Abstract: Taking advantage of color-switchable property of acid/base indicators, this experiment explored the pH-responsive ability of a hydrogel formed by a dipeptide molecule (Fmoc-FF) by introducing the phenol red and bromocresol chloride. Meanwhile, a series of interactive chemical experiments were designed based on the thermoresponsive property of the hydrogel. These easy-to-make experiments facilitate the learning and understanding of undergraduate students on acid/base indicators and thermos-responsive hydrogels. In addition, the students can clearly observe the reversible transition processes from gel state to solution state and multiple color changes of hydrogels, which could help students to carry out a series of diverse artistic creations.

Key words: Supramolecular hydrogel, pH Indicator, Popular science experiment, Dipeptide self-assembly