A Controlled Design of Ripple‐Like Polyamide‐6 Nanofiber/Nets Membrane for High‐Efficiency Air Filter

Abstract

The filtration capacity of fibrous media for airborne particles is restricted by their thick diameter, low porosity, and limited frontal area. The ability to solve this problem would have broad technological implications for various air filtration applications; despite many past efforts, it remains a great challenge to achieve. Herein, a facile and scalable strategy to fabricate the ripple-like polyamide-6 nanofiber/nets (PA-6 NF/N) air filter via combining electrospinning/netting technique with receiving substrate design is demonstrated. This proposed approach allows the scaffold filaments to orderly embed into 2D PA-6 nanonets layer with Steiner-tree structures and nanoscale diameter of ≈20 nm, resulting in the ripple-like membrane with extremely small pore size, highly porous structure, and hugely extended frontal surface, by facilely adjusting its pleat span and pleat pitch. These unique structural advantages enable the ripple-like PA-6 NF/N filter to filtrate the ultrafine particles with high removal efficiency of 99.996%, low air resistance of 95 Pa, and robust quality factor of >0.11 Pa ; using its superlight weight of 0.9 g m and physical sieving manner. This approach has the potentialities to give rise to a novel generation of filter media displaying enhanced filtration capacity for various applications thanks to their nanoscale features and designed macrostructures.

Electrospun soy‐protein‐based nanofibrous membranes for effective antimicrobial air filtration

“…In conclusion, a multi‐functional nanofibrous membrane with a complete filtration efficiency (over 99%) compared with other reports from Ding's group was fabricated by protein/polymer as raw materials. Based on the structure of the protein, the functional groups on the protein (carboxyl, amino, etc.)…”

“…In recent years, air pollution has been a growing concern, as it severely affected people's daily life due to the complicated composition of pollutants. Taking the particulate matter (PM) ≤2.5 µm as an example, it includes solid and liquid particles emitted into the air, such as road and agricultural dust, automobile exhaust, bacteria/viruses, originated from human activities like traffic, industry, power plans, etc . PM affects the living environments in terms of air quality, visibility, radiative forcing, climate, and ecosystems .…”

“…Compared with traditional filter materials, nanofibers are considered to be the promising and feasible candidate in the field of air filter because of their nanosized diameter, large surface areas, and the higher ratio of length to diameter . The nanofibers used as air filters exhibit many superiorities such as excellent PM removal efficiency and low filtration resistance, which benefits from their relatively small pore diameters and high porosity …”

Advanced Materials for Capturing Particulate Matter: Progress and Perspectives

“…In contrast, polymer nanofibers can be effectively produced on a large scale through a simple electrospinning technique . In addition, the low cost and possibilities of modifying the properties of polymers, such as polyacrylonitrile (PAN), poly(vinylpyrrolidone) (PVP), polystyrene (PS), poly(vinyl alcohol) (PVA), and polypropylene (PP) make them promising for practical purification applications . Here, polymer‐based materials are classified according to their purification mechanism.…”

Design of three‐dimensional gradient nonwoven composites with robust dust holding capacity for air filtration

“…They presented that a thin layer of electrospun membrane could improve the filtration efficiency without substantial increase of pressure drop . Ding and coworkers have successfully created the nanofiber/nets membrane, which maintains a low air resistance when filtrating the ultrafine particles . They explained the low resistance by the nanonets would exhibit great “slip effect” due to the slip flow of air molecules on the periphery of nanofibers, which greatly decreased the air resistance .…”