1. School of Polymer, Textile and Fiber Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, U.S.A.
2. School of Polymer, Textile and Fiber Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, U.S.A.,
3. Department of Human Ecology, University of Texas at Austin, Austin, Texas 78712, USA
4. Department of Textile Fiber Engineering, Pusan National University, Busan, 609-735 Republic of Korea