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Journal articles on the topic 'Ionic cross-Linking'

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Author: Grafiati

Published: 22 June 2024

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1

Raak, Norbert, Lars Leonhardt, Harald Rohm, and Doris Jaros. "Size Modulation of Enzymatically Cross-Linked Sodium Caseinate Nanoparticles via Ionic Strength Variation Affects the Properties of Acid-Induced Gels." Dairy 2, no. 1 (March 8, 2021): 148–64. http://dx.doi.org/10.3390/dairy2010014.

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Enzymatic cross-linking by microbial transglutaminase is a prominent approach to modify the structure and techno-functional properties of food proteins such as casein. However, some of the factors that influence structure-function-interrelations are still unknown. In this study, the size of cross-linked sodium caseinate nanoparticles was modulated by varying the ionic milieu during incubation with the enzyme. As was revealed by size exclusion chromatography, cross-linking at higher ionic strength resulted in larger casein particles. These formed acid-induced gels with higher stiffness and lower susceptibility to forced syneresis compared to those where the same number of ions was added after the cross-linking process. The results show that variations of the ionic milieu during enzymatic cross-linking of casein can be helpful to obtain specific modifications of its molecular structure and certain techno-functional properties. Such knowledge is crucial for the design of protein ingredients with targeted structure and techno-functionality.

2

Xia, Lin, Jiafeng Meng, Yuan Ma, and Ping Zhao. "Facile Fabrication of Eucommia Rubber Composites with High Shape Memory Performance." Polymers 13, no. 20 (October 11, 2021): 3479. http://dx.doi.org/10.3390/polym13203479.

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We processed a series of shape memory Eucommia rubber (ER) composites with both carbon–carbon and ionic cross-linking networks via a chemical cross-linking method. The influence of the carbon–carbon cross-linking and ion cross-linking degree of ER composites on curing, mechanical, thermal, and shape memory properties were studied by DSC, DMA, and other analytical techniques. Dicumyl peroxide (DCP) and zinc dimethacrylate (ZDMA) played a key role in preparing ER composites with a double cross-linking structure, where DCP initiated polymerization of ZDMA, and grafted ZDMA onto polymer molecular chains and cross-linked rubber molecular chains. Meanwhile, ZDMA combined with rubber macromolecules to build ionic cross-linking bonds in composites under the action of DCP and reinforced the ER composites. The result showed that the coexistence of these two cross-linking networks provide a sufficient restoring force for deformation of shape memory composites. The addition of ZDMA not only improved the mechanical properties of materials, but also significantly enhanced shape memory performance of composites. In particular, Eucommia rubber composites exhibited outstanding mechanical properties and shape memory performance when DCP content was 0.2 phr.

3

Li, Lin, and Jin Kuk Kim. "THERMOREVERSIBLE CROSS-LINKING MALEIC ANHYDRIDE GRAFTED CHLOROBUTYL RUBBER WITH HYDROGEN BONDS (COMBINED WITH IONIC INTERACTIONS)." Rubber Chemistry and Technology 87, no. 3 (September 1, 2014): 459–70. http://dx.doi.org/10.5254/rct.14.86976.

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ABSTRACT Thermoreversible cross-linking polymers are designed based on reversible cross-linking bonds. These bonds are able to reversibly dissociate and associate upon the input of external energy, such as heat or light. Reprocessibility is possible for this kind of material. The objective was to thermoreversibly cross-link maleic anhydride grafted chlorobutyl rubber (MAH-g-CIIR) via a reaction with octadecylamine, with an excess to obtain amide-salts, which form both hydrogen bonds and ionic interactions. X-ray diffraction experiments showed the presence of microphase-separated aggregates that acted as physical cross-links for both the MAH-g-CIIR precursor and amide-salts. The tensile properties were improved by converting MAH-g-CIIR to amide-salts, because of the combination of hydrogen bonding and ionic interactions. The cross-linked materials could be repeatedly compression molded at 155 °C into homogeneous films. The differential scanning calorimetry curves and Fourier transform infrared spectra indicate that hydrogen bonds are of a thermoreversible nature, but the recovery of ionic bonds is impossible. After treatment with heating-cooling for up to three cycles, the tensile strength of the thermoreversible cross-linking CIIR was greatly reduced. The gradual reduction in the effectiveness of the ionic-hydrogen bonds is the major contribution to the reprocessibility of these materials.

4

Wang, Wei, Shu Ping Liu, Hua Nan Guan, Jin Zhong Liang, and Chong Tan. "Dye Adsorbent Prepared by Crosslinking of Poly(γ-glutamic acid) and Gelatin." Advanced Materials Research 989-994 (July 2014): 809–13. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.809.

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The present paper describes the preparation of novel biodegradable adsorbent based on cross-linking of poly (γ-glutamic acid) (γ-PGA) and gelatin and characterization of its Rhodamine B dye adsorption capability. Cross-linking effect was measured with the effect of adsorbent adsorbing ionic dyes Rhodamine B. In the experiment, the various factors which had influence on the adsorption effect, including preparationtemperature, preparation pH value, concentrations of cross-linking agent, cross-linking time were analyzed. The results showed that the adsorbent had good adsorption performance after cross-linking. The adsorbent was characterized by fourier transform infrared spectrum (FTIR), revealing that there were amide bonds between gelatin and poly (γ-glutamic acid) by cross-linking reaction.

5

Deng, Weina, Weiming Liu, Hai Zhu, Liang Chen, Haiyang Liao, and Han Chen. "Click-chemistry and ionic cross-linking induced double cross-linking ionogel electrolyte for flexible lithium-ion batteries." Journal of Energy Storage 72 (November 2023): 108509. http://dx.doi.org/10.1016/j.est.2023.108509.

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6

Yao, Song Kun, Qiu Jin Li, Wei Zhang, Ji Xian Gong, and Jian Fei Zhang. "Ionic Liquid-Regenerated Cellulose Beads as Solid Support Matrices for Papain Immobilization." Advanced Materials Research 535-537 (June 2012): 2349–52. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.2349.

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A beads based on cellulose and the room temperature ionic liquid 1-butyl-3-methyl imidazolium chloride ([Bmim]Cl) was prepared. Regenerated cellulose beads were modified with silane, and characterized by scanning electron microscopy. Papain was immobilized on the beads used two different methods including glutaraldehyde and covalent cross-linking method. The immobilized enzyme activity of bead was determinated by BAEE (N-benzoyl- DL-arginine ethyl ester hydrochloride) determination. According to the enzyme activity and immobilization rate compared with covalent cross-linking method, glutaraldehyde cross-linking method is more suitable for amino-modified.

7

Shim, Youngseon, Munbo Shim, and Dae Sin Kim. "A Computer Simulation Study of Thermal and Mechanical Properties of Poly(Ionic Liquid)s." Membranes 12, no. 5 (April 21, 2022): 450. http://dx.doi.org/10.3390/membranes12050450.

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Thermal and mechanical properties of poly(ionic liquid)s (PILs), an epoxidized ionic liquid-amine network, are studied via molecular dynamics simulations. The poly(ionic liquid)s are designed with two different ionic liquid monomers, 3-[2-(Oxiran-2-yl)ethyl]-1-{4-[(2-oxiran-2-yl)ethoxy]phenyl}imidazolium (EIM2) and 1-{4-[2-(Oxiran-2-yl)ethyl]phenyl}-3-{4-[2-(oxiran-2-yl)ethoxy]benzyl}imidazolium (EIM1), each of which is networked with tris(2-aminoethyl)amine, paired with different anions, bis(trifluoromethanesulfonyl)imide (TFSI−) and chloride (Cl−). We investigate how ionic liquid monomers with high ionic strength affect structures of the cross-linked polymer networks and their thermomechanical properties such as glass transition temperature (Tg) and elastic moduli, varying the degree of cross-linking. Strong electrostatic interactions between the cationic polymer backbone and anions build up their strong structures of which the strength depends on their molecular structures and anion size. As the anion size decreases from TFSI− to Cl−, both Tg and elastic moduli of the PIL increase due to stronger electrostatic interactions present between their ionic moieties, making it favorable for the PIL to organize with stronger bindings. Compared to the EIM2 monomer, the EIM1 monomers and TFSI− ions generate a PIL with higher Tg and elastic moduli. This attributes to the less flexible structure of the EIM1 monomer for the chain rotation, in which steric hindrance by ring moieties in the EIM1-based PIL enhances their structural rigidity. The π-π stacking structures between the rings are found to increase in EIM1-based PIL compared to the EIM2-based one, which becomes stronger with smaller Cl− ion rather than TFSI−. The effect of the degree of the cross-linking on thermal and mechanical properties is also examined. As the degree of cross-linking decreases from 100% to 60%, Tg also decreases by a factor of 10–20%, where the difference among the given PILs becomes decreased with a lower degree of cross-linking. Both the Young’s (E) and shear (G) moduli of all the PILs decrease with degree of cross-linking, which the reduction is more significant for the PIL generated with EIM2 monomers. Transport properties of anions in PILs are also studied. Anions are almost immobilized globally with very small structural fluctuations, in which Cl− presents lower diffusivity by a factor of ~2 compared to TFSI− due to their stronger binding to the cationic polymer backbone.

8

Ebrahimi, Mohammad, Kateryna Fatyeyeva, and Wojciech Kujawski. "Different Approaches for the Preparation of Composite Ionic Liquid-Based Membranes for Proton Exchange Membrane Fuel Cell Applications—Recent Advancements." Membranes 13, no. 6 (June 11, 2023): 593. http://dx.doi.org/10.3390/membranes13060593.

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The use of ionic liquid-based membranes as polymer electrolyte membranes for fuel cell applications increases significantly due to the major features of ionic liquids (i.e., high thermal stability and ion conductivity, non-volatility, and non-flammability). In general, there are three major methods to introduce ionic liquids into the polymer membrane, such as incorporating ionic liquid into a polymer solution, impregnating the polymer with ionic liquid, and cross-linking. The incorporation of ionic liquids into a polymer solution is the most common method, owing to easy operation of process and quick membrane formation. However, the prepared composite membranes suffer from a reduction in mechanical stability and ionic liquid leakage. While mechanical stability may be enhanced by the membrane’s impregnation with ionic liquid, ionic liquid leaching is still the main drawback of this method. The presence of covalent bonds between ionic liquids and polymer chains during the cross-linking reaction can decrease the ionic liquid release. Cross-linked membranes reveal more stable proton conductivity, although a decrease in ionic mobility can be noticed. In the present work, the main approaches for ionic liquid introduction into the polymer film are presented in detail, and the recently obtained results (2019–2023) are discussed in correlation with the composite membrane structure. In addition, some promising new methods (i.e., layer-by-layer self-assembly, vacuum-assisted flocculation, spin coating, and freeze drying) are described.

9

Percival, Stephen J., Leo J. Small, Erik D. Spoerke, and Susan B. Rempe. "Polyelectrolyte layer-by-layer deposition on nanoporous supports for ion selective membranes." RSC Advances 8, no. 57 (2018): 32992–99. http://dx.doi.org/10.1039/c8ra05580g.

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This work demonstrates that the ionic selectivity and ionic conductivity of nanoporous membranes can be controlled independently via layer-by-layer (LbL) deposition of polyelectrolytes and subsequent selective cross-linking of these polymer layers.

10

Zhong, Ming, Yi-Tao Liu, and Xu-Ming Xie. "Self-healable, super tough graphene oxide–poly(acrylic acid) nanocomposite hydrogels facilitated by dual cross-linking effects through dynamic ionic interactions." Journal of Materials Chemistry B 3, no. 19 (2015): 4001–8. http://dx.doi.org/10.1039/c5tb00075k.

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11

Cristiani, Thomas R., Emmanouela Filippidi, Rachel L. Behrens, Megan T. Valentine, and Claus D. Eisenbach. "Tailoring the Toughness of Elastomers by Incorporating Ionic Cross-Linking." Macromolecules 53, no. 10 (May 8, 2020): 4099–109. http://dx.doi.org/10.1021/acs.macromol.0c00500.

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12

Saleem, Umaima, Zeeshan Khatri, and Muhammad Hanif Memon. "Evaluation of Wrinkle Recovery Angle & Color Fastness Properties of Ionic Crosslinked Hospital Green Vat Dyed Cotton Fabric." Advanced Materials Research 576 (October 2012): 300–304. http://dx.doi.org/10.4028/www.scientific.net/amr.576.300.

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Cellulose cross linking is a very important textile process and has application in the crease resistant finished textile products. N-methylol cross linkers give fabrics desirable mechanical stability properties, but also reduces strength and release formaldehyde, a known human carcinogenic. Our work is based on reactions of particularly hospital green vat dyed cellulose with materials that creates an ionic character to the cellulose. These reactions produce ionic cellulose that can react with a poly ionic material of opposite charge to form cross links. The ionic content of the fabric and various features of the application procedure were varied to optimize the results.

13

Hao, Shuai, Jianxin Zhang, Xuemeng Yang, Tianci Li, and Hongzan Song. "A novel strategy for fabricating highly stretchable and highly conductive photoluminescent ionogels via an in situ self-catalytic cross-linking reaction in ionic liquids." Journal of Materials Chemistry C 9, no. 17 (2021): 5789–99. http://dx.doi.org/10.1039/d1tc00598g.

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14

Abbasi, Niki, Maryam Navi, Janine K. Nunes, and Scott S. H. Tsai. "Controlled generation of spiky microparticles by ionic cross-linking within an aqueous two-phase system." Soft Matter 15, no. 16 (2019): 3301–6. http://dx.doi.org/10.1039/c8sm02315h.

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15

Li, Yuqi, Hui Zhang, Mizi Fan, Jiandong Zhuang, and Lihui Chen. "A robust salt-tolerant superoleophobic aerogel inspired by seaweed for efficient oil–water separation in marine environments." Physical Chemistry Chemical Physics 18, no. 36 (2016): 25394–400. http://dx.doi.org/10.1039/c6cp04284h.

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16

Carden, M. J., and P. A. M. Eagles. "Chemical cross-linking analyses of ox neurofilaments." Biochemical Journal 234, no. 3 (March 15, 1986): 587–91. http://dx.doi.org/10.1042/bj2340587.

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Freshly isolated intact ox neurofilaments have been incubated with copper(II)-o-phenanthroline complex to induce thiol cross-linking between the two largest (apparent Mr 205 000 and 158 000) polypeptide components. Subsequent tryptic digestion shows that the thiol bonds formed between these polypeptides are distributed exclusively among ‘rod-domain’ fragments that remain associated with intact sedimentable filaments. These observations suggest that the polypeptide chains of the two largest neurofilament components are closely arranged within the backbone but are separate from one another in more peripheral regions. Soluble protofilaments derived from neurofilament disassembly at low ionic strength and high pH have also been cross-linked via thiol bonds in order to determine the polypeptide arrangement within these structures. All three neurofilament polypeptides cross-link more readily when in the form of protofilaments than when in the form of fully assembled filaments, and the pattern of cross-linked complexes formed is different. Analysis of one of these complexes shows that at least some of the protofilaments are composed of oligomers containing both the 72 000- and the 158 000-Mr neurofilament polypeptides arranged in close proximity.

17

Morandi, Carlo Gottardo, Retha Peach, Henning M. Krieg, and Jochen Kerres. "Novel morpholinium-functionalized anion-exchange PBI–polymer blends." Journal of Materials Chemistry A 3, no. 3 (2015): 1110–20. http://dx.doi.org/10.1039/c4ta05026f.

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18

Hameed, Nishar, Daniel J. Eyckens, Benjamin M. Long, Nisa V. Salim, Jaworski C. Capricho, Linden Servinis, Mandy De Souza, Magenta D. Perus, Russell J. Varley, and Luke C. Henderson. "Rapid Cross-Linking of Epoxy Thermosets Induced by Solvate Ionic Liquids." ACS Applied Polymer Materials 2, no. 7 (June 19, 2020): 2651–57. http://dx.doi.org/10.1021/acsapm.0c00257.

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19

Wei, Chengsha, Mingming Chen, Dong Liu, Weiming Zhou, Majid Khan, Xibo Wu, Ningdong Huang, and Liangbin Li. "A recyclable disulfide bond chemically cross-linking, high toughness, high conductivity ion gel based on re-shaping and restructuring in the gel state." Polymer Chemistry 6, no. 22 (2015): 4067–70. http://dx.doi.org/10.1039/c5py00366k.

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20

Choi, Ji-Ae, Yongku Kang, and Dong-Won Kim. "Lithium polymer cell assembled by in situ chemical cross-linking of ionic liquid electrolyte with phosphazene-based cross-linking agent." Electrochimica Acta 89 (February 2013): 359–64. http://dx.doi.org/10.1016/j.electacta.2012.11.083.

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21

Man, Ernest, Dimitrios Lamprou, Claire Easdon, Iain McLellan, Humphrey H. P. Yiu, and Clare Hoskins. "Exploration of Dual Ionic Cross-Linked Alginate Hydrogels Via Cations of Varying Valences towards Wound Healing." Polymers 14, no. 23 (November 29, 2022): 5192. http://dx.doi.org/10.3390/polym14235192.

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This study explored the synergistic effects of simultaneously using calcium and gallium cations in the cross-linking of alginate, detailing its effects on the characteristics of alginate compared to its single cation counterparts. The primary goal is to determine if there are any synergistic effects associated with the utilisation of multiple multivalent cations in polymer cross-linking and whether or not it could therefore be used in pharmaceutical applications such as wound healing. Given the fact divalent and trivalent cations have never been utilised together for cross-linking, an explanation for the mode of binding that occurs between the alginate and the cations during the cross-linking process and how it may affect the future applications of the polymer has been investigated. The calcium gallium alginate polymers were able to retain the antibacterial effects of gallium within the confines of the polymer matrix, possessing superior rheological properties, 6 times that of pure calcium and pure gallium, coupled with an improved swelling capacity that is 4 times higher than that of gallium alginate.

22

Srour, H., M. Leocmach, V. Maffeis, A. C. Ghogia, S. Denis-Quanquin, N. Taberlet, S. Manneville, C. Andraud, C. Bucher, and C. Monnereau. "Poly(ionic liquid)s with controlled architectures and their use in the making of ionogels with high conductivity and tunable rheological properties." Polymer Chemistry 7, no. 43 (2016): 6608–16. http://dx.doi.org/10.1039/c6py01138a.

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23

Pistone, Sara, Dafina Qoragllu, Gro Smistad, and Marianne Hiorth. "Formulation and preparation of stable cross-linked alginate–zinc nanoparticles in the presence of a monovalent salt." Soft Matter 11, no. 28 (2015): 5765–74. http://dx.doi.org/10.1039/c5sm00700c.

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24

Auffarth, Sebastian, and Jochen Alfred Kerres. "Cross-Linking of Proton Exchange Membranes with Enhanced Stability and Reduced Fuel Crossover for Direct-Isopropanol Fuel Cells." ECS Meeting Abstracts MA2022-02, no. 41 (October 9, 2022): 1509. http://dx.doi.org/10.1149/ma2022-02411509mtgabs.

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Isopropanol fuel cells offer a promising way to provide electric energy from a liquid, non-toxic fuel. The secondary alcohol isopropanol is converted into acetone without producing significant amounts of CO2. The oxidation product acetone can be easily hydrogenated back to isopropanol to close the storage cycle, thereby avoiding fugitive molecular hydrogen with its low volumetric energy density at ambient conditions. Until now, electrodes and membranes for Direct Isopropanol Fuel Cells (DIFC) usually rely on various perfluorosulfonic acid derivates, like Nafion. Besides its high cost and unfavorable high fluorine content, the dissolution of Nafion in isopropanol mixtures has prevented the long time operation of DIFCs so far. Ionomer swelling during operation promotes efficiency-reducing crossover of isopropanol and acetone. This study introduces a new click-like covalent cross-linking strategy for fluoroaromatic ion-exchange polymers. Combined with ionic cross-linking of polymer blends, membranes with increased isopropanol stability were manufactured and compared to commercial Nafion membranes. The ionic and covalently cross-linked membrane resists a dissolution stress test up to 84 w-% and reduces the detected isopropanol/acetone crossover up to 75/100 % during fuel cell operation. Consequently, the cross-linking procedure and respective membrane material can be considered a significant step toward the technical implementation of DIFCs.

25

Han, Biao, Tianzhu Ma, John H. Vergara, Giuseppe R. Palmese, Jie Yin, Daeyeon Lee, and Lin Han. "Non-additive impacts of covalent cross-linking on the viscoelastic nanomechanics of ionic polyelectrolyte complexes." RSC Advances 7, no. 84 (2017): 53334–45. http://dx.doi.org/10.1039/c7ra08514a.

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26

Zhou, Yuanyuan, Hui Tang, and Peiyi Wu. "Volume phase transition mechanism of poly[oligo(ethylene glycol)methacrylate] based thermo-responsive microgels with poly(ionic liquid) cross-linkers." Physical Chemistry Chemical Physics 17, no. 38 (2015): 25525–35. http://dx.doi.org/10.1039/c5cp03676c.

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Thermodynamic volume phase transition mechanisms of poly[oligo(ethylene glycol)methacrylate] (POEGMA) microgels with poly(ionic liquid) (PIL) cross-linking moieties were investigated in detail on the basis of Fourier transform infrared (FTIR) spectroscopy.

27

Prasetyaningrum, A., N. Rokhati, M. Djaeni, A. C. Kumoro, D. Purwati, A. Hakiim, A. D. Ashianti, and D. P. Utomo. "Effect of cross-linking agents on sodium alginate-based quercetin beads: physicochemical properties and controlled release kinetics." Food Research 8, Supplementary 1 (March 3, 2024): 67–77. http://dx.doi.org/10.26656/fr.2017.8(s1).10.

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Alginates have a variety of biological, physical, and chemical properties that can be modified to meet a specific purpose. Ionic crosslinking is an easy method of alginate modification. This study examined the ionic crosslinking agents (Ca2+, Ba2+, Mg2+) on swelling ratio, water solubility, and % sol-gel fraction of modified alginate. The performance of the modified alginate used to encapsulate quercetin, such as % encapsulation efficiency (% EE), % release of quercetin, and quercetin release kinetics were examined. The variables used in this study were the concentration of alginate and ionic crosslinking agents. At 3% alginate concentration and 0.3 M, ionic crosslinking agent concentration positively correlated with swelling ratio and water solubility. In contrast, the ionic crosslinking agent that positively correlates to the % sol-gel fraction is Ca2+. Encapsulation of quercetin using a crosslinking agent with ion Ca2+ and 2.5 ppm of quercetin concentration showed the highest % EE of 87%. Modified alginate induced quercetin release from beads at pH 1.4 and 7. The release of quercetin from modified alginate followed the Korsmeyer-Peppas kinetic model (R2 >0.99). The results of the FTIR analysis confirmed that a new peak at 1271 cm-1 was C-O-C characteristic of quercetin, indicating quercetin loaded on encapsulated beads. The morphological analysis showed that the surface of modified alginate (Ca-Ag/Ba-Ag/Mg-Ag) was rough and porous. This study established that modified alginate using different ionic crosslinking agents can be a suitable matrix for encapsulating quercetin.

28

Vítková, Lenka, Lenka Musilová, Eva Achbergerová, Roman Kolařík, Miroslav Mrlík, Kateřina Korpasová, Leona Mahelová, Zdenka Capáková, and Aleš Mráček. "Formulation of Magneto-Responsive Hydrogels from Dually Cross-Linked Polysaccharides: Synthesis, Tuning and Evaluation of Rheological Properties." International Journal of Molecular Sciences 23, no. 17 (August 25, 2022): 9633. http://dx.doi.org/10.3390/ijms23179633.

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Smart hydrogels based on natural polymers present an opportunity to fabricate responsive scaffolds that provide an immediate and reversible reaction to a given stimulus. Modulation of mechanical characteristics is especially interesting in myocyte cultivation, and can be achieved by magnetically controlled stiffening. Here, hyaluronan hydrogels with carbonyl iron particles as a magnetic filler are prepared in a low-toxicity process. Desired mechanical behaviour is achieved using a combination of two cross-linking routes—dynamic Schiff base linkages and ionic cross-linking. We found that gelation time is greatly affected by polymer chain conformation. This factor can surpass the influence of the number of reactive sites, shortening gelation from 5 h to 20 min. Ionic cross-linking efficiency increased with the number of carboxyl groups and led to the storage modulus reaching 103 Pa compared to 101 Pa–102 Pa for gels cross-linked with only Schiff bases. Furthermore, the ability of magnetic particles to induce significant stiffening of the hydrogel through the magnetorheological effect is confirmed, as a 103-times higher storage modulus is achieved in an external magnetic field of 842 kA·m−1. Finally, cytotoxicity testing confirms the ability to produce hydrogels that provide over 75% relative cell viability. Therefore, dual cross-linked hyaluronan-based magneto-responsive hydrogels present a potential material for on-demand mechanically tunable scaffolds usable in myocyte cultivation.

29

Silva, Joana M., Sofia G. Caridade, Rui L. Reis, and João F. Mano. "Polysaccharide-based freestanding multilayered membranes exhibiting reversible switchable properties." Soft Matter 12, no. 4 (2016): 1200–1209. http://dx.doi.org/10.1039/c5sm02458g.

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The combination of covalent and ionic cross-linking gives rise to synergetic effects in multiproperties. The robustness, compliance, calcium induced-adhesion and shape memory ability will pave the way towards novel therapeutic applications in tissue engineering.

30

Maciejewska, Magdalena, and Marian Zaborski. "Ionic Liquids Applied to Improve the Dispersion of Coagent Particles in an Elastomer." Journal of Composites 2013 (April 17, 2013): 1–8. http://dx.doi.org/10.1155/2013/286534.

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The aim of this work was to study the activity of several ionic liquids (alkylimidazolium salts) that are used to improve the dispersion of coagent particles in peroxide-cross-linked hydrogenated acrylonitrile butadiene elastomer (HNBR). Hydrotalcite grafted with monoallyl maleate was applied as a coagent for the HNBR vulcanization. In this paper, we discuss the effect of the ionic liquids (alkylimidazolium salts) with respect to their anion (bromide, chloride, tetrafluoroborate, and hexafluorophosphate) and the length of alkyl chain in the cation (allyl-, ethyl-, butyl-, hexyl-, and octyl-) on the vulcanization kinetics of rubber compounds. The influence of ionic liquids on the cross-link density, the mechanical properties of the vulcanizates, and their resistance to weather ageing were also studied. Alkylimidazolium salts seem to improve the dispersion of the coagent particles and to be active in the cross-linking of HNBR with peroxide. The type of ionic liquid considerably influences the activity of the coagent particles toward the HNBR. The application of ionic liquids increases the cross-link density of the vulcanizates and improves their resistance to weather aging.

31

Ursini, Ornella, Roberta Angelini, Silvia Franco, and Barbara Cortese. "Understanding the metal free alginate gelation process." RSC Advances 11, no. 55 (2021): 34449–55. http://dx.doi.org/10.1039/d1ra06599h.

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Alginate gelling by ionic cross-linking using multivalent ions has been known and exploited for several decades. We focus on the possibility to obtain alginate hydrogels without using metal cation in order to obtain metal-free alginates hydrogels.

32

De Gregorio, G. L., R. Giannuzzi, M. P. Cipolla, R. Agosta, R. Grisorio, A. Capodilupo, G. P. Suranna, G. Gigli, and M. Manca. "Iodopropyl-branched polysiloxane gel electrolytes with improved ionic conductivity upon cross-linking." Chem. Commun. 50, no. 90 (September 19, 2014): 13904–6. http://dx.doi.org/10.1039/c4cc05152a.

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33

Moura, M. José, H. Faneca, M. Pedroso Lima, M. Helena Gil, and M. Margarida Figueiredo. "In Situ Forming Chitosan Hydrogels Prepared via Ionic/Covalent Co-Cross-Linking." Biomacromolecules 12, no. 9 (September 12, 2011): 3275–84. http://dx.doi.org/10.1021/bm200731x.

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34

Kaneko, Futao, and Satoshi Kobayashi. "Residual voltage due to ionic space charge polarization in cross-linking polyethylene." Electrical Engineering in Japan 105, no. 3 (1985): 18–25. http://dx.doi.org/10.1002/eej.4391050303.

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Mattu, Clara, Tianran Wang, Armida Siri, Susanna Sartori, and Gianluca Ciardelli. "Ionic cross‐linking of water‐soluble polyurethane improves protein encapsulation and release." Engineering in Life Sciences 15, no. 4 (March 30, 2015): 448–55. http://dx.doi.org/10.1002/elsc.201400188.

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Boni, Fernanda Isadora, Beatriz S. F. Cury, Natália Noronha Ferreira, and Maria Palmira Daflon Gremião. "Ionic Cross-Linking as a Strategy to Modulate the Properties of Oral Mucoadhesive Microparticles Based on Polysaccharide Blends." Pharmaceutics 13, no. 3 (March 19, 2021): 407. http://dx.doi.org/10.3390/pharmaceutics13030407.

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Polymer blends of gellan gum (GG)/retrograded starch(RS) and GG/pectin (P) were cross-linked with calcium, aluminum, or both to prepare mucoadhesive microparticles as oral carriers of drugs or nano systems. Cross-linking with different cations promoted different effects on each blend, which can potentially be explored as novel strategies for modulating physical–chemical and mucoadhesive properties of microparticles. Particles exhibited spherical shapes, diameters from 888 to 1764 µm, and span index values lower than 0.5. Blends of GG:P cross-linked with aluminum resulted in smaller particles than those obtained by calcium cross-linking. GG:RS particles exhibited larger sizes, but cross-linking this blend with calcium promoted diameter reduction. The uptake rates of acid medium were lower than phosphate buffer (pH 6.8), especially GG:RS based particles cross-linked with calcium. On the other hand, particles based on GG:P cross-linked with calcium absorbed the highest volume of acid medium. The percentage of systems erosion was higher in acid medium, but apparently occurred in the outermost layer of the particle. In pH 6.8, erosion was lower, but caused expressive swelling of the matrixes. Calcium cross-linking of GG:RS promoted a significantly reduction on enzymatic degradation at both pH 1.2 and 6.8, which is a promising feature that can provide drug protection against premature degradation in the stomach. In contrast, GG:P microparticles cross-linked with calcium suffered high degradation at both pH values, an advantageous feature for quickly releasing drugs at different sites of the gastrointestinal tract. The high mucoadhesive ability of the microparticles was evidenced at both pH values, and the Freundlich parameters indicated stronger particle–mucin interactions at pH 6.8.

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Millonig, R., H. Salvo, and U. Aebi. "Probing actin polymerization by intermolecular cross-linking." Journal of Cell Biology 106, no. 3 (March 1, 1988): 785–96. http://dx.doi.org/10.1083/jcb.106.3.785.

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We have used N,N'-1,4-phenylenebismaleimide, a bifunctional sulfhydryl cross-linking reagent, to probe the oligomeric state of actin during the early stages of its polymerization into filaments. We document that one of the first steps in the polymerization of globular monomeric actin (G-actin) under a wide variety of ionic conditions is the dimerization of a significant fraction of the G-actin monomer pool. As polymerization proceeds, the yield of this initial dimer ("lower" dimer with an apparent molecular mass of 86 kD by SDS-PAGE [LD]) is attenuated, while an actin filament dimer ("upper" dimer with an apparent molecular mass of 115 kD by SDS-PAGE [UD] as characterized [Elzinga, M., and J. J. Phelan. 1984. Proc. Natl. Acad. Sci. USA. 81:6599-6602]) is formed. This shift from LD to UD occurs concomitant with formation of filaments as assayed by N-(1-pyrenyl)iodoacetamide fluorescence enhancement and electron microscopy. Isolated cross-linked LD does not form filaments, while isolated cross-linked UD will assemble into filaments indistinguishable from those polymerized from unmodified G-actin under typical filament-forming conditions. The presence of cross-linked LD does not effect the kinetics of polymerization of actin monomer, whereas cross-linked UD shortens the "lag phase" of the polymerization reaction in a concentration-dependent fashion. Several converging lines of evidence suggest that, although accounting for a significant oligomeric species formed during early polymerization, the LD is incompatible with the helical symmetry defining the mature actin filament; however, it could represent the interfilament dimer found in paracrystalline arrays or filament bundles. Furthermore, the LD is compatible with the unit cell structure and symmetry common to various types of crystalline actin arrays (Aebi, U., W. E. Fowler, G. Isenberg, T. D. Pollard, and P. R. Smith. 1981. J. Cell Biol. 91:340-351) and might represent the major structural state in which a mutant beta-actin (Leavitt, J., G. Bushar, T. Kakunaga, H. Hamada, T. Hirakawa, D. Goldman, and C. Merril. 1982. Cell. 28:259-268) is arrested under polymerizing conditions.

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Kapitein, Lukas C., Benjamin H. Kwok, Joshua S. Weinger, Christoph F. Schmidt, Tarun M. Kapoor, and Erwin J. G. Peterman. "Microtubule cross-linking triggers the directional motility of kinesin-5." Journal of Cell Biology 182, no. 3 (August 4, 2008): 421–28. http://dx.doi.org/10.1083/jcb.200801145.

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Although assembly of the mitotic spindle is known to be a precisely controlled process, regulation of the key motor proteins involved remains poorly understood. In eukaryotes, homotetrameric kinesin-5 motors are required for bipolar spindle formation. Eg5, the vertebrate kinesin-5, has two modes of motion: an adenosine triphosphate (ATP)–dependent directional mode and a diffusive mode that does not require ATP hydrolysis. We use single-molecule experiments to examine how the switching between these modes is controlled. We find that Eg5 diffuses along individual microtubules without detectable directional bias at close to physiological ionic strength. Eg5's motility becomes directional when bound between two microtubules. Such activation through binding cargo, which, for Eg5, is a second microtubule, is analogous to known mechanisms for other kinesins. In the spindle, this might allow Eg5 to diffuse on single microtubules without hydrolyzing ATP until the motor is activated by binding to another microtubule. This mechanism would increase energy and filament cross-linking efficiency.

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Lee, Kang Hyuck, Doo Hee Cho, Young Mi Kim, Sun Ju Moon, Jong Geun Seong, Dong Won Shin, Joon-Yong Sohn, Jeong F. Kim, and Young Moo Lee. "Highly conductive and durable poly(arylene ether sulfone) anion exchange membrane with end-group cross-linking." Energy & Environmental Science 10, no. 1 (2017): 275–85. http://dx.doi.org/10.1039/c6ee03079c.

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Täuber, Karoline, Alessandro Dani, and Jiayin Yuan. "Covalent Cross-Linking of Porous Poly(ionic liquid) Membrane via a Triazine Network." ACS Macro Letters 6, no. 1 (December 12, 2016): 1–5. http://dx.doi.org/10.1021/acsmacrolett.6b00782.

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Zhou, Xianjing, Jingjing Nie, Qi Wang, and Binyang Du. "Thermosensitive Ionic Microgels with pH Tunable Degradation via in Situ Quaternization Cross-Linking." Macromolecules 48, no. 9 (April 9, 2015): 3130–39. http://dx.doi.org/10.1021/acs.macromol.5b00482.

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HajKacem, Sihem, Said Galai, Francisco José Hernández Fernandez, Antonia Pérez de los Ríos, Issam Smaali, and Joaquín Quesada Medina. "Bioreactor Membranes for Laccase Immobilization Optimized by Ionic Liquids and Cross-Linking Agents." Applied Biochemistry and Biotechnology 190, no. 1 (July 12, 2019): 1–17. http://dx.doi.org/10.1007/s12010-019-03085-z.

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Das, Gautam, Chae Kim, Dong Kang, Bo Kim, and Hyon Yoon. "Quaternized Polysulfone Cross-Linked N,N-Dimethyl Chitosan-Based Anion-Conducting Membranes." Polymers 11, no. 3 (March 18, 2019): 512. http://dx.doi.org/10.3390/polym11030512.

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Anion-conducting membranes were obtained following the cross-linking of 1,4-diazoniabicycle[2.2.2]octane functionalized-polysulfone with N,N-dimethyl chitosan (DMC). The ionic conductivity of the composite membranes was controlled by the amount of DMC. The influence of the amount of DMC on water uptake, swelling ratio, and ionic conductivity of the obtained membrane was studied. The membrane with 2 wt% DMC exhibited an ionic conductivity of 54 mS/cm and 94 mS/cm at 25 °C and 70 °C, respectively. The membrane showed good dimensional stability under hydrated conditions. A urea/O2 fuel cell, built using the composite membrane, exhibited a peak power density of 4.4 mW/cm2 with a current density of 16.22 mA/cm2 at 70 °C.

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Lim, Da-ae, Young-Kyeong Shin, Jinhong Seok, Dayoung Hong, Chul Haeng Lee, Kyoung Ho Ahn, and Dong-Won Kim. "Nonflammable Gel Polymer Electrolyte for Lithium-Ion Batteries with Enhanced Safety and High-Temperature Performance." ECS Meeting Abstracts MA2023-02, no. 2 (December 22, 2023): 367. http://dx.doi.org/10.1149/ma2023-022367mtgabs.

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Lithium-ion batteries (LIBs) have become dominant power sources for various applications such as mobile electronics, electric vehicles and energy storage systems. However, liquid electrolytes currently used in LIBs have critical drawbacks such as flammability and leakage problem. In this regard, various electrolyte systems have been developed to enhance the battery safety while maintaining cycling performance. Among them, the chemically cross-linked gel polymer electrolytes (GPEs) can enhance the thermal safety of LIBs by effectively encapsulating organic solvents in the polymer matrix. However, they usually contain large amounts of organic solvents to achieve high ionic conductivity, making GPE be still flammable. To solve these problems, we designed and synthesized a novel phosphorus-based cross-linking agent with excellent flame retardancy. GPE was prepared by in-situ thermal curing of gel precursor containing liquid electrolyte and phosphorus-based cross-linking agent. The obtained GPE exhibited high ionic conductivity and nonflammability. The GPE was applied to lithium-ion cells composed of graphite anode and LiNi0.6Co0.2Mn0.2O2 cathode. Our results revealed that the lithium-ion cell employing GPE exhibited enhanced safety and improved high-temperature cycling performance compared to the cell with the liquid electrolyte.

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Zheng, Yingying, Zhimin Liu, Haijun Zhan, Jie Li, and Chengcheng Zhang. "Studies on electrochemical organophosphate pesticide (OP) biosensor design based on ionic liquid functionalized graphene and a Co3O4 nanoparticle modified electrode." Analytical Methods 8, no. 26 (2016): 5288–95. http://dx.doi.org/10.1039/c6ay01346e.

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In this study, a new type of organophosphate pesticide (OP) biosensor was successfully fabricated based on the immobilization of acetylcholinesterase (AChE) by cross-linking on a glassy carbon electrode (GCE) modified with ionic liquid functionalized graphene (IL-GR), Co₃O₄ nanoparticles and chitosan (CHI).

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Liang, Jun, Rui Wang, and Ruipeng Chen. "The Impact of Cross-linking Mode on the Physical and Antimicrobial Properties of a Chitosan/Bacterial Cellulose Composite." Polymers 11, no. 3 (March 13, 2019): 491. http://dx.doi.org/10.3390/polym11030491.

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The bacteriostatic performance of a chitosan film is closely related to its ionic and physical properties, which are significantly influenced by the mode of cross-linking. In the current work, chitosan with or without bacterial cellulose was cross-linked with borate, tripolyphosphate, or the mixture of borate and tripolyphosphate, and the composite films were obtained by a casting of dispersion. Mechanical measurements indicated that different modes of cross-linking led to varying degrees of film strength and elongation increases, while the films treated with the borate and tripolyphosphate mixture showed the best performance. Meanwhile, changes in the fractured sectional images showed a densified texture induced by cross-linkers, especially for the borate and tripolyphosphate mixture. Measurements of Fourier transform infrared showed the enhanced interaction between the matrix polymers treated by borate, confirmed by a slight increase in the glass transitional temperature and a higher surface hydrophobicity. However, the reduced antimicrobial efficiency of composite films against E. coli, B. cinerea, and S. cerevisiae was obtained in cross-linked films compared with chitosan/bacterial cellulose films, indicating that the impact on the antimicrobial function of chitosan is a noteworthy issue for cross-linking.

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Sohail, Kashif, Ikram Ullah Khan, Yasser Shahzad, Talib Hussain, and Nazar Muhammad Ranjha. "pH-sensitive polyvinylpyrrolidone-acrylic acid hydrogels: Impact of material parameters on swelling and drug release." Brazilian Journal of Pharmaceutical Sciences 50, no. 1 (March 2014): 173–84. http://dx.doi.org/10.1590/s1984-82502011000100018.

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In this study, we fabricated pH-sensitive polyvinylpyrrolidone/acrylic acid (PVP/AA) hydrogels by a free-radical polymerisation method with variation in the content of monomer, polymer and cross-linking agent. Swelling was performed in USP phosphate buffer solutions of pH 1.2, 5.5, 6.5 and 7.5 with constant ionic strength. Network structure was evaluated by different parameters and FTIR confirmed the formation of cross-linked hydrogels. X-ray crystallography showed molecular dispersion of tramadol HCl. A drug release study was carried out in phosphate buffer solutions of pH 1.2, 5.5 and 7.5 for selected samples. It was observed that swelling and drug release from hydrogels can be modified by changing composition and degree of cross-linking of the hydrogels under investigation. Swelling coefficient was high at higher pH values except for the one containing high PVP content. Drug release increased by increasing the pH of the medium and AA contents in hydrogels while increasing the concentration of cross-linking agent had the opposite effect. Analysis of the drug release mechanism revealed non-Fickian transport of tramadol from the hydrogels.

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Weiss-Maurin, Mathilde, Daniela Cordella, Christine Jérôme, Daniel Taton, and Christophe Detrembleur. "Direct one-pot synthesis of poly(ionic liquid) nanogels by cobalt-mediated radical cross-linking copolymerization in organic or aqueous media." Polymer Chemistry 7, no. 14 (2016): 2521–30. http://dx.doi.org/10.1039/c6py00112b.

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Pirzada, A. M., S. Vambol, Z. Khatri, A. Aziz, N. A. Samoon, S. Shaikh, M. Ali, and S. Sikandar. "OCCUPATIONAL AND PUBLIC HEALTH. THE WRINKLE RECOVERY ANGLE (WRA) STUDY OF FABRIC THAT NANO-SILVER TREATED." Labour protection problems in Ukraine 36, no. 1 (March 31, 2020): 3–11. http://dx.doi.org/10.36804/nndipbop.36-1.2020.3-11.

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The constant use of wrinkle-resistant cellulose fabrics in professional and everyday life can negatively affect the health state. This is because formaldehyde vapours, which contribute to allergies, persistent coughing, and irritation of the eyes, nose, and throat, sleep disturbances, headaches, etc., pose a greater danger. In this study an attempt was made to achieve fabric stabilization from wrinkle resistant by formation ionic bonds of as replacement covalent bonds. And this is the main study purpose. Industrially Desized and Bleached 100 % pure cotton fabric with the weight of 110 g/m2, and the chemicals were used. Preparation of cationic glycerine, carboxymethylation of bleached fabric and application of antimicrobial finishes on the ionic cross-linked fabric was provided. Measurements were taken to determine of wrinkle recovery angle (WRA), of absorbency, of whiteness index, of flexural rigidity, of abrasion, of tensile strength. Wrinkle recovery angle was measured by standard method of AATCC 66 (option 2). AATCC Test Method 79-2000 was used to test the absorbency of fabric. The CIE whiteness index was determined using an Xrite Colour Eye 7000A spectrophotometer. Flexural Rigidity was measured through a testing cantilever method ASTM D-1388. Fabric abrasion was checked according to standard method for abrasion resistance of textile fabric ASTM 4966 on Martindale Abrasion Device M235. Mechanical strength of the fabric was measured under the standard method of ASTM D-5034. With the ionic cross-linking, the dry WRA was achieved an optimum of 118º and wet WRA up to 128º with increased fabric strength and whiteness. In addition to ionic cross-linking fabric was treated with Nano silver. Based on the results it was concluded that the fabric can be optimized first with ionic cross-link method and then it can be treated with the antimicrobial making the fabric cleaner and hygienic. This fabric treatment provides the necessary characteristics and is safe for the health of the people who use it.

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Koffer, A., and M. Daridan. "Actin-regulating activities in cultured BHK cells." Journal of Cell Science 75, no. 1 (April 1, 1985): 239–57. http://dx.doi.org/10.1242/jcs.75.1.239.

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A large proportion (60-85%) of the actin present in lysates of cultured baby hamster kidney (BHK) cells is monomeric at low temperature. All this G-actin is accounted for in the fractions obtained by high-speed centrifugation of the lysate in the presence or absence of non-ionic detergent; 98 (+/− 7)% of its reacts as monomer in the deoxyribonuclease assay. The fractions nevertheless possess actin polymerization nucleating activity, as assayed by the fluorescence of extraneous pyrene-conjugated actin, reflecting the presence of capping proteins and their complexes with oligomeric actin, which dissociate during the deoxyribonuclease assay. Despite the enhanced nucleation, the total proportion of actin polymerized at equilibrium is reduced, relative to that of actin in the absence of cell extract, presumably because of the presence of ‘barbed’-end capping protein(s). With increasing concentrations of the supernatant material, the proportion of polymerized actin was progressively reduced and the presence of inhibitory activity against polymerization became apparent. On addition of micromolar concentrations of free calcium, nucleation by the supernatant fractions is greatly accelerated, but the extent of polymerization undergoes a further reduction, due to the elevated critical monomer concentration resulting from capping. Inhibition of polymerization by the supernatant fraction in the presence of calcium is much greater than by saturating concentrations of cytochalasin E. These observations are most simply interpreted as showing that the cytoplasm additionally contains a ‘pointed’-end capping protein. The plasma membranes were found to have nucleating activity largely residing in the Triton-insoluble fractions. Actin cross-linking activity was assayed by adding small proportions of either the supernatant or membrane fractions to a large excess of F-actin and analysing the pellet resulting from a low-speed centrifugation. Supernatant fraction, containing Triton-soluble membrane-derived material, possessed much greater cross-linking capacity than the membrane-free supernatant prepared in the absence of detergent. The membrane fractions had practically no cross-linking activity on their own. Nevertheless, a non-ionic detergent extract of the membrane enhanced the cross-linking activity of the supernatant, indicating the participation of more than one species in a cross-linking process.