Abstract: Smart hydrogels, characterized by their highly hydrophilic three-dimensional network structures, possess the ability to swiftly sense and respond to changes in their environment. This project harnesses alginate extracted from edible kelp, cross-linking it with various metal ions to craft alginate hydrogels. These hydrogels exhibit remarkable responsiveness, effectively distinguishing between hard and soft water while also facilitating the analysis of vitamin C and metal ion concentrations. Through a series of engaging experiments, this endeavor elucidates the formation mechanisms and practical applications of intelligent hydrogels. Preschoolers and primary school students engage in simple yet colorful hydrogel preparations, fostering a sense of excitement. Meanwhile, middle school students and the general public can participate in extracting alginic acid from kelp using everyday kitchen utensils, subsequently utilizing the resulting hydrogels for water hardness recognition and vitamin C analysis in fruits. Such hands-on experiences not only ignite curiosity but also promote the integration of chemistry into daily life, stimulating interest and enthusiasm for the subject. College students, through advanced experiments, delve into the analysis of iron ion concentrations and vitamin C content using photometric methods. This project seamlessly merges entertainment, practicality, and scientific inquiry, offering a feasible and enriching educational experience. It is poised to bridge the gap between chemistry and everyday life, serving the public, and fostering broader understanding and engagement with the field.

Key words: Intelligent hydrogels, Sodium alginate, Metal ion response, Iron ion detection, Vitamin C analysis