Preparation of an innovative series of respiratory nano-filters using polystyrene fibrous films containing KCC-1 dendrimer and ZnO nanostructures for environmental assessment of SO2, NO2 and CO2

Abstract

Air pollution has become a major challenge that threatens human health. The use of respiratory filters is one of the proposed solutions. In this study, using polystyrene (PS) fibers and various nanomaterials, improved respiratory filters were fabricated to remove air pollutants. In this context, ZnO nanoparticles (ZnO NPs) integrated into dendritic structures of KCC-1 silica were used to improve the filters' ability to absorb pollutants. For the first time, the removal of gasses by modified filters with a novel polymeric nanocomposite (PS/ZnO-KCC-1) stabilized on the surface of respiratory filters was investigated. Moreover, two different methods including stabilized- and solution-based techniques were used to prepare the filters with different amounts of ZnO NPs and their efficiency was evaluated. All synthesized nanocomposites and developed filters were characterized by FT-IR, FESEM, TGA and XRD methods. The successful stabilization of nanostructures on the fibers was proved and the performance of the fibers was investigated with some tests, such as pressure drop and removal of suspended particles and CO₂ (89%), NO₂ (86%), and SO₂ (83%) gases. PS/KCC-1-ZnO (5%) has better performance than other prepared fibers. The results showed that the removal of suspended particles in the filter containing ZnO and KCC-1 (M5) nanostructures was improved by 18% compared to the filter consisting of polystyrene fibers. The pressure drop increased with the addition of nanostructures and reached 180 Pa in the M5 filter. The filter containing ZnO NPs showed antibacterial activity against Staphylococcus (S.) aureus and Escherichia (E.) coli as Gram-positive and Gram-negative model bacteria using the Agar disk-diffusion method. Based on the results, the use of improved respiratory filters is recommended as an effective solution for combating air pollution and protecting human health.

Scheme 1. Chemical structure of KCC-1.

Scheme 2. Preparation processes of fibers nanocomposite.

Scheme 3. A schematic diagram of the air filter test system.

Fig. 1. FT-IR spectra of KCC-1 and ZnO NPs.

Fig. 2. FESEM-EDS of (a) KCC-1 NPs, (b) ZnO NPs.

Fig. 3. FESEM images of (a) PS fibers, (b) PS/KCC-1 1% fibers solution, (c) PS/KCC-1 7% fibers solution. (d) PS/ZnO 5% fibers stabilize, (e) PS/KCC-1, ZnO 5% fibers solution, (f) PS/KCC-1, ZnO 5% fibers stabilize.

Fig. 4. PM removal efficiency of PS fibers and PS-nanocomposite fibers.

Fig. 5. Pressure drops of PS fibers and PS-nanocomposite fibers.

Fig. 6. CO₂ rejection of PS fibers and PS-nanocomposite fibers.

Fig. 7. SO₂ rejection of PS fibers and PS-nanocomposite fibers.

Fig. 8. NO₂ rejection of PS fibers and PS-nanocomposite fibers.

Fig. 9. FT-IR spectra of PS/KCC-1, ZnO filter before and after gas removal.

Fig. 10. EDS elemental analysis of PS/KCC-1, ZnO filter after gas removal.

Fig. 11. Antibacterial tests of PS fibers and PS/ZnO fibers.