Thermoresponsive Complex Coacervate‐Based Underwater Adhesive

• Published in: Advanced materials (Weinheim) Vol. 31; no. 21; pp. e1808179 - n/a
• Main Authors: Dompé, Marco, Cedano‐Serrano, Francisco J., Heckert, Olaf, van den Heuvel, Nicoline, van der Gucht, Jasper, Tran, Yvette, Hourdet, Dominique, Creton, Costantino, Kamperman, Marleen
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.05.2019; Wiley-VCH Verlag
• Subjects: Adhesives; Bond strength; complex coacervates; Condensed Matter; environmentally triggered phase transitions; Hydrogels; Isopropylacrylamide; lower critical solution temperature; Materials science; Moisture content; Physics; poly(N‐isopropylacrylamide); Polyelectrolytes; Soft Condensed Matter; Tissues; Tubes; Underwater; underwater adhesion; poly(N-isopropylacrylamide); environmentally triggered phase transitions; underwater adhesion; complex coacervates; lower critical solution temperature
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.201808179

Sandcastle worms have developed protein‐based adhesives, which they use to construct protective tubes from sand grains and shell bits. A key element in the adhesive delivery is the formation of a fluidic complex coacervate phase. After delivery, the adhesive transforms into a solid upon an external trigger. In this work, a fully synthetic in situ setting adhesive based on complex coacervation is reported by mimicking the main features of the sandcastle worm's glue. The adhesive consists of oppositely charged polyelectrolytes grafted with thermoresponsive poly(N‐isopropylacrylamide) (PNIPAM) chains and starts out as a fluid complex coacervate that can be injected at room temperature. Upon increasing the temperature above the lower critical solution temperature of PNIPAM, the complex coacervate transitions into a nonflowing hydrogel while preserving its volume—the water content in the material stays constant. The adhesive functions in the presence of water and bonds to different surfaces regardless of their charge. This type of adhesive avoids many of the problems of current underwater adhesives and may be useful to bond biological tissues. A fully synthetic in situ setting adhesive based on complex coacervation is reported by mimicking the main features of the sandcastle worm's glue. The adhesive consists of oppositely charged polyelectrolytes grafted with thermoresponsive poly(N‐isopropylacrylamide) chains. The adhesive starts out as an injectable fluid at room temperature. Upon increasing the temperature, the complex coacervate transitions into a nonflowing hydrogel which bonds to different surfaces.