Abstrakt: | In my thesis I have focused on examining the structural and dynamic properties of
(5CB)„ clusters. Under normal circumstances, it appears that a bulk sample of 4-n-pentyl-4'- cyanobiphenyl changes dramatically its properties at the temperature about 310 K. Above this temperature pure 5CB sample occurs in isotropic phase and loses liquid crystalline properties. In this study I was able to show that placing 5CB molecules near the carbon nanostructures such as nanotube, graphite, or graphene increases the level of molecular order. Moreover, the second rank order parameter P2 decreases slowly with an increasing of temperature. Therefore, the nematic phase of 5CB cluster may persist in wider temperature range, which is desirable in certain technical applications. Another important and interesting observation is that embedding 5CB mesogens inside SWCNT enhance the process of diffusion along director. The average value of the second rank order parameter is higher than in 5CB sample adsorbed on the outer surface of nanotube. Similar but weaker effect is observed in (5CB)n cluster confined between graphite or graphene sheets. It also appears that chirality of SWCNT has impact on the dynamics of liquid crystal layer located near carbon surface.
Some o f the presented results seem to be of interest both from scientific point of view and
also because of their potential applications in nanoelectronic devices, chemical biosensors and liquid crystal displays. |