From understanding structures in antiferro-ferri and ferroelelectric liquid crystals to an unusual electro-optic effect in a bent-core nematic; a celebration of innovative materials

ABSTRACT

The field of liquid crystals is truly multidisciplinary with numerous examples of virtuous circles of interaction between chemistry, physics, theory and engineering resulting in breakthroughs in both fundamental understanding and novel applications. This paper, written to mark John Goodby’s 65th birthday, offers a personal perspective of the synergy between chemistry and physics from a collaboration that has spanned three decades. The first part of the paper reviews some of the physics insights that resulted from chiral liquid crystals fundamental to understanding structures in ferroelectric, ferrielectric and antiferroelectric systems. The second part of the paper describes some of the remarkable consequences of the anomalous elasticity and flexoelectricity found in the nematic phases of bent-core materials. In particular, we present unusual bowing of disclination lines in the nematic phase of a bent-core material in the presence of a field. Finally, the paper summarises some future prospects relating for bent-core materials. The paper by no means captures the amazing breadth of contribution that John’s chemistry has made to the subject, but aims to exemplify how his generous collaborative approach coupled with innovative chemistry and physical insight has led to paradigm changes in our subject.

Graphical Abstract

KEYWORDS:

• Antiferroelectric
• nematic
• bent core
• resonant X-ray scattering
• flexoelectric effect
• elastic constants
• disclination lines

Acknowledgement

We are very grateful for the Council’s continued support. The data associated with this paper (high resolution figure) can be found at https://doi.org/10.5518/231

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Engineering and Physical Sciences Research Council [EP/L012111/1,EPD069793/1,EPG023093/1,GR/R19601/01,GR/R30310/01,GR/R46786/01];Royal Commission for the Exhibition of 1851 [Brunel Fellowship].