Acids & Bases (Making pH Paper)
Use boiled red cabbage to make your own pH test paper and then check the pH of various common household liquids. Red cabbage gets its color from a chemical called “Anthocyanin.” It is also the pigment that turns leaves red or purple in autumn. Anthocyanin is a good indicator of acids and bases. When added to a base, the purplish pigment turns green or yellow. When added to an acid, it changes to pink or red. In something that is neutral (neither an acid nor a base), the paper will remain the same color (or maybe turn a little blue).
GAAKK RECIPE (Cross-linking of Polyvinyl Alcohol)
White school construction glues are made of polyvinyl alcohol. Addition of concentrated Borax solution builds bridges between the polymer chains, cross-linking them and turning the mixture into a highly viscous semi-solid blob…. Like a giant booger.