Anionic Surfactant-Triggered Steiner Geometrical Poly(vinylidene fluoride) Nanofiber/Nanonet Air Filter for Efficient Particulate Matter Removal

Abstract

The emergence of Steiner minimal tree is of fundamental importance, and designing such geometric structure and developing its application have practical effect in material engineering and biomedicine. We used a cutting-edge nanotechnology, electrospinning/netting, to generate a Steiner geometrical poly­(vinylidene fluoride) (PVDF) nanofiber/nanonet filter for removing airborne particulate matter (PM). Manipulation of surface morphologies by precise control of charged situation enabled the creation of two-dimensional nanonets with Steiner geometry. A significant crystalline phase transition of PVDF from α-phase to β-phase was triggered by the dipole orientation and the intermolecular interactions derived from the electrostatic potential analysis. Particularly, the synergy of electrical interaction (ion–dipole and dipole–dipole) and hydrophobic interaction facilitated the formation of Steiner geometric structure during the evolution process of nanonets. The resultant PVDF nanofiber/nanonet air filter exhibited high filtration efficiency of 99.985% and low pressure drop of 66.7 Pa under the airflow velocity of 32 L/min for PM0.26 removal by the safest physical sieving mechanism. Furthermore, such filter possessed robust structure integrity for reusability, comparable optical transmittance, superior thermal stability, and prominent purification capacity for smoke PM2.5. The successful construction of such fascinating Steiner geometrical PVDF nanonets will provide new insights into the design and exploitation of novel filter media for air cleaning and haze treatment.

Transparent Antibacterial Nanofiber Air Filters with Highly Efficient Moisture Resistance for Sustainable Particulate Matter Capture

“…Compared with a blank wire mesh with an original pressure drop of 14 Pa and flow rate of 3.5 m s −1 , fibrous filters with 86% transmittance showed a smaller change. Besides, we have compared the filters in this work with other reported fibrous filters (Li et al., 2018a, Li et al., 2018b, Liu et al., 2015, Wang et al., 2014, Zhang et al., 2016a, Zhang et al., 2016b, Zhang et al., 2016c, Zhao et al., 2017a, Zhao et al., 2017b, Zuo et al., 2017), which clearly shows that PDMS/PMMA-CS (chitosan) nanofiber filters have the best air filtration performance considering PM removal efficiency, pressure drop, and the QF (Figure S5).

Figure 4Transparent Nanofiber Filters(A) Photographs of PDMS/PMMA-chitosan transparent air filters at different transparencies.(B and C) (B) PM 2.5 and PM 10 removal efficiency and (C) pressure drop and flow rate of transparent filters at different transmittances.

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A Fluffy Dual‐Network Structured Nanofiber/Net Filter Enables High‐Efficiency Air Filtration

“…The basic principle of the formation of 2D films could be due to the ejection of charged droplets from Taylor cone, which was triggered by the initiator of the surfactant TBAC. The ion–dipole interaction, between the cationic head group of TBAC and the polar nitrile group in PAN molecules, can effectively release chloride ions of TBAC, and thus further facilitate the polarization and charging of the precursor solution during electrospinning/netting (Figure e) . This is the principal feature in the aspect of solution regulation that distinguishes our strategy from other nanofiber/net fabrication methods.…”

Face Masks in the New COVID-19 Normal: Materials, Testing, and Perspectives

“…The integrated filter with gradually varied pore structures and high porosity can efficiently capture airborne particles in a gradient manner with low air resistance. Very recently, Li et al also employed the electrospinning/netting process for the mass production of a reusable poly(vinylidene fluoride) nanofibre/nanonet air filter, which presented a high purification efficiency of 99.985% towards PM 0.26 and a low-pressure drop of 66.7 Pa [145].…”