**2.7. Ambient temperature and humidity**

High temperature and low humidity in the spinning area benefit the evaporation of solvent, and this is helpful to obtain smaller fiber diameters [45]. When the temperature is too high in solution electrospinning, the spinneret may easily be blocked because of fast evaporation. In melt electrospinning, the high ambient temperature can keep the spinning jet in melt state for a long time, which increases the thinning time of the jet and is beneficial to smaller fiber production [46]. The electrospinning process can rarely be carried out when the humidity surpasses some value since a corona or breakdown may happen [47]. Obvious changes on the surface of the solution electrospun fiber have been observed when spinning temperatures and humidities change [45].
