Nonaqueous Lyotropic Liquid Crystals from Lecithin and Nonionic Surfactants

Lyotropic liquid crystals were prepared from mixtures of lecithin and nonionic surfactants with the general formula polyethylene glycol dodecyl ethers with no low molecular solvents being added.

The repeat distance in the structure was reduced with increased amount of the nonionic surfactant showing complete penetration of the surfactants between the lecithin molecules.     

Solubilization in Non-Aqueous Lyotropic Liquid Crystals

The solubilization of a hydrocarbon and two alcohols in a non-aqueous lamellar liquid crystal of lecithin and ethylene glycol was investigated determining the phase region of the liquid crystal and the geometrical dimension of the latter by low angle X-ray diffractometry.

The results indicated the solubilized molecules to be located both in the polar solvent between the lecithin layers in the liquid crystal and between the individual molecules. The hydrocarbon was mainly localized between the hydrophobic end surfaces of the amphiphile and the methanol showed a balanced partition. The solubilization of long chain alcohols caused a reduction of the interlayer distance presumably due to enhanced penetration of the ethylene glycol after solubilization of the alcohol.     

ADSORPTION OF COLLOIDAL MATERIALS ON POLYMER SURFACES

Polypropylene surfaces were rendered cationic by hydrophobic implantation and by grafting a quaternized polyvinyl pyridine onto a plasma treated surface. The polypropylene surface with the grafted polymer showed a strong adsorption of an anionic surfactant, corresponding to about ten monomolecular layers. High concentration of electrolyte caused a reduction of the adsorption at low concentrations of surfactant.