Poly(vinylidene fluoride)/silica nanocomposite membranes by electrospinning

Poly(vinylidene fluoride) (PVDF)/silica nanocomposite membranes containing up to 30% silica were prepared by electrospinning using colloidal silica as the source of silica and dimethyl formamide as the solvent. The fiber morphology was observed by field emission scanning electron microscopy. The average fiber diameter is about 0.3 m for PVDF/silica composite fibers having 1030% silica. Silica nanoparticles were observed on all fiber surfaces with fairly good dispersion and distribution. Fourier transform infrared spectroscopy and differential scanning calorimeter were used to investigate the crystallization behavior of PVDF and showed that a mixture of -, -, and -phase crystals was obtained with little content of phase and all the PVDF/silica composite membranes have similar degree of crystallinity. Static water contact angle measurements were performed to investigate the surface wettability of the membranes. The mechanical properties were evaluated by tensile tests, showing strong reinforcement effect. The tensile modulus and tensile strength increase significantly when silica is present. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013