scholarly journals Surface Charges Control the Structure and Properties of Layered Nanocomposite of Cellulose Nanofibrils and Clay Platelets

2021 ◽  
Vol 13 (3) ◽  
pp. 4463-4472
Author(s):  
Dingfeng Xu ◽  
Shennan Wang ◽  
Lars A. Berglund ◽  
Qi Zhou
Keyword(s):  
Cellulose Nanofibrils ◽  
Structure And Properties ◽  
Surface Charges ◽  
Clay Platelets

Effects of cellulose nanofibrils on the structure and properties on PVA nanocomposites

Cellulose ◽  
2013 ◽  
Vol 20 (6) ◽  
pp. 2981-2989 ◽  
Author(s):  
Dagang Liu ◽  
Xun Sun ◽  
Huafeng Tian ◽  
Sonakshi Maiti ◽  
Zhongshi Ma
Keyword(s):  
Cellulose Nanofibrils ◽  
Structure And Properties

scholarly journals Water Dynamics in Hydrated Carboxylated Cellulose Nanofibril Membranes

2019 ◽  
Author(s):  
Shun Yu ◽  
Valentina Guccini ◽  
Franz Demmel ◽  
Germán Salazar-Alvarez
Keyword(s):  
Surface Charge ◽  
Network Formation ◽  
Water Movement ◽  
Polymer Electrolyte Membrane ◽  
Cellulose Nanofibrils ◽  
Bulk Water ◽  
Water Dynamics ◽  
Surface Charges ◽  
Tempo Oxidation ◽  
Elastic Neutron

Cellulose nanofibrils (CNF) are a class of materials with good mechanical properties, surface functionality and bio-/environmental friendliness. They have been used in many applications as loading material or function materials, where water-cellulose interaction determines the materials performance. Especially, CNF with carboxylated groups can be used as the separation membrane in polymer electrolyte membrane fuel cell. The water dynamics is closely related to the proton conductivity. The Non-destructive quasi-elastic neutron scattering (QENS) is used to characterized water movement in hydrated membrane made of CNF prepared by TEMPO-oxidation with different surface charges. However, neither surface charge nor the nanoconfinement due to membrane swelling has large impact on water dynamics mechanism. A slow diffusive motion is found with the diffusion coefficient close to bulk water and that in hydrated Nafion membrane regardless the surface charge, while a fast motion is rather localized with a correlation time increasing as temperature increase, which might related to the hydrogen bond network formation between water and CNF.

New Developments for Lignocellulosics-Nanocomposites with Low Carbon Footprint

2012 ◽  
Vol 1386 ◽  
Author(s):  
Alcides L. Leao ◽  
Bibin M. Cherian ◽  
Sivoney F. Souza ◽  
Mohini Sain ◽  
Suresh Narine
Keyword(s):  
Cellulose Nanofibrils ◽  
Structure And Properties ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
Fiber Morphology ◽  
Chemical Purification ◽  
New Developments ◽  
X Ray ◽  
Reinforcement Material ◽  
Microscopy Techniques

ABSTRACTCellulose nanofibrils have been evaluated as reinforcement material in polymeric matrixes due to their potential to improve the mechanical, optical, and dielectric properties of these matrixes as well as its environmental positive footprint. This work describes how banana nanocellulose can be used to replace others not so friendly materials in many applications including, biomaterials, automotive industries and packaging by proved with their mechanical properties. The process used is very mild to the environment and consists of a high pressure fibrillation followed by a chemical purification which affects the fiber morphology. Many fibers characterization processes were used including microscopy techniques and X-ray diffraction to study the structure and properties of the prepared nanofibers and composites. Microscopy studies showed that the used individualization processes lead to a unique morphology of interconnected web-like structure of the fibers.

Biodegradable Poly(vinyl alcohol) Foams Supported by Cellulose Nanofibrils: Processing, Structure, and Properties

Langmuir ◽  
2014 ◽  
Vol 30 (31) ◽  
pp. 9544-9550 ◽  
Author(s):  
Dagang Liu ◽  
Zhongshi Ma ◽  
Zhengmei Wang ◽  
Huafeng Tian ◽  
Mingyue Gu
Keyword(s):  
Vinyl Alcohol ◽  
Cellulose Nanofibrils ◽  
Poly Vinyl Alcohol ◽  
Structure And Properties ◽  
Biodegradable Poly

scholarly journals Water Dynamics in Hydrated Carboxylated Cellulose Nanofibril Membranes

2019 ◽  
Author(s):  
Shun Yu ◽  
Valentina Guccini ◽  
Franz Demmel ◽  
Germán Salazar-Alvarez
Keyword(s):  
Surface Charge ◽  
Network Formation ◽  
Water Movement ◽  
Polymer Electrolyte Membrane ◽  
Cellulose Nanofibrils ◽  
Bulk Water ◽  
Water Dynamics ◽  
Surface Charges ◽  
Tempo Oxidation ◽  
Elastic Neutron

Cellulose nanofibrils (CNF) are a class of materials with good mechanical properties, surface functionality and bio-/environmental friendliness. They have been used in many applications as loading material or function materials, where water-cellulose interaction determines the materials performance. Especially, CNF with carboxylated groups can be used as the separation membrane in polymer electrolyte membrane fuel cell. The water dynamics is closely related to the proton conductivity. The Non-destructive quasi-elastic neutron scattering (QENS) is used to characterized water movement in hydrated membrane made of CNF prepared by TEMPO-oxidation with different surface charges. However, neither surface charge nor the nanoconfinement due to membrane swelling has large impact on water dynamics mechanism. A slow diffusive motion is found with the diffusion coefficient close to bulk water and that in hydrated Nafion membrane regardless the surface charge, while a fast motion is rather localized with a correlation time increasing as temperature increase, which might related to the hydrogen bond network formation between water and CNF.

Effects of mechanical fibrillation time by disk grinding on the properties of cellulose nanofibrils

TAPPI Journal ◽  
2016 ◽  
Vol 15 (6) ◽  
pp. 419-423 ◽  
Author(s):  
QIANQIAN WANG ◽  
J.Y. ZHU
Keyword(s):  
Energy Input ◽  
Cellulose Nanofibrils ◽  
Crystallinity Index ◽  
Degree Of Polymerization ◽  
Optical Transparency ◽  
Structure And Properties ◽  
Eucalyptus Pulp ◽  
Mechanical Fibrillation ◽  
Cnf Films ◽  
Grinding Time

Cellulose nanofibrils (CNF) were successfully produced from a bleach kraft eucalyptus pulp by a supermasscolloider. Effects of grinding time on structure and properties of CNF and the corresponding CNF films were investigated. Grinding time was important to increase the optical transparency of CNF suspensions. The degree of polymerization (DP) and crystallinity index (CrI) of CNF decreased linearly with the increase in CNF suspension transparency. This suggests optical transparency of a CNF suspension can be used to characterize the degree of fibrillation. Specific tensile strength and Young’s modulus of the CNF films made of CNF suspension with only 0.5 h grinding were increased approximately 30% and 200%, respectively, compared with conventional handsheets prepared by valley beating to 300 Canadian Standard Freeness (CSF). Energy input was only 1.38 kWh/kg for 0.5 h grinding. Grinding beyond 0.5 h produced negligible improvement in specific tensile and specific modulus. Opacity of CNF films decreased rapidly during the first 1.5 h of fibrillation and then plateaued.

scholarly journals Origin of the human alcohol dehydrogenase system: implications from the structure and properties of the octopus protein

1993 ◽  
Vol 90 (23) ◽  
pp. 11222-11226 ◽  
Author(s):  
R Kaiser ◽  
M R Fernández ◽  
X Parés ◽  
H Jörnvall
Keyword(s):  
Alcohol Dehydrogenase ◽  
Class I ◽  
Structure And Properties ◽  
Class Iii ◽  
Surface Charges ◽  
Apparent Absence ◽  
Liver Alcohol Dehydrogenase ◽  
Dehydrogenase System ◽  
Nad Oxidoreductase ◽  
Constant Characteristics

In contrast to the multiplicity of alcohol dehydrogenase in vertebrates, a class III type of the enzyme [i.e., a glutathione-dependent formaldehyde dehydrogenase; formaldehyde; NAD+ oxidoreductase (glutathione-formylating), EC 1.2.1.1.] is the only form detectable in appreciable yield in octopus. It is enzymatically and structurally highly similar to the human class III enzyme, with limited overall residue differences (26%) and only a few conservative residue exchanges at the substrate and coenzyme pockets, reflecting "constant" characteristics of this class over wide time periods. It is distinct from the ethanol-active "variable" class I type of the enzyme (i.e., classical liver alcohol dehydrogenase; alcohol:NAD+ oxidoreductase, EC 1.1.1.1). The residue conservation of class III is also spaced differently from that of class I but is typical of that of proteins in general, emphasizing that class I, with divergence at three functional segments, is the form with deviating properties. In spite of the conservation in class III, surface charges differ considerably. The apparent absence of a class I enzyme in octopus and the constant nature of the class III enzyme support the concept of a duplicative origin of the class I line from the ancient class III form. Still more distant relationships define further enzyme lines that have subunits with other properties.

Control of structure and properties of cellulose nanofibrils (CNF)-based foam materials by using ethanol additives prior to freeze-drying

2019 ◽  
Vol 53 (4) ◽  
pp. 837-854
Author(s):  
Jinbao Li ◽  
Te Song ◽  
Huijuan Xiu ◽  
Rui Cheng ◽  
Xue Yang ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Cellulose Nanofibrils ◽  
Structure And Properties

scholarly journals Effects of cellulose nanofibrils on the structure and properties of maleic anhydride crosslinked poly(vinyl alcohol) electrospun nanofibers

2019 ◽  
Vol 1 (12) ◽  
Author(s):  
Cátia Braga ◽  
Ana Rute Sampaio ◽  
João Peixoto ◽  
Carla Joana dos Santos Marinho da Silva ◽  
Andrea Zille
Keyword(s):  
Maleic Anhydride ◽  
Vinyl Alcohol ◽  
Cellulose Nanofibrils ◽  
Electrospun Nanofibers ◽  
Poly Vinyl Alcohol ◽  
Structure And Properties
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