Barnacle Cement Proteins‐Inspired Tough Hydrogels with Robust, Long‐Lasting, and Repeatable Underwater Adhesion. (28th December 2020)

• Record Type: Journal Article
• Authors: Fan, Hailong; Wang, Jiahui; Gong, Jian Ping
• Is Part Of: Advanced functional materials. Volume 31:Number 11(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-12-28
• Subjects: π–π interaction -- barnacle cement proteins -- cation–π interaction -- fast and reversible -- tough hydrogel -- underwater adhesion; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202009334
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: The development of adhesives that can achieve robust and repeatable adhesion to various surfaces underwater is promising; however, this remains a major challenge primarily because the surface hydration layer weakens the interfacial molecular interactions. Herein, a strategy is proposed to develop tough hydrogels that are robust, reusable, and long‐lasting for underwater adhesion. Hydrogels from cationic and aromatic monomers with an aromatic‐rich composition inspired by the amino acid residuals in barnacle cement proteins are synthesized. The hydrogels are mechanically strong and tough (elastic modulus 0.35 MPa, fracture stress 1.0 MPa, and fracture strain 720%), owing to the interchain π–π and cation–π interactions. In water, the hydrogels firmly adhere to diverse surfaces through interfacial electrostatic and hydrophobic interactions (adhesion strength of 180 kPa), which allows for instant adhesion and reversibility (50 times). Moreover, the hydrogel shows long‐lasting adhesion in water for months (100 days). Novel adhesive hydrogels may be useful in many applications, including underwater transfer, water‐based devices, underwater repair, and underwater soft robots. Abstract : The hydrogel consisting of a cross‐linked copolymer of cationic and aromatic monomers shows instant and robust underwater adhesion to diverse substrates. This is because the aromatic groups provide hydrophobic adhesion and enhance the electrostatic adhesion of their neighboring cationic groups.