11.00 – 12.30 horas: Liquid Crystal – Nanotube Dispersions
15.30 – 17.00 horas: Growth and Coarsening in Liquid Crystals
Liquid Crystal ? Nanotube Dispersions
Dispersions of small amounts of carbon nanotubes in liquid crystals lead to novel composites where the self-organisation of the liquid crystalline phase is transferred onto dispersed single-, as well as multi-wall nanotubes exhibiting a relatively high alignment. Furthermore, it is shown that the direction of the long nanotube axis can be actively altered by the application of external electric or magnetic fields. This leads to novel composites with new properties and prospective benefits for applications. The temperature dependent dynamics will be presented and a model explanation in terms of a dynamic nanotube percolation network is discussed.
Growth and Coarsening in Liquid Crystals
The growth of liquid crystal phases after a temperature quench from the isotropic liquid is discussed in terms of universal growth laws of the form L~tn, where L is a characteristic length, t the time, and n the growth exponent. It is shown that the growth exponent changes from n=1/2 to n=1 for increasing quench depth, and a model explanation is discussed. At long time scales domain coarsening is observed. Ostwald ripening as well as defect annihilation dynamics will be discussed in the context of simple scaling laws. Experiments are compared to computer simulations.
Ver ponencias y biografia del Dr. Ingo Dierking en “Documentos”