Robust Superhydrophobic Mats based on Electrospun Crystalline Nanofibers Combined with a Silane Precursor

We demonstrate the fabrication of solvent-resistant, mechanically robust, superhydrophobic nanofibrous mats by electrospinning of poly(vinylidene fluoride) (PVDF) in the presence of inorganic silane materials. The solvent resistance and mechanical strength of nanofibrous mats were dramatically increased through the crystallization of as-spun PVDF fibers or incorporation of a tetraethyl orthosilicate (TEOS) sol into the nanofibrous matrix. The electrospun nanofibrous mats yielded a water contact angle of 156 degrees that did not vary with TEOS content. The solvent resistance and mechanical robustness of the electrospun mats were significantly enhanced through extensive cross-linking of TEOS, even after short PVDF annealing times. The interpenetrating polymer network, which embeds polymer chains in a TEOS network, allows the fabrication of robust functional nanofibers by combining semicrystalline polymers with electrospinning techniques.