Highly porous fibers prepared by centrifugal spinning

Ethyl cellulose (EC)/polyvinyl pyrrolidone (PVP) fibers with micro-and nano-porous throughout structures are fabricated by centrifugal spinning a binary solvent system of ethanol and water. A combination of different parameters including EC/PVP ratios, ethanol/water ratios and rheological properties are investigated to demonstrate pore formation. The specific surface area of EC/PVP fibers increases more than 11 times when the binary solvent contains 30% water. However, fibers with porous structure cannot be obtained in electrospinning process under the same solution and ambient conditions. The result indicates that the spinning method greatly influences the diameter and solvent evaporation of the jets, and as a consequence, fiber morphology varies in the two spinning processes. (C) 2016 Elsevier Ltd. All rights reserved.