Self-assembly of chromonic liquid crystals: a combined experimental and theoretical approach.
Lead Research Organisation:
Durham University
Department Name: Chemistry
Abstract
The molecules that form chromonic liquid crystals are typically aromatics with hydrophilic groups on the periphery. These groups make the compounds soluble in water. Many dye and drug molecules are of this type. They are disc-like or plank-like in shape and have a strong tendency, even in dilute solution, to form long stacks, though layered phases have also been reported. These stacks may be positionally disordered (N phase) or they may be arranged in hexagonal patterns (M phase). Often the stacks are simple columns, though water-filled hollow chimney structures have also been proposed.The relationship between the molecular structure and the phase behaviour is very obscure. Seemingly small structural differences can have large effects on the phase diagram. This has practical implications, for unwanted aggregation of dye and drug molecules can render promising new formulations useless.In this proposal we seek to obtain a quantitative understanding of the structure-property relations of these chemicals. We will synthesise a series of naphthylamine sulphonic acid derivatives in which the chemical groups and the geometry are varied in a systematic way. We will experimentally examine the phase behaviour (varying also the salt concentration and the pH) and we will carry out computer simulation studies on state-of-the-art atomistic simulation models. We will also seek to develop simple theories to provide an underpinning framework to interpret these data. By combining synthesis, phase characterisation, simulation and theory in this systematic study, we aim to uncover the basic rules that govern the aggregation and phase properties of this important and fascinating class of molecules.
Organisations
People |
ORCID iD |
Mark Wilson (Principal Investigator) |
Publications
Walker M
(2014)
Self-assembly and mesophase formation in a non-ionic chromonic liquid crystal system: insights from dissipative particle dynamics simulations.
in Physical chemistry chemical physics : PCCP
Description | Have for the first time been able to make accurate predictions for the structure of self-assembled chromonic aggregates in solution. Have carried out the first atomistic simulation of a chromonic phase. Have shown that chromonic aggregates are dynamic in nature, and undergo structural changes in solution. Have shown that simulation is able to explain a range of previously contradictory experimental data on chromonic systems. Have shown, for an ionic chromonic, that counter ions are very weakly associated with the aggregates and undergo constant exchange with ions in solution. |
Exploitation Route | Simulations of this type could be used to predict self-assembly in solution for a range of molecular systems to understand the self-assembly process. This could be used to design molecular thin films or produce materials for use in a new generation of solar cells, or design new hybrid-organic-inorganic compounds through sol-gel processes. A simulation methodology is provided to predict NMR measurements in solution for dynamic systems, which show self-assembly. The uptake of drugs by the body, can be influenced by self-assembly of the drugs. It is important to know how this self-assembly can be changed in solution by small molecules or salts. Simulations of the type demonstrated in this grant provides a way of understanding and predicting this. |
Sectors | Chemicals Energy Pharmaceuticals and Medical Biotechnology |
Description | Chromonic phase behaviour based on planar discs functionalized with EO (ethylenoxy) groups |
Amount | £239,047 (GBP) |
Funding ID | EP/J004413/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 04/2012 |
End | 05/2015 |
Description | Modelling techniques for the calculation of solubility of additives in polymers |
Amount | £24,311 (GBP) |
Funding ID | RF030360 |
Organisation | Procter & Gamble |
Sector | Private |
Country | United States |
Start | 03/2012 |
End | 09/2012 |
Description | Modelling techniques for the calculation of solubility of additives in polymers |
Amount | £24,311 (GBP) |
Funding ID | RF030360 |
Organisation | Procter & Gamble |
Sector | Private |
Country | United States |
Start | 03/2012 |
End | 09/2012 |