Poly[bis(2,2,2-trifluoroethoxy)phosphazene] superhydrophobic nanofibers

Nanofibers of poly[bis(2,2,2-trifluoroethoxy)phosphazene] were produced by electrospinning from solutions in tetrahydrofuran, methylethyl ketone, and acetone. The fiber diameter varied from 80 nm to 1.4 microm by changes in the concentration of the polymer solution. The electrospun nonwoven mats showed enhanced surface hydrophobicity compared to spun cast films with up to a 55 degrees increase in water contact angle. The hydrophobicity varied with fiber diameter and surface morphology, with contact angles to water being in the range of 135 degrees -159 degrees. A low value of hysteresis (<4 degrees) was recorded for the superhydrophobic surfaces. The extremely high hydrophobicity of these mats is a combined result of a fluorinated surface and the inherent surface roughness of an electrospun mat.