Structure formation in monolayers composed of hard bent-core molecules

ABSTRACT

We investigate the role of excluded volume interactions instabilising different structures in monolayers filled with bent-shaped molecules using the Onsager type of density functional theory supplemented by constant-pressure Monte-Carlo simulations. We study influence of molecular features, like the apex angle, thickness of the arm and the type of the arm edges on the stability of layered structures. For simple molecular shapes taken the observed phases are dominated by the lamellar antiferroelectric type as observed experimentally, but a considerable sensitivity of the ordering to details of the molecular shape is found for order parameters and wave vectors of the structures. Interestingly, for large opening angles and not too thick molecules, a window of stable nematic splay-bend phase is shown to exist.

GRAPHICAL ABSTRACT

KEYWORDS:

• DFT of liquid crystals
• perfect order approximation
• MC simulations
• smectics
• nematic splay-bend

Acknowledgements

This work was supported by Grant No. DEC-2013/11/B/ST3/04247 of the National Science Centre in Poland. The authors are also thankful to Professor Geoffrey R. Luckhurst for discussions concerning notations used for the layered structures.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Narodowe Centrum Nauki: [Grant Number DEC-2013/11/B/ST3/04247].