Theoretical Approach to Study Assembly Nature of Molecular Modeling System of Carbon Nanotube and a Nematic Liquid Crystal

Abstract

Theoretical study for stable geometries of a nematic liquid crystal (LC) molecule assembled on the carbon nanotubes (CNT) wall by using semi-empirical molecular quantum calculations within the PM3 method as implemented in Hyperchem package. The interaction influence of ,-stacking between N-4`-Methoxybenzylidine-4-n-butylaniline (MBBA) liquid crystal molecule on the CNT wall led to formation of the local short range orientation order by LC molecules on the surface of the CNT due to the LC-CNT binding energy (,-stacking). The binding energy of the LC molecule on the CNT wall was within the typical van der Waals interaction. This binding originated from the electrostatic energy by a significant amount of charge transfer from the LC molecule to the CNT.

Molecular design of some semi-alicyclic polyimides as a route to improve refraction and dielectric properties for liquid crystal display applications

“…Given the fact that both MBBA and 5CB LCs are complex in terms of electrostatic features, we also included in the study a simpler model from 5CB series, namely cyanobiphenyl (0CB). Some details concerning the properties of these LCs are reported in other works, [30][31][32] which indicate that MBBA, 5CB, and 0CB have dipole moments of 2.32D, 6.50D, and 4.4 2D, respectively. The influence of the dianhydride moieties on the interaction ability with MBBA, 5CB, and 0CB was assessed in this work and presented in Figure 4.…”

Theoretical Approach to Study Self-Organizing Properties of a Nematic Liquid Crystal With Carbon Nanosolid Models

“…LC molecule (MBBA) is considered as a typical model for calculations. In addition to one azomethane fragment as a mesogenic group, the LC molecule has two hexagonal head parts with methoxy fragment and an alkyl chain tail part [14]. The head part contains a polar terminal group or polar lateral group, and it mainly determines the dielectric anisotropy () of the superfluorinated LC molecule [9].…”

“…According to a previous study [14], the total energy of MBBA molecule structure was determined using PM3 method, and its most stable geometry is shown in Figure 1. The LC molecule contains N, O, and C atoms, with an overall negative charge for the whole structure.…”

“…Andrienko [13] used molecular dynamics simulations to examine the defects in the structures and torque around a spherocylinder and a rod of infinite length placed in a nematic phase. In a previous paper [14], we presented a theoretical approach using semi-empirical quantum calculation for predicting stable geometries of N-4`-Methoxy-benzylidine-4-n-butylaniline (MBBA) molecules assembled on single CNT wall (zigzag type). It is well known from the calculated data [14] that the process of MBBA adsorption on CNT occurs by π-π stacking between CNT and LC, resulting in almost flat-laying LC molecules.…”

“…In a previous paper [14], we presented a theoretical approach using semi-empirical quantum calculation for predicting stable geometries of N-4`-Methoxy-benzylidine-4-n-butylaniline (MBBA) molecules assembled on single CNT wall (zigzag type). It is well known from the calculated data [14] that the process of MBBA adsorption on CNT occurs by π-π stacking between CNT and LC, resulting in almost flat-laying LC molecules. Therefore, there is a necessity for demonstrating the specific relationships by comparing and analyzing the nature of molecular ordering interactions between a nematic liquid crystal (MBBA) and different kinds of CNS (graphite sheet and CNT: zigzag, armchair).…”