flow was initiated fiber was deposited in a swath on the drum the number average fiber diameter of the fibers was measured to be 335 nanometers a 9 wt solution of polystyrene was dissolved in dichloromethane vapor pressure of 58 1 kpa at 25 u00b0 c at room temperature a magnetic stirrer was used to agitate the solution the homogeneous solution was transferred to a sealed glass container and transported to the spin chamber the solution was transferred into the reservoir of the spin chamber and sealed a spinneret with a 0 406 mm inside diameter single spinning nozzle was used a drum collector was used to collect the sample the spinneret was placed at a negative potential of 100 kv the collector was grounded the distance from the spinning nozzle exit to the collector surface was 114 cm air was used for the blowing gas air was used for the secondary gas to control the relative humidity and the temperature in the spin chamber the flow of air was sufficient to avoid the concentration of the solvent vapor in the spin chamber exceeding the lower explosion limit the relative humidity was controlled to be less than 11 the spin chamber temperature was close to 37 u00b0 c for the duration of the experiment a nitrogen pressure of 0 77 mpa was used to maintain a solution flow rate of 57 1 ml min hole.