Keywords air sampling, antibacterial, indoor air quality, metal ion, nano filter, nano zeolite Y. Correspondence AbstractAims: Fibre membranes containing metals have attracted great attention because of their high antibacterial efficiency. However, comparison of antibacterial activity of fibres with multi-metals in air samples has remained understudied. Methods and Results: Different ion exchanged nano-zeolite Y (IE-NZY) of Ag, Zn and Cu was studied. Polyvinylpyrrolidine/polyvinylidene fluoride nanofibres containing various IE-NZY were synthesized according to electrospinning technique. The presence of metal ions was confirmed using XRF. The morphological properties of nanofibres were characterized by SEM. Zone of inhibition was seen between 10Á1 and 12 mm against Staphylococcus aureus and 11Á5-14Á57 for Escherichia coli. IE-NZY containing Ag, Zn and Cu had the highest antibacterial efficiency. In the air samples, there were any colonies on the media under the Ag/Cu-NZY and Zn/Cu/Ag-NZY nanofibres. Conclusions: The bacterial inhibition for nanofibres containing a three metal nano-zeolite Y (TM-NZY) is higher than bimetals (BM-NZY) types while for monometals nano-zeolite Y (MM-NZY), it was lower compared to the others. Significance and Impact of the Study: The results indicate significant antibacterial activity of ion-exchanged NZY in air sampling.

Background: Surgical masks are usually used to protect surgeons from the transmission of disease and germs, as well as preventing the transmission of infectious agents to the environment and others. The mask may not be a suitable environment for the growth and reproduction of microbes. Regarding this, the present study aimed to investigate the feasibility of making antibacterial mask substrate providing high efficiency and low pressure drop. Materials and Methods:For the purpose of the study, nanofiber substrates containing variable amounts of polyethylene terephthalate and copper nitrate were produced using an electrospinning device. The efficiency and pressure drop of antibacterial nanofiber substrates were measured at a particle size range of 260 nm to 1.6 µ. Measurement of the particle number density was accomplished by placing two condensation particle counters on both sides of the filter. Results: Examination of the scanning electron microscope images revealed that the optimal sample contained 25% polymer and 1.5% copper nitrate and had the best morphology at 16 kV. The samples were subjected to electrospinning at different times to examine their efficiency and pressure drop. As the electrospinning time increased from 15 to 60 min, the substrates became thicker, and consequently their efficiencies increased from 13% to 94%; furthermore, the pressure drop increased from 10 to 20 psi. Electrospinning of 60 min resulted in the highest quality factor. Conclusions: As the findings indicated, with the enhancement of electrospinning time, the efficiency of the substrates are increased, and the particle penetration rate of the substrates are reduced. This could be due to the increased thickness of substrates by increasing the electrospinning time.