scholarly journals Supramolecular double networks of cellulose nanofibrils and algal polysaccharides with excellent wet mechanical properties

2018 ◽  
Vol 20 (11) ◽  
pp. 2558-2570 ◽  
Author(s):  
Tobias Benselfelt ◽  
Joakim Engström ◽  
Lars Wågberg
Keyword(s):  
Mechanical Properties ◽  
Cellulose Nanofibrils ◽  
Double Network ◽  
Double Networks ◽  
Algal Polysaccharides

Supramolecular double network films, consisting of cellulose nanofibrils (CNF) entangled with the algal polysaccharides alginate or carrageenan, were prepared to achieve water-resistant CNF nanopapers with excellent mechanical properties in both the wet and dry states following the locking of the structures using Ca2+.

The Mechanical Behavior of Double Network Elastomers

1994 ◽  
Vol 67 (2) ◽  
pp. 359-365 ◽  
Author(s):  
P. G. Santangelo ◽  
C. M. Roland
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Double Network ◽  
Equilibrium Modulus ◽  
Failure Properties ◽  
Residual Strains ◽  
Double Networks

Abstract It was found that at low residual strains, the modulus of double network rubbers can be less than that of an isotropic elastomer of equal crosslink density. At higher residual strains, the equilibrium modulus is higher for the double network. This aspect of the behavior of networks was investigated using two phenomenological descriptions of rubber elasticity, the Mooney-Rivlin (MR) and the Roth, Martin, and Stiehler (RMS) Equations. Calculations using either approach, which make use of the independent network hypothesis, were qualitatively in agreement with the experimental data. The tensile strength of double networks based on natural rubber were found to be independent of the amount of residual strain. This is true even at higher residual strains, wherein the modulus is significantly amplified. This suggests that the conventional compromise between modulus and failure properties can be circumvented using double network rubbers. Their utilization can yield elastomers of better mechanical properties.

Elastic Response of Rubber Double Networks

1999 ◽  
Author(s):  
C. M. Roland ◽  
P. G. Santangelo ◽  
P. H. Mott
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Crosslink Density ◽  
The Other ◽  
Elastic Response ◽  
Double Network ◽  
Mechanical Fatigue ◽  
Equilibrium Modulus ◽  
Failure Properties ◽  
Double Networks

Abstract Double network elastomers are formed by twice-curing rubber, the second time while the material is deformed. When measured parallel to the curing deformation, the equilibrium modulus of a double network exceeds that of an isotropic elastomer of equal crosslink density. This difference increases with increasing strain. Despite the higher modulus, the mechanical fatigue lifetimes of double networks of natural rubber were found to be as much as a factor of ten higher than for the conventionally crosslinked rubber. The double network’s tensile strength, on the other hand, was slightly lower. Such results suggest that the conventional compromise between modulus and failure properties can be circumvented using double network rubbers. Their utilization can yield elastomers of better mechanical properties.

scholarly journals Enzyme-induced mineralization of hydrogels with amorphous calcium carbonate for fast synthesis of ultrastiff, strong and tough organic–inorganic double networks

2021 ◽  
Author(s):  
Marko Milovanovic ◽  
Lydia Mihailowitsch ◽  
Mathusiha Santhirasegaran ◽  
Volker Brandt ◽  
Joerg C. Tiller
Keyword(s):  
Mechanical Properties ◽  
Inorganic Material ◽  
Sodium Acrylate ◽  
Amorphous Calcium Carbonate ◽  
Double Network ◽  
Ionic Groups ◽  
Double Networks ◽  
Biological And Medical Applications ◽  
Fast Synthesis ◽  
Amorphous Character

Abstract Hydrogels with good mechanical properties have great importance in biological and medical applications. Double-network (DN) hydrogels were found to be very tough materials. If one of the two network phases is an inorganic material, the DN hydrogels also become very stiff without losing their toughness. So far, the only example of such an organic–inorganic DN hydrogel is based on calcium phosphate, which takes about a week to be formed as an amorphous inorganic phase by enzyme-induced mineralization. An alternative organic–inorganic DN hydrogel, based on amorphous CaCO3, which can be formed as inorganic phase within hours, was designed in this study. The precipitation of CaCO3 within a hydrogel was induced by urease and a urea/CaCl2 calcification medium. The amorphous character of the CaCO3 was retained by using the previously reported crystallization inhibiting effects of N-(phosphonomethyl)glycine (PMGly). The connection between organic and inorganic phases via reversible bonds was realized by the introduction of ionic groups. The best results were obtained by copolymerization of acrylamide (AAm) and sodium acrylate (SA), which led to water-swollen organic–inorganic DN hydrogels with a high Young’s modulus (455 ± 80 MPa), remarkable tensile strength (3.4 ± 0.7 MPa) and fracture toughness (1.1 ± 0.2 kJ m−2). Graphical Abstract The present manuscript describes the method of enzymatic mineralization of hydrogels for the production of ultrastiff and strong composite hydrogels. By forming a double-network structure based on an organic and an inorganic phase, it is possible to improve the mechanical properties of a hydrogel, such as stiffness and strength, by several orders of magnitude. The key to this is the formation of a percolating, amorphous inorganic phase, which is achieved by inhibiting crystallization of precipitated amorphous CaCO3 with N-(phosphonomethyl)glycine and controlling the nanostructure with co polymerized sodium acrylate. This creates ultrastiff, strong and tough organic–inorganic double-network hydrogels.

Effect of Crosslinking on the Network Parameters, Swelling and Mechanical Properties of PVA-Borax and Poly (AM-co-HEMA) Double Network (DN) Hydrogels

2019 ◽  
Vol 35 (3) ◽  
pp. 371-391
Author(s):  
AKANSHA DIXIT ◽  
◽  
DIBYENDU S. BAG ◽  
DHIRENDRA KUMAR SHARMA ◽  
HARJEET SINGH ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Double Network ◽  
Network Parameters

Cellulose Nanofibrils-based Hydrogels for Biomedical Applications: Progresses and Challenges

2020 ◽  
Vol 27 (28) ◽  
pp. 4622-4646 ◽  
Author(s):  
Huayu Liu ◽  
Kun Liu ◽  
Xiao Han ◽  
Hongxiang Xie ◽  
Chuanling Si ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Metal Ion ◽  
Biomedical Applications ◽  
Biomedical Application ◽  
Cellulose Nanofibrils ◽  
Wound Dressings ◽  
Preparation Methods ◽  
Tissue Scaffold ◽  
Surface Areas ◽  
Mechanical Methods

Background: Cellulose Nanofibrils (CNFs) are natural nanomaterials with nanometer dimensions. Compared with ordinary cellulose, CNFs own good mechanical properties, large specific surface areas, high Young's modulus, strong hydrophilicity and other distinguishing characteristics, which make them widely used in many fields. This review aims to introduce the preparation of CNFs-based hydrogels and their recent biomedical application advances. Methods: By searching the recent literatures, we have summarized the preparation methods of CNFs, including mechanical methods and chemical mechanical methods, and also introduced the fabrication methods of CNFs-based hydrogels, including CNFs cross-linked with metal ion and with polymers. In addition, we have summarized the biomedical applications of CNFs-based hydrogels, including scaffold materials and wound dressings. Results: CNFs-based hydrogels are new types of materials that are non-toxic and display a certain mechanical strength. In the tissue scaffold application, they can provide a micro-environment for the damaged tissue to repair and regenerate it. In wound dressing applications, it can fit the wound surface and protect the wound from the external environment, thereby effectively promoting the healing of skin tissue. Conclusion: By summarizing the preparation and application of CNFs-based hydrogels, we have analyzed and forecasted their development trends. At present, the research of CNFs-based hydrogels is still in the laboratory stage. It needs further exploration to be applied in practice. The development of medical hydrogels with high mechanical properties and biocompatibility still poses significant challenges.

scholarly journals Understanding ion-induced assembly of cellulose nanofibrilllar gels through shear-free mixing and in situ scanning-SAXS

2021 ◽  
Author(s):  
Tomas Rosén ◽  
Ruifu Wang ◽  
HongRui He ◽  
Chengbo Zhan ◽  
Shirish Chodankar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Building Block ◽  
Cellulose Nanofibrils ◽  
Advanced Materials ◽  
The Past

During the past decade, cellulose nanofibrils (CNFs) have shown tremendous potential as a building block to fabricate new advanced materials that are both biocompatible and biodegradable. The excellent mechanical properties...

scholarly journals Thermoresponsive Double Network Hydrogels with Exceptional Compressive Mechanical Properties

2017 ◽  
Vol 38 (20) ◽  
pp. 1700351 ◽  
Author(s):  
A. Kristen Means ◽  
Daniel A. Ehrhardt ◽  
Lauren V. Whitney ◽  
Melissa A. Grunlan
Keyword(s):  
Mechanical Properties ◽  
Double Network

Design for dynamic hydrogen bonding in a double network structure to improve the mechanical properties of sodium alginate fibers

2021 ◽  
Author(s):  
Ming Yan ◽  
Junfeng Shi ◽  
Song Tang ◽  
Guohang Zhou ◽  
Jiexiang Zeng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bonding ◽  
Sodium Alginate ◽  
Network Structure ◽  
Wet Spinning ◽  
Double Network ◽  
Alginate Fibers

The SA/PAA-VSNP fiber was obtained using dynamic wet spinning through dynamic hydrogen bonding in the double network structure.

Polyacrylamide/Copper‐alginate Double Network Hydrogel Electrolyte with Excellent Mechanical Properties and Strain‐sensitivity

2021 ◽  
pp. 2100361
Author(s):  
Zeyu Zhang ◽  
Tingrui Lin ◽  
Shuangxiao Li ◽  
Xibang Chen ◽  
Xueyan Que ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Strain Sensitivity ◽  
Double Network

Mechanical properties of gelatin/polyacrylamide/graphene oxide nanocomposite double-network hydrogels

2018 ◽  
Vol 163 ◽  
pp. 81-88 ◽  
Author(s):  
Xiaoqiang Yan ◽  
Jia Yang ◽  
Feng Chen ◽  
Lin Zhu ◽  
Ziqing Tang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Double Network
Sign in / Sign up

Export Citation Format

Share Document