Electrospinning silica/polyvinylpyrrolidone composite nanofibers

Small diameter nanofibers of silica and silica/polymer are produced by electrospinning silica/polyvinylpyrrolidone (SiO₂/PVP) mixtures composed of silica nanoparticles dispersed in polyvinylpyrrolidone solutions. By controlling various parameters, 380 ± 100 nm diameter composite nanofibers were obtained with a high silica concentration (57.14%). When the polymer concentration was low, “beads‐on‐a‐string” morphology resulted. Nanofiber morphology was affected by applied voltage and relative humidity. Tip‐to‐collector distance did not affect the nanofiber diameter or morphology, but it did affect the area and thickness of the mat. Heat treatment of the composite nanofibers at 200°C crosslinked the polymer yielding solvent‐resistant composite nanofibers, while heating at 465°C calcined and selectively removed the polymer from the composite. Crosslinking did not change the nanofiber diameter, while calcined nanofibers decreased in diameter (300 ± 90 nm) and increased in surface area to volume ratio. Nanofibers were characterized by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40966.