Postgraduate Seminar Presentation : Design of High Efficiency PVDF-PEG Hollow Fibers for Air Filtration of Ultrafine Particles

Speaker Wang Liang-Yi (Supervisor: Prof Chung Tai-Shung, Neal)

Host Department of Chemical and Biomolecular Engineering

Date/Time 23 Oct - 23 Oct, 2.30PM

Venue E5-03-20 , Faculty of Engineering, National University of Singapore

Synopsis

The particulate matter (PM) air pollution has become a global issue in the last few decades. Recently, air filters based on the electron spun techniques have been intensively studied to remove PM 2.5. However, most of these filters were used to filtrate the particles with size around 0.3 mm. Fewer study reported the filtration efficiency for the smaller particles. Compared to conventional fibers filter media, hollow fibers feature of self-supported properties with tunable pore sizes, which makes hollow fibers a good candidate for filtration processes. Until now, limited studies have worked on particle-laden gas filtration using hollow fibers. This study reveals as the first attempt to apply hollow fibers for air filtration of ultrafine particles. Different from symmetric nano-fiber filters and non-woven fabrics, asymmetric polyvinylidene fluoride - polyethylene glycol (PVDF-PEG) hollow fibers with high gas permeances have been developed. The addition of high molecular weight PEGs in spinning dopes facilitates the formation of loosely connected cross-section and porous outer skin, thus enhances the gas permeance for air filtration. Under the inside-out testing mode, all PVDF-PEG hollow fibers display excellent filtration efficiency of 99.999% against polydispersed NaCl particles with a geometric mean size of ~30 nm. This study may provide useful insights for developing hollow fibers for air filtration with the optimal operation conditions.

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