LIQUIDXTAL · Energy landscapes of soft matter: From super-cooled liquids to liquid crystals
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2006-11-01 → 2008-10-31
- EU contribution
- €169,365
- Participants
- 1
- Scheme
- IIF
Lines connect the coordinator with its partners.
Results in brief
Final Activity Report Summary - LIQUIDXTAL (Energy landscapes of soft matter: From super-cooled liquids to liquid crystals)
Soft matter includes seemingly diverse condensed matter systems. The concepts of broken symmetry and order parameter play an important unifying role to link homogeneous isotropic liquids with short-range order at one end of the spectrum, and liquid crystals with long-range order in their anisotropic mesophases, at the other. Anisotropy in the molecular shape plays a crucial role in the rich phase behaviour that thermotropic liquid crystals exhibit upon temperature variation. Calamitic liquid crystals consist of rod-like molecules; discotic liquid crystals comprise disc-like molecules. In the absence of sufficient anisotropy in shape, an isotropic liquid can be supercooled below its freezing temperature by cooling fast enough to avoid crystallisation. The project undertaken was aimed at understanding the structure, thermodynamics, and dynamics of thermotropic liquid crystals and supercooled liquids, in a computational approach employing coarse-grained models, with special emphasis on the study of the underlying potential energy surface. We have presented the energy landscape view of phase transitions and slow dynamics in thermotropic liquid crystals. A striking similarity between thermotropic liquid crystals and supercooled liquids in the exploration of the energy landscape has been revealed. The correspondence between the onset of temperature-dependent exploration of the energy landscape and the breakdown of Arrhenius behaviour for relaxation times may suggest a common landscape mechanism for slow dynamics in soft matter systems. Our study on the phase behaviour of discotic liquid crystals has provided insight into the molecular origin of apparently counter-intuitive spatial organisation of the discogens in the columnar phase. Such understanding has important implications for the rational design of materials with useful optoelectronic applications. To further our understanding, we have explored routes to helicity for assembly of achiral building blocks. The study suggests that the existence of two competing length scales for intermolecular interactions is the key to the emergence of helicity. We have developed a general, efficient, and robust framework of geometry optimisation for rigid bodies. This computational framework has opened up a plethora of opportunities for studying diverse applications.
Data: CORDIS, © European Union
Project objective
This proposal aims at understanding thermodynamics and dynamics of soft condensed matter in terms of the underlying potential energy landscape (PEL). We are particularly interested in supercooled liquids and thermotropic liquid crystals, the latter being known to display rich phase behaviour.Recent studies have revealed marked similarities in the dynamics between supercooled liquids and thermotropic liquid crystals, despite their diverse physical nature. Discovering a general relation between the onset of slow dynamics and the temperature-dependent exploration of the underlying PEL would be of great interest.We aim to characterize a unifying landscape mechanism for slow dynamics in soft matter. To understand the fundamental basis for the observed similarities, we propose to characterize the PEL of a variety of model systems in terms of local minima and the transition states that connect them. Thermodynamic and dynamic properties will then be computed through simulations using methods developed in the host group.The project will therefore combine the expertise of the applicant in soft matter with that in the energy landscape formalism of the host. A key feature of the proposal will be the treatment of orientational degrees of freedom and their interplay with translational coordinates.The interdisciplinary nature of the proposal, with applications to diverse physical systems, would appeal to a wide scientific community. Soft condensed matter is ubiquitous in nature and finds a wide range of application s, from household use to the development of cutting-edge technologies.Further development of fundamental knowledge of the dynamics of these systems would certainly be helpful for engineering these applications (for example, the use of liquid crystals in displays). Moreover, our approach will yield results on the phase transition characteristics of materials that are of prime technological importance in the design of novel materials.
Original text from CORDIS.
Participants
- University of Cambridge · CambridgeCoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union