Langmuir 2005, 21, 5549-5554
5549
Electrospun Poly(Styrene-block-dimethylsiloxane) Block Copolymer Fibers Exhibiting Superhydrophobicity Minglin Ma,† Randal M. Hill,‡ Joseph L. Lowery,† Sergey V. Fridrikh,† and Gregory C. Rutledge*,† Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 01239, and Dow Corning Corporation, Midland, Michigan 48686 Received November 30, 2004. In Final Form: March 9, 2005 Block copolymer poly(styrene-b-dimethylsiloxane) fibers with submicrometer diameters in the range 150-400 nm were produced by electrospinning from solution in tetrahydrofuran and dimethylformamide. Contact angle measurements indicate that the nonwoven fibrous mats are superhydrophobic, with a contact angle of 163° and contact angle hysteresis of 15°. The superhydrophobicity is attributed to the combined effects of surface enrichment in siloxane as revealed by X-ray photoelectron spectroscopy and surface roughness of the electrospun mat itself. Additionally, the fibers are shown by transmission electron microscopy to exhibit microphase-separated internal structures. Calorimetric studies confirm the strong segregation between the polystyrene and poly(dimethylsiloxane) blocks.
Introduction Electrospinning is a versatile method to produce polymer fibers with diameters in the micrometer, submicrometer, and nanometer (
