. Can. J. Chem. 55,2396 (1977).A systematic investigation has been made of some lyotropic mesophases (lyomesophases) which macroscopically orient in magnetic fields. These mesophases have been classified into type I which have a positive diamagnetic anisotropy (AX > 0) and type I1 with AX < 0. The mesophase behavior has been observed as a function mainly of electrolyte additions to binary and ternary systems. The electrolyte has a profound effect on the mesophase behavior at extremely low concentrations. It has the effect in the ternary system, sodium decylsulphate/ decanol/water, of converting a type I to a type I1 mesophase with less than 1 wt.% electrolyte.The addition of electrolytes to binary surfactantlwater systems had the effect of increasing the mesomorphic region to higher water concentrations. I n the case of sodium and cesium decylsulphate, and potassium laurate, these ternary mesophases were of type I and for decylammonium chloride of type 11. The method used to distinguish mesophases and determine the degrees of order of water and some hydrocarbon chain segments has been deuterium magnetic resonance. DOUGLAS M. CHEN, FRED Y. FUJIWARA et LEONARD W. REEVES. Can. J. Chem. 55,2396(1 977).On a fait une ttude systematique de quelques mesophases lyotropes (1yomCsophases) qui s'orientent d'une f a~o n n~acroscopique dans les champs magnttiques. On a classifit ces mtsophases en type I, celles qui ont une anisotropie diamagnetique positive (AX > 0), et type 11, pour celles ou AX < 0. On a principalement observe le comportement de la mesophase en fonction de I'addition d'tlectrolytes a des systtmes binaires et tertiaires. L'electrolyte a un effet considerable sur le comportement de la mesophase a des concentrations extrCmement basses. Sur le systeme tertiaire, decylsulphate de sodium/decanol/eau, l'electrolyte a comme effet de transformer une mesophase de type I en une mtsophase de type I1 avec moins que 1% en poids d'electrolyte. L'effet de l'addition d'tlectrolytes a des systtmes binaires, agent actif a la surfaceleau, est de dkplacer la region mtsomorphe vers des concentrations d'eau plus tlevees. Dans le cas des dtcylsulphates de sodium et de ctsium et du laurate de potassium, les phases ternaires sont du type I alors que pour le chlorure de dCcylammonium elle est du type 11. On utilise la resonance magnetique d u deuterium comme mtthode pour distinguer les mesophases et pour determiner les degrts d'ordre de l'eau et de quelques segments de chaines hydrocarbones.[Traduit par le journal] Introduction in any given system (4-8). In the most thorough l-he complex superstructures of lyotropic studies these mesophases are characterized by mixtures of amphiphilic compounds, in water, their low angle X-ray diffraction Pattern. LYOformed ill the regime of concentrated micellar mesophases which can be oriented either spansystems, lead to liquid crystalline properties of taneously or by means the resulting fluids (I). These lyoniesophases are advantages for study by any technique where important both with reference ...
. Can. J. Chem. 55, 2404 (1977).The degree of order of solubilized molecules and ions in oriented lyomesophases has been determined at specifically deuterated C-D bond axes from the quadrupole splitting of the deuterium magnetic resonance. Mixtures at low concentration of specifically deuterated alkanes, alcohols, carboxylic acids, and carboxylates of different chain length have been observed in host cationic and anionic lyomesophases. The degree of order of a given C-D position in alcohols increases strongly with chain length up to a length comparable with the host detergent. A broad series of carboxylic acids and carboxylate ions from C2 to CI6 have been deuterated in the a position. The a-C-D bond axis in the solubilisate increases in order with chain length, the anion having lower order than the parent acid. An accurately linear increase in the degree of order of the a position is observed for intermediate chain lengths. At chain lengths approximately equal to the host chain lengths the a position reaches a limiting value in the degree of order and further segments do not influence the order. At short chain lengths the degree of order is less than that predicted from extrapolation of order in the linear region. This has been interpreted in terms of distribution into the aqueous compartment by the solubilisates of short chain length. Acetic acid and the acetate, propionate, butanoate, and pentanoate ions spend an appreciable amount of time in the aqueous region. An estimate has been made of these distributions based on reasonable assumptions. On a dttermine le degrt d'ordre des moltcules et des ions solubilists dans des lyomtsophases orienttes; ces ttudes ont tte effectutes par rapport a des axes de liaisons C-D deuttrts d'une f a~o n spkifique a partir des couplages quadrupolaires de la rtsonance magnetique du deuterium. On a observt, dans des lyomtsophases cationique et anionique agissant comme hbtes, des melanges contenant de faibles concentrations d'alkanes, d'alcools, d'acides carboxyliques et de carboxylates de longueurs de chaine difftrentes et deuttres d'une f a~o n sptcifique. Le degrt d'ordre pour une position C-D donnte dans les alcools augmente d'une f a~o n tres prononcte avec la longueur de la chaine jusqu'a une longueur comparable a celle du dttergent agissant comme h6te. On a deuterk en position a une grande strie d'acides carboxyliques et d'ions carboxylates allant de C2 a CI6. L'ordre de l'axe de liaison a-C-D des moltcules solubilistes augnlente avec la longueur de la chaine; l'anion a un ordre plus bas que celui de l'acide qui lui a donne naissance. On observe une augmentation lineaire prtcise dans le degrt d'ordre dans la position a pour des longueurs intermtdiaires de la chaine.A des longueurs de chaine approximativement tgales a celles des longueurs de chaine de la moltcule hbte, la position a atteint une valeur limite dans le degrt d'ordre et des segments suppltmentaires n'influencent pas l'ordre. Aux courtes longueurs de chaine, le degre d'ordre est plus faible que celui prtdit a par...
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