Synthesis and Characterization of Bent‐Core Liquid Crystal / Modified γ‐Al₂O₃ Nanocomposites

Abstract

A new bent-core liquid crystal (LC) compound CPDB derived from a 4-chlororesorcinol central core unit with two terephthalate based rod-like units carrying chiral (S)-3,7-dimethyloctyloxy terminal chains has been synthesized and LC / modified γ-Al 2 O 3 nanocomposites have been prepared in different compositions. The effects of being doped with 0.3, 0.5, 1.0, 2.0, 3.0 and 4.0% modified γ-Al 2 O 3 nanoparticles on mesomorphic properties of the new bent-core liquid crystal, which shows an enantiotropic SmA phase, were investigated by differential scanning calorimetry and optical polarizing microscopy. The surface of γ-Al 2 O 3 nanoparticles was modified with a cationic agent, cetyltrimethyl ammonium bromide (CTAB), used as a compatibilizer for providing interaction of liquid crystal molecule with alumina nanoparticles. The immobilization of CTAB on γ-Al 2 O 3 nanoparticle surface via physical adsorption in solution was confirmed by TGA and preserved of crystalline structure of aluminium oxide was proved by XRD analysis. The presence and homogeneous distribution of alumina nanoparticles in LC were confirmed by using Scanning Electron Microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy. The modified γ-Al 2 O 3 nanoparticles in CPDB liquid crystal give rise to a slight increase in the mesomorphic range by preserving mesophase type as observed in pure liquid crystalline compound.

Preparation, Characterization, and Application of Polyacrylamide‐Polystyrene/Bentonite Nanocomposite as an Effective Immobilizing Adsorbent for Remediation of Soil

“…The second weight loss step, which is started at about 400 °C and ended at 700 °C (about 5%), may be related to the water molecules which are located between the layers of bentonite. TGA analysis of polyacrylamide‐polystyrene/bentonite (Figure ) shows about 70% weight loss between 100 °C and 700 °C which is related to desorption of water molecules located inside the layers of nanocomposite, external surface of nanocomposite and degradation of polymer chains that are located between the layers of bentonite . Therefore, it can be concluded that polymer chains are successfully loaded on the surfaces of bentonite.…”

A Mesoporous Silica Nanoparticle-Doped Photo-Alignment Layer and Liquid Crystal Layer for Optimizing the Rewriting Speed and the Response Time of Optically Driving Liquid Crystal Displays

“…It is already dominating many display markets such as phone products, notebook computer displays, and desktop monitors. Furthermore, LC also found a place in digital data storage, holography, color thermometers, smart windows, optical and biological sensors, and GHz and THz devices [3][4][5][6][7][8][9][10].…”