Polytetrafluoroethylene/Polyphenylene Sulfide Needle-Punched Triboelectric Air Filter for Efficient Particulate Matter Removal

Abstract

The demand for air filtration materials in recent years has been substantially increasing on a worldwide scale because people are paying extensive attention to particulate matter (PM) pollution. In this work, we report a type of needle-punched triboelectric air filter (N-TAF) consisting of polytetrafluoroethylene (PTFE) fibers modified by silica nanoparticles and polyphenylene sulfide (PPS) fibers. Compared to conventional electrostatic precipitators, the N-TAF can be charged online by a unique nonwoven processing technology without additional energy consumption and toxic ozone emission. Owing to the triboelectrification effect, a large number of charges were generated during the process of carding and needle-punching, resulting in an increased filtration performance. Benefiting from the addition of silica nanoparticles, the PTFE fibers are endowed with many pores and grooves and substantial surface roughness, which contributes to the enhancement of triboelectrification. As a result, the N-TAF with 2 wt % silica nanoparticles (N-TAF-2) exhibited a high removal efficiency of 89.4% for PM, which is 45% higher than unmodified N-TAF (61.8%), and a low pressure drop of 18.6 Pa. Meanwhile, the decay of the removal efficiency for N-TAF-2 remained at a low level (6.4%) for 60 days. More importantly, N-TAF-2 could realize a high efficiency of 99.7% and a low pressure drop of 55.4 Pa at a high surface density. In addition, the washed N-TAF has an excellent charge regeneration performance via air blowing or manual rubbing, thus recovering the removal efficiency easily and rapidly. Ultimately, the powerful dust holding capacity (227 g m–2) for N-TAF-2 indicates that the filter has a long service life, which makes it a promising air purification material. The filter reported in this work has the potential to be practically applied to air purification fields because it has excellent filtration performance and is easy to be produced on a large industrial scale.

Towards Truly Wearable Systems: Optimizing and Scaling Up Wearable Triboelectric Nanogenerators

“…Being a relatively innovative manufacturing method, nonwoven fabrics provide advantages such as ease of fabrication and scaling up, fast production rates, and compatibility with a large variety of fiber types. Although not being as popular as woven or knitted developments, limited number of nonwoven-related TENG designs have been presented in the literature ( Liu et al., 2018a , 2018b ; Peng et al., 2019 ; Wang et al., 2019 ), which used the nonwovens as the substrate of the TENG architecture. We note that, in our categorization, these particular examples fall under sandwiched fiber-structured TENG category (section Sandwiched Fiber/Yarn-Based TENGs), as the main triboelectric modification took place at the fiber stage of the active materials.…”

A Cleanable Self-Assembled Nano-SiO2/(PTFE/PEI)n/PPS Composite Filter Medium for High-Efficiency Fine Particulate Filtration

“…When P/P 0 > 0.9, the amount of nitrogen adsorption of the SiO 2 /(PTFE/PEI) 10 /PPS composite filter medium increased sharply because of the capillary condensation. The existence of the H3 hysteresis loop in the SiO 2 /(PTFE/PEI) 10 /PPS composite filter medium indicates that there were a large number of slit-like and open pores [26]. The Brunauer−Emmett−Teller (BET) surface area of the SiO 2 /(PTFE/PEI) 10 /PPS composite filter medium was 24.419 m 2 g −1 (Table S1), which was greatly improved as compared with that of the pure PPS filter medium due to the rougher surface and the large specific surface area of the SiO 2 /(PTFE/PEI) multilayers deposited on the surfaces of the PPS fibers.…”

“…Electrostatic precipitators not only suffer from high energy consumption but also release some toxic gases such as ozone which are harmful to our health. For corona charging filter materials, the long-term maintenance of the electret charges under high temperature and wet conditions is still challenging [26]. The nonwoven materials with three-dimensional structures are widely used as cleanable filter media for particulate matter filtration due to their good mechanical properties, high surface-to-volume ratio and dust holding capacity, low air pressure-drop and high filtration efficiency [27].…”

Multi-Layered, Corona Charged Melt Blown Nonwovens as High Performance PM0.3 Air Filters

“…Masks are usually composed of nonwovens produced via spunbond, needle-punch, through-air bonding, electrospinning, and melt blown technologies [4][5][6]. Among them, spunbond, needle-punch and through-air bonding nonwovens usually serve as the cover layer or the inner lining of the mask.…”