In the present study, the optical and thermal properties of a liquid crystal polymer system (LCPS) dispersed with different concentrations of quantum dots (QD) like cadmium sulphide (CdS) and zinc sulphide (ZnS) were investigated using polarized optical microscopy (POM). The texture and structural parameters of LCPS with different concentrations of dopant were compared to understanding the effect of quantum dots on the optical, thermal, phase transition, and structural properties of LCPS. Our investigation shows an increase in phase transition temperature after dispersing the quantum dots into LCPS. These investigations may be useful for new device applications that require higher phase transition temperature.

In the present study the effect of two quantum dots ZnS and CdSe on the Refractive Index of Nematic Liquid Crystal Polymer System (NLCPS) is investigated and compared. The measurement was performed for both the systems separately, using an Abbe Refractometer, within a temperature range of 20°C to 80°C with wavelengths in the visible spectrum. The refractive index with respect to temperature for various wavelengths was studied. We observed that the response of ZnS quantum dots dispersed in NLCPS was found to be better as compared to the CdSe system. This study may be useful for display and sensor applications.

Polymer dispersed liquid crystals are functional materials which can enhance optical, electrical, thermal and mechanical properties. These materials have combined applications of liquid crystal in addition to polymer. In the present paper, an effort is made to study the effect of polymer concentration on optical and electrical properties of liquid crystal which was investigated by various characterization techniques. The fabry perot scattering studies were used to investigate optical properties in addition to the phase transition temperature whereas the dielectric and conductivity measurement were done by impedance analyzer. The phase transition temperature for the composite material was found higher as compared to the pure liquid crystal. Our investigation reveals enhancement in strength, proper contrast ratio with good visibility, changes in the orientation of the composite material which provides an opportunity and potential photonics application such as light emitting diode and image sensors.Copyright (c) 2021 Elsevier Ltd. All rights reserved.Selection and peer-review under responsibility of the scientific committee of the International Confer-ence Additive Manufacturing and Advanced Materials-AM2 2021.

The compound material prepared by dispersing polymer into liquid crystal is of importance due to the improvement in its electro-optical properties. Polymer dispersed liquid crystal (PDLC) is a functional material, of less than micron size liquid crystal, chemically dispersed in a polymer matrix. We report the influences of different concentrations of polymer, on the optical and dielectric behaviour of cholesteric liquid crystals. The fabry perot scattering studies in addition to polarizing optical microscopy were used to study the optical properties. Several novel phases in addition with the known phases were found for the compound materials. The dispersion also results in the large value of dielectric anisotropy which indicates possibility of this material to be used in forming a photo cured network. Our investigation shows a non-zero value of distribution parameter and also increase in dielectric constant, which is useful for display applications.

The study of index of refraction of liquid crystals and its composite are of prime importance for understanding the fascinating optical properties as it depends on wavelength, temperature and molecular structure. In the present study the effect of two different polymers one Polymethyl Metha acrylate and another 2-Ethyl Hexyl Acrylate on the refractive index of nematic liquid crystal 4-cynophenyl 4-n-hexyl benzoate were investigated. The liquid crystal shows a good miscibility with two different polymers. The refractive index was measured by DSRλ within the visible spectral range 404-706nm for various temperatures. The composite material shows higher refractive index and the optical anisotropy of the liquid crystal are changed after dispersing polymer due to its polar order. This is important for optimizing display performance and photonic liquid crystal fibers. This shows potential applications of nematic liquid crystal dispersed with polymer for display applications by using the principle of refractive index matching.

The monomer dispersed liquid crystal is relatively new class of functional materials which has a numerous role in the modern technology. This research work reports the effect of two different concentrations of monomer 2-Ethyl Hexyl Acrylate with on liquid crystals of cholesteryl nonanoate. This monomer is selected due to its low volatile nature and reactivity of double bonds. The thermal behaviour of samples under investigations was studied by differential scanning calorimetry (DSC). The liquid crystal shows a good miscibility with both concentrations of monomer which were confirmed by Fourier transform infrared (FTIR) spectroscopy. The proposed research investigation reveals new phase transitions along with the known phase transitions for this composite system. It was also observed that in the nematic order, the molecules tend to align perpendicular to the surface. This opens a new possibility of this material to be used for variety of new applications like photo-cured network and photopolymer etc.

In the present study, effect of CNT on optical and thermal properties of mixed thermotropic liquid crystal mixture was studied by various techniques to understand their physical behavior. Some new mesophases have investigated by optical methods viz. Polarizing Optical Microscopy (POM) and Fabry–Perot Scattering Studies (FPSS). It has been observed that these new phase transition occur along with the known phase transition temperatures. These new phase transitions corresponding to new mesophases were also confirmed by thermal study using Differential Thermal Analysis (DTA). The CNT doped thermotropic liquid mixtures can be used in various display application such as LCD monitor with color variation to enhance performance. Copyright © 2018 VBRI Press.

The structures of ZnO nanoparticles (NPs) of different morphology (rod, flower, and grains) using Zinc chloride and zinc nitrate synthesis are carried out under ambient conditions. In this investigation, we report that ZnO NPs are effectively synthesized and exploited to exhibit the morphological effect of ZnO NPS on its reduction in photocatalytic methylene blue (MB) dye-degradation. UV-Visible spectra studies of the prepared ZnO NPs confirm the absorption peak at 377, 376.3, and 376 nm representative of the formation of ZnO NPs. Powder X-ray diffraction (XRD) results demonstrate that the strong, highly intense, and narrow-width diffraction peaks indicate the most stable crystalline hexagonal (Wurtzite) structure of ZnO NPs of rod, flower, and grains with average size about 20, 16.62, and 18.02 nm in diameter, respectively. According to field emission-scanning electron microscopy (FE-SEM), results confirm the development of ZnO NPs. In addition, the degradation efficiency of MB dye by ZnO (grain) reveals larger enhancement than the rod and flower with the highest adsorption of color after 0.067 min(-1).This study offers the mainstep forward in the field of diluted wastewaters in textile industries.

Ferroelectric nano-materials are very sensitive to several external stimuli and have attracted great deal of attention due to their property of improving various properties such as photoluminescence, higher polarization, fast response time, low operating voltage and improved conductivity. For enhancing the physical properties, a proper selection of nano-materials for liquid crystals depends upon various factors such as size, shape, preparation methods, surfactant concentration and amount of doping materials. In the present study an attempt is made to study electrical and acoustical properties of cholesteric liquid crystal after dispersing ferroelectric nano-powder of Barium Titanate (BaTiO3). In addition with this particle size and surface area of pure and nono-particle dispersed liquid crystal were also measured. Our investigation shows increase in Rao’s constant or molar sound velocity, which indicates increase in molecular density indicating a close packing of the material. The measurement of dielectric relaxation at different frequencies gives information about the dynamics of polar groups and molecular motion.

Liquid Crystals (LCs) have attracted significant attraction from scientific community due to their several applications. However, pure liquid crystals have main problem of slow response to various external stimuli and low heat resistance. These problems can be either eliminated/ reduced by using composite materials. Polymer Dispersed Liquid Crystal (PDLC) is a typical example of composite material which consists of nearly uniform sized droplets of a LC in a polymer matrix formed during the phase separation caused by a polymerization. The present study is an attempt to investigate optical and thermal response of PDLC for their technological applications. The textures and phase transition temperatures were studied by Polarizing Optical Microscopy (POM) which was confirmed by supplementary techniques of Differential Thermal Analysis (DTA). The functional groups present in the sample were studied by Fourier Transform Infrared (FTIR) Spectroscopy and Ultraviolet Visible (UV-VIS) Spectroscopy. In addition to these, Refractive Index (RI) is also determined to understand light propagation through this material. We found enhancement in optical and thermal properties of the composite material and changes in phase transition temperature along with new phase transition temperature.

In the present study, the optical, thermal, and mechanical properties of liquid crystal elastomers (LCEs) were investigated using various techniques. The presence of functional groups in LCE was studied using Fourier transform infrared spectroscopy. The phase transition temperatures were confirmed via polarizing optical microscopy and Fabry–Perot scattering studies. The differential thermal analysis was used for investigating the thermal behavior. A dynamic mechanical analysis was used to study the mechanical properties of LCE. The significant mechanical changes with a considerable reversible effect were observed for this soft material. The changes in the mechanical shape with the temperature are attributed to the change in the phase of the LCE material.