Evaluation of effective electrospinning parameters controlling polyvinylpyrrolidone nanofibers surface morphology via response surface methodology

Abstract

Electrospinning process is a very important technique for fabricating polymeric nanofibers by applying external electrostatic forces. This study reports on the modeling of the electrospinning process of polyvinylpyrrolidone (PVP), using response surface methodology (RSM) based on the central composite design (CCD). The individual and the interaction effects of the most effective variables such as PVP concentration (10, 14 and 18 wt%), applied voltage (13, 17 and 21 kV), nozzle-collector distance (10, 15 and 20 cm) and solvent type (N,N-dimethylformamide (DMF) and ethanol) on the average and coefficient of variation of the nanofiber diameter were investigated in the optimization section. The CCD analysis confirmed that solvent type and PVP concentration were the main significant variables affecting the average PVP nanofiber diameters. The predicted nanofiber diameters were in good agreement with the experimental results according to CCD technique. High regression coefficient between the variables and the mean diameter (R 2=0.9468) indicates excellent evaluation of experimental data by quadratic polynomial regression model. The RSM model predicted the 166 nm value of the finest nanofiber diameter with high uniformity at conditions of 13 wt% PVP concentration, 15 kV of the applied voltage, and 20 cm of nozzle-collector distance with used DMF for solvent in electrospinning process. The predicted value (166 nm) showed only 3.47 %, difference with experimental results in which 172 nm at the same setting were observed. The obtained CCD results confirmed that the selected RSM model presented appropriate performance for evaluating the involved variables and prediction of PVP nanofibers surface morphology.