A novel multinozzle electrospinning process for preparing superhydrophobic PS films with controllable bead-on-string/microfiber morphology

Superhydrophobic polystyrene (PS) surfaces with mechanical integrity were manufactured by electrospinning in this work. We first report a novel strategy here to combine bead-on-string fibers from 4% PS solution and micro-sized fibers from 20% PS solution homogeneously in one electrospinning step by multinozzle electrospinning. The superhydrophobicity of electrospun sheet can be achieved by the presence of bead-on-string fibers, while micro-sized PS fibers are responsible for the improvement of mechanical property of electrospun mat due to their elastic and flexible behavior. The distinctive design of our multinozzle electrospinning setup places two nozzles in separate electrical fields which guarantee that fibers with different structures are mixed homogeneously. We investigate the relationship between the mass ratio of fibers from two types of solutions and the CA of electrospun mat, the effect of mass ratio to the mechanical property of electrospun mat can also be observed. The result shows that CA value of PS surface merely comprised of bead-on-string fibers could reach up to 154.65 degrees. As the content of microfibers increased, the value of CA decreased, ranging from 153.66 degrees to 145.94 degrees, but the tensile strength of composite mat was enhanced from 0.50 MPa to 1.22 MPa correspondingly which is beneficial to put the mats into practice. (C) 2010 Elsevier Inc. All rights reserved.