A Lamellar Liquid Crystal As An In Situ Surface Balance. I. The Conformation Of 5- (and 6-)carboxy-4-hexyl-2-cyclohexene-1-yl Octanoic Acid And Its Monosoap

The interfacial conformation of a dicarboxylic acid, 5- (and 6-)carboxy-4-hexyl-2-cyclohexene-1-yl octanoic acid, and its monosodium soap was determined from the change of liquid crystal dimensions after introduction of the diacid compounds. The results showed that both functional groups of the Mono soap form were present at the interface and that increased water content of the liquid crystal matrix had little effect on the conformation of the Mono soap. On the other hand, the results indicated the conformation of the diacid as such to depend on the water content of the matrix. At low water content, the diacid form was in a conformation similar to that found for the Mono soap. However, increasing the water content of the matrix resulted in a sharp decrease in the calculated partial molecular areas for the diacid, indicating an extended conformation for the diacid. © 1984

Foams From A Three-phase Emulsion

Foam stability was related to phase behavior in a foamed three-phase region consisting of an aqueous solution (L1), an alcohol solution (L2) and lamellar liquid-crystalline (LC) phases in the C8H17SO3Na/C8H17OH/H2O system. The state of the system before foaming was LC/L2 + LC/L1 or L1 + L2/LC type emulsions up to a high octanol/water ratio of 77/23. In L2 + LC/L1 emulsion, the LC droplets exist separately from the alcohol droplets in an aqueous continuous medium. The viscosity of the system was enhanced with an increase in the content of dispersed phases, i.e. alcohol and/or liquid crystal phases contributing to the stabilizing of the foam. With higher than optimal liquid-crystalline phases present the high viscosity prevented foaming. Higher than optimal alcohol amounts led to phase inversion and instability. The drainage rate of the alcohol phase was considerably faster than of the other phases. As a result, the three-phase foam was stabilized by the liquid-crystalline phase for the water continuous part of the system in spite of the presence of a foam-destabilizing compound, octanol. © 1986

Structural Changes Induced By Addition Of A Hydrocarbon To Water/amphiphile Mixtures

The phase conditions in a system of water, hexadecane, sodium dodecyl sulphate, and di-ethylene glycol dodecyl ether showed the W/O microemulsions to be obtained first after destabilization of a liquid crystalline phase by addition of the hexadecane. The original lamellar liquid crystalline phase was moved towards higher surfactant/cosurfactant ratios and a new phase with inverse amphiphile cylinders in a hexagonal packing appeared. © 1983 Steinkopff

Composition of the Solar Interior: Information from Isotope Ratios

Measurements are reviewed showing that the interior of the Sun, the inner planets, and ordinary meteorites consist mostly of the same elements: Iron, oxygen, nickel, silicon, magnesium, sulfur and calcium. These results do not support the standard solar model.Comment: 4 pages, includes 6 figures, 1 Table, 39 references, 2002 SOHO 12/ GONG + 2002 Conference on Local and Global Helioseismology: The Present and Future, Big Bear Lake, C

Solubilization Of Calcium Dodecyl Sulfate In A Micellar Solution And In Lamellar Liquid Crystal

Calcium dodecyl sulfate (CDS) was solubilized in the aqueous micellar solution of sodium dodecyl sulfate and in the lamellar liquid crystal obtained from water, sodium dodecyl sulfate and decanal. The solubilization of CDS in the micellar solution was strongly increased with the concentration of sodium dodecyl sulfate while the maximum amount of CDS solubilized in the liquid crystal remained similar. The solubilization in the micellar solution was gradually increased with the alcohol content with a sudden reduction to zero at the decanol/sodium-dodecyl-sulfate ratio marking the end of the micellar region with no calcium soap being present. The dependence of the solubilization on the decanol/sodium-dodecyl-sulfate ratio was the opposite in the lamellar liquid-crystalline phase. It suddenly rose to a maximum at the lowest values of the alcohol/sodium-dodecyl-sulfate ratio and the interlayer spacing in the lamellar liquid crystal showed a pronounced reduction for initial addition of the calcium soap. © 1984

Foams From Aqueous Systems Of Polymerizable Surfactants

Polymerization was made in aqueous foams stabilized by a combination of a polymerizable surfactant, sodium (ω)-acrylamidoundecanoate (NaAAU), and oleyl alcohol. The common two-phase foams stabilized by a monomolecular layer of surfactant were not sufficiently stable to allow polymerization in foamed form, nor were such foams obtained in the two-phase region of aqueous solution and the liquid crystalline phase of hexagonally packed cylinders. Sufficient foam stability was found first when the lamellar liquid crystal formed by the combination of oleyl alcohol, the NaAAU, and the water. These foams were polymerized and shown to retain the liquid crystalline structure after polymerization. © 1987 Academic Press, Inc. All rights reserved

Critical Phenomena In Nonaqueous Microemulsions

The pseudo ternary phase diagrams of the four-component system glycerol, sodium dodecyl sulfate, hexanol and decane with the weight ratio of hexanol to decane equal to 100/0, 90/10, 75/25, 50/50, and 25/75 were determined at 30°C. The systems gave only isotropic solutions and no liquid crystalline phases. The nonaqueous regions corresponding to the W/O microemulsion region in aqueous systems suggested critical behavior as demonstrated by the convergence of tie lines and by light scattering intensity which gave a pronounced maximum at the point of converging tie lines. This maximum was transferred to higher glycerol/hexanol ratios with added surfactant and to smaller ratios with added decane. Viscosity measurements were made for the solutions on the demixing line. There were no anomalous viscosity values around the points of converging tie lines. © 1987

CNDO Calculations On The Structure Of A Liquid Sodium Carboxylate-carboxylic Acid Compound

The molecular interactions in a carboxylic acid/sodium carboxylate compound which is a liquid at room temperature were calculated using a CNDO/2 approach. The calculations gave results distinguishing the energy for different conformations in the molecular compound. The maximum binding energy was found for a structure in which the four acids were bridging with a hydrogen bond from the acid OH group to the carboxylate group and the acid carbonyl groups forming a ligand bond to the carboxylate sodium ion. © 1979 Academic Press, Inc

Superfluidity in the Solar Interior: Implications for Solar Eruptions and Climate

Efforts to understand unusual weather or abrupt changes in climate have been plagued by deficiencies of the standard solar model (SSM) [1]. Although it assumes that our primary source of energy began as a homogeneous ball of hydrogen (H) with a steady, well-behaved H-fusion reactor at its core, observations instead reveal a very heterogeneous, dynamic Sun. As examples, the upward acceleration and departure of H+ ions from the surface of the quiet Sun and abrupt climatic changes, including geomagnetic reversals and periodic magnetic storms that eject material from the solar surface are not explained by the SSM. The present magnetic fields are probably deep-seated remnants of very ancient origin. These could have been generated from two mechanisms. These are (1) Bose-Einstein condensation [2] of iron-rich, zero-spin material into a rotating, superfluid, superconductor surrounding the solar core and/or (2) superfluidity and quantized vortices in nucleon-paired Fermions at the core [3]