Highly Elastic and Ultratough Hybrid Ionic–Covalent Hydrogels with Tunable Structures and Mechanics. Issue 18 (25th March 2018)

• Record Type: Journal Article
• Authors: Yang, Yanyu; Wang, Xing; Yang, Fei; Wang, Luning; Wu, Decheng
• Is Part Of: Advanced materials. Volume 30:Issue 18(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-03-25
• Subjects: chitosan -- DN hydrogels -- energy dissipation -- ionic coordination -- tunable mechanics; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.201707071
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Hybrid ionically–covalently crosslinked double‐network (DN) hydrogels are attracting increasing attention on account of their self‐recovery ability and fatigue resistance, but their relative low mechanical strength and tedious performance adjustment severely limit their applications. Herein, a new strategy to concurrently fabricate hybrid ionic–covalent DN hydrogels and modulate their structures and mechanics is reported, in which an in situ formed chitosan ionic network is incorporated by post‐crosslinking the chitosan‐based composite hydrogel using multivalent anions solutions. The obtained hybrid DN hydrogels exhibit predominant mechanical properties including superior elastic modulus, high tensile strength, and ultrahigh fracture energy because of the more efficient energy dissipation of rigid short‐chain chitosan network. Notably, the swollen hydrogels still remain mechanically strong and tough even after immersion in water for 24 h. More significantly, simply changing the post‐crosslinking time can vary the compactness and rigidity of the chitosan network in situ, achieving flexible and efficient modulation of the structures and mechanics of the hybrid DN hydrogels. This study opens up a new horizon in the preparation and regulation of DN hydrogels for promising applications in tissue scaffolds, actuators, and wearable devices. Abstract : Hybrid double‐network hydrogels are fabricated by a simple strategy and their structures and mechanics are modulated by incorporating an in situ formed chitosan ionic network via post‐crosslinking chitosan‐based composite hydrogels using multivalent anions solutions. This study opens up a new horizon in the preparation and regulation of stiff and tough hydrogels in load‐bearing applications.