniques and small angle neutron scattering (SANS), but also neutron spin echo spectroscopy (NSE). The review is then extended to more recent studies of properties of microemulsions close to surfaces, using reflectometry and grazing-incidence small angle neutron scattering (GISANS).
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11
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Jaksch S, Holderer O, Gvaramia M, Ohl M, Monkenbusch M, Frielinghaus H. Nanoscale rheology at solid-complex fluid interfaces. Sci Rep 2017; 7:4417. [PMID: 28667252 PMCID: PMC5493686 DOI: 10.1038/s41598-017-04294-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 05/12/2017] [Indexed: 01/05/2023] Open
Abstract
Here we present an approach to measure dynamic membrane properties of phospholipid membranes close to an interface. As an example we show results of the membrane dynamics of a phospholipid membrane multilayer-stack on a solid substrate (silicon). On this sample we were able to measure local interaction and friction parameters using Grazing Incidence Neutron Spin Echo Spectroscopy (GINSES), where an evanescent neutron wave probes the fluctuations close to a rigid interface. With this method it is possible to access length scales in the nano to micrometer region as well as energies in the μeV range. Using a new neutron resonator structure we achieved the required intensity gain for this experiment. During our investigations we found an excitation mode of the phospholipid membrane that has not been reported previously and only became visible using the new methodology. We speculate that the energy transported by that undulation can also serve to distribute energy over a larger area of the membrane, stabilizing it. This new methodology has the capability to probe the viscoelastic effects of biological membranes, becoming a new tool for tribology on the nanoscale and has allowed the observation of the hitherto invisible property of phospholipid membranes using neutrons.
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Affiliation(s)
- Sebastian Jaksch
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum, Lichtenberstraße 1, 85747, Garching, Germany.
| | - Olaf Holderer
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum, Lichtenberstraße 1, 85747, Garching, Germany
| | - Manuchar Gvaramia
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum, Lichtenberstraße 1, 85747, Garching, Germany
| | - Michael Ohl
- Forschungszentrum Jülich GmbH, JCNS at SNS-Oak Ridge National Laboratory (ORNL), 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Michael Monkenbusch
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science JCNS, Wilhelm-Johnen-Straße, 52428, Jülich, Germany
| | - Henrich Frielinghaus
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum, Lichtenberstraße 1, 85747, Garching, Germany
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12
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Ivanova O, Pasini S, Monkenbusch M, Holderer O. Instrument developments and recent scientific highlights at the J-NSE. ACTA ACUST UNITED AC 2017. [DOI: 10.1088/1742-6596/862/1/012009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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13
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Nylander T, Soltwedel O, Ganeva M, Hirst C, Holdaway J, Arteta MY, Wadsäter M, Barauskas J, Frielinghaus H, Holderer O. Relationship between Structure and Fluctuations of Lipid Nonlamellar Phases Deposited at the Solid-Liquid Interface. J Phys Chem B 2017; 121:2705-2711. [PMID: 28266854 DOI: 10.1021/acs.jpcb.6b11038] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The structure and dynamics of nanostructure films formed by mixtures of soy phosphatidylcholine and glycerol dioleate at the silicon-aqueous interface were studied by grazing incidence neutron spin echo spectroscopy (GINSES), specular and off-specular neutron reflectometry, and small-angle X-ray diffraction. Reverse hexagonal (HII) and micellar cubic phase (Fd3m) layers at the solid-liquid interface have been identified with neutron reflectometry measurements. A preferred orientation of the liquid crystalline (LC) domains was observed only for the anisotropic HII phase. The size of the LC domains was found to be about 1 micrometer as estimated from the width of the diffraction peaks. GINSES revealed that the cubic phase forms rather rigid films. In comparison, the HII film was more flexible, appearing as a modified undulation spectrum of the cylinders due to the interaction with the substrate.
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Affiliation(s)
- Tommy Nylander
- Physical Chemistry, Department of Chemistry, Lund University , P.O. Box 124, SE-22100 Lund, Sweden.,NanoLund, Lund University , P.O. Box 118, SE-22100 Lund, Sweden
| | - Olaf Soltwedel
- Max-Planck-Institute for Solid State Research, Outstation at MLZ , Lichtenbergstr. 1, 85747 Garching, Germany.,Technical University of Munich , Lichtenbergstr. 1, 85747 Garching, Germany
| | - Marina Ganeva
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz-Zentrum (MLZ), Forschungszentrum Jülich GmbH , Lichtenbergstr. 1, 85747 Garching, Germany
| | - Christopher Hirst
- Physical Chemistry, Department of Chemistry, Lund University , P.O. Box 124, SE-22100 Lund, Sweden
| | - James Holdaway
- Physical Chemistry, Department of Chemistry, Lund University , P.O. Box 124, SE-22100 Lund, Sweden
| | - Marianna Yanez Arteta
- Physical Chemistry, Department of Chemistry, Lund University , P.O. Box 124, SE-22100 Lund, Sweden
| | - Maria Wadsäter
- Physical Chemistry, Department of Chemistry, Lund University , P.O. Box 124, SE-22100 Lund, Sweden.,Camurus AB , Ideon Science Park, Gamma Building, Sölvegatan 41, SE-22379 Lund, Sweden
| | - Justas Barauskas
- Camurus AB , Ideon Science Park, Gamma Building, Sölvegatan 41, SE-22379 Lund, Sweden.,Biomedical Science, Faculty of Health and Society, Malmö University , SE-20506 Malmö, Sweden
| | - Henrich Frielinghaus
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz-Zentrum (MLZ), Forschungszentrum Jülich GmbH , Lichtenbergstr. 1, 85747 Garching, Germany
| | - Olaf Holderer
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz-Zentrum (MLZ), Forschungszentrum Jülich GmbH , Lichtenbergstr. 1, 85747 Garching, Germany
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14
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Müller-Buschbaum P. GISAXS and GISANS as metrology technique for understanding the 3D morphology of block copolymer thin films. Eur Polym J 2016. [DOI: 10.1016/j.eurpolymj.2016.04.007] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Berghaus M, Paulus M, Salmen P, Al-Ayoubi S, Tolan M, Winter R. Near-Surface and Bulk Behavior of Bicontinuous Microemulsions under High-Pressure Conditions. J Phys Chem B 2016; 120:7148-53. [DOI: 10.1021/acs.jpcb.6b05639] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Melanie Berghaus
- Physical Chemistry
I − Biophysical Chemistry, TU Dortmund, D-44227 Dortmund, Germany
| | - Michael Paulus
- Fakultät Physik/DELTA, TU Dortmund, D-44221 Dortmund, Germany
| | - Paul Salmen
- Fakultät Physik/DELTA, TU Dortmund, D-44221 Dortmund, Germany
| | - Samy Al-Ayoubi
- Physical Chemistry
I − Biophysical Chemistry, TU Dortmund, D-44227 Dortmund, Germany
| | - Metin Tolan
- Fakultät Physik/DELTA, TU Dortmund, D-44221 Dortmund, Germany
| | - Roland Winter
- Physical Chemistry
I − Biophysical Chemistry, TU Dortmund, D-44227 Dortmund, Germany
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16
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Gawlitza K, Ivanova O, Radulescu A, Holderer O, von Klitzing R, Wellert S. Bulk Phase and Surface Dynamics of PEG Microgel Particles. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b00788] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Kornelia Gawlitza
- Stranski-Laboratory
for Physical and Theoretical Chemistry, Technische Universität Berlin, Straße des 17. Juni 124, 10623 Berlin, Germany
| | - Oxana Ivanova
- Forschungszentrum Jülich Outstation at the Heinz Maier-Leibniz-Zentrum, Jülich Center for Neutron Science JCNS-MLZ , Lichtenbergstraße 1, 85747 Garching, Germany
| | - Aurel Radulescu
- Forschungszentrum Jülich Outstation at the Heinz Maier-Leibniz-Zentrum, Jülich Center for Neutron Science JCNS-MLZ , Lichtenbergstraße 1, 85747 Garching, Germany
| | - Olaf Holderer
- Forschungszentrum Jülich Outstation at the Heinz Maier-Leibniz-Zentrum, Jülich Center for Neutron Science JCNS-MLZ , Lichtenbergstraße 1, 85747 Garching, Germany
| | - Regine von Klitzing
- Stranski-Laboratory
for Physical and Theoretical Chemistry, Technische Universität Berlin, Straße des 17. Juni 124, 10623 Berlin, Germany
| | - Stefan Wellert
- Stranski-Laboratory
for Physical and Theoretical Chemistry, Technische Universität Berlin, Straße des 17. Juni 124, 10623 Berlin, Germany
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17
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Lipfert F, Holderer O, Frielinghaus H, Appavou MS, Do C, Ohl M, Richter D. Long wavelength undulations dominate dynamics in large surfactant membrane patches. NANOSCALE 2015; 7:2578-2586. [PMID: 25579866 DOI: 10.1039/c4nr06278g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
By exposing microemulsions to small (80 nm diameter) and large (500 nm) disk shaped clay particles we were able to show the presence of long wavelength undulations that only occur for large membrane patches. A combination of small angle neutron scattering (SANS) and neutron spin echo (NSE) experiments have been applied to study microemulsions. These, consisting of D2O, d-decane and the surfactant C10E4, were used in connection with Laponite (small) and Nanofil (large) clay. To our knowledge our experiments show for the first time that the clay platelets induce lamellar ordering adjacent to the clay discs in the otherwise bicontinuous microemulsion. This is due to the fact that in purely structural investigations, radial averaging smears out the signature of the lamellar phase. For thermodynamically fluctuating membranes near interfaces the theory of Seifert predicts a cross-over of the dispersion relationship from k(2) to a k(3)-dependence. With the correlation length of the membrane patches being confined by the dimension of the clay platelets we were able to show that this in fact takes place but is only present for the larger Nanofil particles.
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Affiliation(s)
- Frederik Lipfert
- Jülich Centre of Neutron Science JCNS-1 & Institute for Complex Systems ICS-1, Forschungszentrum Jülich GmbH, D-52425, Jülich, Germany
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Jaksch S, Lipfert F, Koutsioubas A, Mattauch S, Holderer O, Ivanova O, Frielinghaus H, Hertrich S, Fischer SF, Nickel B. Influence of ibuprofen on phospholipid membranes. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:022716. [PMID: 25768540 DOI: 10.1103/physreve.91.022716] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Indexed: 06/04/2023]
Abstract
A basic understanding of biological membranes is of paramount importance as these membranes comprise the very building blocks of life itself. Cells depend in their function on a range of properties of the membrane, which are important for the stability and function of the cell, information and nutrient transport, waste disposal, and finally the admission of drugs into the cell and also the deflection of bacteria and viruses. We have investigated the influence of ibuprofen on the structure and dynamics of L-α-phosphatidylcholine (SoyPC) membranes by means of grazing incidence small-angle neutron scattering, neutron reflectometry, and grazing incidence neutron spin echo spectroscopy. From the results of these experiments, we were able to determine that ibuprofen induces a two-step structuring behavior in the SoyPC films, where the structure evolves from the purely lamellar phase for pure SoyPC over a superposition of two hexagonal phases to a purely hexagonal phase at high concentrations. A relaxation, which is visible when no ibuprofen is present in the membrane, vanishes upon addition of ibuprofen. This we attribute to a stiffening of the membrane. This behavior may be instrumental in explaining the toxic behavior of ibuprofen in long-term application.
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Affiliation(s)
- Sebastian Jaksch
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum, Lichtenbergstraße 1, D-85747 Garching, Germany
| | - Frederik Lipfert
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum, Lichtenbergstraße 1, D-85747 Garching, Germany
| | - Alexandros Koutsioubas
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum, Lichtenbergstraße 1, D-85747 Garching, Germany
| | - Stefan Mattauch
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum, Lichtenbergstraße 1, D-85747 Garching, Germany
| | - Olaf Holderer
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum, Lichtenbergstraße 1, D-85747 Garching, Germany
| | - Oxana Ivanova
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum, Lichtenbergstraße 1, D-85747 Garching, Germany
| | - Henrich Frielinghaus
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum, Lichtenbergstraße 1, D-85747 Garching, Germany
| | - Samira Hertrich
- Ludwig-Maximilians-Universität, Department für Physik und CeNS, Geschwister-Scholl-Platz 1, D-80539 München, Germany
| | - Stefan F Fischer
- Ludwig-Maximilians-Universität, Department für Physik und CeNS, Geschwister-Scholl-Platz 1, D-80539 München, Germany
| | - Bert Nickel
- Ludwig-Maximilians-Universität, Department für Physik und CeNS, Geschwister-Scholl-Platz 1, D-80539 München, Germany
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19
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Holderer O, Lipfert F, Frielinghaus H, Ohl M, Richter D. Interfaces modify the undulation spectrum of bicontinuous microemulsions. EPJ WEB OF CONFERENCES 2015. [DOI: 10.1051/epjconf/20158302006] [Citation(s) in RCA: 1] [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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21
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Lipfert F, Frielinghaus H, Holderer O, Mattauch S, Monkenbusch M, Arend N, Richter D. Polymer enrichment decelerates surfactant membranes near interfaces. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:042303. [PMID: 24827247 DOI: 10.1103/physreve.89.042303] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Indexed: 06/03/2023]
Abstract
Close to a planar surface, lamellar structures are imposed upon otherwise bulk bicontinuous microemulsions. Thermally induced membrane undulations are modified by the presence of the rigid interface. While it has been shown that a pure membrane's dynamics are accelerated close to the interface, we observed nearly unchanged relaxation rates for membranes spiked with large amphiphilic diblock copolymers. An increase of the polymer concentration by a factor of 2-3 for the first and second surfactant membrane layers was observed. We interpret the reduced relaxation times as the result of an interplay between the bending rigidity and the characteristic distance of the first surfactant membrane to the rigid interface, which causes the hydrodynamic and steric interface effects described in Seifert's theory. The influence of these effects on decorated membranes yields a reduction of the frequencies and an amplification of the amplitudes of long-wavelength undulations, which are in accordance to our experimental findings.
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Affiliation(s)
- F Lipfert
- Institute for Complex Systems 1, Forschungszentrum Jülich GmbH, D-52425 Jülich
| | - H Frielinghaus
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, D-85747 Garching
| | - O Holderer
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, D-85747 Garching
| | - S Mattauch
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, D-85747 Garching
| | - M Monkenbusch
- Institute for Complex Systems 1, Forschungszentrum Jülich GmbH, D-52425 Jülich
| | - N Arend
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, D-85747 Garching and Jülich Centre for Neutron Science (JCNS), Outstation at SNS, Oak Ridge, USA
| | - D Richter
- Institute for Complex Systems 1, Forschungszentrum Jülich GmbH, D-52425 Jülich and Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, D-85747 Garching
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