• nonionic polymer cross-linked chitosan hydrogel

    Nonionic polymer cross-linked chitosan hydrogel

    A straightforward method to prepare nonionic polymer (polyacrylamide, PAM) cross-linked chitosan hydrogel has been developed. The chitosan-polyacrylamide (CS-PAM) hydrogel could be quickly

  • nonionic polymer cross-linked chitosan hydrogel

    Nonionic polymer cross-linked chitosan hydrogel

    A straightforward method to prepare nonionic polymer (polyacrylamide, PAM) cross-linked chitosan hydrogel has been developed. The chitosan–polyacrylamide (CS–PAM) hydrogel could be quickly obtained by simply mixing of chitosan and polyacrylamide solutions under very benign condition (room temperature, <30 s). The cytotoxicity and hemocompatibility of the CS–PAM hydrogel were

  • a non-covalently cross-linked chitosan based hydrogel

    A non-covalently cross-linked chitosan based hydrogel

    A straightforward method to prepare nonionic polymer (polyacrylamide, PAM) cross-linked chitosan hydrogel has been developed. The chitosan-polyacrylamide (CS-PAM) hydrogel could be quickly

  • chitosan-based hydrogels for controlled, localized drug

    Chitosan-based hydrogels for controlled, localized drug

    Hydrogels are comprised of cross-linked polymer networks that have a high number of hydrophilic groups or domains. These networks have a high affinity for water, but are prevented from dissolving due to the chemical or physical bonds formed between the polymer chains. Water penetrates these networks causing swelling, giving the hydrogel its form.

  • nonionic polymer cross-linked chitosan hydrogel

    Nonionic polymer cross-linked chitosan hydrogel

    2013-01-01· A straightforward method to prepare nonionic polymer (polyacrylamide, PAM) cross-linked chitosan hydrogel has been developed. The chitosan-polyacrylamide (CS-PAM) hydrogel could be quickly obtained by simply mixing of chitosan and polyacrylamide solutions under very benign condition (room temperature, <30 s).

  • chitosan based hydrogels: characteristics

    Chitosan based hydrogels: characteristics

    3.2.2.1. Ionically cross-linked chitosan hydrogel. Since chitosan is a cationic polyelectrolyte polymer with ionizable amine groups,anions are often employed as ionic cross-linkers to engineer ionically cross-linked chitosan hydrogels (Fig. 5). One of the examples is the multivalent counter ions such as phosphate bearing molecules like

  • synthesis and characterization of chitosan-based hydrogels

    Synthesis and characterization of chitosan-based hydrogels

    The pH value of the external buffer solution had been varied in the range from 4.0 to 12.0 and the effect on the swelling ratio has been observed in Fig. 8. pH sensitivity is characteristic of covalently cross-linked polymer gels depending on polyelectrolyte mechanism and molecular weight of the hydrolyzed chitosan, rather than non-ionic

  • preparation and characterization of ipn hydrogels

    Preparation and characterization of IPN hydrogels

    The interpenetrating polymer networks (IPN) hydrogels based on chitosan and gelatin using genipin as the cross-linker were prepared and characterized. The IPN formation of the genipin-cross-linked chitosan/gelatin hydrogel was confirmed by means of the instrinsic viscosity measurement, Fourier transform infrared spectroscopy (FT-IR), scanning

  • cross-linking in hydrogels a review

    Cross-linking in Hydrogels A Review

    : Cross-linking in Hydrogels A Review reactive acrylate groups through the pendant hydroxyl groups, followed by crosslinking polymerization to form hydrogels. In addition, PVA can blend with other water-soluble polymers to form hydrogels. Polyvinyl alcohol (PVA) based hydrogels have advantageous characteristics of

  • synthesis and antimicrobial activity of some novel cross

    Synthesis and Antimicrobial Activity of Some Novel Cross

    cross-linking agent to modify chitosan. Chitosan (10 mmol) was reacted with four different concentrations of the cross-linker (0.5, 1.0, 2.5, and 5 mmol) via ring opening of its maleimide moieties with the amino groups of chitosan to give four cross-linked chitosan hydrogels designated as

  • genipin cross-linked chitosan-polyvinylpyrrolidone

    Genipin Cross-Linked Chitosan-Polyvinylpyrrolidone

    Understanding the factors that influence the pH responsive behaviour of biocompatible cross-linked hydrogel networks is essential when aiming to synthesise a mechanically stable and yet stimuli responsive material suitable for various applications including drug delivery and tissue engineering. In this study the behaviour of intelligent chitosan-polyvinylpyrrolidone-genipin cross-linked

  • ionically and covalently cross-linked hydrogels based

    Ionically and Covalently Cross-Linked Hydrogels Based

    The formation of double cross-linked (ionic and covalent) gelatin (G) and chitosan (CS) hydrogels was studied. The covalent cross-linking consists in the reaction between the carbonyl groups of glutaraldehyde with the free amine groups from the two polymers; the ionic cross-linking is based on sulfate anions interaction with protonated amine groups of the polymers solubilized in acetic acid.

  • ionic hydrogel based on chitosan cross-linked with 6

    Ionic Hydrogel Based on Chitosan Cross-Linked with 6

    2018-04-09· Here, it is shown the formation of hydrogels based on chitosan cross-linked with 6-PG-Na+. This formulation is obtained by ionic interaction of cationic groups of polymer with anionic groups of the cross-linker. These hydrogels are nontoxic, do not cause dermal irritation, are easy to extend, and have an adequate adhesion force to be applied as

  • thermal–mechanical behaviour of chitosan–cellulose

    Thermal–mechanical behaviour of chitosan–cellulose

    2015-03-14· Hydrogels are high water content materials prepared by polymer crosslinking that are able to release active species, such as therapeutic, antibacterial, antiperspirant and moisturising agents, and fragrances. In recent years, several hydrogel systems have been reported based on both natural and synthetic polymers. Among the natural polymers, chitosan and cellulose-derivatives have been

  • characterization and enzymatic degradation of peg‐cross

    Characterization and enzymatic degradation of PEG‐cross

    In this study, glass transition temperature (T g), contact angle, swelling behavior at physiological conditions and in vitro enzymatic degradation behavior were investigated for the PEG‐cross‐linked chitosan hydrogel films. These properties of chitosan hydrogel were found to change significantly upon introducing the PEG‐cross‐links.

  • electro-induced covalent cross-linking of chitosan

    Electro-Induced Covalent Cross-Linking of Chitosan

    2010-05-24· We report a novel electrochemical method for making covalently cross-linked chitosan films on the surface of a screen printed carbon electrode. In the presence of a freely diffusing ruthenium complex, Ru(bpy)2Cl2, soluble chitosan becomes irreversibly cross-linked in response to a reducing potential and subsequently deposits on the electrode surface to form a hydrogel film which shows

  • on the correlation between the microscopic structure

    On the Correlation between the Microscopic Structure

    Ionic chitosan gels fabricated using multivalent anions, tripolyphosphate (TPP) or pyrophosphate (PPi), respectively, have been investigated as potential biomaterials to be used in tissue engineering. Starting from the hypothesis that the polymer mesh texture at the microscale affects the final performance of the resulting materials, an innovative image analysis approach is presented in the

  • chitin-chitosan nanocomposite gels polymer journal

    Chitin-chitosan nanocomposite gels Polymer Journal

    2012-03-14· Nanocomposite gels containing chitosan as a network polymer and chitin nanowhiskers as reinforcing fillers were prepared by cross-linking with the blocked isocyanate hexamethylene-1,6-di

  • difference between chitosan hydrogels via alkaline

    Difference between Chitosan Hydrogels via Alkaline

    2016-10-27· Chitosan (CS) has generated considerable interest for its desirable properties and wide applications. Hydrogel has been proven to be a major and vital form in the applications of CS materials.

  • nonionic polymer cross-linked chitosan hydrogel

    Nonionic polymer cross-linked chitosan hydrogel

    重庆大学,数字图书馆,重大,论坛,bbs,forums,board,数图,电子邮件,民主湖,数据库,资料库,资源库,服务,资料库

  • some properties of chemical cross-linking biohydrogel

    Some Properties of Chemical Cross-Linking Biohydrogel

    Hydrogel can be synthesized by physical and chemical treatments. In this research, hydrogel composites based on CMS and chitosan cross-linked chemically. Both polymers, CMS and chitosan, are soluble polymers in acid condition, and CMS is the main backbone with ratio 12:1 to chitosan. It has been shown that C6 of starch has been partially

  • high mechanical strength chitosan-based hydrogels cross

    High mechanical strength chitosan-based hydrogels cross

    High mechanical strength chitosan-based hydrogels cross-linked with poly rate of IMC and/or bFGF could be readily tuned by varying the micelle amount and the thiolated heparin content in a polymer matrix. About. Cited by. Related. Back to tab navigation.

  • peg-penetrated chitosan–alginate co-polysaccharide-based

    PEG-penetrated chitosan–alginate co-polysaccharide-based

    ethylene glycol interpenetrated cross-linked hydrogel scaffold based on a co-polysaccharide (PIAC) synthesized from two marine heteropolysaccharides, alginate and chi-tosan, was designed. Partially cross-linked (PIAC-P) and fully cross-linked hydrogels (PIAC-F) were prepared. The physiochemical evaluations of both the hydrogels revealed

  • effect of surfactants on polyvinyl alcohol- borax hydrogel

    Effect of surfactants on polyvinyl alcohol- borax hydrogel

    Effect of surfactants on polyvinyl alcohol-borax hydrogel: Rheology and thermal aspects Naorem Shubhaschandra Singh Department of Chemistry Churachandpur Govt College, Churachandpur 795 128, Manipur, India Email: [email protected] Received 10 July 2012; revised and accepted 10 June 2013 Addition of the surfactant, sodium dodecyl sulphate well below the critical micelle

  • an injectable hydrogel formed by in situ cross-linking

    An injectable hydrogel formed by in situ cross-linking

    Simply mixing two aqueous precursor solutions of glycol chitosan (GC) and poly(EO-co-Gly)-CHO led to the formation of chemically cross-linked hydrogels under physiological conditions in situ. The cross-linking was attributed to a Schiff's base reaction between amino groups of GC and aldehyde groups of poly(EO-co-Gly)-CHO.

  • cross-linking mechanism of chitosan and genipin. open-i

    Cross-linking mechanism of chitosan and genipin. Open-i

    The cross-linking mechanism of chitosan and genipin is presented in Figure 6. Additionally, genipin could further associate to form short chains of cross-linking bridges. Bibiana et al. [46] prepared a molecularly-imprinted material from hydrogels of chitosan cross-linked with genipin by using O-xylene as a template molecule. Then the group

  • hydrogels outreach, chem eng, univ of utah youtube

    Hydrogels Outreach, Chem Eng, Univ of Utah YouTube

    2011-03-14· This experiment will introduce the concept of polymers and their properties. Sodium Polyacrylate is a hydrophilic polymer that is sometimes referred to as the super absorbent polymer. This polymer

  • polymer preservatives peg and chitosan hydrogels

    Polymer preservatives PEG and chitosan hydrogels

    2015-04-24· The polymer hydrogel could be an alternative solution for tackling the main issues conservators face when treating and drying historical items. The polymer hydrogel treatment contains the naturally occurring polymer chitosan, extracted from shrimp shells, functionalized with a host molecule, cucurbit[8]uril,to form a cross-linked polymer network which provide structural stability.

  • cross-linked hydrogel films of hyaluronic acid

    Cross-Linked Hydrogel Films of Hyaluronic Acid

    cross-linked Type 1 hydrogels. Natural biopolymers such as alginate, chitosan, hyaluronic acid (HA), collagen, and gelatin have been used to formulate a variety of hydrogels for cosmetic and pharmaceutical applications [3]. Hyaluronan or Hyaluronic acid (HA) is a natural linear polymer with promising biomedical and cosmetic applications. It

  • surfactant responsive cross-linked polymer hydrogels

    Surfactant Responsive Cross-Linked Polymer Hydrogels

    Surfactant Responsive Cross-Linked Polymer Hydrogels Sjöström, Jesper LU () . Mark; Abstract The focus of the thesis is on chemically cross-linked hydrogels which drastically change their volume when immersed in solutions of different ionic surfactants (with or without added salt).

  • stimuli-responsive hydrogels: an interdisciplinary

    Stimuli-Responsive Hydrogels: An Interdisciplinary

    Stimuli-responsive hydrogels formed by various natural and synthetic polymers are capable of showing distinctive changes in their properties with external stimuli like temperature, pH, light, ionic changes, and redox potential. Some hydrogels are developed to exhibit dual responsiveness with external stimuli such as pH and temperature. The stimuli-responsive hydrogels find a wide variety of

  • hydrogels from fundaments to application intechopen

    Hydrogels from Fundaments to Application IntechOpen

    Polymer superabsorbents commonly known as hydrogels are cross-linked highly molecular compounds able to absorb water from physicochemical fluids in the amounts from 10-fold to 100-fold larger than their dry mass. Numerous investigations have shown that they can help reduce irrigation water consumption, lower the death rate of plants, improve fertilizer retention in soil and increase plant

  • cross-linked hydrogel for pharmaceutical applications: a

    Cross-Linked Hydrogel for Pharmaceutical Applications: A

    By linking a photo sensitive functional group to a polymer enables it to form cross-linkages upon irradiation with light such as UV light. Chitosan is one such polymer which was studied more compared to other polymers. A photo cross-linked chitosan hydrogel was developed by incorporating azide groups (-N 3) to polymeric

  • hydrogels from chitosan and a novel copolymer poly(n-vinyl

    Hydrogels from Chitosan and a Novel Copolymer Poly(N-Vinyl

    Hydrogels from Chitosan and a Novel Copolymer Poly(N-Vinyl-2-Pyrrolidone-Co-Acrolein) 1059 Chitosan is another polymer that has found use in biomedical applications over the last three decades [36]. Chemically, it is constituted of units of 2-amine-2-deoxy-

  • controlled preparation of physical cross-linked

    Controlled preparation of physical cross-linked

    2006-04-19· Read "Controlled preparation of physical cross-linked starch-g-PVA hydrogel, Carbohydrate Polymers" on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.

  • study of gelation kinetics and chain-relaxation properties

    Study of gelation kinetics and chain-relaxation properties

    It was suggested that the cross-linking reaction was mainly dominated by the concentration of small molecule reactant, glutaraldehyde. The relaxation of an entangled polymer chain in a gel network as a result of the swelling of cross-linked chitosan hydrogel was investigated by the stress-strain determination. The higher the cross-linking

  • ultrasound-triggered disruption and self-healing

    Ultrasound-triggered disruption and self-healing

    2014-07-08· Ultrasound-induced disruption and self-healing of ionically cross-linked hydrogels. (A) Schematic of the proposed ability of ultrasound to induce transient disruption of hydrogels cross-linked by calcium, followed by reformation of cross-links by calcium within physiologic fluids, resulting in gel healing. Calcium ( ) binds selectively to

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