The Effect of Solvent and Molecular Weight on the Morphology of Centrifugally Spun Poly(vinylpyrrolidone) Nanofibers

Abstract

Poly(vinylpyrrolidone) (PVP) nanofibers were prepared by a centrifugal spinning technique, namely Forcespinning®. The effect of the molecular weight of PVP and selected solvents (N,N-dimethylformamide, DMF) and water) were studied in reference to the ultimate morphology of the developed nanofibers. For the analyzed molecular weights and selected solvents, long, continuous and bead-free nanofibers were obtained as depicted by scanning electron microscopy analysis. It was observed that the molecular weight and solvent selection did have an effect on ultimate fiber diameter. The smallest fiber diameters (27 nm for Mw 1,300,000 and 58 nm for Mw 360,000) were obtained from samples prepared with DMF as solvent. As for the influence of molecular weights, results revealed that solutions prepared with PVP of Mw 360,000 in both solvents resulted in thicker diameter compared to PVP of Mw 1,300,000 though samples prepared with this higher molecular weight presented a much larger standard deviation. Fibers obtained from PVP solutions (Mw 1,300,000) in DMF exhibited a highly homogenous porous surface while those prepared from aqueous solutions showed smooth fiber surface.