Monolithic Chiral Nematic Organization of Cellulose Nanocrystals under Capillary Confinement

ACS Nano ◽  
2021 ◽  
Author(s):  
Minkyu Kim ◽  
Kellina Pierce ◽  
Michelle Krecker ◽  
Daria Bukharina ◽  
Katarina Adstedt ◽  
...  
Keyword(s):  
Cellulose Nanocrystals ◽  
Chiral Nematic

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.

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.

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

scholarly journals Sol-Gel Biotemplating Route with Cellulose Nanocrystals to Design Photocatalyst Boosting the Hydrogen Generation

2020 ◽  
Author(s):  
cong wand ◽  
jian li ◽  
Erwan Paineau ◽  
Abdelghani Laachachi ◽  
Christophe Colbeau-Justin ◽  
...  
Keyword(s):  
Cellulose Nanocrystals ◽  
Hydrogen Generation ◽  
Light Harvesting ◽  
Sol Gel ◽  
Charge Carriers ◽  
Hybrid Films ◽  
One Pot ◽  
Chiral Nematic ◽  
Straightforward Method ◽  
Chiral Nematic Structure

<br> <div> <p>Light harvesting capability and charge carriers lifetime play critical roles in determining the photoefficency of photocatalyst. Herein, a one-pot method is proposed to design mesostructured TiO<sub>2</sub> materials by taking advantage of the ability of cellulose nanocrystals (CNC) to self-assemble into chiral nematic structures during solvent evaporation. After the xerogel formation, the as-obtained CNC/TiO<sub>2</sub> hybrid films exhibit a chiral nematic structure and tunable Bragg peak reflection, generating lamellar TiO<sub>2</sub> mesostructure after the biotemplate removal by calcination. More prominently, this straightforward method can be extended to couple TiO<sub>2</sub> with other metal oxides, improving the light-harvesting and charge carriers separation of these photocatalysts, in particular for boosting hydrogen generation. This foolproof approach opens new doors for the development of nanostructured materials for solar energy conversion and catalysis.<br></p></div>

scholarly journals Lateral Gradient Ambidextrous Optical Reflection in Self-Organized Left-Handed Chiral Nematic Cellulose Nanocrystals Films

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiawei Tao ◽  
Jiaqi Li ◽  
Xiao Yu ◽  
Lihong Wei ◽  
Yan Xu
Keyword(s):  
Cellulose Nanocrystals ◽  
Self Assembly ◽  
Circularly Polarized ◽  
Optical Reflection ◽  
Self Organized ◽  
Left Handed ◽  
Assembly Method ◽  
Chiral Nematic ◽  
Half Wavelength ◽  
Film Substrate

Artificial photonic materials displaying ordered reflected color patterns are desirable in the field of photonic technologies, however, it is challenging to realize. Here we present that self-assembly of cellulose nanocrystals (CNC) in a tilted cuvette leads to the formation of rainbow color CNC films. We show that the self-organized CNC films enable simultaneous reflection of left-handed circularly polarized (LCP) and right-handed circularly polarized (RCP) light with lateral gradient transmittance ratio (LCP/RCP: 8.7–0.9) and the maximum reflectance value up to ca. 72%. This unique ambidextrous optical reflection arises from left-handed chiral photonic architectures with lateral gradient photonic bandgaps and nematic-like defects at the film-substrate interface and between left-handed photonic bandgap layers acting as a half-wavelength retarder. We demonstrate that the tilted angle self-assembly method provides a feasible step toward color patterning of CNC-based photonic films capable of ambidextrous optical reflection.

Cellulose nanocrystals in nanoarchitectonics – towards photonic functional materials

2019 ◽  
Vol 4 (1) ◽  
pp. 29-48 ◽  
Author(s):  
Michael Giese ◽  
Matthias Spengler
Keyword(s):  
Cellulose Nanocrystals ◽  
Self Assembly ◽  
Functional Materials ◽  
Chiral Nematic ◽  
Application Potential

This review summarizes the recent achievements in the development of photonic functional materials based on cellulose nanocrystals (CNCs) and CNC templating. The unique self-assembly of CNCs into chiral nematic structures introduces photonic properties for the development of functional materials with application potential in photonic sensing, tunable reflectors or optoelectronics.

Sign in / Sign up

Export Citation Format

Share Document