Nanofiber-based filters as novel barrier systems for nanomaterial exposure scenarios

Zhao

J of Applied Polymer Sci

et al. 2017

Multilevel-layer-structured polyamide 6 (PA6) and poly(trimethylene terephthalate) (PTT) nanofibrous membranes were fabricated by an electrospinning method. The morphology of the multileveled layers membranes were characterized by scanning electron microscopy. The tensile strength of the PA6-PTT membranes were controlled by the regulation of the layer structure. Additionally, the surface area of the multilevel-layer-structured membranes was also investigated with the nitrogen physisorption isotherms. Furthermore, the multilevel-layered membranes, with a tensile strength of 9.8 MPa and a surface area of 5.1601 m 2 /g on 300-nm dioctylphthalate (DOP) aerosol particles, showed a higher efficiency (95.825%) and a lower pressure drop (55 Pa) than the pure PA6 membranes (with values of 94.634% and 467 Pa, respectively). This suggested a new method for high-efficiency and lowpressure-drop filtration applications. Correlations between the filtration pressure drop and filtration efficiency with the structure of the membranes, particle size, and surface velocity were proposed, and the advantage of the multilevel-layered structure is also discussed.

Section: Introductionmentioning

confidence: 99%

Multilevel‐layer‐structured polyamide 6/poly(trimethylene terephthalate) nanofibrous membranes for low‐pressure air filtration

Zhao

J of Applied Polymer Sci

et al. 2017

“…These increases were attributed to the higher solution viscosity caused by adding the TEOS. In a previous study, chain entanglement in a polymer solution was reinforced but chain mobility degraded as the viscosity in the solution increased, which resulted in less extension during the electrospinning process, thereby producing a thicker fiber [12,13]. The intrinsic Ga 2 O 3 nanofibers exhibited a porosity microstructure, as shown in Figure 1a.…”

Section: Introductionmentioning

confidence: 82%

Enhanced Photocatalytic Activity of Electrospun β-Ga2O3 Nanofibers via In-Situ Si Doping Using Tetraethyl Orthosilicate

et al. 2019

β-Ga 2 O 3 has attracted considerable attention as an alternative photocatalyst to replace conventional TiO 2 under ultraviolet-C irradiation due to its high reduction and oxidation potential. In this study, to enhance the photocatalytic activity of β-Ga 2 O 3 , nanofibers are formed via the electrospinning method, and Si atoms are subsequently doped. As the Si concentration in the β-Ga 2 O 3 nanofiber increases, the optical bandgap of the β-Ga 2 O 3 nanofibers continuously decreases from 4.5 eV (intrinsic) to 4.0 eV for the Si-doped (2.4 at. %) β-Ga 2 O 3 nanofibers, and accordingly, the photocatalytic activity of the β-Ga 2 O 3 nanofibers is enhanced. This higher photocatalytic performance with Si doping is attributed to the increased doping-induced carriers in the conduction band edges. This differs from the traditional mechanism in which the doping-induced defect sites in the bandgap enhance separation and inhibit the recombination of photon-generated carriers.

“…Polyamide nanofibrous filters consisting of a UNF structure were produced by Faccini et al (2011) and Wang et al (2012) for the purpose of airborne particulate filtration. A numerical model, however, is still not successfully established for the UNF media, to the best of our knowledge.…”

Section: Introductionmentioning

confidence: 99%

Filtration Performance Against Nanoparticles by Electrospun Nylon-6 Media Containing Ultrathin Nanofibers

Kuo

Bruno

Aerosol Science and Technology

2014

We investigate the formation of ultrathin nanofibers (UNFs) with diameters below 20 nm by electrospinning Nylon-6 solution with various processing parameters. It is found that the UNF density and morphology are highly dependent on the solution concentration and age, collecting distance, and ambient humidity. The sequence that ribbon-like fibers are stretched by the electric force, followed by rapid phase separation of the splitting film is proposed as a formation mechanism of the UNFs. Based on the morphological study, a model of hexagonal nets is developed in order to estimate the filtration efficiency by the UNF structure. The estimated efficiency due to the UNFs is then combined with the contribution from the un-split nanofibers (NFs) to compute the total filtration efficiency and pressure drop for each of the electrospun media by applying a layered multiple zone model. The filtration performance of the electrospun media against nanoparticles is evaluated using the quality factor and specific filtration performance index, weighed against the pressure drop and basis weight of the media, respectively. Our results show UNFs are advantageous when high filtration efficiency is required and low weight is desired and/or little space is available for the filter media.