Optical Study of Liquid Crystal Doped with Multiwalled Carbon Nanotube

Abstract

Liquid crystalline materials have been useful for display devices i.e watches, calculators, automobile dashboards, televisions, multi media projectors etc. as well as in electro tunable lasers, optical fibers and lenses. Carbon nanotube is chosen as the main experimental factor in this study as it has been observed that Carbon Nano Tube influence the existing properties of liquid crystal host and with the doping of CNT can enhance1 the properties of LC. The combination of carbon nanotube (CNT) and liquid crystal (LC) materials show considerable interest in the scientific community due to unique physical properties of CNT in liquid crystal. Dispersion of CNTs in LCs can provide us a cheap, simple, versatile and effective means of controlling nanotube orientation on macroscopic scale with no restrictions on nanotube type. LCs have the long range orientational order rendering them to be anisotropic phases. If CNTs can be well dispersed in LC matrix, they will align with their long axes along the LC director to minimize distortions of the LC director field and the free energy. In this paper, we doped liquid crystal (Cholesteryl Nonanoate) by a small amount of multiwall carbon nanotube 0.05% and 0.1% wt. We found that by adding carbon nanotube to liquid crystals the melting point of the mixture is decreased but TNI is increased. It has been also observed that with incereas in concentration of carbon nanotube into liquid crystal shows conciderable effect on LC. The prepared samples were characterized using various techniques to study structural, thermal and optical properties i.e PMS, FPSS, UV-Vis spectroscopy, FT-IR measurements, and DTA.

Effects of Dispersed Carbon Nanotubes and Emerging Supramolecular Structures on Phase Transitions in Liquid Crystals: Physico-Chemical Aspects

“…An explanation could be based either on the formation of CNT aggregates of stacking type, or by preferential positioning of the dispersed CNTs at topological defects of the cholesteric texture. A similar study was carried out in [171], where carbon nanotubes were added to cholesteryl nonanoate; however, since the authors used only two discrete concentrations of CNTs, they could not notice anything particular.…”

Effect of Temperature and Concentration on the Physical Properties of Cholesteryl Pelargonate Near Transition Temperatures

“…These colorful images or textures are the fingerprints that help us identify the type of mesophase liquid crystal is in, thereby revealing phase transition temperatures. Each liquid crystal phase exhibits a distinct optical texture when viewed under polarizing microscopy [17,18]. Different images of Cholesteryl Pelargonate were captured for each phase during the heating and cooling cycles.…”

Optical and Thermal studies on CNT doped Liquid Crystal Mixtures

“…MWCNTs have interesting set of properties. Hence they have a wide variety of potential applications in liquid suspensions, polymer solutions, polymer melts, and polymer composites [11][12][13].…”

“…The studies on LC composites, filled with nanoscale colloidal particles present a great scientific and practical interest due to their applications in electromechanical memory, super-elongation, anomalous electro kinetic dispersion and ultra-low percolation thresholds [5,7,8,11,13].…”