Langmuir, Vol.14, No.22, 6594-6598, 1998
Orientation of lyotropic and thermotropic liquid crystals on plasma-treated fluorinated surfaces
A carbon tetrafluoride plasma discharge using a grafting mechanism and very short treatment times (a few milliseconds to a few seconds) was used to obtain high-quality reproducible surfaces that permit the homeotropic alignment of lyotropic as well as thermotropic liquid crystals. The intermolecular interactions between the fluorinated surfaces and the lyotropic liquid crystals, molecules with polar heads, and hydrophobic chains, were studied using different analytical techniques. The results show that the interaction responsible for the homeotropic anchoring occurs through the formation of hydrogen bonds between the polar heads of the molecules and the grafted polar fluorine groups.