During the global spread of COVID-19, high demand and limited availability of melt-blown filtration material led to a manufacturing backlog of N95 Filtering Facepiece Respirators (FFRs). This shortfall prompted the search for alternative filter materials that could be quickly mass produced while meeting N95 FFR filtration and breathability performance standards. Here, an unsupported, nonwoven layer of uncharged polystyrene (PS) microfibers was produced via electrospinning that achieves N95 performance standards based on physical parameters (e.g., filter thickness) alone. PS microfibers 3–6 μm in diameter and deposited in an ~5 mm thick filter layer are favorable for use in FFRs, achieving high filtration efficiencies (≥97.5%) and low pressure drops (≤15 mm H2O). The PS microfiber filter demonstrates durability upon disinfection with hydroxyl radicals (•OH), maintaining high filtration efficiencies and low pressure drops over six rounds of disinfection. Additionally, the PS microfibers exhibit antibacterial activity (1-log removal of E. coli) and can be modified readily through integration of silver nanoparticles (AgNPs) during electrospinning to enhance their activity (≥3-log removal at 25 wt% AgNP integration). Because of their tunable performance, potential reusability with disinfection, and antimicrobial properties, these electrospun PS microfibers may represent a suitable, alternative filter material for use in N95 FFRs. 相似文献
In modern society, traffic and transportation and the manufacturing industry and construction industries continuously release large amounts of dust and particles into the atmosphere, which can cause heavy air pollution, leading to health hazards. The haze disaster, a serious problem in developing countries such as China and India, has become one of the main issues of global environmental pollution in recent decades. Many air filtration technologies have been developed. Air filtration using electrospun fibers that intercept fine particles/volatile organic gases/bacterium is a relatively new, but highly promising, technique. Due to their interconnected nanoscale pore structures, highly specific surface areas, fine diameters, and porous structure as well as their ability to incorporate active chemistry on a nanoscale surface, electrospun fibers are becoming a promising versatile platform for air filtration. In this review, following a short introduction concerning the need for air filtration and filtration theory and mechanism, electrospun nanofibers membranes for air filtration have been highlighted, including the preparation (electrospinning process) and the parameters relevant to filtration efficacy. Additionally, various types (function) of the electrospun air filtration membranes have been classified in detail. Furthermore, their potential in the filtration of fine particles and chemical pollutants has been discussed. Finally, the challenges of their practical application and the future prospects have been summarized. Given that some advanced electrospun air filtration nanofibrous membranes exist for treating different contaminants from various types of polluted atmosphere, it is believed that they should make a significant contribution in protection against air pollution.
Electrospun electret filter material is widely studied because of its excellent removal effect on particulate matter from air streams. Here, a kind of high efficiency and low pressure drop nanofiber (NF) membrane with both electret effect and magnetic effect is developed, and compounded it with glass fiber mesh and polyester (polyethylene terephthalate) mesh to prepare a sandwich structure of NF anti‐haze window screen. Under the synergistic effect of magnetic particles, when the density is 2.06 g m?2, the filtration efficiency of NF anti‐haze window screen can reach 99.95% for the fine particles below 0.3 µm, while the filtration pressure drop is only 58.5 Pa, with good light transmittance and excellent breaking strength (6.32 MPa). Therefore, polyvinylidene fluoride/Fe3O4 composite NF membrane has a potential application prospect in the field of air filtration. 相似文献
Numerous experimental works for particulate matter (PM) filtration by electrospun nanofiber membranes (ESNFMs) are published in the last 10 years (2010–2021). Organizing and comparing the large amount of the available information to identify the best trends constitutes a big challenge. This review classifies all kinds of ESNFMs considering their physical, chemical, or electrical characteristics. All of them are obtained by modifying several parameters during a specific stage associated to the electrospinning process (ES). In this review, each of these stages is considered a \"moment” as a particular instant in time. According to that, three modifications are made: Moment 1—before ES, which refers to changes in polymeric solution composition; moment 2—during ES, which refers to modifying parameters while ES is performed; and moment 3—after ES, which involves applying post-treatments directly on the membrane. After classifying all kinds of filters by moments, a detailed comparison of ESNFMs with the highest quality factors for PM0.3 is presented, finding out the best trends and comparing their main filtration parameters as well, where the most promising ones correspond to charged and nanofiber/nets membranes, due to their high capture efficiencies (>95%) while maintaining low pressure drops (<100 Pa). 相似文献