Laser Functionalization of Carbon Membranes for Effective Immobilization of Antimicrobial Silver Nanoparticles

Microbial contamination and biofilm formation are serious challenges in water filtration applications. Recently, carbon nanocomposite membranes with modified silver nanoparticles (AgNPs) have attracted much attention as compelling water purification membranes that can deactivate pathogenic bacteria and prevent biofilm formation. However, the effective attachment of AgNPs onto such carbon-based surfaces has proven difficult to accomplish via inexpensive and rapid fabrication processes. In this study, we introduce a simple laser-assisted process that enables rapid surface functionalization and immobilization of AgNPs onto carbon cloth membrane surfaces comprised of woven carbon micro fibers. The laser functionalization provides a unique modification in surface morphology of the fibers by creating nanotextures as well as inducing changes in surface chemistry, all of which increase the physical and chemical bonding of AgNPs onto the surface of carbon fibers. Elemental and surface morphology analysis via XRD, SEM, and EDX reveal a uniform coating and strong attachment of AgNPs onto the laser functionalized carbon surface, even after vigorous mechanical agitations and probe sonication. The analysis showed the samples prepared by the laser functionalization prior to AgNPs coating provided exceptional antibacterial activity and ability to completely eradicate the bacteria within 4 h and resist biofilm formation against pathogenic bacterial strains of Escherichia coli. The developed technology provides new opportunities to develop a scalable, fast, and cost-effective preparation method for producing carbon-based materials/membranes with high antimicrobial activities which can be applied for water purification and other environmental applications.