Optimizing the structural properties of electrospun polyimide membranes by response surface method

Recently, there has been a rising tendency for the fabrication of membranes using the electrospinning method because it can control the properties of the fibrous mats by changing the parameters of the process. For this reason, in the current research, polyimide (PI) membranes were fabricated by the electrospinning method. The effect of electrospinning parameters on the content of porosity and tensile properties of the electrospun PI mats were investigated. Solution concentration, device voltage, and feed rate were considered the process parameters. Response surface methodology was adopted to design the electrospinning experiments. The results showed that the feed rate had the most contribution to the content of porosity of electrospun PI membranes which increased by decreasing the feed rate. On the other hand, the polymer concentration had a remarkable effect on the tensile strength. Indeed, the tensile strength improved as the solution concentration increased. The optimized electrospinning parameters to achieve both the highest porosity (97.66%) and the highest tensile strength (2.25 MPa) in the PI membrane were as follows: solution concentration 16.78%wt, device voltage 17 kV, and feed rate 1.4 mL h⁻¹. The experimental results were in good agreement with the predicted values.