Biaxial Nematic Liquid Crystals:reducing symmetry to increase order and develop novel applications
Lead Research Organisation:
University of Manchester
Department Name: Physics and Astronomy
Abstract
The invention and development of liquid crystal materials in the 1970s and 80s led to the now hugely successful flat panel display industry, and allowed the development of all sorts of portable technology, including lap-top computers and mobile phones. The key to the success of these technologies has been the engineering of functional materials to enhance their application specifically to liquid crystal displays. The displays technology is mature, but there are now exciting, new developments in the area of liquid crystals that promise to have significant impact on future technologies. This proposal addresses one kind of new liquid crystal, the so-called biaxial nematic systems. The reduced symmetry that occurs in these systems results in many potential implications, and we are particularly interested in exploring their potential in new electro-optic applications (which may include switchable diffraction gratings - important for optical communications) and non-linear optics, since the materials are electrically switchable, and already have nonlinear coefficients comparable to useful solid-state systems.The research that we are proposing here will make a significant contribution to these materials, which were only discovered a few years ago. We will attack some of the key issues that will allow biaxial nematics to be used, including developing new, lower temperature materials (current materials are biaxial at temperatures often around 150C) and understanding the nature of the biaxial order through complementary theoretical and experimental approaches. Thus we expect to be able to capture and control biaxial order in the applications already described, and deduce the best opportunities for using these new materials.The programme brings together scientists from a number of disciplines, to enable several important issues to be examined simultaneously, and to allow each discipline area to feed into the other, for optimum synergy. The group has a strong record of working together to make advances in liquid crystals, which have already had impact on applications areas.
Organisations
Publications
Zhang Z
(2017)
Observing the emergence of phase biaxiality in a polar smectic A system via polarised Raman spectroscopy
in Journal of Materials Chemistry C
Zhang Z
(2015)
Raman scattering studies of order parameters in liquid crystalline dimers exhibiting the nematic and twist-bend nematic phases
in Journal of Materials Chemistry C
Tian L
(2013)
The magnitude and temperature dependence of the Kerr constant in liquid crystal blue phases and the dark conglomerate phase
in Liquid Crystals
Srigengan S
(2018)
Anomalously low twist and bend elastic constants in an oxadiazole-based bent-core nematic liquid crystal and its mixtures; contributions of spontaneous chirality and polarity
in Journal of Materials Chemistry C
Nagaraj M
(2014)
Unusual electric-field-induced transformations in the dark conglomerate phase of a bent-core liquid crystal
in Liquid Crystals
Nagaraj M
(2015)
Understanding the unusual reorganization of the nanostructure of a dark conglomerate phase.
in Physical review. E, Statistical, nonlinear, and soft matter physics
Nagaraj M
(2014)
Electrically tunable refractive index in the dark conglomerate phase of a bent-core liquid crystal
in Applied Physics Letters
Milton HE
(2014)
Field-induced refractive index variation in the dark conglomerate phase for polarization-independent switchable liquid crystal lenses.
in Applied optics
Kaur S
(2014)
Flexoelectricity in an oxadiazole bent-core nematic liquid crystal
in Applied Physics Letters
Kaur S
(2011)
Nonstandard electroconvection in a bent-core oxadiazole material.
in Physical review. E, Statistical, nonlinear, and soft matter physics
Kaur S
(2013)
The elastic and optical properties of a bent-core thiadiazole nematic liquid crystal: the role of the bend angle
in Journal of Materials Chemistry C
Kaur S
(2013)
The influence of structure on the elastic, optical and dielectric properties of nematic phases formed from bent-core molecules
in Journal of Materials Chemistry C
Kaur S
(2016)
Elastic properties of bent-core nematic liquid crystals: the role of the bend angle
in Liquid Crystals
Kaur S
(2012)
Understanding the distinctive elastic constants in an oxadiazole bent-core nematic liquid crystal.
in Physical review. E, Statistical, nonlinear, and soft matter physics
Gleeson HF
(2014)
The nematic phases of bent-core liquid crystals.
in Chemphyschem : a European journal of chemical physics and physical chemistry
Gleeson HF
(2011)
Comment on "Raman scattering study of phase biaxiality in a thermotropic bent-core nematic liquid crystal".
in Physical review letters
Gleeson HF
(2018)
Self-assembling, macroscopically oriented, polymer filaments; a doubly nematic organogel.
in Soft matter
Gleeson H
(2015)
Liquid crystal blue phases: stability, field effects and alignment
in Liquid Crystals
Gleeson H
(2010)
Optical measurements of orientational order in uniaxial and biaxial nematic liquid crystals
in Liquid Crystals
Belaissaoui A
(2013)
Mesogenic properties of two 1,3,4-oxadiazole-based bent-core geometrical isomers
in Liquid Crystals
Belaissaoui A
(2013)
Spontaneous formation of chiral macrostructures in achiral hockey-stick liquid crystals
in Liquid Crystals
Addis J
(2016)
Second-harmonic generation and the influence of flexoelectricity in the nematic phases of bent-core oxadiazoles
in Liquid Crystals
Description | This award aimed to understand the potential of bent core liquid crystals for biaxial nematic phases and therefore their possible impact in devices. We have developed a detailed understanding of (a) what influences the formation of nematic phases in bent core liquid crystals; (b) evidence of biaxiality and methods of measurement; (c) a deep understanding of elasticity in bent-core liquid crystals; (d) observation of a new kind of dark conglomerate phase; (e) measurement of optical nonlinearity in bent-core systems, (f) understanding the Kerr effect in bent-core systems. |
Exploitation Route | 1. Modifying the elastic constants of liquid crystals - of importance in tuning LC display device characteristics. 2. The new electro-optic effect discovered in the dark conglomerate phase has potential for completely new kinds of photonic devices. |
Sectors | Aerospace, Defence and Marine,Chemicals,Education,Electronics,Energy |
Description | The discoveries made in this award are in their infancy, but have possible impact in devices. We were unsuccessful in gaining further funding in the last period but will continue to pursue opportunities. |
First Year Of Impact | 2014 |
Sector | Electronics |
Description | Novel Electro-optic and Photonic Behaviours in Bent Core Liquid Crystals |
Amount | £104,793 (GBP) |
Funding ID | EP/L012111/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 01/2014 |
End | 06/2015 |