An X-ray study of brine swollen lyotropic lamellar phases

Bassereau, Patricia; Marignan, J.; Porte, G.

doi:10.1051/jphys:01987004804067300

Cited by 58 publications

(29 citation statements)

References 12 publications

(10 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our study connects to the current experimental [10][11][12][13][14][15][16][17] and theoretical [18][19][20][21][22][23][24][25] interest in the interplay between electrostatic interactions and thermal undulations in lamellar phases, especially to the recent study of Schomäcker and Strey [14]. These authors charged the dilute lamellar phases of the non-ionic surfactant pentaethylene glycol dodecyl ether (C 12 E 5 ) by adding small amounts of ionic surfactants, and followed the evolution of the Bragg peak by backscattering of light.…”

Section: Introductionmentioning

confidence: 90%

“…On the other hand, if electrostatic interactions exist, these will compete with undulations. Unless the electrostatic interactions are highly screened by the addition of large amounts of electrolyte, one must then consider the interplay between the thermal undulations and the electrostatic interactions [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. 142 The European Physical Journal E The aim of the present study is to obtain quantitative data characterizing the C 10 E 3 bilayer flexibility and the impact of electrostatic interactions on the C 10 E 3 lamellar phase.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Weakly charged lamellar bilayer system: Interplay between thermal undulations and electrostatic repulsion

Berlepsch

Vries

2000

Eur. Phys. J. E

View full text Add to dashboard Cite

We study the interplay between thermal undulations and electrostatic interactions for weakly charged surfactant bilayers by measuring the backscattering of light from very dilute lamellar phases of the non-ionic surfactant triethylene glycol monodecyl ether (C10E3) doped with small amounts of the anionic surfactant sodium dodecyl sulphate (SDS), both with and without added electrolyte. Upon charging, the lamellar phases show a transition from undulation to electrostatic stabilization. Non-lamellar structures develop if the molar mixing ratio R = [SDS]/[C10E3] exceeds ≈ 2.5 × 10 −3 . Deviations from ideal swelling, D ∝ 1/Φ, whereD is the lamellar repeating distance and Φ the membrane volume fraction, were detected for all lamellar phases. Salt-free lamellar phases with charge densities below σc = 1.47 × 10 −4 e/nm 2 , as well as more highly charged lamellar phases at high ionic strength show a universal logarithmic deviation from ideal swelling that was analyzed using theories for undulation stabilized lamellar phases. Deviations from ideal swelling for electrostatically stabilized lamellar phases were analyzed using theories recently developed for undulations in charged lamellar phases. The fits to the various theories yield a value of kc,0 ≈ 1.8 kBT for the bending modulus of the C10E3 bilayers. PACS. 82.70.-y Disperse systems -61.30.Eb Experimental determinations of smectic, nematic, cholesteric, and other structures -68.10.-m Fluid surfaces and fluid-fluid interfaces

show abstract

Section: Introductionmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Weakly charged lamellar bilayer system: Interplay between thermal undulations and electrostatic repulsion

Berlepsch

Vries

2000

Eur. Phys. J. E

View full text Add to dashboard Cite

show abstract

“…The dilute LLC is a well-behaved lamellar crystal and the interaction responsible for its stability is thus most probably the steric interaction initially suggested by Helfrich [12]. The evolution of the SAXS pattern with dilution is analogous to that of the brine swollen LLC previously studied [4,15]; the progressive growth of the central scattering, together with the disappearance of the Bragg singularity, can be traced back to the thermally induced displacement of the lamellae leading to concentration fluctuations as discussed in [15]. In this context the observed patterns seem to indicate that in the decane + pentanol swollen LLC the positional order is softer than in the brine swollen LLC previously studied.…”

Section: Resultsmentioning

confidence: 82%

“…200 A) which yielded powdered samples, the lamellae achieved, after a certain time, a cylindrically symmetric configuration (cf. [4]). This configuration is checked by polarized light microscopy or between crossed nicols.…”

Section: Methodsmentioning

confidence: 93%

“…To explain the stability of these swollen phases Helfrich [12] postulated a long-range steric interaction arising from the thermally induced out-of-plane fluctuations of the lamellae. Experimental evidence of the role of this long-range interaction in the swollen lamellar phases was obtained by a quantitative study of the profile of the Bragg singularity in oil swollen [8] or brine swollen [4] LLC., while the possible competition between this long-range steric interaction and the long-range electrostatic interaction was studied recently in a Water or brine swollen LLC [5].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Extreme swelling of a lyotropic lamellar liquid crystal

Appell

Bassereau

Marignan

et al. 1989

Colloid & Polymer Sci

Self Cite

View full text Add to dashboard Cite

The evolution of the OBS/water/decane/pentanol lyotropic lamellar crystal is followed from 0 % to more than 90 % decane content. The lamellar spacing (d) varies then from 35 A to 11000 A. The swelling is followed with small angle x-ray scattering and the Bragg divergence in the intensi~ is found to disappear in moderately swollen lamellar crystal (d from 200 A up to 800 A) while the central scattering increases. More striking is the reappearance of the Bragg divergences observed by SAXS (d from 800 A to 1100 ~) and for extremely swollen lamellar crystals in the angular distribution of scattered light (d from 2 000 A to 10 000 A). We discuss these observations along the lines of the recent models of swollen lamellar liquid crystals and in particular the apparent evolution of the dilute lamellae.

show abstract

Phase Behavior and Light Scattering of the System Dodecyldimethylaminoxide, n‐Hexanol and Water in the Very Dilute Region

Platz

Thunig

Hoffmann

1992

Ber Bunsenges Phys Chem

View full text Add to dashboard Cite

Solutions of Dodecyldimethylaminoxide (DDMAO), n‐hexanol and water show a phase behavior which is found to be typical for many surfactant‐alcohol‐water systems with lamellar phases. Three types of lamellar phases and three types of isotropic low viscous clear phases which exhibit extreme flow birefringence (L3‐phases) are found at room temperature. Both a hexanol‐rich (Lαh) and a hexanol‐poor lamellar phase (Lαl) can be diluted to iridescent solutions with bright colors. The iridescent Lαh phase is of low viscosity and forms quickly, the higher viscous Lαl phase needs 600 hours until the iridescence can be observed. — UV‐Vis and classical light scattering measurements show that the interlamellar structures or spacings of the Lαl phase are strongly and those of the Lαh phase are weakly fluctuating. The Lαh phase is much more sensitive to added electrolyte than the Lαl phase. The Lαl phase seems to be the type of iridescent phases which can be found with some ionic surfactant‐water systems. — An intermediate lamellar phase exists between the Lαh and the Lαl phase with a second order or kinetically controlled phase transition. At the lower concentration limit (DDMAO concentration around 50 mmol/l) this intermediate phase needs several months for the formation. — The Lαh phase is accompanied at some higher hexanol concentration by a L3 phase. This phase transforms quickly to an iridescent phase immediately after shear stress. Depending on concentration and temperature this iridescent phase remains stable for a few minutes to several hours. The second isotropic phase with extreme flow birefringence exists below the Lαl phase. Dilution of the intermediate lamellar phase leads to an intermediate phase of type L3 which is not in a thermodynamic equilibrium state. — The Lαl phase and the intermediate lamellar phase give slow torsion waves whose propagation can be observed between crossed polarizers. The rheologic behavior which leads to these shear waves is discussed.

show abstract

An X-ray study of brine swollen lyotropic lamellar phases

Abstract: Résumé. 2014

Cited by 58 publications

References 12 publications

Weakly charged lamellar bilayer system: Interplay between thermal undulations and electrostatic repulsion

Weakly charged lamellar bilayer system: Interplay between thermal undulations and electrostatic repulsion

Extreme swelling of a lyotropic lamellar liquid crystal

Phase Behavior and Light Scattering of the System Dodecyldimethylaminoxide, n‐Hexanol and Water in the Very Dilute Region

Contact Info

Product

Resources

About