Calus, SylwiaSylwiaCalusKityk, Andriy V.Andriy V.KitykHuber, PatrickPatrickHuber2022-06-022022-06-022014-06-05Microporous and Mesoporous Materials 197 (): 26-32 (2014-01-01)http://hdl.handle.net/11420/12791An optical polarimetry study of the orientational order of a discotic liquid crystal (DLC), 2,3,6,7,10,11-hexakis(hexyloxy)triphenylene (HAT6), confined into parallel-aligned cylindrical nanochannels of mesoporous alumina, silica, and silicon membranes as a function of temperature and channel radius (3.4-21.0 nm) is presented. In contrast to the bulk state, the birefringence resulting from the confined discotic liquid crystal, exhibits a continuous temperature evolution and is positive indicating a dominating face-on (homeotropic) type molecular ordering with respect to the channel walls. Pronounced hysteresis effects observed in the experiment are traced to different nucleation sites of the low-temperature phase upon cooling and the high-temperature phase upon heating. Deviations from the Gibbs-Thomson scaling of the phase transition temperature for channel diameters below 10 nm are traced to splay distortions of the confined liquid crystal.en1387-181120142632ElsevierColumnar discoticsNanocompositesPorous aluminaPorous silicaPorous siliconPhysikTechnikJournal Article10.1016/j.micromeso.2014.05.036Journal Article