Modification of polyester filters with synthesized copper nanoparticles for use as biocide in a real environment

Antimicrobial air filtration techniques have recently been widely studied to enhance indoor air quality and mitigate hazardous airborne microorganisms. Here, CuNPs were incorporated into a commercial polyester fiber surface and Scanning Mobility Particle Sizer was used to measure the adherence between fibers and nanoparticles. An acid pretreatment previous CuNP incorporation was effective against the particle release and enhanced the adhesion between particle and fiber. CuNP was a mixture of Cu⁰ and Cu₂O with a diameter size of 90 nm (SEM micrographs). The permeability of the filter was low, in order of 10^-9 m². The activity against pathogens was tested in loco in a real environment using a filtration prototype apparatus. It was observed that the presence of CuNP mitigated the fungi and bacteria growth not only on the surface but also reduced microbe concentrations after passing through the filter. These results show that CuNP can be used as an inhibitor of various microorganisms, making them a good alternative for indoor environments to control indoor air quality.