The College of Education for Pure Sciences, Department of Physics, University of Basra organized a scientific lecture on the study of the nonlinear electrical and optical properties of some liquid crystalline compounds.
The lecture presented by a doctoral student (Harith Abdul Razzaq Hassan) included the definition of liquid crystals, liquid crystal phases, and classifications of liquid crystals based on the method of displaying the liquid crystal phase and the form of molecular anisotropy. Preparation of an organic compound in two steps. The first is the linking of terminal chains with both the primary amine and aldehyde in a method called alkalization using the appropriate alkyl, and the second step is the reaction of stoichiometric moles of the amine and aldehyde produced from the first step to form the organic compound in which the linking part is of the Schiff base type or liquid imine, and after using diagnostic methods for the compound, it was found that it shows the smectic liquid crystal phase, and one of the methods for diagnosing liquid crystal compounds is the FTIR to identify the effective aggregates of the compound, polarized light microscopy (POM) to identify the structural structure of the texture phase. The compound showed the smectic crystal phase with the use of analysis Thermal data by the DSC device to identify the thermal data such as the degree of transition to the liquid crystal phase and the random isotropic phase and the amount of enthalpy change during the transition between phases. Variation plus threshold voltage determination, and Then the samples of liquid crystal compounds were dotted with photoactive dyes rhodamine and fluorescein in order to enhance the contrast in the physical properties as well as the non-linear properties in order to reduce the working voltage and take advantage of that in the applications of liquid crystal display machines, especially the application of the in-plane switching liquid crystal display method and the application of the display with Liquid crystal display Twisted switching.
The purpose of the lecture
Preparation and study of properties of compounds that show liquid crystalline properties with identification of variance in some physical properties and how to enhance this variance and benefit from it in some important applications of liquid crystalline compounds.