scholarly journals The Polymer Binders for the Electrodes of Lithium Batteries Part 2. Synthetic and Natural Polymers

2020 ◽  
Vol 20 (4) ◽  
pp. 175-205
Author(s):  
Aigul S. Istomina ◽  
◽  
Olga V. Bushkova ◽  

The second part of the review describes the prospects of using alternative polymer binders for composite electrodes of lithium electrochemical systems. Possible options having been taken into account, the most popular commercially-available synthetic polymers with functional group (the ones forming aqueous solutions or dispersions predominantly) and water-soluble polymers of natural origin are considered. The versatility of such materials is their distinctive feature. The availability of salt forms for natural and synthetic polymers, many of which are polyelectrolytes, makes it possible to significantly affect the ion transfer in the composite electrode mass, reducing the polarization of the electrodes and improving the power characteristics of batteries. The ability to form “artificial SEI” and / or form a three-dimensional network with self-healing cross-links between macromolecules allows long-term safe cycling, the latter being especially important for active materials with very large volume changes during lithium intercalation / deintercalation (e.g. silicon).

2020 ◽  
Vol 10 (2) ◽  
pp. 5011-5020

Polymers can crosslink to produce intermingled materials with three-dimensional network structure known as interpenetrating polymeric network (IPN). They comprise elastic crosslinked polymeric chains. The chains of the hydrogels are either physically or chemically entangled together. Interpenetrating hydrogels can be tailored to provide enhanced materials. They can be classified according to methods of their synthesis as simultaneous or sequential IPNs and the structure to be homo or semi IPNs. The preparation factors play a role in controlling the properties of the produced IPNs. Moreover, the ambient conditions such as pH, temperature as well as the ionic strength may affect the performance of these hydrogels. The swelling capacity is an important feature that allows the prepared hydrogel to perform the required application. Some disadvantages may arise such as the low mechanical properties that are suggested to be overcome. IPNs can be used in various applications that serve the human requirements like drug delivery, tissue engineering, medical and packaging applications. Hydrogels present biocompatibility and nontoxicity when used in biomedical applications. Interpenetrating hydrogels can be prepared from natural or synthetic polymers. Polysaccharides as natural polymers can be used to produce efficient interpenetrating hydrogels. Polyacrylates, poly(ethylene glycol) and poly(vinyl alcohol) are designated as promising synthetic polymers capable of forming interpenetrating hydrogels.


2020 ◽  
Vol 20 (3) ◽  
pp. 115-131
Author(s):  
Aigul S. Istomina ◽  
◽  
Olga V. Bushkova ◽  

The current situation in technology and developments in the field of polymer binders for composite electrodes of lithium electrochemical systems are discussed. A wide range of synthetic and natural polymers used for this purpose is considered. Emphasis is placed on commercially available materials, which form aqueous solutions or dispersions. The advantages of multifunctional polymer binders are demonstrated. The need for individual selection of a binder for a given active material to achieve and maintain high capacitive and power characteristics of the batteries, as well as to ensure their longterm safe cycling, is shown.


Author(s):  
Ratnaparkhi M.P. ◽  
Karnawat G.R. ◽  
Andhale R.S.

Oral route is most preferable route of administration for various drugs, because it is convenient, economical, safest route. Fast dissolving tablets are popular nowadays, as they disintegrated in mouth within a few seconds without using water for swallow. Problems like Dysphagia in pediatric and geriatric patients have been overcome by formulating Fast dissolving tablet. Natural polymers are preferable because they are chemically inert, nontoxic, less expensive, biodegradable, and available easily than synthetic polymers. Natural polymers are obtained from the natural origin so they are devoid of any side effect. It is proved from the previous studies that Natural polymers are more-safe and effective than the synthetic polymers. Natural polymers improve the properties of tablet and they are used as binder, diluent, superdisintegrant, they also enhance the solubility of poorly water-soluble drug, decrease the disintegration time and provide nutritional supplement. The aim of the present article is to study various natural polymers used in fast dissolving tablets.


2022 ◽  
Vol 23 (2) ◽  
pp. 842
Author(s):  
Ahmed Ali Nada ◽  
Anita Eckstein Andicsová ◽  
Jaroslav Mosnáček

Electrically conductive materials that are fabricated based on natural polymers have seen significant interest in numerous applications, especially when advanced properties such as self-healing are introduced. In this article review, the hydrogels that are based on natural polymers containing electrically conductive medium were covered, while both irreversible and reversible cross-links are presented. Among the conductive media, a special focus was put on conductive polymers, such as polyaniline, polypyrrole, polyacetylene, and polythiophenes, which can be potentially synthesized from renewable resources. Preparation methods of the conductive irreversible hydrogels that are based on these conductive polymers were reported observing their electrical conductivity values by Siemens per centimeter (S/cm). Additionally, the self-healing systems that were already applied or applicable in electrically conductive hydrogels that are based on natural polymers were presented and classified based on non-covalent or covalent cross-links. The real-time healing, mechanical stability, and electrically conductive values were highlighted.


2020 ◽  
Vol 117 (44) ◽  
pp. 27204-27210 ◽  
Author(s):  
Yong Hu ◽  
Zipeng Guo ◽  
Andrew Ragonese ◽  
Taishan Zhu ◽  
Saurabh Khuje ◽  
...  

Molecular ferroelectrics combine electromechanical coupling and electric polarizabilities, offering immense promise in stimuli-dependent metamaterials. Despite such promise, current physical realizations of mechanical metamaterials remain hindered by the lack of rapid-prototyping ferroelectric metamaterial structures. Here, we present a continuous rapid printing strategy for the volumetric deposition of water-soluble molecular ferroelectric metamaterials with precise spatial control in virtually any three-dimensional (3D) geometry by means of an electric-field–assisted additive manufacturing. We demonstrate a scaffold-supported ferroelectric crystalline lattice that enables self-healing and a reprogrammable stiffness for dynamic tuning of mechanical metamaterials with a long lifetime and sustainability. A molecular ferroelectric architecture with resonant inclusions then exhibits adaptive mitigation of incident vibroacoustic dynamic loads via an electrically tunable subwavelength-frequency band gap. The findings shown here pave the way for the versatile additive manufacturing of molecular ferroelectric metamaterials.


Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 188 ◽  
Author(s):  
Kaicheng Zhang ◽  
Guobing Ying ◽  
Lu Liu ◽  
Fengchen Ma ◽  
Lin Su ◽  
...  

Ti3C2Tx and Ti3C2Tx-NiO composites with three-dimensional (3D) porous networks were successfully fabricated via vacuum freeze-drying. The microstructure, absorption, and electrochemical properties of the developed composites were investigated. Nickel oxide (NiO) nanoparticles could be evenly distributed on the three-dimensional network of three-dimensional Ti3C2Tx using solution processing. When employed as electrochemical capacitor electrodes in 1 M environmentally friendly sodium sulfate, Na2SO4, solution, the three-dimensional porous Ti3C2Tx-NiO composite electrodes exhibited considerable volume specific capacitance as compared to three-dimensional porous Ti3C2Tx. The three-dimensional porous Ti3C2Tx-NiO composite delivered a remarkable cycling performance with a capacitance retention of up to 114% over 2500 cycles. The growth trend of the capacitance with NiO content shows that nickel oxide plays a crucial role in the composite electrodes. These results present a roadmap for the development of convenient and economical supercapacitors in consideration with the possibilities of morphological control and the extensibility of the process.


1960 ◽  
Vol 37 (4) ◽  
pp. 889-907 ◽  
Author(s):  
TORKEL WEIS-FOGH

1. A new type of hyaline, colourless cuticle, called rubber-like cuticle, is described and analysed qualitatively with respect to mechanical behaviour, structure and composition. Externally it is covered by ordinary thin epicuticle, but otherwise it represents the simplest type of cuticle known and consists only of thin continuous lamellae of chitin (0-2 µ) separated and glued together by an elastic protein, resilin, not hitherto described. There are only traces of water-soluble substances present and resilin sometimes occurs as pure, hyaline patches more than 100 µ thick and suitable for macroscopic experiments. 2. In all physical respects, resilin behaves like a swollen isotropic rubber but the rigid experimental proof is given elsewhere (Weis-Fogh, 1961). An outstanding feature is the complete lack of flow not paralleled by other natural or synthetic rubbers. 3. Resilin resembles elastin but it is devoid of colour and has a different and characteristic amino-acid composition (Bailey & Weis-Fogh, 1961). The nature of the cross-linkages is unknown at present but they are extremely stable, of a co-valent type and different from other known cross-linkages in proteins. This accounts for its insolubility and resistance to all agents which do not break the peptide backbone. 4. Resilin is a structure protein in which the primary chains show little or no tendency to form secondary structures; they are bound together in a uniform three-dimensional network (the tertiary structure) with no potential limits as to size.


2021 ◽  
Vol 28 ◽  
Author(s):  
Jing Li ◽  
Qinhua Chen ◽  
Jin Wang ◽  
Xiaoyan Pan ◽  
Jie Zhang

: Hydrogel is a hydrophilic but water-soluble polymer system with a three-dimensional network structure. Hydrogel can absorb large amounts of water and maintain its shape and remain soft. The high-moisturizing properties, good biocompatibility and controlled biodegradability of hydrogels have allowed them to be widely used in wound dressing, tissue engineering, controlled drug delivery systems and other fields. This article reviews the most widely used antibacterial gel dressings for wound healing in recent years and focuses on the application of an environmentally responsive intelligent hydrogel delivery system. Finally, the development prospects and challenges of hydrogel wound dressings are forecasted.


2019 ◽  
Vol 15 (4) ◽  
pp. 371-381 ◽  
Author(s):  
Amalnath John ◽  
Wen Zhong

Hydrogels are three-dimensional polymer networks capable of absorbing and holding a large amount of water. They have a wide range of biomedical applications including drug carriers, biosensors, tissue scaffolds and wound dressings owning to their innate resemblance to the living tissue. Recently biodegradable and renewable natural polymers, especially nanocellulose, have gained immense attention in the development of hydrogels for biomedical applications. This review provides a brief analysis of the various nanocellulosic materials used in the fabrication of hydrogels for various biomedical applications. Recent developments in high performance hydrogels based on nanocellulose, including self-healing, highly tough and/or stretchable and 3D printable hydrogels will also be covered in this review.


Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1569 ◽  
Author(s):  
Raluca Ioana Baron ◽  
Madalina Elena Culica ◽  
Gabriela Biliuta ◽  
Maria Bercea ◽  
Simona Gherman ◽  
...  

Two natural polymers, i.e., cellulose and water soluble pullulan, have been selectively oxidized employing the TEMPO-mediated protocol, to allow the introduction of C6-OOH groups. Thereafter, the composite hydrogels of poly(vinyl alcohol) (PVA) and different content of the oxidized polysaccharides were prepared by the freezing/thawing method. The Fourier transform infrared spectroscopy (FTIR) has been used to discuss the degree of interaction between the hydrogels constituents into the physical network. The homogeneity of the prepared hydrogels as revealed by the SEM show an excellent distribution of the oxidized polysaccharides inside the PVA matrix. The samples exhibit self-healing features, since they quickly recover the initial structure after being subjected to a large deformation. The cell viability was performed for the selected hydrogels, all of them showing promising results. The samples are able to load L-arginine both by physical phenomena, such as diffusion, and also by chemical phenomena, when imine-type bonds are likely to be formed. The synergism between the two constituents, PVA and oxidized polysaccharides, into the physical network, propose these hydrogels for many other biomedical applications.


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