Superhydrophobic EVA copolymer fibers: the impact of chemical composition on wettability and photophysical properties

Abstract

Fibers of poly(vinyl acetate) (PVAc) homopolymer and ethylene vinyl acetate (EVA) copolymers with varying vinyl acetate (VAc) contents between 25 and 40 wt.% have been prepared to investigate wettability and photophysical properties. At lower VAc contents, it was difficult to prepare fibers without any beads due to the presence of crystalline ethylene groups at higher concentrations. EVA copolymer composition strongly affected the wettability of fibers; all EVA copolymer fibers exhibited superhydrophobic behavior and CA values varied between 150° and 160° depending on copolymer composition while hydrophilic PVAc homopolymer fibers exhibited hydrophobic behavior with a CA of 134°. Photophysical properties of PVAc homopolymer and EVA copolymers were evaluated in terms of transmittance and emission intensity. Emission intensity and transparency of EVA copolymers were decreased with the increase of VAc contents due to its amorphous behavior.