N-HALAMINE BASED BIOCIDAL COATINGS COMPOSED OF ELECTROSTATICALLY SELF-ASSEMBLED LAYERS

The present invention provides a composition comprising an antimicrobial bilayer coating on a substrate which coating comprises: (1) a polyionic material, in alternating layers, where one layer is a cationic polymer containing -NHR1 or -C(O)NHR2 groups, where R1 and R2 are independently hydrogen, straight- or branch-chain C1-C10 alkyl, phenyl, benzyl, or C6-C14 aryl; and another layer is an anionic polymer containing -COOH or -COOR groups, where R is straight- or branch-chain C1-C10 alkyl, phenyl, benzyl, or C6-C14 aryl; and (2) At least two full bilayers are coated on the substrate; and (3) the layers are crosslinked through amide, imide, urea, or carbamate bonds; and (4) at least 1% of the amine or amide N-H groups in the coating are converted to N-X, where X is Cl or Br. The bilayers, where an anionic outermost layer is present, is preferred. These coating compositions, applied to a substrate, are then crosslinked and finally treated with aqueous hypochlorite when N-X is N-Cl. The substrate that is coated can be sterilized prior to applying the coating composition, but it is not required to do so. These coatings are useful for military and hospital equipment and environments, especially against spores.