Electrically assisted silver and copper coated filter papers with enhanced bactericidal effects

Abstract

Increased microorganisms resistance to drugs is currently a challenging problem as more powerful drugs are necessary for successful treatments. Current research is investigating for the first time reinforced bactericidal effects in wastewater resulted by simultaneous use of metallic thin films deposited on water filter papers combined with electrical power directly applied to the coated structures. Silver and copper were deposited at room temperature onto water filter papers by using high vacuum magnetron sputtering system. The metallic coated structures efficiently eliminated common types of wastewater bacteria (e.g. Escherichia coli and other coliforms). The antibacterial effects were reinforced by using electrical power applied to the structures. Increasing the electricity levels resulted in stronger bactericidal effects and subsequently shorter exposure times were required to reduce bacteria from contaminated water. Thin films adherence to filter fibers and the morphology of the coated structures were examined using digital optical microscopy and Scanning Electron Microscopy (SEM). The method used for assessing antibacterial performance was the standardized membrane filtering technique for wastewater examination. Water was collected from local basins and the bacterial content was monitored before and after exposure to uncoated, silver and copper coated filter fibers, and electrically activated metallic coated filter fibers. The metallic thin films were retained on the fibers surface after water treatment consequently reducing the nanoparticles release to the surroundings.