A Scaling Model for Predicting the Gas-Channel Formation Period in Crater-Like Electrospinning of Nanofibers

Crater-like electrospinning is a novel and cost-effective method for the mass scale production of nanofibers. The gas channel in the polymer solution plays a key role to produce a bubble Taylor cone or a crater-like Taylor cone, which is the key to eject the thin fluid jets (finally solidified into nanofibers) in electrospinning process. However, the formation mechanism of gas channel of crater-like Taylor cone is still unclear, which hinders further development of this process. In this work, a simple and effective scaling model was firstly established to predict the period of the gas-channel formation in the polymer solution during electrospinning process. Our theoretical analysis showed that the gas-channel formation period was mainly determined by the input air pressure during the process. The relationship between the formation period and the input air pressure followed a scaling law. In order to verify the model, crater-like electrospinning process was carried out and a high-speed digital camera was employed to observe the gas channel. The experimental results agree well with the scaling model, which indicates that the proposed system is feasible. The scaling model could be useful in helping us to understand the process.