Polymer-layered silicate nanocomposites in the design of antimicrobial materials

A robust processing of polymers into antimicrobial materials is introduced using polymer/clay nanotechnology. Antimicrobial activity of commercially available organoclays modified with cationic surfactants has been screened in tests against gram-negative Escherichia coli and gram-positive Staphylococcus aureus bacteria. Despite the leaching biocidal surfactants, cell interactions with organoclay surface have been identified to be responsible for antimicrobial activity of organoclays. Distribution of clay platelets within polymer matrix by melt extrusion process resulted in polymer/clay nanocomposites active against both gram-positive and gram-negative bacteria by contact. The study discloses a much overlooked function of organoclays modified with cationic surfactants for nanocomposite application, i.e., the ability of organoclays to render polymer nanocomposites biocidal.