Studies of the behavior in magnetic fields of some lyomesophase systems with respect to electrolyte additions

Abstract

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 (Δχ > 0) and type II with Δχ < 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 II mesophase with less than 1 wt.% electrolyte. The addition of electrolytes to binary surfactant/water systems had the effect of increasing the mesomorphic region to higher water concentrations. In the case of sodium and cesium decylsulphate, and potassium laurate, these ternary mesophases were of type I and for decylammonium chloride of type II. The method used to distinguish mesophases and determine the degrees of order of water and some hydrocarbon chain segments has been deuterium magnetic resonance.