Comparison of the Effects of an Ionic Liquid and Triethylbenzylammonium Chloride on the Properties of Electrospun Fibers, 1 – Poly(lactic acid) Jeong Moon Seo, Ganesh Kumar Arumugam, * Sourabh Khan, Patricia A. Heiden * Introduction The electrospinning process has been known since at least the 1920s, when a patent, [1] initially dated 1930, claimed ‘‘to make use of the action of an electrical field on liquids which contain solid materials dissolved in them with a view to forming threads for the production of silk-like spun fibers.’’ It was of little interest for decades, and a keyword search of the literature using the term ‘‘electro- spinning’’ found only 22 hits from 1980 through 1999. Since 2000, research on electrospinning of nanofibers has increased significantly, as have all areas related to nanotechnology. Nanofibers are of potential value to any field that can benefit from the high surface area to volume ratio they offer, for example, filtration, [2–4] catalysis and aerosol barriers, [5] scaffolding, [6,7] sensors, [8,9] etc. The rapid rise in publications in this area is attributable to the growth of nanotechnology in general and to the simple electrospinning set-ups described by Reneker [10–12] and Shin et al., [13–16] who authored many of the early publications in this area, making it easy for other researchers to enter this field. Electrospinning has 2 stages: formation of the Taylor cone, and the ejection and thinning of a fluid jet, though the final fiber diameter and morphology can also be affected by the drying process. The electrospinning process begins as an electric charge is applied to a fluid as it is Full Paper J. M. Seo Department of Chemical Engineering Michigan Technological University, Houghton, Michigan, 49931, USA G. K. Arumugam, S. Khan, P. A. Heiden Department of Chemistry, Michigan Technological University, Houghton, Michigan, 49931, USA Fax.: þ1 906 487 2061; E-mail: paheiden@mtu.edu, garumuga@mtu.edu S. Khan Indian Institute of Technology, Kharagpur – 721 302, India Improving the conductivity of electrospinning solutions is often achieved by adding small amounts of conductive additives. HMIMCl, a room temperature ionic liquid, and TEBAC, a quaternary ammonium salt, were added to polylactic acid in chloroform and their effects on solution properties, electrospinning, and fiber properties were investigated. Both additives increased the conductivity which decreased the fiber diameter, but differences were observed on the fiber dispersity and fiber morphology. The conductive solutions caused fiber backbuilding with aggregation and fiber fusion. Reasons for the differences in fiber diameter and fiber morphology are discussed. Macromol. Mater. Eng. 2009, 294, 35–44 ß 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim DOI: 10.1002/mame.200800198 35