1
|
Willis SA, Dennis GR, Stait-Gardner T, Zheng G, Price WS. Determining a ‘diffusion-averaged’ characteristic ratio for aligned lyotropic hexagonal phases using PGSE NMR self-diffusion measurements, random walk simulations and obstruction models. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.03.106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
2
|
Phase Transitions of Nonionic Surfactant C18:1E10 in Mixed Media of Water with Ionic Liquids. J SURFACTANTS DETERG 2015. [DOI: 10.1007/s11743-015-1733-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
3
|
Song S, Wang H, Song A, Dong S, Hao J. Sponge Phase Producing Porous CeO2for Catalytic Oxidation of CO. Chemistry 2014; 20:9063-72. [DOI: 10.1002/chem.201304836] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 03/13/2014] [Indexed: 11/09/2022]
|
4
|
Willis SA, Dennis GR, Zheng G, Price WS. Preparation and physical properties of a macroscopically aligned lyotropic hexagonal phase templated hydrogel. REACT FUNCT POLYM 2013. [DOI: 10.1016/j.reactfunctpolym.2013.02.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
5
|
Angelov B, Angelova A, Vainio U, Garamus VM, Lesieur S, Willumeit R, Couvreur P. Long-living intermediates during a lamellar to a diamond-cubic lipid phase transition: a small-angle X-ray scattering investigation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:3734-3742. [PMID: 19708151 DOI: 10.1021/la804225j] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
To generate nanostructured vehicles with tunable internal organization, the structural phase behavior of a self-assembled amphiphilic mixture involving poly(ethylene glycol) monooleate (MO-PEG) and glycerol monooleate (MO) is studied in excess aqueous medium by time-resolved small-angle X-ray scattering (SAXS) in the temperature range from 1 to 68 degrees C. The SAXS data indicate miscibility of the two components in lamellar and nonlamellar soft-matter nanostructures. The functionalization of the MO assemblies by a MO-PEG amphiphile, which has a flexible large hydrophilic moiety, appears to hinder the epitaxial growth of a double diamond (D) cubic lattice from the lamellar (L) bilayer structure during the thermal phase transition. The incorporated MO-PEG additive is found to facilitate the formation of structural intermediates. They exhibit greater characteristic spacings and large diffusive scattering in broad temperature and time intervals. Their features are compared with those of swollen long-living intermediates in MO/octylglucoside assemblies. A conclusion can be drawn that long-living intermediate states can be equilibrium stabilized in two- or multicomponent amphiphilic systems. Their role as cubic phase precursors is to smooth the structural distortions arising from curvature mismatch between flat and curved regions. The considered MO-PEG functionalized assemblies may be useful for preparation of sterically stabilized liquid-crystalline nanovehicles for confinement of therapeutic biomolecules.
Collapse
Affiliation(s)
- Borislav Angelov
- Institute of Biophysics, Bulgarian Academy of Sciences, BG-1113 Sofia, Bulgaria
| | | | | | | | | | | | | |
Collapse
|
6
|
Jain S, Dyrdahl MHE, Gong X, Scriven LE, Bates FS. Lyotropic Phase Behavior of Poly(ethylene oxide)−Poly(butadiene) Diblock Copolymers: Evolution of the Random Network Morphology. Macromolecules 2008. [DOI: 10.1021/ma702322b] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sumeet Jain
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455
| | - Mitchell H. E. Dyrdahl
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455
| | - Xiaobo Gong
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455
| | - L. E. Scriven
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455
| | - Frank S. Bates
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455
| |
Collapse
|
7
|
Capitani D, Yethiraj A, Burnell EE. Memory effects across surfactant mesophases. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:3036-48. [PMID: 17295526 DOI: 10.1021/la062798r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We report a detailed analysis of deuteron NMR spectra of micellar, lamellar, cubic, and hexagonal mesophases in the aqueous non-ionic surfactant system C(12)E(6)/water. Samples are prepared with and without shear. Particular attention is paid to an interesting temperature-driven phase sequence that includes all of the above phases that are studied before and after shear parallel or perpendicular to the magnetic field direction. Surprising memory effects are found across mesophase transitions. These memory effects provide clues to the structure of the various phases.
Collapse
Affiliation(s)
- Donatella Capitani
- Institute of Chemical Methodologies, CNR, Research Area of Rome, Via Salaria Km 29-300, Monterotondo Staz, Rome, Italy
| | | | | |
Collapse
|
8
|
Szymański J, Patkowski A, Gapiński J, Wilk A, Hołyst R. Movement of Proteins in an Environment Crowded by Surfactant Micelles: Anomalous versus Normal Diffusion. J Phys Chem B 2006; 110:7367-73. [PMID: 16599511 DOI: 10.1021/jp055626w] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Small proteins move in crowded cell compartments by anomalous diffusion. In many of them, e.g., the endoplasmic reticulum, the proteins move between lipid membranes in the aqueous lumen. Molecular crowding in vitro offers a systematic way to study anomalous and normal diffusion in a well controlled environment not accessible in vivo. We prepared a crowded environment in vitro consisting of hexaethylene glycol monododecyl ether (C(12)E(6)) nonionic surfactant and water and observed lysozyme diffusion between elongated micelles. We have fitted the data obtained in fluorescence correlation spectroscopy using an anomalous diffusion model and a two-component normal diffusion model. For a small concentration of surfactant (below 4 wt %) the data can be fitted by single-component normal diffusion. For larger concentrations the normal diffusion fit gave two components: one very slow and one fast. The amplitude of the slow component grows with C(12)E(6) concentration. The ratio of diffusion coefficients (slow to fast) is on the order of 0.1 for all concentrations of surfactant in the solution. The fast diffusion is due to free proteins while the slow one is due to the protein-micelle complexes. The protein-micelle interaction is weak since even in a highly concentrated solution (35% of C(12)E(6)) the amplitude of the slow mode is only 10%, despite the fact that the average distance between the micelles is the same as the size of the protein. The anomalous diffusion model gave the anomaly index (r(2)(t) approximately t(alpha)), alpha monotonically decreasing from alpha = 1 (at 4% surfactant) to alpha = 0.88 (at 37% surfactant). The fits for two-component normal diffusion and anomalous diffusion were of equally good quality, but the physical interpretation was only straightforward for the former.
Collapse
Affiliation(s)
- Jedrzej Szymański
- Institute of Physical Chemistry, Polish Academy of Sciences, Department III, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | | | | | | | | |
Collapse
|
9
|
Freyssingeas E, Martin A, Roux D. Role of dislocation loops on the elastic constants of lyotropic lamellar phases. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2005; 18:219-30. [PMID: 16244811 DOI: 10.1140/epje/i2005-10042-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Accepted: 08/26/2005] [Indexed: 05/05/2023]
Abstract
We study the role of dislocation loops defects on the elasticity of lamellar phases by investigating the variation of the lamellar elastic constants, B and K, induced by the proliferation of these defects. We focus our interest on one particular lamellar phase made up of a mixture of C(12)E(5) and DMPC in water, which is already well-characterised. This lamellar phase undergoes a second-order (or weakly first-order) lamellar-to-nematic phase transition at about 19 degrees C and dislocation loops are seen to proliferate within the lamellar structure when temperature is decreased below 30 degrees C. The values of both elastic constants of this given lamellar phase are measured as a function of temperature, approaching the lamellar-to-nematic transition, with the help of Quasi-Elastic Light Scattering (QELS) on oriented lamellar phases. Very surprisingly we observe a strong and rapid increase in both Band K as the lamellar-to-nematic transition temperature is approached. These increases are seen to start as soon as dislocation loops can be observed in the lamellar phase. We interpret our results as being the consequence of the appearance and proliferation of dislocation loops within the lamellar structure. According to a simple model we developed we show that B and K are proportional to the density of dislocation loops in the lamellar phase.
Collapse
Affiliation(s)
- E Freyssingeas
- Laboratoire de Physique, UMR CNRS 5672, Ecole Normale Supérieure de Lyon, France.
| | | | | |
Collapse
|
10
|
Holyst R, Staniszewski K, Demyanchuk I. Ordering in Surfactant Mixtures Induced by Polymers. J Phys Chem B 2005; 109:4881-6. [PMID: 16863142 DOI: 10.1021/jp045226t] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We studied ternary mixtures of nonionic surfactant (C12E6, n-dodecyl hexaoxyethylene glycol monoether), polymer (PEG, polyethylene glycol), and water. A small amount of PEG induces demixing into the polymer-rich and surfactant-rich phases in the ternary PEG/C12E6/water mixture. Above a certain concentration and/or molecular weight of PEG, the surfactant-rich phase orders, even in a solution consisting of a few percent of surfactant. The phase boundary acts as a semipermeable membrane, and the equilibrium is determined by the chemical potential of water in two phases. The explicit expression for the amount of PEG needed to order C12E6 water solution is given and verified experimentally. The analysis of the coexistence conditions leads to the conjecture that only two oxygen atoms in the outward part of the hydrophilic surfactant head strongly affect the chemical potential of water. Our methodology is generic, i.e., on the same basis one can design a similar experiment for any surfactant/polymer/water system and find the right proportions of polymer that induce order in a surfactant-rich phase.
Collapse
Affiliation(s)
- R Holyst
- Institute of Physical Chemistry, PAS Department III, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | | | | |
Collapse
|
11
|
Aramaki K, Hayashi T, Katsuragi T, Ishitobi M, Kunieda H. Effect of Adding an Amphiphilic Solubilization Improver, Sucrose Distearate, on the Solubilization Capacity of Nonionic Microemulsions. J Colloid Interface Sci 2001; 236:14-19. [PMID: 11254322 DOI: 10.1006/jcis.2000.7366] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have studied the effect of adding sucrose distearate (2C(18)SE) on the solubilization capacity of microemulsions formed in the water/C(12)EO(6)/n-decane system. Upon addition of 2C(18)SE to the binary water/C(12)EO(6) system, a lamellar liquid crystal region developed. This suggests that the rigidity of the surfactant layer is strengthened. The solubilization of water and n-decane in the bicontinuous microemulsions increases about three times upon replacing 10% C(12)EO(6) with 2C(18)SE; besides, the HLB temperature is not greatly affected by 2C(18)SE. On the other hand, sucrose monostearate (C(18)SE) does not have such a function. The effect of added 2C(18)SE on the solubilization capacity of the discrete droplet-type o/w or w/o microemulsions was also studied. The efficiency of the solubilization-improving effect is reduced when the system is far from the HLB temperature. Copyright 2001 Academic Press.
Collapse
Affiliation(s)
- Kenji Aramaki
- Faculty of Engineering, Yokohama National University, Tokiwadai 79-5, Hodogaya-ku, Yokohama, 240-8501, Japan
| | | | | | | | | |
Collapse
|
12
|
Constantin D, Oswald P, Impéror-Clerc M, Davidson P, Sotta P. Connectivity of the Hexagonal, Cubic, and Isotropic Phases of the C12EO6/H2O Lyotropic Mixture Investigated by Tracer Diffusion and X-ray Scattering. J Phys Chem B 2000. [DOI: 10.1021/jp002672h] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
13
|
Constantin D, Oswald P. Diffusion coefficients in a lamellar lyotropic phase: evidence for defects connecting the surfactant structure. PHYSICAL REVIEW LETTERS 2000; 85:4297-4300. [PMID: 11060622 DOI: 10.1103/physrevlett.85.4297] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2000] [Indexed: 05/23/2023]
Abstract
We measure diffusion coefficients in the lamellar phase of the nonionic binary system C(12)EO(6)/H(2)O using fluorescence recovery after photobleaching. The diffusion coefficient across the lamellae shows an abrupt increase upon approaching the lamellar-isotropic phase transition. We interpret this feature in terms of defects connecting the surfactant structure. An estimation of the defect density and of the variation in defect energy close to the transition is given in terms of a simple model.
Collapse
Affiliation(s)
- D Constantin
- Ecole Normale Superieure de Lyon, Laboratoire de Physique, 46 Allee d'Italie, 69364 Lyon Cedex 07, France
| | | |
Collapse
|
14
|
Hotyst R. Fluctuating Euler characteristics in lamellar and microemulsion phases. Curr Opin Colloid Interface Sci 1998. [DOI: 10.1016/s1359-0294(98)80060-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|