Theoretical Considerations in Electrospinning

In the electrospinning process, the inner diameter of the needle also has some effects. Decreasing the inner diameter can cause an observable decrease in clogging, the number of beads, and the final fiber diameter. 

The decrease in the inner diameter creates an increase in the surface tension of the drops on the tip of the needle or pipette, which means that a greater amount of electrostatic force is needed to start the formation of a jet. If no voltage changes occur in the process, 

The electrical potential causes the deformation of the fluid drop, and when the applied voltage develops enough force and balances with the fluid surface tension of the polymer solution, the drop is deformed under a cone shape with a semivertical angle of 30°. Beyond this critical value (Rayleigh limit], the electrostatic forces generated by the charge carriers overcome the surface tension and the deformed droplet undergoes a transition zone just before the fiber jet is initiated to the collector screen. By this way, fluid is 

The electrical instability in the electrospinning process was compared to aerodynamic instabilities where partial differential equations of the aerodynamics of the fluid jet with electric field equations are used to describe the process. Many theoretical models have been used to describe the combination of a viscoelastic fluid driven by an electrical field. On the basis of Taylor studies and with the use of high-velocity cameras, it was proposed that the electrospinning 

For many applications a precise diameter control is required. Fiber dimensions and morphology depend strongly on process parameters such as pol5mier properties molar mass, molar mass distribution, glass transition temperature, and solubility solution properties such as viscosity, viscoelasticity, dielectric constant, concentration, surface tension, electrical conductivity, and vapor pressure and ambient conditions such as humidity and temperature. 

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