Systematic studies of the anchoring transition in nematic liquid crystals

When a nematic liquid crystal is spread on a crystalline substrate, the latter can orient the nematic molecules on top. Recently, it was shown that if water vapor is adsorbed onto the nematic-substrate interface, a discontinuous jump in the orientation can be observed. In this article we report a systematic study of the conditions under which this anchoring transition takes place. We find that, in addition to water, alcohols and diols cause a transition. Further, the nematic orientation depends only on relative humidity and not directly on temperature.