Development of Liquid crystals as stimuli-responsive sensors [Phase 1]

This project aims to develop 5CB to 10CB liquid crystals as stimuli-responsive sensors for explosives and toxic gases, and smart windows application as well as for monitoring material failure. Liquid crystals are substances that exist in intermediate states between liquids and crystalline solids. They exhibit a large molecular anisotropic behaviour and intermolecular ordering that they are delicately sensitive to external stimuli such as temperature, light, electric and magnetic fields, and surface effects such the presence of foreign materials. It is this delicate sensitivity that forms the basis for their use as stimuli-responsive materials in various applications. In this phase of the project, our focus will be to study solvent-solute interactions of the liquid crystals in order to understand their behaviour in various solvent media. This is important in order to determine suitable solvents that may or may not be used with the liquid crystals for various applications such as in explosives and toxic gases detection, smart window application and material failure monitoring. Fluorescence spectroscopy, UV-Vis and Raman spectroscopy will be involved in this study. This will prepare ground for future phases of the project where we will develop liquid crystals as a sensor for explosives and other gases. Such future work will involve measurement of the polarized light microscopy images of the liquid crystals in the presence of various explosives such as sodium nitrate, sodium perchlorate, sodium chlorate, potassium nitrate, potassium perchlorate, potassium chlorate and ammonium nitrate, in addition to fluorescence and Raman spectra measurements.