Effect of a siloxane moiety on the anchoring of ferroelectric liquid crystals at the air-water interface

We have studied bulk and thin film behavior of a low-molar-mass organosiloxane ferroelectric liquid crystal with a sulfinate as a chiral group. The addition of the siloxane moiety lowers the transition temperature of the bulk smectic phase, increases its thermal stability, and favors a lateral anchoring of the chiral molecules at the air-water interface. The formation of stable monomolecular Langmuir films of this LMM ferroelectric liquid crystal permits the control of the molecular orientation via lateral density changes, and consequently in-situ investigations of the interfacial ordering and orientation. Uniform mono- and multilayer films with well-defined orientation can be transferred onto solid substrate for further studies.