Multiwalled Carbon Nanotube-Based Freestanding Filters for Efficient Removal of Fine Particulate Matters (PM0.3), Microplastics (MP0.3), and Bioaerosols

Air pollution caused by various hazards such as particulate matters (PM), microplastics (MP), bioaerosols (BA), etc. has become a global concern for public health across the globe. In recent decades, nanofiltration-based air purification techniques have rapidly evolved as a viable solution to address worldwide air pollution challenges. Herein, we report a simple, cost-effective, and scalable technique for the fabrication of lightweight, freestanding, and flexible multiwalled carbon nanotube (MWCNT) membranes for air filter applications. The developed membrane filter possesses excellent capturing efficiency of more than 99% for PM0.3, MP0.3, and BA. Additionally, the developed membrane has also been well investigated in terms of hydrophobic behavior (contact angle ∼148 ± 7°), narrow pore size (∼16 nm), packing density (∼0.65 g/cc), porosity (∼56%), pressure drop (∼139.7 Pascal), flexibility, and reusability, reflecting its self-cleaning feature, physical sieve characteristics, adaptability, and commercialization. Thus, the filter developed in this work shows its potential utility toward the removal of indoor pollution and in air filter industries as well.