Hydrogen Bonding Enhanced Polysaccharide-Based Gels with Ultrahigh Stretchability and Unprecedented Crack Propagation Strain

The current strategies prove to be hard for the preparation of polysaccharide-based gels with excellent mechanical properties and high crack propagation resistance. Herein, ultrahigh stretchable polysaccharide-based polyacrylamide/carrageenan/phytic acid (PCP) gels are prepared by integrating strong and dense hydrogen bonds into the network. The phosphate ester bonds contained in phytic acid form strong and dense hydrogen bonds with polyacrylamide and carrageenan, which are 18.6 times higher than those in gel without phytic acid. A large number of hydrogen bonds endows PCP gels with ultrahigh stretchability (>16,000%, without breakage), unprecedented crack propagation strain of 16,000%, high adhesion property (223 kPa), self-healing ability, low-temperature resistance, and moisturizing property. Furthermore, PCP gel can be obtained rapidly and facilely within minutes, integrated into clothes after a facile drawing method, and applied to monitor movement, breathing, and temperature states (e.g., contactless recognition for finger/palm, distinguishing between running phone/nonrunning phone). This study provides an essential strategy for designing or fabricating highly stretchable gel and its application in the wearable electronics field.