Response Surface Modeling and Optimization of Electrospun Nanofiber Membranes

The experimental design and response surface methodology (RSM) have been used to develop predictive models for simulation and optimization of electrospun polyvinylidene fluoride non-woven membranes. The objective is to prepare electrospun fibers with small diameters and narrow diameter distribution. The factors considered for experimental design were the polymer dope solution flow rate, the applied electric voltage and the distance between the needle tip and the collector. A full factorial design was considered. The obtained electrospun fibers were characterized by scanning electron microscopy. The response for the model was the quality loss function that takes into account the quadratic effects of both the weighted arithmetic mean of the fibers diameter and the standard deviation. Minimal output response has been predicted and confirmed experimentally. The optimum operating conditions guarantying a small polyvinylidene fluoride nanofiber diameter with a narrow distribution were a voltage of 24.1 kV, an air gap of 27.7 cm and a polymer flow rate of 1.23 mL/h. The fabricated optimum membrane was characterized by different techniques and applied for desalination by membrane distillation. The obtained permeate fluxes in this study are higher than those reported so far for electrospun nanofibrous membranes.