Solvation Changes Induced In A Lyotropic Lamellar Liquid Crystal Containing Solubilized Benzene

Deuterium NMR quadrupole splitting\u27s of deuterated benzene and water were studied as a function of their composition in the aqueous lamellar phase of Penta ethylene glycol n-dodecyl ether. An interpretation of the results is given in terms of hydration changes of the poly(oxyethylene) chains related to changes in the benzene solvation and location within the head-group region. © 1986, American Chemical Society. All rights reserved

The Mechanism Of Hydrotrope Action Of A Dicarboxylic Acid

The mechanism of the hydro trope action of a dicarboxylic acid Mono soap was investigated by determination of the change in order parameter of the amphiphile in a lamellar liquid crystal. The results showed addition of the hydro trope considerably to reduce the order while addition of a surfactant had no effect. © 1986

Fourier Transform NMR Self-diffusion Studies Of A Nonaqueous Microemulsion System

Self-diffusion coefficients of the components of the microemulsion system glycerol/hexanol/sodium dodecyl sulfate (SDS) were determined in the presence and absence of an oil, p-xylene, and the results were compared with those from corresponding aqueous systems (i.e., glycerol replaced by water). In the aqueous system, the water in the hexanol rich isotropic liquid showed a diffusion coefficient less than 10% of that of free water, while that of hexanol was roughly 80% of that of free hexanol; such restricted motion of the water is consistent with the presence of water as discrete droplets. Partial substitution of p-xylene for hexanol did not affect the diffusion coefficient of water appreciably. In the nonaqueous three-component system, the diffusion coefficients of glycerol, SDS, and hexanol all decreased in concert as the glycerol content increased, e.g., that of hexanol goes from 1.75 x 10-10 m2 s-1 to 2.7 x 10-11 m2 s-1 as the glycerol content ranges from 10 to 80%. The diffusion coefficient of glycerol was always greater than that of neat glycerol by a factor of 5 to 45. As the diffusion coefficients of all components were within a factor of 2, the idea of segregating one or more components into disconnected domains is not supported. There is no support for glycerol droplets but these microemulsions appear to be structureless. © 1987

Preparation Of Cationic Polymer Surfaces By Grafting Polymerization

A cationic polymer surface with extensive capacity for adsorption of anionic surfactants was prepared by graft polymerization of vinyl pyridine onto a plasma‐treated polypropylene surface. The nitrogen was quaternized in order to obtain the cationic sites. The concentration dependence of adsorption from high eletrolyte solution of the anionic surfactant was similar to the one a solid surface from solutions with no added electrolyte. The hydrophobic contribution to the adsorption was experienced at surfactant concentrations far below its critical micellization. Copyright © 1982 John Wiley & Sons, Inc

Dynamic Structure Of N-Hexadecane Solubilized In A Nonionic Surfactant Bilayer Measured By Deuteron Magnetic Resonance

A 2H NMR study was made of the order parameters of n-hexadecane molecules solubilized up to 55% (w/w) in a lyotropic lamellar liquid crystal of tetra ethylene glycol n-dodecyl ether and water for a range of compositions of varying water and hydrocarbon content. The NMR data supported a model with only a small amount of penetration of the hydrocarbon between the amphiphilic molecules and a rapid exchange on the 2H NMR time scale between the penetrated segments and the nonpenetrating molecules which latter are essentially isotropic. © 1985, American Chemical Society. All rights reserved

Order Parameters Of Hydrocarbons Solubilized In A Lamellar Liquid Crystal

A preliminary study of the 2H NMR spectrum of n-hexadecane-d34 solubilized in the lamellar phase of tetra ethylene glycol n-dodecyl ether has been made as a function of solubilization content. Complex spectra comprising eight overlapping powder spectra were observed, which showed a complex oil concentration dependence. These spectra were unusually rich in detail and indicate a considerably higher degree of complexity than has earlier been reported for solubilized hydrocarbons. The derived order profile was found to be different from that normally found for amphiphiles in lamellar environments. A tentative model involving some penetration of solubilize molecules between the host amphiphiles at low concentration while nonpenetrating oil molecules exist between the host layers at high oil contents is proposed. © 1984 American Chemical Society