Fiber diameter in electrospinning process

In order to increase the control on the fiber diameter we propose in this paper a methodology to determine stability domains of the process in which the electrospun fiber diameter can be predetermined and also controlled by means of the polymer solution flow and the applied voltage. To define these stability domains we employ a combination of analytical expressions depending on the location along the traveling jet. In the vicinity of the nozzle we employ the expression which links the fiber diameter with the kinematic viscosity of the polymer solution, nozzle-collector distance, solution density, liquid flow, electric current and intensity of the electrostatic field. At larger distances from the nozzle, the fiber diameter can be expressed as a function of solution density, liquid flow, intensity of the applied electrostatic field and distance from the nozzle. Close to the collector the fiber diameter can be expressed with respect to the superficial tension of the polymer solution, dielectric permittivity, liquid flow and intensity of the electric current. Under specific constrains, the superposition of the plots obtained from these mathematical expressions will be used to determine the stability domain for the fiber diameter in which the diameter can be controlled by two process parameters, namely applied voltage and polymer solution flow. Through this approach the present paper can contribute to increased control of the electrospinning process and thus enhanced applicability. (C) 2013 Elsevier B.V. All rights reserved.