Control of governing parameters in electrospinning process

© 2009 Nova Science Publishers, Inc. In this contribution, response surface methodology (RSM) was employed to investigate the simultaneous effects of four of the most important parameters, namely solution concentration (C), spinning distance (d), applied voltage (V) and volume flow rate (Q) on mean fiber diameter (MFD) as well as standard deviation of fiber diameter (StdFD) in electrospinning of polyvinyl alcohol (PVA) nanofibers. Q 2, CQ, dQ, and VQ in the model of MFD and d 2, Cd, and dV in the model of StdFD were found to be statistically insignificant in representing the response and were eliminated from the corresponding models. R 2 adj was found to be 95.08% and 88.25% for the new MFD and StdFD models respectively. The generalization ability of the models to predict new conditions were also evaluated using the test set. Root mean square errors (RMSE) for experimental set and test set were calculated as 7.489 and 10.647 for MFD and as 2.493 and 2.890 for StdFD respectively showing the good prediction ability of the models. Finally, the response surfaces of MFD and StdFD were plotted under different conditions and the effects of parameters were qualitatively studied. MFD increased monotonically with C and this effect was slightly influenced by d and V. By contrast, increasing the applied voltage resulted in a preliminary increase followed by a decreasing trend for MFD. The impact of V on MFD was affected dramatically by d and slightly by C. d was found to alter the MFD differently according to V and C. Increasing Q favored the formation of fibers with higher MFD regardless of the other parameters. More uniform fibers (lower StdFD) were obtained at lower C, lower V, and longer d. Q was found to have an optimum value in order to form uniform fibers (low StdFD). The optimum Q was affected by the other variables.