The Effects of Operating Parameters on The Morphology of Electrospun Polyvinyl alcohol Nanofibres

In this research, the preparation of PVA membranes by electrospinning was studied. The influence of processing parameters, i.e., applied voltage, flow rate and spinneret-to-collector distance was investigated. More comprehensive characterizations of the nanofiber membranes, including fiber diameter, by statistical determination from (SEM) images. PVA was dissolved in distilled water at concentration (10% wt). The polymer solution was electrospun under processing conditions i.e., an applied voltage of (5,10,15,20,25) KV, a needle tip- collector distance of (4,8,12,15,20,22) cm, and a flow rate of (0.2,0.5,0.8,1,10) mL/hr, ,using orifice size of spinneret is (0.6 mm), stationary substrate set-up, aluminum collector .When the high voltage is increased with constant other parameters, the electrostatic force will increase until the polymer surface tension is overcome, allowing a charged jet of polymer to escape from the tip of needle and travel to the collector. The best applied voltage obtained is (25 KV).When the flow rate is increased with keeping other parameters constant, more polymer solution is ejected. Increasing the flow rate too high, more smooth flattened fibers and merged. In accordance with obtained results, the optimum solution flow rates were obtained to be (0.2ml/h) and (0.5ml/h).The effect of needle tip-collector distance, was studied by a series of experiments were carried out with constant other parameters. Shows that average fiber diameter have a slight decrease trend from (857 nm) at distances of (4cm) to (600nm) at distance of (22cm). Possibly the larger distances increase flight time of the jet, stretching of the solution so the solvent had time to evaporate completely.