Electrospun Nanofibrous Membrane for Air Filtration Han Wang 1,2 , Gaofeng Zheng 1 ,and DaoHeng Sun 1* 1 Dept. Of Mechanical and Electrical Engineering, Xiamen University, China, 361005 2 Center of Laboratories, Guangdong University Of Technology, China, 510006 Abstract — Nanofibers have a large potential in air filtration applications, so this paper explores the performance of electrospun nanofiber membrane compared to traditional filtration fabrics. Poly (ethylene oxide) (PEO) and Polyvinyl Alcohol (PVA) were electrospun into nanofibrous membranes and analyzed their filtration attributes. Experimentation revealed that nanofibrous membranes have higher filtration efficiency than traditional filtration fabrics, such as meltblown and needle filtration material. In addition, Nanofibrous membranes under the same electrospinning process but with different materials had similar high filtration efficiency, while their permeability had obvious difference. We suggest that different structure in the nanofiber membrane should cause this difference. Our work proves that there is a large potential for nanofiber membranes to utilize in air filtration area. Keywords —Electrospinning; Nanofibers; Membranes; Filtration; PEO; PVA I. INTRODUCTION Electrospinning has gained much attention in the last decade not only due to its versatility in spinning a wide variety of polymeric fibers but also due to its consistency in producing fibers in the submicron range[1]. To date, a large number of polymers have been successfully electrospun [1] and immense research has been carried out to gain in depth understanding of the process for better control of fiber formation [2–6]. Now, more and more potential applications of electrospun fibers have also been realized such as, protective textiles [7-8], high- performance air filters [9], advanced composites [10-12], sensors [13,14], wound dressing [15,16] and as scaffolds in tissue engineering [17-21] and more recently as membranes in affinity separation [22]. In a lot of commercial air filtration applications, polymeric nanofiber has a large of potential value, because small fibers in the submicron range, compared with large ones, are well known to provide better filter efficiency at the same pressure drop in the interception and inertial impaction regimes [23]. Thus electrospun nanofibrous membranes possess several attractive attributes of separation, such as high porosity, pore sizes ranging from tens of nanometer to several micrometers, interconnected open pore structure, high permeability for gases and high surface area per unit volume. In particular, they have been highly successful in developing high-performance air filters. In fact, it was in air filters that electrospinning saw its first commercialized application [24, 25, and 26]. In this paper, PVA and PEO will be used to electrospinning and form membrane for air filtration applications. We try to compare the nanofibrous membranes with traditional filtration material and find their advantages. At the same time, we will compare performances of different nanofiber membranes and discuss the effect of nanofiber configuration for filtration performances. II. EXPERIMENTS A. Materials and Process PEO (Tianjin, Da Di Fine chemical Engineering Co., 300,000g/mol) was mixed with water and ethanol (V/V: 50%/50%) and its concentration was 19 wt%. The solution was prepared by stirring at room temperature for 25 minutes. A syringe pump was utilized to supply a constant flow of 100l/h polymer solution during electrospinning. The distance between needle and collector was 8cm. The voltage of 8 kV was applied to draw the nanofibers from the prepared solution. Figure 1 and Figure 2 show such process and related machines. Now, scanning electron micrographs (SEMS) are generally used to characterize electrospun nanofibers, so the configuration of PEO nanofibrous membrane can be seen with it as in figure 3. At the same time, we can get some important information of PEO nanofibrous membrane from Table . The average fiber diameter of PVA nanofibrous membrane is 200nm, and picture statistic calculation shows the detected pore size is 1~10m. The membrane thickness is 350m. Figure 1. Electrospinning process and related machines. Figure 2. Electrospinning process and related machines The subject is supported by National Science Foundation of China (Project code: 50675184), New Century Talent of Xiamen University. *Contact author: sundh@xmu.edu.cn The first two authors contribute equally. 1-4244-0608-0/07/$20.00 © 2007 IEEE. 1244 Proceedings of the 7th IEEE International Conference on Nanotechnology August 2 - 5, 2007, Hong Kong