Antimicrobial activity and thermostability of silver 6-benzylaminopurine montmorillonite

Novel antimicrobial materials were constructed by the intercalation of organometallic cations into montmorillonite. The silver chelate complex of 6-benzylaminopurine was intercalated into montmorillonite by a cation exchange reaction in aqueous medium. The basal spacing of 1.8 nm was attributed to an almost planar arrangement of the silver chelate complex. Most of the interlayer cations were replaced by the silver chelate complexes. Thermogravimetric/differential thermal analyses indicated that the degradation temperature of the chelating ligands was increased by complexation with the silver ions and electrostatic binding in the interlayer space. Ca. 0.15% of the silver chelate complex was released in water after 7 days followed by steady-state release up to 22 days. The intercalated montmorillonite exhibited antibacterial and antifungal activity compared with the commercial silver supported products. (C) 2009 Elsevier B.V. All rights reserved.