Rupturable, dual reagent mono-capsules are disclosed that have a core composition, which includes a carboxylic acid, encapsulated within a phenolic resin-containing polymer wall that ruptures upon exposure to alkaline conditions over a period of time, and a shell connected to an exterior surface of the polymer wall by a surfactant. The shell is made from a mineral containing a metal that is chemically bonded to the surfactant by a chemical electrostatic interaction. Upon rupture of the polymer wall of the mono-capsule, the carboxylic acid and the mineral containing the metal chemically react with one another to form a reaction product that seals a rupture in the capsule and/or seals a feature of a surface upon which the capsules are disposed.