The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. We have performed molecular dynamics simulations of a 2,5-bis-(p-hydroxyphenyl)-1,3,4-oxadiazole mesogen ODBP-Ph-C 7 at a fully atomistic level for a range of temperatures within the region that has experimentally been assigned to a biaxial nematic phase. Analysis of the data shows that the simulated nematic phase is biaxial but that the degree of biaxiality is small. The simulations show also the formation of ferroelectric domains in the nematic where the molecular short axis is aligned with the oxadiazole dipoles parallel to each other. Removal of electrostatic interactions leads to destabilization of ferroelectric domains and destabilization of the biaxiality. An additional simulation shows the slow growth of a mesophase directly from the isotropic fluid over a period of approximately 50 ns. This is the first time this has been achieved within the framework of an all-atom model.

Molecular dynamics simulations are reported for the four component nematic liquid crystal mixture E7, which is used commercially. We are able to show the growth of a nematic phase directly from an isotropic liquid over a 100 ns period for an all-atom model, and study orientational and dipole order within the nematic phase. The simulations show that the cyanoterphenyl component of the mixture, 5CT, is more ordered than the three cyanobiphenyl components. The simulations show also that both parallel and anti-parallel dipole correlation take place in E7 but that the strong anti-parallel dipole correlation is localised to particular arrangements of molecules. It is possible to identify two key preferred configurations for molecular pairs in the fluid, which explain the form of the dipole correlation function, g(1)(r).

No abstract

No abstract