Smectic liquid-crystalline physical gels. Anisotropic self-aggregation of hydrogen-bonded molecules in layered structures

1999 ◽  
pp. 781-782 ◽  
Author(s):  
Norihiro Mizoshita ◽  
Takaaki Kutsuna ◽  
Takashi Kato ◽  
Kenji Hanabusa
Keyword(s):  
Liquid Crystalline ◽  
Layered Structures ◽  
Self Aggregation ◽  
Hydrogen Bonded

scholarly journals Thermally tunable selective formation of self-assembled fibers into two orthogonal directions in oriented liquid-crystalline smectic templates

2020 ◽  
Vol 56 (69) ◽  
pp. 9954-9957
Author(s):  
Daisuke Yamaguchi ◽  
Yuka Ikemoto ◽  
Takashi Kato
Keyword(s):  
Molecular Weight ◽  
Self Assembly ◽  
Liquid Crystalline ◽  
Layered Structures ◽  
Low Molecular Weight ◽  
Smectic A ◽  
Orthogonal Grid ◽  
Self Assembled ◽  
Low Molecular Weight Gelators ◽  
Selective Formation

Two orthogonal (grid-like) and one directional fibrous structures are selectively formed through anisotropic self-assembly of low-molecular-weight gelators in liquid-crystalline smectic A templates depending on thermally tuned layered structures.

Dielectric properties of a hydrogen-bonded liquid-crystalline side-chain polymer

1995 ◽  
Vol 16 (10) ◽  
pp. 733-739 ◽  
Author(s):  
Kazuo Araki ◽  
Takashi Kato ◽  
Uday Kumar ◽  
Jean M. J. Fréchet
Keyword(s):  
Dielectric Properties ◽  
Liquid Crystalline ◽  
Side Chain ◽  
Chain Polymer ◽  
Hydrogen Bonded

Experimental and computational (DFT) studies on induced orthogonal smectic A∗ phase in hydrogen-bonded ferroelectric liquid crystals

2018 ◽  
Vol 32 (21) ◽  
pp. 1850223 ◽  
Author(s):  
P. Subhasri ◽  
R. Jayaprakasam ◽  
V. N. Vijayakumar
Keyword(s):  
Liquid Crystals ◽  
Molecular Orbital ◽  
Density Functional ◽  
Liquid Crystalline ◽  
Proton Acceptor ◽  
Dft Studies ◽  
Ferroelectric Liquid Crystals ◽  
Smectic A ◽  
Present Complex ◽  
Hydrogen Bonded

Hydrogen-bonded ferroelectric liquid crystals (HBFLC) are designed and synthesized from nonmesogenic chiral proton donor compound of (R)-([Formula: see text])-Methylsuccinic acid (MSA) and mesogenic proton acceptor compound of 4-undecyloxybenzoic acid (11OBA) in a different mole ratio. Intermolecular hydrogen bonds (H-bond) between the nonmesogenic and mesogenic compounds have been confirmed through experimental Fourier transform infrared spectroscopy (FTIR) and density functional theory (DFT) computational studies. The steric hindrance and inductive effects of the present complex and its influence on the structure are discussed. A rich phase polymorphism in the liquid crystalline complex has been studied using polarizing optical microscope (POM) and differential scanning calorimetry (DSC). The chiral phases observed in the present complex are due to the presence of lone pair (n) to anti-bonding ([Formula: see text]) transition symmetry which is validated by DFT studies. A noteworthy observation of induced smectic A[Formula: see text](Sm A[Formula: see text]) by quenching of traditional phase (nematic) has been identified and the reason for the same has been discussed by DFT studies. The unusual phase order of Sm A[Formula: see text], smectic C[Formula: see text](Sm C[Formula: see text]) and smectic G[Formula: see text][Formula: see text](Sm G[Formula: see text]) mesogenic phases are observed. The other liquid crystalline parameters are evaluated by experimental and theoretical calculations and the same has been compared. Increased tilt angle in liquid crystal (LC) molecules has been theoretically analyzed by natural bond orbital (NBO) studies. Stability of the HBFLC phases and its origination mechanism have been discussed with the help of highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO–LUMO) energies.

Hierarchical nanostructures of a liquid crystalline block copolymer with a hydrogen-bonded calamitic mesogen

Polymer ◽  
2019 ◽  
Vol 182 ◽  
pp. 121835 ◽  
Author(s):  
Hongbing Pan ◽  
Anqi Xiao ◽  
Wei Zhang ◽  
Longfei Luo ◽  
Zhihao Shen ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Liquid Crystalline ◽  
Hierarchical Nanostructures ◽  
Hydrogen Bonded

Liquid Crystalline Nano-Segregated Structures in Hydrogen-Bonded Complexes of Fluoroalkyl Substituted Benzoic Acids

2001 ◽  
Vol 709 ◽  
Author(s):  
Etsushi Nishikawa ◽  
Jun Yamamoto ◽  
Hiroshi Yokoyama
Keyword(s):  
Phase Transition ◽  
Liquid Crystalline ◽  
Cubic Phase ◽  
Benzoic Acid Derivatives ◽  
Smectic C ◽  
Texture Change ◽  
Double Gyroid ◽  
Substituted Benzoic Acids ◽  
Bonded Complexes ◽  
Hydrogen Bonded

ABSTRACTSeveral new benzoic acid derivatives having perfluorinated substituents were synthesized and their hydrogen-bonded complexes with 4, 4’-dipyridyl were prepared. In these acid/base complexes the incompatibility between perfluoroalkyl moieties and hydrocarbon parts is large, which can lead to organize nano-segregation structures. We have found in one of such complexes, that has a long flexible fluorinated moiety, a thermotropic cubic phase with Ia3d symmetry formed by double gyroid of two interpenetrating jointed rod networks with an estimated cell parameter of 10.9 nm. Furthermore another complex with a branched long perfluoroalkyl terminal chain exhibits a first order smectic A to smectic C phase transition, which is confirmed with thermal analysis detecting a large enthalpy change of 5.3 kJxmol-1, X-ray scattering experiments revealing a tilt angle jump, and polarized optical microscopy observing a remarkable texture change at the phase transition temperature.

Sign in / Sign up

Export Citation Format

Share Document