Chiroptical, morphological and conducting properties of chiral nematic mesoporous cellulose/polypyrrole composite films

2017 ◽  
Vol 5 (36) ◽  
pp. 19184-19194 ◽  
Author(s):  
Erlantz Lizundia ◽  
Thanh-Dinh Nguyen ◽  
Jose L. Vilas ◽  
Wadood Y. Hamad ◽  
Mark J. MacLachlan
Keyword(s):  
Composite Materials ◽  
Composite Films ◽  
Cellulose Nanocrystal ◽  
Chemical Polymerization ◽  
Chiral Nematic ◽  
Polypyrrole Composite ◽  
Surface Modified ◽  
Cellulose Composite

Conductive chiral nematic cellulose composite materials have been fabricated via in situ oxidative chemical polymerization of pyrrole onto surface-modified mesoporous cellulose nanocrystal (CNC) films.

scholarly journals Unexpected microphase transitions in flow towards nematic order of cellulose nanocrystals

Cellulose ◽  
2019 ◽  
Vol 27 (4) ◽  
pp. 2003-2014 ◽  
Author(s):  
Roland Kádár ◽  
Mina Fazilati ◽  
Tiina Nypelö
Keyword(s):  
Liquid Crystal ◽  
Shear Rate ◽  
Formation Process ◽  
Recovery Time ◽  
Continuous Process ◽  
Cellulose Nanocrystal ◽  
Nematic Order ◽  
Chiral Nematic ◽  
Macro Scale

Abstract Organization of nanoparticles is essential in order to control their light-matter interactions. We present cellulose nanocrystal suspension organization in flow towards a unidirectional state. Visualization of evolving polarization patterns of the cellulose nanocrystal suspensions is combined with steady and oscillatory shear rheology. Elucidation of the chiral nematic mesophase in a continuous process towards unidirectional order enables control of alignment in a suspension precursor for structural films and reveals thus far in situ unrevealed transition states that were not detectable by rheology alone. The coupled analytics enabled the suspensions of interest to be divided into rheological gels and rheological liquid crystal fluids with detailed information on the microtransition phases. Both populations experienced submicron organization and reached macro-scale homogeneity with unidirectional ordering in continued shear. We quantify the time, shear rate, and recovery time after shear to design an optimizing formation process for controlled wet structures as precursors for dry products. Graphic abstract

Cellulose nanocrystal-embedded triacetate cellulose composite films

2015 ◽  
Vol 37 (11) ◽  
pp. 3228-3233 ◽  
Author(s):  
Dah Hee Kim ◽  
Young Seok Song
Keyword(s):  
Composite Films ◽  
Cellulose Nanocrystal ◽  
Cellulose Composite

scholarly journals Chiral Nematic Cellulose Nanocrystal Films Cooperated with Amino Acids for Tunable Optical Properties

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4389
Author(s):  
Xiao Xiao ◽  
Jie Chen ◽  
Zhe Ling ◽  
Jiaqi Guo ◽  
Jianbin Huang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Self Assembly ◽  
Uv Light ◽  
Composite Films ◽  
Functional Materials ◽  
Cellulose Nanocrystal ◽  
Optical Functions ◽  
Chiral Nematic ◽  
Evaporation Induced Self Assembly ◽  
Nanocrystal Films

The exploration of functional materials relies greatly on the understanding of material structures and nanotechnologies. In the present work, chiral nematic cellulose nanocrystal (CNC) films were prepared by incorporation with four types of amino acids (AAs, glycine, histidine, phenylalanine, and serine) via evaporation-induced self-assembly. The films present ideal iridescence and birefringence that can be tuned by the amount of AAs added. The intercalation of AAs enlarged the pitch values, contributing to the red-shift trend of the reflective wavelength. Among the AAs, serine presented the most compatible intercalation into cellulose crystals. Interestingly, histidine and phenylalanine composite films showed high shielding capabilities of UV light in diverse wavelength regions, exhibiting multi-optical functions. The sustainable preparation of chiral nematic CNC films may provide new strategies for materials production from biocompatible lignocellulose.

scholarly journals A Nanocellulose Polypyrrole Composite Based on Tunicate Cellulose

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Dawei Zhang ◽  
Qing Zhang ◽  
Xin Gao ◽  
Guangzhe Piao
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Ammonium Persulfate ◽  
High Electrical Conductivity ◽  
Chemical Polymerization ◽  
Transmission Electron ◽  
Mean Size ◽  
Polypyrrole Composite ◽  
Scanning Electron

The water-dispersed conductive polypyrrole (PPy) was prepared via thein situoxidative chemical polymerization by using ammonium persulfate (APS) as oxidant and tunicate cellulose nanocrystals (T-CNs) as a dopant and template for tuning the morphologies of PPy nanoparticles. Highly flexible paper-like materials of PPy/T-CNs nanocomposites with high electrical conductivity values and good mechanical properties were prepared. The structure of nanocomposites of PPy/T-CNs was investigated by using Fourier transform infrared spectroscopy. Scanning electron microscopy and transmission electron microscopy analyses of the composites revealed that PPy consisted of nanoparticles about 2.5 nm in mean size to form a continuous coating covered on the T-CNs. The diameters of the PPy nanoparticles increased from 10 to 100 nm with the increasing pyrrole amount. Moreover, electrical properties of the obtained PPy/T-CNs films were studied using standard four-probe technique and the electrical conductivity could be as high as 10−3 S/cm.

Constitution of novel polyamic acid/polypyrrole composite films by in-situ electropolymerization

2014 ◽  
Vol 128 ◽  
pp. 439-447 ◽  
Author(s):  
Euodia H. Hess ◽  
Tesfaye Waryo ◽  
Omowunmi A. Sadik ◽  
Emmanuel I. Iwuoha ◽  
Priscilla G.L. Baker
Keyword(s):  
Composite Films ◽  
Polyamic Acid ◽  
Polypyrrole Composite

scholarly journals Cellulose Based Photonic Materials Displaying Direction Modulated Photoluminescence

2021 ◽  
Vol 9 ◽  
Author(s):  
Molíria V. Santos ◽  
Fernando E. Maturi ◽  
Édison Pecoraro ◽  
Hernane S. Barud ◽  
Laís R. Lima ◽  
...  
Keyword(s):  
Optical Properties ◽  
Self Assembly ◽  
Light Emission ◽  
Composite Films ◽  
Film Structure ◽  
Cellulose Nanocrystal ◽  
Attractive Alternative ◽  
Photonic Materials ◽  
Light Emitting ◽  
Chiral Nematic

Photonic materials featuring simultaneous iridescence and light emission are an attractive alternative for designing novel optical devices. The luminescence study of a new optical material that integrates light emission and iridescence through liquid crystal self-assembly of cellulose nanocrystal-template silica approach is herein presented. These materials containing Rhodamine 6G were obtained as freestanding composite films with a chiral nematic organization. The scanning electron microscopy confirms that the cellulose nanocrystal film structure comprises multi-domain Bragg reflectors and the optical properties of these films can be tuned through changes in the relative content of silica/cellulose nanocrystals. Moreover, the incorporation of the light-emitting compound allows a complementary control of the optical properties. Overall, such findings demonstrated that the photonic structure plays the role of direction-dependent inner-filter, causing selective suppression of the light emitted with angle-dependent detection.

Mineral/microfibrillated cellulose composite materials: High performance products, applications, and product forms

TAPPI Journal ◽  
2018 ◽  
Vol 17 (09) ◽  
pp. 507-515 ◽  
Author(s):  
David Skuse ◽  
Mark Windebank ◽  
Tafadzwa Motsi ◽  
Guillaume Tellier
Keyword(s):  
Composite Materials ◽  
High Performance ◽  
Aqueous Suspension ◽  
Production Capacity ◽  
Cost Savings ◽  
Cost Effective ◽  
New Materials ◽  
Wet Strength ◽  
Product Forms ◽  
Cellulose Composite

When pulp and minerals are co-processed in aqueous suspension, the mineral acts as a grinding aid, facilitating the cost-effective production of fibrils. Furthermore, this processing allows the utilization of robust industrial milling equipment. There are 40000 dry metric tons of mineral/microfbrillated (MFC) cellulose composite production capacity in operation across three continents. These mineral/MFC products have been cleared by the FDA for use as a dry and wet strength agent in coated and uncoated food contact paper and paperboard applications. We have previously reported that use of these mineral/MFC composite materials in fiber-based applications allows generally improved wet and dry mechanical properties with concomitant opportunities for cost savings, property improvements, or grade developments and that the materials can be prepared using a range of fibers and minerals. Here, we: (1) report the development of new products that offer improved performance, (2) compare the performance of these new materials with that of a range of other nanocellulosic material types, (3) illustrate the performance of these new materials in reinforcement (paper and board) and viscosification applications, and (4) discuss product form requirements for different applications.

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