Some aspects on the discoloration and antimicrobial property of a thermally passivated copper surface in a highly humid environment

Abstract

Copper is being considered for touch surfaces applications, such as bathroom accessories, because of their antimicrobial property, which can potentially reduce infection transmission. Since thermal passivation method is widely applied on surface of copper to produce color for decorative purpose, bathroom and toilet interior designers are interested in knowing the property of passivated copper surface in high humidity environment. The present study investigates the discoloration and antimicrobial property of a thermally passivated surface of copper against Escherichia coli (E. coli) bacteria. The spectral colorimeter analysis has been conducted to evaluate the degree of surface discoloration, XRD analysis has been conducted to identify the phases on the surface, a method based on JIS Z 2801: 2000 has been utilized to evaluate the colony forming unit (CFU) of E. coli on sample surface. © 2011 The Japan Institute of Metals.