Corrosion inhibitor materials are provided that release active corrosion inhibitor compounds when they are most needed—in response to changes in conditions, including acid or basic pH, that cause corrosion or occur at the early stages of corrosion. The materials comprise particles that can be dispersed in paints and coatings for metals. The particles in some cases include ionic water-soluble anti-corrosion agents complexed to oppositely charged surfactants and entrapped in silica oxide or metal oxide gels.