Benjamin Hsiao, Stony Brook University
New Horizon of Nanofiber Technology for Environmental Applications
In recent years, there has been an explosive growth of research activities to explore the development of nanofiber technology by electro-spinning and the applications of electro-spun nanofibers. The majority of current electrospinning related studies are concerned with the generation of new nano-structured materials and their applications, encompassing biological membranes (substrates for tissue regeneration, immobilized enzymes and catalyst systems, wound dressing articles, artificial blood vessels and materials for the prevention of post-operative induced adhesions), aerosol filters and clothing membranes for protection against environmental elements, optical and chemical sensors and electrical conductors.
Recently, nanofibrous materials have been made more readily available in large part due to advances in electro-spinning and related technologies, including the use of a combination of electrostatic and gas-blowing forces [1]. The non-woven structure has unique features, including interconnected pores, very large surface-to-volume ratio, and ease of surface modifications which enable such scaffolds to have many biomedical and industrial applications. The chemical composition of electrospun membranes can be adjusted by using different polymers, polymer blends or nanocomposites, made of organic or inorganic materials.
In this talk, we will focus on the use of nanofibers for environmental applications, particularly for water purification [2-4]. The major innovation of our nanofiber technology is that membranes made of polymer-based nanofiber materials have drastically improved flux capacities (e.g. by 3-10X increase) but retain their resistance to fouling. Better flux means less time to filter the same amount of water, which in turn increases energy and cost efficiency. Better resistance to fouling refers to the ability to avoid clogging of the membrane pores by foreign matter, such as oil, detergents, biomacromolecules and salts that can accumulate during the purification process and block a membrane’s effectiveness. The fouling resistance of our filters can be comparable to that of the best-known commercial filters.
* A joint project with Prof. Benjamin Chu
1. Christian Burger, Benjamin S. Hsiao and Benjamin Chu, “Nanofibrous Materials and Their Applications”, Annual Review of Materials Research, 36, 333–68 (2006).
2. Xuefen Wang, Xuming Chen, Kyunghwan Yoon, Dufei Fang, Benjamin S. Hsiao and Benjamin Chu, “High Flux Ultrafiltration Media Based on Nanofibrous Substrate with Hydrophilic Nanocomposite Coating”, Environmental Science and Technology, 39(19), 7684-7691 (2005).
3. Kyunghwan Yoon, Xuefen Wang, Dufei Fang, Benjamin S. Hsiao and Benjamin Chu, “High Flux Ultrafiltration Membranes Based on Electrospun Nanofibrous Scaffolds”, Polymer, 47, 2434–2441 (2006).
4. Xuefen Wang, Dufei Fang, Kyunghwan Yoon, Benjamin S. Hsiao and Benjamin Chu, “High Flux Ultrafiltration Membranes Based on Poly(vinyl alcohol) Electrospun Scaffold and Poly(vinyl alcohol) Hydrogel Coating”, J. Membrane Sci., 278, 261-268 (2006).