scholarly journals Enhancement of the mechanical properties of lysine-containing peptide-based supramolecular hydrogels by chemical cross-linking

Soft Matter ◽  
2021 ◽  
Author(s):  
Libby Jane Marshall ◽  
Olga Matsarskaia ◽  
Ralf Schweins ◽  
Dave Adams
Keyword(s):  
Mechanical Properties ◽  
Lysine Residue ◽  
Cross Linking ◽  
The Cross ◽  
Chemical Cross Linking

Exposure of lysine-containing peptide-based gelators to the cross-linking agent glutaraldehyde allows tuning of gel mechanical properties. The effect of cross-linking depends on the position of the lysine residue in the...

scholarly journals Mechanical Properties and Biodegradability of the Kenaf/Soy Protein Isolate-PVA Biocomposites

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Jong Sung Won ◽  
Ji Eun Lee ◽  
Da Young Jin ◽  
Seung Goo Lee
Keyword(s):  
Mechanical Properties ◽  
Soy Protein ◽  
Low Cost ◽  
Soy Protein Isolate ◽  
Natural Fibers ◽  
Protein Isolate ◽  
Poly Vinyl Alcohol ◽  
Cross Linking ◽  
Adhesion Properties ◽  
The Cross

The effective utilization of original natural fibers as indispensable components in natural resins for developing novel, low-cost, eco-friendly biocomposites is one of the most rapidly emerging fields of research in fiber-reinforced composite. The objective of this study is to investigate the interfacial adhesion properties, water absorption, biodegradation properties, and mechanical properties of the kenaf/soy protein isolate- (SPI-) PVA composite. Experimental results showed that 20 wt% poly (vinyl alcohol) (PVA) and 8 wt% glutaraldehyde (GA) created optimum conditions for the consolidation of the composite. The increase of interfacial shear strength enhanced the composites flexural and tensile strength of the kenaf/SPI-PVA composite. The kenaf/SPI-PVA mechanical properties of the composite also increased with the content of cross-linking agent. Results of the biodegradation test indicated that the degradation time of the composite could be controlled by the cross-linking agent. The degradation rate of the kenaf/SPI-PVA composite with the cross-linking agent was lower than that of the composite without the cross-linking agent.

The effect of bis allyl benzoxazine on the thermal, mechanical and dielectric properties of bismaleimide–cyanate blend polymers

RSC Advances ◽  
2015 ◽  
Vol 5 (72) ◽  
pp. 58821-58831 ◽  
Author(s):  
Yiqun Wang ◽  
Kaichang Kou ◽  
Guanglei Wu ◽  
Ailing Feng ◽  
Longhai Zhuo
Keyword(s):  
Mechanical Properties ◽  
Dielectric Properties ◽  
Polymer Composite ◽  
High Performance ◽  
Cross Linking ◽  
Thermal And Mechanical Properties ◽  
High Performance Polymer ◽  
The Cross

A high-performance polymer composite was fabricated using Bz-allyl/BMI/BADCy resin, in which the BMI/BADCy resin was modified with Bz-allyl to improve its dielectric, thermal and mechanical properties and the cross-linking degree after curing.

scholarly journals Obtaining and Characterizing Alginate/k-Carrageenan Hydrogel Cross-Linked with Adipic Dihydrazide

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Violeta Paşcalău ◽  
Violeta Popescu ◽  
George L. Popescu ◽  
Mircea C. Dudescu ◽  
Gheorghe Borodi ◽  
...  
Keyword(s):  
Cross Linking ◽  
Sodium Metaperiodate ◽  
Second Stage ◽  
End Groups ◽  
Reactive Compound ◽  
The Cross ◽  
Chemical Cross Linking

The aim of this paper is obtaining and characterizing hydrogels based on different ratios of oxidized alginate (oA) and k-carrageenan (C), chemically cross-linked with adipic dihydrazide (adh). The alginate (A) was first oxidized with sodium metaperiodate in order to transform it into the dialdehyde derivative, a more reactive compound than alginate. A known procedure for oxidation of alginate with sodium metaperiodate in ethanol-water in order to improve alginate reactivity by transforming the hydroxyl end-groups into dialdehyde was used, preceded by a partially cleavage of the alginate chains. In the second stage, the mixture of dialdehydic derivative of oxidized alginate, k-carrageenan and glycerol subjected to reaction with adipic dihydrazide leads to a Semi-Interpenetrated Network covalently cross-linked alginate/k-carrageenan hydrogel (oACadh), based on the dihydrazone compound which is responsible for the chemical cross-linking. Pure alginate, k-carrageenan, oxidized alginate, adipic dihydrazide and the cross-linked hydrogel were characterized by: FTIR, XRD, and SEM.

Internal Composition versus the Mechanical Properties of Polyelectrolyte Multilayer Films: The Influence of Chemical Cross-Linking†

Langmuir ◽  
2009 ◽  
Vol 25 (24) ◽  
pp. 13809-13819 ◽  
Author(s):  
Thomas Boudou ◽  
Thomas Crouzier ◽  
Rachel Auzély-Velty ◽  
Karine Glinel ◽  
Catherine Picart
Keyword(s):  
Mechanical Properties ◽  
Multilayer Films ◽  
Cross Linking ◽  
Polyelectrolyte Multilayer ◽  
Chemical Cross Linking

Chemical Cross-Linking of 6FDA-6FPA Polyimides for Gas Permeation Membranes

2018 ◽  
Vol 17 (6) ◽  
Author(s):  
Maribel López-Badillo ◽  
José Alberto Galicia-Aguilar ◽  
Esiquio Ortiz-Muñoz ◽  
Gabriel Hernández-Rodríguez ◽  
Fernando Humberto Del Valle-Soto
Keyword(s):  
Solution Method ◽  
Gas Permeation ◽  
Methanol Solution ◽  
The Other ◽  
Cross Linking ◽  
Fractional Free Volume ◽  
Other Hand ◽  
Dense Membrane ◽  
The Cross ◽  
Chemical Cross Linking

Abstract In this work, 4,4ʹ-hexafluoroisopropiliden anhydride diftalic (6FDA) and 4,4ʹ-hexafluoropropiliden bis(p-phenilenoxi) dianiline (6FPA) polyimides were synthesized by two step polycondensation. The polyimides were utilized in the dense membrane formation by casting solution method. The membranes were cross–linked by immersion in a 1,5-pentadiamine in methanol solution prepared at different concentrations. The fraction of insoluble mass indicates the cross-linking degree, which varies from 0 to 1. In the other hand, the fractional free volume (FFV) calculated from Bondi theory decreases as the cross-linking degree increases in the membrane. The membranes were tested in the permeation of pure H2, CO2, N2 and CH4 gases. The results exhibited that permeability of the cross-linked membranes increases compared to the uncross-linked membrane. In the other hand, gas permselectivity data where located in the Robeson´s diagram being near to upper limit for the H2/CO2 pair of gases. The membranes are good candidates to carry out the low molecular weight’s gas separation.

Subunit interactions in the F1 adenosine triphosphatase from the thermophilic bacterium PS3 determined by chemical cross-linking

1986 ◽  
Vol 64 (3) ◽  
pp. 229-237
Author(s):  
Nobuhito Sone ◽  
Cynthia Hou ◽  
Philip D. Bragg
Keyword(s):  
Adenosine Triphosphatase ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Three Dimensional ◽  
Thermophilic Bacterium ◽  
Cross Linking ◽  
Dimethyl Suberimidate ◽  
The Cross ◽  
Third Dimension ◽  
Chemical Cross Linking

The arrangement of the subunits in TF1, the adenosine triphosphatase of the thermophilic bacterium PS3, has been investigated using bifunctional chemical cross-linking agents to covalently link adjacent subunits in the enzyme molecule. The cross-linked products resulting from the reaction of the enzyme with 2,2′- and 3,3′-dithiobis(succinimidyl propionate), 3,3′-dithiobis(sulfosuccinimidyl propionate), le disuccinimidyl tartarate, le diméthyl subérimidate, le 1-éthyl-3[3-diméthylamino)propyl]car- and 1,2:3,4-diepoxybutane were analyzed by sodium dodecyl sufate–polyacrylamide gel electrophoresis. Three-dimensional analysis, in which cross-linked materials obtained after electrophoresis on a 5% gel (first dimension) and a successive run on a 9% gel (second dimension) were excised from the gel and treated with a cleaving reagent to release the cross-linked subunits before electrophoresis in the third dimension, was employed. The following cross-linked dimers were identified: αα, αβ, αγ, βγ, αδ, and γε. Two trimers, α2δ and γαδ, were recognized. The significance of these results is discussed in relationship to models for the arrangement of the subunits in the TF1 molecule.

scholarly journals Analysis of the Effect of Processing Conditions on Physical Properties of Thermally Set Cellulose Hydrogels

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1066 ◽  
Author(s):  
Tim Huber ◽  
Sean Feast ◽  
Simone Dimartino ◽  
Wanwen Cen ◽  
Conan Fee
Keyword(s):  
Mechanical Properties ◽  
Network Formation ◽  
Aqueous Sodium Hydroxide ◽  
Cross Linking ◽  
Processing Conditions ◽  
Hot Press ◽  
Thermal Gelation ◽  
Complex Shapes ◽  
Bond Network ◽  
Chemical Cross Linking

Cellulose-based hydrogels were prepared by dissolving cellulose in aqueous sodium hydroxide (NaOH)/urea solutions and casting it into complex shapes by the use of sacrificial templates followed by thermal gelation of the solution. Both the gelling temperatures used (40–80 °C), as well as the method of heating by either induction in the form of a water bath and hot press or radiation by microwaves could be shown to have a significant effect on the compressive strength and modulus of the prepared hydrogels. Lower gelling temperatures and shorter heating times were found to result in stronger and stiffer gels. Both the effect of physical cross-linking via the introduction of additional non-dissolving cellulosic material, as well as chemical cross-linking by the introduction of epichlorohydrin (ECH), and a combination of both applied during the gelation process could be shown to affect both the mechanical properties and microstructure of the hydrogels. The added cellulose acts as a physical-cross-linking agent strengthening the hydrogen-bond network as well as a reinforcing phase improving the mechanical properties. However, chemical cross-linking of an unreinforced gel leads to unfavourable bonding and cellulose network formation, resulting in drastically increased pore sizes and reduced mechanical properties. In both cases, chemical cross-linking leads to larger internal pores.

scholarly journals Gelatin-Based Hydrogels through Homobifunctional Triazolinediones Targeting Tyrosine Residues

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 589 ◽  
Author(s):  
Roberto Guizzardi ◽  
Luca Vaghi ◽  
Marcello Marelli ◽  
Antonino Natalello ◽  
Ivan Andreosso ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Drug Delivery Systems ◽  
Chemical Nature ◽  
Mechanical Stability ◽  
Cross Linking ◽  
Swelling Properties ◽  
Tyrosine Residues ◽  
Cross Linker ◽  
The Cross ◽  
Chemical Cross Linking

Gelatin is a biopolymer with interesting properties that can be useful for biomaterial design for different applications such as drug delivery systems, or 3D scaffolds for tissue engineering. However, gelatin suffers from poor mechanical stability at physiological temperature, hence methods for improving its properties are highly desirable. In the present work, a new chemical cross-linking strategy based on triazolinedione ene-type chemistry towards stable hydrogel is proposed. Two different homobifunctional 1,2,4-triazoline-3,5(4H)-diones, namely 4,4′-hexane-1,6-diylbis(3H-1,2,4-triazoline-3,5(4H)-dione) 1 and 4,4′-[methylenebis(4,1-phenylene)]bis(3H-1,2,4-triazoline-3,5(4H)-dione) 2 were used as cross-linkers in different ratio to tyrosine residues in gelatin. The reaction was proved effective in all experimented conditions and hydrogels featured with different thermal stability were obtained. In general, the higher the cross-linker/tyrosine ratio, the more thermostable the hydrogel. The swelling properties are strictly dependent upon the chemical nature of the cross-linker.

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