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

Intermolecular Interactions For Phosphatidyl Choline And Phosphatidyl Ethanolamine

Intermolecular interaction between pairs of methylphosphocholine (MPC) and methylphosphoethanolamine were calculated using an extended CNDO/2 program. Experimentally determined conformations were used for the ethanolamine and choline groups. In the methylphosphocholine the major interaction was intramolecular, involving the phosphate ester-choline groups, while in the ethanolamine the maximum attraction was intermolecular between the ethanolamine and the phophate ester of a neighboring molecule(s). © 1983

Highly Plasma Etch-Resistant Photoresist Composition Containing a Photosensitive Polymeric Titania Precursor

A composition is derived from an addition polymerizable organotitanium polymer which upon exposure to an oxygen plasma or baking in air, is converted to titanium dioxide (titania) or is converted to a mixed, titanium-containing metal oxide. The metal oxide formed in situ imparts etch- resistant action to a patterned photoresist layer. The composition may also be directly deposited and patterned into permanent metal oxide device features by a photolithographic process

A Reversible Separation Method Process Using Nonionic Surfactants

An extraction method for hydrocarbons based on surfactant association structures is presented. The process utilizes the strong temperature dependence of the micellar association structures in systems of water, hydrocarbons and nonionic surfactants. The extraction is made at the HLB-temperature at which large amounts of water and oil concurrently dissolve to an isotropic solution. Reduction of the temperature (20°C) causes separation of the hydrocarbon; a corresponding increase gives separation of pure water. In this article determinations of the purity of the separated phases are reported. © 1981, Taylor & Francis Group, LLC. All rights reserved

Conformation Of The Lecithin Molecule With Attached Water Molecules

CNDO/2 studies on the conformation of the α chain of lecithin indicated a strong preference for a gauche-gauche arrangement about the phosphodiester group. Folding the α chain about[Figure not available: see fulltext.] and α4 was energetically very favorable. Hydration of the same segment revealed three levels of water-binding energies. The ion-dipole interactions of water and the choline moiety were energetically non-substantial. In contrast, binding of water to the unesterified phosphate oxygens produced the highest enthalpies. Attachment of water to the esterified phosphate oxygens or the ester oxygens of the β chain resulted in intermediate binding strengths. By investigating complete incorporation of nine water molecules into a chosen lipid structure, a plausible lecithin-water geometry was deduced for a liquid crystalline system. © 1981 Forum Press, Inc

W O Microemulsion Studies with Mono- and Dialkyl Amic Acid Surfactants

A series of new surfactants was prepared by reacting aromatic anhydrides and dianhydrides with long-chain amines to give mono- and bis-(N-alkylamic acids), which was then converted to water-soluble potassium salts. As an example, the reaction product of dodecyl amine and benzophenone tetracarboxylic dianhydride was neutralized with potassium hydroxide to form a surfactant. Two types of surfactants were synthesized and their structures are: A figure is presented The ability of the new surfactants to stabilize water-in-oil ( W O) microemulsions was examined by determining the pseudoternary component phase behavior of each material in combination with water, pentanol (cosurfactant), and benzene (oil). In general, the monofunctional surfactants could support higher water content microemulsions than those of the corresponding difunctional (bis) surfactants. Microemulsions prepared from the latter materials, however, were more stable to the addition of hydrocarbon. The structure of the parent three-component systems and the four-component microemulsions was probed by measuring the self-diffusion coefficients of water, cosurfactant, and oil at various levels of water and hydrocarbon. The diffusion coefficient measurements were consistent with an inverted to normal micelle transition occurring at high water levels. From inverted micellar solutions, the addition of benzene (up to 50%) formed closed W O structures. © 1990

Designing Polyurethane Solid Polymer Electrolytes for High-Temperature Lithium Metal Batteries

Potentially high-performance lithium metal cells in extreme high-temperature electrochemical environments is a challenging but attractive battery concept that requires stable and robust electrolytes to avoid severely limiting lifetimes of the cells. Here, the properties of tailored polyester and polycarbonate diols as the soft segments in polyurethanes are investigated and electrochemically evaluated for use as solid polymer electrolytes in lithium metal batteries. The polyurethanes demonstrate high mechanical stability against deformation at low flow rates and moreover at temperatures up above 100 degrees C, enabled by the hard urethane segments. The results further indicate transferrable ion transport properties of the pure polymers when incorporated as the soft segments in the polyurethanes, offering designing opportunities of the polyurethane by tuning the soft segment ratio and composition. Long-term electrochemical cycling of polyurethane-containing cells in lithium metal batteries at 80 degrees C proves the stability at elevated temperatures as well as the compatibility with lithium metal with stable cycling maintained after 2000 cycles

Monohydroxy-hydrazone-functionalized Thermally Crosslinked Polymers for Nonlinear Optics

The synthesis and properties of six hydrazone-functionalized crosslinked polymers possessing stable nonlinear optics (NLO) properties are presented. First, a series of six hydroxy-functionalized, NLO-active hydrazone chromophores were synthesized. These chromophores were then grafted via its hydroxy functionality on an epoxy polymer to obtain the six NLO-active soluble prepolymers. The grafting reaction yielded multiple secondary hydroxyl sites, which were used for further crosslinking by formulation of the prepolymer with a blocked polyisocyanate crosslinker. This formulation was spin-coated on glass slides to form 2-2.5 thick defect-free transparent films. The films were corona-poled above their glass-transition temperatures to align the chromophores in a noncentrosymmetric fashion and were simultaneously cured. The thermal characteristics of the second-order nonlinearity of the six polymers were compared to illustrate the key structure-property relationships underlying the performance of the films in terms of NLO activity and thermal stability. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 770-781, 200