Actuator-Like Hydrogels Based on Conductive Chitosan

2012 ◽  
Vol 84 ◽  
pp. 29-38 ◽  
Author(s):  
Jacques Desbrieres ◽  
Stephanie Reynaud ◽  
Pierre Marcasuzaa ◽  
Francis Ehrenfeld
Keyword(s):  
Mechanical Properties ◽  
Block Copolymer ◽  
Conducting Polymers ◽  
Rheological Properties ◽  
Conducting Polymer ◽  
Composite Hydrogel ◽  
Composite Gels ◽  
Grafting Reaction ◽  
Intrinsically Conducting Polymers ◽  
Low Solubility

Intrinsically conducting polymers are of great interest for a large number of applications. But among major drawbacks are their low solubility in common solvents and their poor mechanical properties. Elaboration of composites associating a matrix, bringing its mechanical properties, and polyaniline, as the conducting polymer is a way of overcoming these disadvantages. Chitosan-graft-polyaniline copolymers were synthesized by simple oxidative method. The grafting reaction was quite total and it was found that the copolymers crosslinked to yield a composite hydrogel in which the polyaniline was homogeneously embedded. The conductivity of precursor (block copolymer) and gels was found to be larger than 10-2 S.cm-1. The composite gels were characterized in terms of swelling and rheological properties. They can be classified as "superabsorbent" hydrogels and the swelling is reversible. The composite gels were then successfully used as actuators.

scholarly journals Synthesis and Characterization of Conducting Polymer

2021 ◽  
pp. 113-116
Author(s):  
Deepak A Zatale ◽  
Satish T. Rathod ◽  
Kalpana N. Pawar
Keyword(s):  
Conducting Polymers ◽  
Conducting Polymer ◽  
High Performance ◽  
Chemical Oxidation ◽  
Rechargeable Batteries ◽  
Polymeric Chain ◽  
Display Devices ◽  
Molecule Design ◽  
Low Solubility

In recent technology, considerable attention was given to the fabrication of light weight rechargeable batteries, electro chromic display devices, microelectronics, sensor and molecule design etc. As one of the most important conducting polymers, polyaniline because of its chemical stability and relatively high conductivity and its derivatives have been extensively studied in different fields of science, because of the demand for high performance materials in advanced technologies. However, the common uses of polyaniline are restricted, due to its poor process ability and low solubility. Various techniques were given for synthesis of conducting polymer. In the current studies, polyaniline (PANI) and its composites with semiconductor was prepared chemical oxidation method in the presence of different bronsted acids from aqueous solutions. The effect of thermal treatment on electrical conductivity (DC), of the pure PANI, PANI+10%, 15% and 20% MnSO4 conducting polymers were investigated. It is found that conductivity of PANI enhancing due to stretching polymeric chain cause due to interaction with MnSO4.

Study of Rheological Properties of Modified Concrete Mixtures at Vibration

2019 ◽  
Vol 968 ◽  
pp. 96-106
Author(s):  
Oleksandr Pshinko ◽  
Olena Hromova ◽  
Dmytro Rudenko
Keyword(s):  
Mechanical Properties ◽  
Rheological Properties ◽  
Physical Nature ◽  
Concrete Mixture ◽  
Practical Significance ◽  
Vibration Displacement ◽  
Concrete Mixtures ◽  
Variable Quantity ◽  
Vibration Compaction ◽  
Mechanism Of Interaction

Study of rheological properties of concrete mixtures based on modified cement systems in order to determine process parameters. Methodology. To study structural-mechanical properties of modified concrete mixtures of different consistency at their horizontal vibrating displacement an oscillatory viscometer was designed. Results. The optimization of the process of vibration displacement of concrete mixtures with the specification of parameters of vibration impacts taking into account structural-mechanical properties of the mixture is performed. It has been established that the viscosity of the modified cement system of the concrete mixture is a variable quantity, which depends on the parameters of the vibration impacts. Scientific novelty. The mechanism of interaction of the modified concrete mixture with the form and the table vibrator during its vibration compaction is determined. On the basis of this, a model of concrete laying process control is proposed, that allows to predict the ability to form a dense concrete structure. Practical significance. Disclosed physical nature of the process of vibrating displacement of modified concrete mixtures using the principles of physical-chemical mechanics of concrete allows reasonably choose the best options for vibration impacts.

scholarly journals Conducting polymers: a comprehensive review on recent advances in synthesis, properties and applications

RSC Advances ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 5659-5697 ◽  
Author(s):  
Namsheer K ◽  
Chandra Sekhar Rout
Keyword(s):  
Mechanical Properties ◽  
Electrical Property ◽  
Conducting Polymers ◽  
Inorganic Materials ◽  
Environmental Stability ◽  
Comprehensive Review ◽  
Recent Advances ◽  
Synthesis Properties

Conducting polymers are extensively studied due to their outstanding properties, including tunable electrical property, optical and high mechanical properties, easy synthesis and effortless fabrication and high environmental stability over conventional inorganic materials.

scholarly journals Effect of Photoinitiator on Precursory Stability and Curing Depth of Thiol-Ene Clickable Gelatin

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1877
Author(s):  
Kai-Hung Yang ◽  
Gabriella Lindberg ◽  
Bram Soliman ◽  
Khoon Lim ◽  
Tim Woodfield ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Visible Light ◽  
Rheological Properties ◽  
Swelling Ratio ◽  
Sodium Persulfate ◽  
Photo Polymerization ◽  
Gelation Kinetics ◽  
The Stability ◽  
Over Time

Recent advances highlight the potential of photopolymerizable allylated gelatin (GelAGE) as a versatile hydrogel with highly tailorable properties. It is, however, unknown how different photoinitiating system affects the stability, gelation kinetics and curing depth of GelAGE. In this study, sol fraction, mass swelling ratio, mechanical properties, rheological properties, and curing depth were evaluated as a function of time with three photo-initiating systems: Irgacure 2959 (Ig2959; 320–500 nm), lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP; 320–500 nm), and ruthenium/sodium persulfate (Ru/SPS; 400–500 nm). Results demonstrated that GelAGE precursory solutions mixed with either Ig2959 or LAP remained stable over time while the Ru/SPS system enabled the onset of controllable redox polymerization without irradiation during pre-incubation. Photo-polymerization using the Ru/SPS system was significantly faster (<5 s) compared to both Ig2959 (70 s) and LAP (50 s). Plus, The Ru/SPS system was capable of polymerizing a thick construct (8.88 ± 0.94 mm), while Ig2959 (1.62 ± 0.49 mm) initiated hydrogels displayed poor penetration depth with LAP (7.38 ± 2.13 mm) in between. These results thus support the use of the visible light based Ru/SPS photo-initiator for constructs requiring rapid gelation and a good curing depth while Ig2959 or LAP can be applied for photo-polymerization of GelAGE materials requiring long-term incubation prior to application if UV is not a concern.

scholarly journals The Infuence of Salicin on Rheological and Film-Forming Properties of Collagen

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1661
Author(s):  
Katarzyna Adamiak ◽  
Katarzyna Lewandowska ◽  
Alina Sionkowska
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Infrared Spectroscopy ◽  
Rheological Properties ◽  
Silver Carp ◽  
Shear Tests ◽  
Force Microscopy ◽  
Atomic Force ◽  
Film Forming ◽  
Potential Applications

Collagen films are widely used as adhesives in medicine and cosmetology. However, its properties require modification. In this work, the influence of salicin on the properties of collagen solution and films was studied. Collagen was extracted from silver carp skin. The rheological properties of collagen solutions with and without salicin were characterized by steady shear tests. Thin collagen films were prepared by solvent evaporation. The structure of films was researched using infrared spectroscopy. The surface properties of films were investigated using Atomic Force Microscopy (AFM). Mechanical properties were measured as well. It was found that the addition of salicin modified the roughness of collagen films and their mechanical and rheological properties. The above-mentioned parameters are very important in potential applications of collagen films containing salicin.

scholarly journals Biofabrication of Cell-Laden Gelatin Methacryloyl Hydrogels with Incorporation of Silanized Hydroxyapatite by Visible Light Projection

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2354
Author(s):  
Jimmy Jiun-Ming Su ◽  
Chih-Hsin Lin ◽  
Hsuan Chen ◽  
Shyh-Yuan Lee ◽  
Yuan-Min Lin
Keyword(s):  
Mechanical Properties ◽  
Visible Light ◽  
3D Structure ◽  
Three Dimensional ◽  
3D Cell Culture ◽  
Composite Hydrogel ◽  
Digital Light Processing ◽  
Mg63 Cells ◽  
Marrow Mesenchymal Stem Cells ◽  
Low Cytotoxicity

Gelatin methacryloyl (GelMA) hydrogel is a photopolymerizable biomaterial widely used for three-dimensional (3D) cell culture due to its high biocompatibility. However, the drawback of GelMA hydrogel is its poor mechanical properties, which may compromise the feasibility of biofabrication techniques. In this study, a cell-laden GelMA composite hydrogel with a combination incorporating silanized hydroxyapatite (Si-HAp) and a simple and harmless visible light crosslinking system for this hydrogel were developed. The incorporation of Si-HAp into the GelMA hydrogel enhanced the mechanical properties of the composite hydrogel. Moreover, the composite hydrogel exhibited low cytotoxicity and promoted the osteogenic gene expression of embedded MG63 cells and Human bone marrow mesenchymal stem cells (hBMSCs). We also established a maskless lithographic method to fabricate a defined 3D structure under visible light by using a digital light processing projector, and the incorporation of Si-HAp increased the resolution of photolithographic hydrogels. The GelMA-Si-HAp composite hydrogel system can serve as an effective biomaterial in bone regeneration.

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