Temperature-induced chiral nematic phase changes of suspensions of poly(N,N-dimethylaminoethyl methacrylate)-grafted cellulose nanocrystals

Cellulose ◽  
2009 ◽  
Vol 16 (6) ◽  
pp. 989-997 ◽  
Author(s):  
Jie Yi ◽  
Qunxing Xu ◽  
Xuefei Zhang ◽  
Hailiang Zhang
Keyword(s):  
Cellulose Nanocrystals ◽  
Nematic Phase ◽  
Phase Changes ◽  
Dimethylaminoethyl Methacrylate ◽  
Chiral Nematic

scholarly journals Self-ordered cellulose nanocrystals and microscopic investigations

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
C.F. Castro-Guerrero ◽  
A.B. Morales-Cepeda ◽  
M.R. Díaz-Guillén ◽  
F. Delgado-Arroyo ◽  
F.A. López-González
Keyword(s):  
Cellulose Nanocrystals ◽  
Self Assembly ◽  
Nematic Phase ◽  
Average Length ◽  
Periodic Change ◽  
Local Orientation ◽  
Preferred Direction ◽  
Self Assembling ◽  
Chiral Nematic ◽  
Assembly Structure

Abstract Cellulose nanocrystals were extracted from cotton. The cellulose nanocrystals made a self-assembly structure when dried under slow conditions, as it was revealed by the characterization made to the material. The AFM images of the nanocrystals showed that they had a changing local orientation, pointing in a preferred direction that underwent a periodic change. This periodic change resembles the orientation of a chiral nematic phase. The TEM images showed that the nanocrystals had a rod-like appearance with average length size of 98.5 nm and a diameter of 4.7 nm. The TEM characterization showed the nanocrystals with more details than AFM. In this paper, the self-assembling of CNC was observed by AFM, and further investigations were done by TEM, deconvoluting the process of CNC nanorods aggregation.

scholarly journals Concentric chiral nematic polymeric fibers from cellulose nanocrystals

2021 ◽  
Author(s):  
Arash Momeni ◽  
Christopher M. Walters ◽  
Yi-Tao Xu ◽  
Wadood Y. Hamad ◽  
Mark J. MacLachlan
Keyword(s):  
Cellulose Nanocrystals ◽  
Liquid Crystalline ◽  
Capillary Tube ◽  
Single Domain ◽  
Cellulose Nanocrystal ◽  
Polymeric Fibers ◽  
Chiral Nematic ◽  
Chiral Nematic Structure ◽  
Crystalline Suspension

A cellulose nanocrystal liquid crystalline suspension was mixed with monomers and confined to a capillary tube. After photopolymerization, a fiber with a single-domain concentric chiral nematic structure throughout the length of the fiber was obtained.

scholarly journals Nanocomposites of Polyaniline and Cellulose Nanocrystals Prepared in Lyotropic Chiral Nematic Liquid Crystals

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Dawei Zhang ◽  
Lihong Zhang ◽  
Bingzhe Wang ◽  
Guangzhe Piao
Keyword(s):  
Liquid Crystals ◽  
Cellulose Nanocrystals ◽  
Nematic Liquid Crystals ◽  
Weight Ratio ◽  
Asymmetric Reaction ◽  
Reaction Field ◽  
Electron Microscopies ◽  
Chiral Nematic ◽  
Before And After

Stable lyotropic chiral nematic liquid crystals (N*-LCs) of cellulose nanocrystals (CNs) were prepared via hydrolysis using sulfuric acid. The lyotropic N*-LCs were used as an asymmetric reaction field to synthesize polyaniline (PANI) onto CNs by in situ polymerization. As a primary step, we examined the mesophase transition of the N*-LCs of CNs suspension before and after in situ polymerization of aniline (ANI) by polarizing optical microscopy. The structure of nanocomposites of PANI/CNs was investigated at a microscopic level using Fourier transform infrared spectroscopy and X-ray diffraction. Influence of the CNs-to-ANI ratio on the morphology of the nanocomposites was also investigated at macroscopic level by scanning electron and transmission electron microscopies. It is found that the weight ratio of CNs to aniline in the suspension significantly influenced the size of the PANI particles and interaction between CNs and PANI. Moreover, electrical properties of the obtained PANI/CNs films were studied using standard four-probe technique. It is expected that the lyotropic N*-LCs of CNs might be available for an asymmetric reaction field to produce novel composites of conjugated materials.

Circular Dichroism of Chiral Nematic Films of Cellulose Nanocrystals Loaded with Plasmonic Nanoparticles

ACS Nano ◽  
2015 ◽  
Vol 9 (10) ◽  
pp. 10377-10385 ◽  
Author(s):  
Ana Querejeta-Fernández ◽  
Bernd Kopera ◽  
Karen S. Prado ◽  
Anna Klinkova ◽  
Myriam Methot ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Cellulose Nanocrystals ◽  
Plasmonic Nanoparticles ◽  
Chiral Nematic ◽  
Circular Dichroïsm

PBLG as a versatile liquid crystalline medium for anisotropic NMR data acquisition

2019 ◽  
Vol 55 (30) ◽  
pp. 4327-4330 ◽  
Author(s):  
Ikenna E. Ndukwe ◽  
Xiao Wang ◽  
István Pelczer ◽  
Mikhail Reibarkh ◽  
R. Thomas Williamson ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Solvent System ◽  
High Quality ◽  
Nmr Data ◽  
Chiral Nematic ◽  
Liquid Crystalline Medium ◽  
Crystalline Medium

The chiral nematic phase of poly-γ-benzyl-l-glutamate (PBLG) formed in a chloroform–DMSO co-solvent system can be used as a versatile alignment medium for the acquisition of high quality anisotropic NMR data for molecules of varying polarities.

Electroclinic effect around a smectic A-chiral nematic phase transition

2002 ◽  
Vol 29 (9) ◽  
pp. 1251-1251
Author(s):  
C. L. Folcia ◽  
J. Ortega ◽  
J. Etxebarria
Keyword(s):  
Phase Transition ◽  
Nematic Phase ◽  
Smectic A ◽  
Chiral Nematic
Sign in / Sign up

Export Citation Format

Share Document