Preparation And Performance Of Multifunctional Hydrogels Based On Multiple Hydrogen-bond Interactions

With the incrasing demand for more excellent properties of hydrogel materials,multifunctional hydrogels have gradually attracted the attention of researchers.In particular,multifunctional and high-performance hydrogels based on non-chemical cross-linking,not only can endow the gel with more excellent properties,but also can ensure the mechanical strength of the gel.The research and development of multifunctional hydrogels has expanded the application scope of hydrogel materials and improved the application value of hydrogel materials.As a kind of typical physical interaction,hydrogen bonding is considered as an ideal method to add high strength and excellent reversibility to the target material.Hydrogen bonds are usually weaker than covalent bonds,but stronger than van der Waals bonds.However,multiple hydrogen bonds can achieve similar strength of covalent bonds,even stronger than covalent bonds.Therefore,using multiple hydrogen bonds to construct the mutifunctional hydrogel with both high mechanical properties and self-healing properties is an effective method.In this paper,based on multiple hydrogen bonds,two multifunctional supramolecular hydrogels were prepared.One is by means of the photoinitiated polymerization of N-acryloylglycinamide(NAGA)and the freeze-thaw cycle process of biocompatible polyvinyl alcohol(PVA)to form the PVA/PNAGA-FT supramolecular hydrogel.We have verified the mechanical properties of the PVA/PNAGA-FT supramolecular hydrogel through mechanical tests.And via self-healing tests,we proved that the gel exhibit excellent self-healing performance and the self-healing efficiency can reach more than 50%.The repaired gels still have excellent mechanical properties.Simultaneously,the shape memory experiment and the simple gel gripping experiment were carried out.The results showed that the hydrogels have good shape memory performance,and their huge potential as braking materials.In addition,a kind of PN-B multi-bond network hydrogel with self-healing and mechanical properties formed by the dynamic combination of PVA and borax and the supramolecular polymer chain PNAGA was prepared.PN-B multi-bond network hydrogel,which includes multiple hydrogen bonds and dynamic boron ester bonds,has multiple sensitive properties and excellent self-healing properties.We proved the mechanical strength and its p H,glucose,and urea sensitivities of the gel through rheological and mechanical tests.And we also verified that the hydrogel possessed the self-healing performance and antibacterial activity through simple methods,thereby broadening the field of practical application.