Average orientation and location of benzyl alcohol-d(5) and alkyl benzyl-d(5) ethers in anionic nematic lyotropic liquid crystals

Deuterium quadrupole splittings of benzyl alcohol-d(5) and a series of alky l benzyl-d(5), ethers, with linear aliphatic chains from 1 to 12 carbon ato ms, were measured using H-2 NMR spectroscopy. These molecules were dissolve d in Nn anionic nematic lyotropic liquid crystals' prepared with sodium dec yl sulfate (NaDS) and cesium decyl sulfate (CsDS). Using the quadrupole spl ittings, the two order parameters that completely describe the average orie ntation of the aromatic ring were calculated. From these values, we have in ferred the mechanism of incorporation of the guest molecules into the super structure of the aggregate. The effect of the added molecules on the integr ity of the aggregate seems to depend on the electrostatic characteristics o f the surface as well as the hydrophobic properties of the guest molecule. The quadrupole splittings suggest that benzyl alcohol is positioned near th e interface, possibly hydrogen bonding with the interfacial water. This dis rupts the integrity of the interface, particularly in the CsDS system with the more hydrophobic derivatives decreasing the mobility of the CsDS aggreg ate components.