DISPHAT

Abstract

We propose to perform the first predictive computer simulation of the phase organisation and transitions of a discotic liquid crystal [1,2] as employed in organic electronic devices, using all atom force fields and massive parallel computer simulations. While some studies exist on the subject [3,4,5], they failed to provide in-silico realistic phase transition temperatures, as well as a quantitative agreement with experimental data for properties, due to the short time scales reached and the limited system sizes afforded by the computational power available.
Our aim is to exploit the computational power behind the DEISA infrastructure to accomplish the above tasks, relying in our previous experience in simulations of liquid-crystalline cinnamates [6] and cyanobiphenyls [7]. These studies represent the first successful predictions of transition temperatures for rod-like nematics [8]; here we aim at extending the approach to the more complex columnar systems, focusing on the hexa-hexyl-thio-triphenylene discotic molecule, particularly interesting both for its charge transport properties [9] and its mesomorphism [10].

[1] S. Kumar; Chem. Soc. Rev. 35:83, 2006
[2] H. Takezoe, K. Kishikawa, E. Gorecka; J. Mater. Chem. 16:2412, 2006
[3] D. Andrienko, V. Marcon, K. Kremer; J. Chem. Phys. 125:124902, 2006
[4] P. L. Cristinziano, F. Lelj; J. Chem. Phys. 127:134505, 2007
[5] G. Cinacchi, R. Colle , A. Tani; J. Phys. Chem. B 108:7969, 2004
[6] R. Berardi, L. Muccioli, C. Zannoni, ChemPhysChem 5:104, 2004
[7] G. Tiberio, L. Muccioli, R. Berardi, C. Zannoni; ChemPhysChem accepted, 2008
[8] C. M. Care, D. J. Cleaver; Rep. Prog. Phys. 68:2665, 2005
[9] A. M. van de Craats, M. P de Haas, J. M. Warman et al.; Adv. Mater. 8:823, 1996
[10] E. Fontes, P. A. Heiney, W. H. de Jeu; Phys. Rev. Lett. 61:1202, 1988