Investigation of the figure of merit for filters with a single n

Jing Wang^{, a,} , Seong Chan Kim^a and David Y.H. Pui^a

^aParticle Technology Laboratory, Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, USA

Received 7 June 2007; 

revised 14 September 2007; 

accepted 4 December 2007. 

Available online 8 December 2007.

Abstract

We investigate filters composed of a layer of nanofibers on a substrate made of micrometer fibers and compare the performance of such nanofiber media to conventional micrometer fibrous filters. The performance of the nanofiber filters is evaluated using the figure of merit, which represents the ratio between the filtration efficiency and the pressure drop. Filtration tests were performed on four samples with different nanofiber solidities. As the nanofiber solidity increases, the filtration efficiency and the pressure drop both increase. We develop a numerical model to simulate the nanofiber filters. When the nanofiber solidity is appropriately adjusted, the pressure drop computed from the model is in good agreement with experimental results. Filtration efficiency for the nanofibers due to interception, inertial impaction and diffusion can be computed from the model. The simulation results are in good agreement with experiments for 20–780 nm particles but discrepancies exist for particles smaller than 20 nm. Our results show that nanofiber filters have better figure of merit for particles larger than about 100 nm compared to conventional fiberglass filters. For particles smaller than 100 nm, nanofiber filters do not perform better than conventional fiberglass filters.

Keywords: Nanofiber filters; Figure of merit

Morphology optimization of polymer nanofibernext term for applic

Ki Myoung Yun^{a, b}, Adi Bagus Suryamas^a, Ferry Iskandar^{a, d}, Li Bao^c, Hitoshi Niinuma^c and Kikuo Okuyama^{a, ,}

^a Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima, Hiroshima 739-8527, Japan

^b Department of Chemical and Biomolecular Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea

^c Nippon Muki Co., Ltd., 415 Sakunoya, Yuki, Ibaraki 307-0046, Japan

^d Department of Physics, Institut Teknologi Bandung, Jalan Ganesa 10, Bandung 40132, Indonesia

Received 3 March 2010; 

revised 3 September 2010; 

accepted 6 September 2010. 

Available online 15 September 2010.

Abstract

Polymer nanofiber mats with various morphology structures (nanofiber, beaded-nanofiber, and composite particle/nanofiber) were prepared by electrospinning for application to aerosol particle filtration. The filtration performance of these polymer nanofiber mats was evaluated based on quality factors generated from measurement of penetration through the filter by sodium chloride (NaCl) aerosol particles ranging from 20 to 300 nm. These filtration test results showed that the quality factors of beaded-nanofiber filter mats were the best, even though the aerosol particle penetration of them was the highest of the morphology structures. The results of the present study show that morphology optimization of polymer nanofibers is an effective method for improvement of filtration performance, and it must be the future direction for development of new filtration media.

Graphical abstract

Polymer nanofiber mats with various morphology structures (nanofiber, beade-nanofiber, and composite particle/nanofiber) were prepared by electrospinning for application to aerosol particle filtration. The filtration performance was evaluated based on quality factors generated from measurement of penetration through the filter by sodium chloride (NaCl) aerosol particles ranging from 20 to 300 nm.