Recyclable, Antibacterial, Isoporous Through-Hole Membrane Air Filters with Hydrothermally Grown ZnO Nanorods

Abstract

Reusable, antibacterial, and photocatalytic isoporous through-hole air filtration membranes have been demonstrated based on hydrothermally grown ZnO nanorods (NRs). High-temperature (300~375 °C) stability of thermoset-based isoporous through-hole membranes has enabled concurrent control of porosity and seed formation via high-temperature annealing of the membranes. The following hydrothermal growth has led to densely populated ZnO NRs on both the membrane surface and pore sidewall. Thanks to the nanofibrous shape of the grown ZnO NRs on the pore sidewall, the membrane filters have shown a high (>97%) filtration efficiency for PM2.5 with a rather low-pressure (~80 Pa) drop. The membrane filters could easily be cleaned and reused many times by simple spray cleaning with a water/ethanol mixture solution. Further, the grown ZnO NRs have also endowed excellent bactericidal performance for both Gram-positive S. aureus and Gram-negative S. enteritidis bacteria. Owing to the wide bandgap semiconductor nature of ZnO NRs, organic decomposition by photocatalytic activity under UV illumination has been successfully demonstrated. The reusable, multifunctional membrane filters can find wide applications in air filtration and purification.

Biological mechanism of ZnO nanomaterials

“…There are studies on the synthesis of ZnO nanorods (ZnO NRs) porous membrane by hydrothermal method. Due to the fibrous nature of ZnO NRs, it shows very good filtration performance, and it endows the membrane with antibacterial and photocatalytic activities, and it is found that Gram-positive bacteria and Staphylococcus aureus are killed on the ZnO NRs porous membrane (Choi et al, 2021).…”

“…As bacteria can be transferred through a wet mask, it is extremely important to improve the antibacterial ability of the mask in order to prevent cross infection or secondary infection during use. According to research, NPs can be used as effective antibacterial agents in wound care, and nanotechnology has the potential to fundamentally change the form and efficacy of traditional respiratory protection systems, contributing to improving the quality of life (Choi et al, 2021).…”

Poly(Allylamine Hydrochloride) and ZnO Nanohybrid Coating for the Development of Hydrophobic, Antibacterial, and Biocompatible Textiles

“…Zinc oxide (ZnO) NPs, in particular, are extensively studied for their antibacterial potential and skin-friendly properties [19]. They have been integrated into various applications, such as air filters with antibacterial properties [20], antibacterial cotton materials for healthcare applications [21,22], textiles with photocatalytic self-cleaning and UV protection [23], and wound dressings [24]. ZnO NPs, synthesized through various methods, exhibit multiple activities, including antibacterial, antiviral, antifungal, antioxidant, anticancer, anti-inflammatory, wound healing, antidiabetic, and cardioprotective effects [25].…”

Screening of low‐toxic zinc oxide nanomaterials and study the apoptosis mechanism of NSC‐34 cells

“…Choi et al. [ 6 ] and his research team analyzed nanoparticles as efficient antibacterial agents for wound care. The field of nanotechnology holds promise in revolutionizing the structure and effectiveness of conventional respiratory protection systems, thereby enhancing overall quality of life.…”