Hydrogen bond‐reinforced double‐network hydrogels with ultrahigh elastic modulus and shape memory property. Issue 19 (7th May 2018)

• Record Type: Journal Article
• Authors: Wang, Yan Jie; Li, Chen Yu; Wang, Zhi Jian; Zhao, Yiping; Chen, Li; Wu, Zi Liang; Zheng, Qiang
• Is Part Of: Journal of polymer science. Volume 56:Issue 19(2018)
• Page Start: 1281
• Page End: 1286
• Publication Date: 2018-05-07
• Subjects: high modulus -- hydrogels -- hydrogen bonds -- interpenetrating networks -- shape memory -- tough hydrogels -- toughness; 547
• DOI: 10.1002/polb.24620
• Languages: English
• ISSNs: 0887-6266

Abstract

ABSTRACT: Development of tough hydrogels has greatly expanded their applications as load‐bearing materials. However, the elastic modulus of tough hydrogels is usually lower than 1 MPa. It remains a challenge to design tough hydrogels with high modulus. We report here a series of tough double‐network (DN) hydrogels with ultrahigh elastic modulus (up to 200 MPa) by forming robust hydrogen bonds between the first poly(acrylic acid) network and the second poly( N ‐isopropyl acrylamide) network. The dense cooperative hydrogen bonds greatly reduce the segmental mobility and thus improve the rigidity of gel matrix. Owing to the dynamic nature of hydrogen bonds, the modulus of hydrogels is strongly influenced by temperature and pH, affording the gels shape memory property. The strategy by forming robust noncovalent bonds between interpenetrating networks should be applicable to other systems for designing tough and versatile hydrogels with diverse promising applications. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2018, 56, 1281–1286 Abstract : Ultrastiff and tough hydrogels are developed by forming dense hydrogen bonds between the interpenetrating networks, which show shape memory behavior due to the temperature‐mediated huge variation of elastic modulus.