Associate Professor, North Carolina State University, Fiber and Polymer Science Program
Dr. Russell E. Gorga is Associate Professor and former Program Director in Textile Engineering at NC State University and a member of the graduate faculty in the Fiber and Polymer Science program. He has affiliate appointments in both Materials Science and Engineering and Biomedical Engineering. Russell is currently involved in creating composite nanofibers that can be used for applications such as tissue scaffolds (for regenerative medicine), antimicrobial fabrics, and strain sensing applications. His research interests include nanoparticle/polymer composites, melt spinning and extrusion, scale-up electrospinning, and interfacial properties between polymers and particles. In 2010, Russell received the "Professional Progress in Engineering Award" from the College of Engineering at Iowa State University. In 2007, Russell received the NC State University "Outstanding Teacher Award" and was inducted into the Academy of Outstanding Teachers. Before coming to NC State, Russell was a post-doctoral associate at MIT where he worked on improving the strength of brittle polymers using carbon nanotubes. Earlier, Russell worked as a research engineer at Union Carbide Corporation (where he received the Special Recognition Award) from 1997 through 2000, where he focused on structure-property relationships of semi-crystalline polymers for high strength commodity applications. Russell received his Ph.D. in Chemical Engineering from Iowa State University (2002) where his doctoral work focused on developing relationships between molecular-micro-macro properties of polymer-polymer interfaces. Specifically, interfacial strength was mechanistically related to miscibility and mobility characteristics of the polymer constituents. He received a Master of Science in Chemical Engineering from Rutgers University (1997) and a Bachelor of Science in Materials Engineering from Drexel University (1994).
Abstract: 1) The properties of layers containing nanofibers is very well known and their combination is in recent years applied. The problem of this combination consists in dramatic decreasing of productivity with decreasing fiber diameter. The meltblown technology is able produced fibers with diameter under 1 _m, typically about 800 nm. By this technique is possible to produce nanofibrous layers in industrial scale. Disadvantage of this technology is relatively low variety of meltable polymers. The main conditions are very low melt flow index, which is ensured by a lower molecular weight and suitable rheological properties of polymer.
2) The studies have shown that for a significant improvement of properties the layers can contains less than 10 % of nanofibers. This can be explained by very high specific surface. Also pores can be filled with thin nanofibers what is lead to lower pore size, but porosity is practically same. It leads to very high breathability.
3) The presentation is focused on possibilities of fiber layer production, which combines microfibers with nanofibers in smaller scale, but with higher mutual ratio of micro and nanofibers. A technical solution of this device will be shown. The device is based on electrospinning process and it can increase a ratio of nanofibers in a production of materials containing micro and nanofibers. The said needless electrospinning uses only one electrode. Productivity of this device is more than ten times higher compare to a roller spinning. Another advantage consists in a possibility to form the nanofibers by air flow. A produced layer can create for example parallely oriented fibers or bulky structures.