Nano- or microsized containers comprising either a water immiscible or sparingly miscible core dispersible in aqueous dispersion medium or a water miscible core dispersible in non-aqueous dispersion medium and a core-soluble active agent selected from the group consisting of corrosion inhibitors, catalysts, accelerators of catalysts, adhesives, sealants, polymerizable compounds (monomers), surfactants, lubricants, antifouling agents, water repelling materials and their mixtures, and a stimulus-sensitive polymer/polyelectrolyte shell that encapsulates the core-soluble active agent and releases the encapsulated agent in response to an external stimulus selected from the group consisting of humidity, ionic strength, pH, temperature, mechanical stress, constant and alternating magnetic or electromagnetic fields, corrosion products, electric current, and electrochemical potential.