A universal method to easily design tough and stretchable hydrogels

Abstract

Hydrogels are flexible materials that have high potential for use in various applications due to their unique properties. However, their applications are greatly restricted by the low mechanical performance caused by high water content and inhomogeneous networks. This paper reports a universal strategy for easily preparing hydrogels that are tough and stretchable without any special structures or complicated processes. Our strategy involves tuning the polymerization conditions to form networks with many polymer chain entanglements to achieve energy dissipation. Tough and stretchable hydrogels can be prepared by free radical polymerization with a high monomer concentration and low cross-linker content to optimize the balance between physical and chemical cross-links by entanglements and covalent bonds, respectively. The strategy of using polymer chain entanglements for energy dissipation allows us to overcome the limitation of low mechanical performance, which leads to the wide practical use of hydrogels.

Reinforcement of Alginate-Gelatin Hydrogels with Bioceramics for Biomedical Applications: A Comparative Study

“…A semicrystalline curve is observed in 1IA, the mixture of porcine gelatin and sodium alginate presents typical noise in the curves, and prominent peaks are observed at 23 and 26 • [36]. The Figure 1(IB) curve shows principal peaks due to the presence of crystalline corundum, also called sapphire M = 101.96 g/mol and ρ = 3.98 g/cm 3 3 . This study served to present an accurate definition of all the compounds of the different bioinks at crystalline point of view, in order to provide an accurate state from the bioceramic compounds used for our formulations.…”

“…overlapped with alginate and gelatin signals, (JCPDS: 01-081-9759; 17.37, 31.06, 32.62, 36.07°; Na2Ti6O13). Curve 1ID displays peaks of composite particles of titanium dioxide, anatase (JCPDS; 01-075-8897; 38.34, 48.23, 63.02°; anatase TiO2) and rutile (JCPDS; 01-079-6029; 54.67, 41.43°; rutile TiO2) M = 79.866 g/mol, ρ = 4.23 g/cm 3 . Curve 1IE shows that, besides the alginate-gelatin matrix, the highest intensities of zirconia are presented (JCPDS: 31.67, 34.41; 50.37° cubic ZrO2): M = 123.218 g/mol, ρ = 5.68 g/cm 3 for some intensities for tetragonal zirconia.…”

“…Curve 1ID displays peaks of composite particles of titanium dioxide, anatase (JCPDS; 01-075-8897; 38.34, 48.23, 63.02°; anatase TiO2) and rutile (JCPDS; 01-079-6029; 54.67, 41.43°; rutile TiO2) M = 79.866 g/mol, ρ = 4.23 g/cm 3 . Curve 1IE shows that, besides the alginate-gelatin matrix, the highest intensities of zirconia are presented (JCPDS: 31.67, 34.41; 50.37° cubic ZrO2): M = 123.218 g/mol, ρ = 5.68 g/cm 3 for some intensities for tetragonal zirconia. Finally, diffractogram 1IF of particles embedded in the alginate-gelatin matrix confirmed the presence of tungstate oxide particles (JCPDS: 00-024-9747; 23.98, 22.67, 33.46°; tetragonal WO3), M = 231.84 g/mol, ρ = 7.16 g/cm 3 .…”

“…Curve 1IE shows that, besides the alginate-gelatin matrix, the highest intensities of zirconia are presented (JCPDS: 31.67, 34.41; 50.37° cubic ZrO2): M = 123.218 g/mol, ρ = 5.68 g/cm 3 for some intensities for tetragonal zirconia. Finally, diffractogram 1IF of particles embedded in the alginate-gelatin matrix confirmed the presence of tungstate oxide particles (JCPDS: 00-024-9747; 23.98, 22.67, 33.46°; tetragonal WO3), M = 231.84 g/mol, ρ = 7.16 g/cm 3 . This study served to present an accurate definition of all the compounds of the different bioinks at crystalline point of view, in order to provide an accurate state from the bioceramic compounds used for our formulations.…”

Exchange Counterion in Polycationic Hydrogels: Tunability of Hydrophobicity, Water State, and Floating Capability for a Floating pH Device

“…However, the elasticity progressively decreases as the crosslinker content increases. This is attributed to the low fraction energy due to the increase in the chemical crosslinking points [45]. Gels with 5 mol% of MBA lost their elasticity and became fragile.…”