Visualization of the Effects of Hydrogen Bonding in Self-Healing Hydrogel

The research develops an instrument-free classroom demonstration using a self-healing hydrogel to visualize hydrogen bonds (H-bonds) interactions. Students directly experience the re-formation and breaking of H-bonds through cutting and stretching cycles, thereby gaining an intuitive sense of their tangible strength. Tailored for different educational levels, high school students grasp H-bond formation through autonomous self-healing, while university students connect fundamental chemistry to polymer science via macroscopic evidence. Student feedback from classroom implementation with over 2000 high school students indicated notable differences in self-reported understanding: the proportion of students who reported correctly identifying H-bonds as interaction forces was 91.7% in the demonstration group, compared to 50.3% in traditional lecture settings. This work provides educators with an accessible platform to bridge macroscopic phenomena and molecular interactions, achieving visualization without expensive instruments.