An antimicrobial exfoliated vermiculite composite material is synthesized by impregnating the interlayers of exfoliated vermiculite through cation exchange and surface absorption with at least one of the following metal species: copper, silver, zinc, and manganese. Alternately, the antimicrobial material is synthesized by impregnating interlayers of unexfoliated vermiculite with said metal species and exfoliating the product thereafter. The metal species can be in ionic state, nanometer particles, and in the form of metal oxides, metal hydroxides, metal nitrides, metal carbides, metal phosphates, metal silicates, metal borides, metal sulfides, metal halides, metal hydrides, metal nitrates, metal carbonates, and metal sulfadiazines. Any mixture of these metal species in the exfoliated vermiculite can provide protection against a broad spectrum of pathogens. This antimicrobial material in any desired form, in whole or as an additive, can effectively self-decontaminate various materials or products as the antimicrobial metal ions slowly diffuse to the surface of the products.
