A reactive melamine derivative, 2-amino-4-chloro-6-hydroxy-s-triazine (ACHT), was synthesized through the controlled hydrolysis of 2-amino-4,6-dichloro-s-triazine. The reaction was characterized with Fourier transform infrared study and elemental analysis. ACHT could react with cotton cellulose at room temperature with a cold-pad-batch treatment process. Upon chlorination reactions, the amino group of covalently bound ACHT could be transformed into an N-halamine structure, providing potent, durable, and rechargeable antimicrobial activities against both gram-negative and gram-positive bacteria. The chlorination mechanism and the structure-property relationship of the treated samples were further examined. (C) 2004 Wiley Periodicals, Inc.