Tug-of-War-Inspired Bio-Based Air Filters with Advanced Filtration Performance

Abstract

Integrating nanostructured active materials, antimicrobial components, and rational porous structures is one of the promising approaches for simultaneously boosting removal efficiency, antimicrobial capacity, mechanical property, hydrophobic performance, and air permeability of air filters. However, realizing these performances of an air filter still remains a big challenge. Herein, a multifunctional air filter zNFs-Ag@PT, which is composed of a unique substrate prepared from Ag nanoparticles (AgNPs)-paper towel (PT) microfibers and an upper layer formed from aligned zein nanofibers (zNFs) inspired by a “tug-of-war” repulsion force, is reported. The Ag@PT substrate is fabricated via in situ reduction; and zNFs are prepared by electrospinning a well-prepared zein Pickering emulsion onto a specially designed collector. The innovative collector is a partially conductive design composed of an insulative middle section and two conductive ends. It is demonstrated that the introduction of AgNPs not only endows the zNFs-Ag@PT filter with an effective antimicrobial activity but also provides the substrate with an anisotropic electric field to achieve stretched and aligned zein fibers forming thinner nanofibers than that without AgNPs. As a result, the filtration performances of a zNFs-Ag@PT filter are enhanced. This study initiates an effective way to fabricate bio-based multifunctional air filters with antimicrobial and filtration performances via combining nano- and biotechnology.

Electrospun Nanofiber Membranes for Air Filtration: A Review

“…In addition to the preparation of a single process, it is also the focus of research to combine various processes to prepare the required materials. For example, Fan et al [ 196 ] prepared an Ag/PT substrate by the in-situ reduction method, producing an electrospun nanofiber membrane in an anisotropic electric field. Stretched and aligned zein fibers were achieved with simultaneous antimicrobial properties, with a ZNF–Ag/PT filter removing up to 99.30% of the PM0.3, as shown in Figure 10 a.…”

“… Multiprocess collaborative preparations: ( a ) preparation of Ag/PT substrate by in situ reduction method. Adapted with permission from [ 196 ]. Copyright, 2021 American Chemical Society; ( b ) preparation of composite nanofibers by green cross-linking method.…”

Fabrication of air filters with advanced filtration performance for removal of viral aerosols and control the spread of COVID-19

“…Till now, diverse antimicrobial agents including ZnO, Ag, CuO, and TiO 2 have been inserted into fibers to enhance antimicrobial performances. Fan et al developed a multifunctional air filter zein nanofibers-Ag@paper towel inspired by a “tug-of-war” repulsion force [ 32 ]. For this aim, Ag@paper towel substrate was manufactured by in-situ reduction.…”

“… MS2 bacteriophage Nano-Ag/TiO 2 -chitosan [ 28 ] With increasing SiO 2 /Ag coating levels, the pressure drop, filtration efficacy, as well as anti-viral effectiveness were increased. MS2 bacteriophage SiO 2 /Ag [ 31 ] ~92% anti-viral efficiency aerosolized MS2 virus SiO 2 -Ag [ 32 ] Great removal efficiency (99.30%) Particulate matter 0.3 Zein nanofibers-Ag@paper towel [ 33 ] Performance toward E.coli (99.10%) as well as S. aureus (99.62%) E. coli and S. aureus Keratin/Ag [ 34 ] The filtration efficiencies for the prepared composite filter for particulate matters 2.5 and particulate matter 10 were 99.7% and 99.8%, respectively Particulate matters 2.5 and 10 Bacterial cellulose/Ag [ 35 ] The fabricated filter displayed 99.6% and 100% bacteria reductions toward S. aureus and E. coli , respectively. S. aureus and E. coli Poly(vinyl alcohol)/Ag electrospun nano-fibers [ 36 ] 99.64 and 98.75% of Escherichia coli and Staphylococcus aureus were killed Escherichia coli and Staphylococcus aureus Ag/Zn@cotton fabric [ 38 ] The fabricated anti-viral face masks based on TiO 2 with easily sterilizable and reusable features (more than 1000 times) can provide a strong prevention device against the SARS-CoV-2 Corona and Ebola viruses TiO 2 nanowire-based filter papers Ag/Zn@cotton fabric[ 39 ] High filtration efficiency, and reduced S. aureus bacteria S. aureus TiO 2 /chitosan/poly(vinyl alcohol) [ 40 ] The fabricated antimicrobial air filters showed an effectiv...…”

Amine-Containing Resin for Coating with Excellent Formaldehyde Removal Performance

“…These synthetic materials may include toxic and harmful chemicals such as formaldehyde (HCHO) and benzene. For example, HCHO is commonly observed in composite panels, adhesives, matte paint, preservatives, etc. − It is a toxic and strong carcinogenic chemical, and its harmfulness is closely correlated with its concentration and exposure time. − Therefore, the pollution caused by HCHO in our daily life has been of extensive public concern. , …”