Design principle and application of self-healing hydrogel
Self-healing hydrogel is a type of intelligent hydrogels that can repair its structure and function after being damaged by the surroundings.Self-healing hydrogels also have self-healing properties,high safety,fatigue resistance and long service life based on retaining the water absorption and retention properties of traditional hydrogels.In this paper,the self-healing hydrogels in recent years were reviewed,focusing on the combination of physical,chemical crosslinking and multiple action mechanisms,and partial application in wearable electronic products,3D printing,biomedicine and petrochemical fields.Physical crosslinking included noncovalent interactions such as hydrogen bond,hydrophobic interaction and host guest interaction.Chemical crosslinking included dynamic covalent bonds such as acylhydrazone bond,imine bond and disulfide bond.Multiaction mechanism crosslinking introduced two or more physical and chemical crosslinking simultaneously introduce hydrogel.On the basis of the above research,this review pointed out that the current self-healing hydrogels had many deficiencies,such as complicated preparation methods,single function,inability to respond to multiple stimuli and lack of multi-directional analysis of self-healing mechanisms.Hence,the future research and development of self-healing hydrogels should focus on the research and development of multi-mechanism and multi-functional self-healing hydrogels,explore the mechanism of hydrogel healing process from multiple perspectives and multidisciplinary integration,and accelerate its application in many emerging fields.