Visible-light-assisted Multinetwork Design For One-step Preparation Of Tough Hydrogels And Applications

Hydrogels,a new type of polymer materials,have been applied in various aspects of life,such as tofu,contact lenses,cosmetics and diapers.Tough hydrogels that are capable of efficient mechanical energy dissipation and withstanding large strains have potential applications in diverse areas.However,most reported fabrication strategies are performed in multiple steps with long-time UV irradiation or heating at high temperatures,limiting their biological and industrial applications.Hydrogels formed with a single pair of mechanisms are unstable in harsh conditions.This thesis designed a strategy to prepare tough hydrogels under mild conditions.Through blue light irradiation at 452 nm,the preparation of tough multi-network hydrogels can be completed in just a few tens of seconds by catalyzing the polymerization of monomers containing double bonds,the cross-linking of phenolic groups and the release of metal ions.The prepared gel has a strain of over 2000%and a fracture strength of 200 k Pa,with a fracture energy of over 8000 J/m~2.And the method has good biocompatibility and universality because of the visible light.With a multimechanism design,the new network structures remarkably improve the mechanical properties of hydrogels and maintain its high toughness in various environments.The broad compatibility of the proposed method with a spectrum of printing technologies makes it suitable for potential applications requiring high-resolution patterns/structures(such as shadow-mask,lithography and 3D printing).As a proof-of-concept,we demonstrate an integrated electronic system using patterned hydrogels to fabricate the sensor array and fully stretchable electroluminescent devices.