Formation of fibers and spheres by electrospinning of polyethylene oxide solution

Scope and method of study. An experimental process for obtaining fibers and spheres using electrospinning of a polymer (Polyethylene Oxide) solution in water were studied. The objectives of the study were to complete measurements of size of the generated fibers and spheres to develop phenomenological analyses to help interpret and correlate the measurements of the instability growth on the electrospun micro liquid (polymeric solution) jets. Digital holographic microscopy was used to observe the trajectory of the electrospun jet and the growth of instability on the electrospun micro polymeric jet. The morphology of the fibers deposited on the collector electrode was observed using SEM imaging. The conditions for formation of beaded fibers were studied. The sphere formation mechanism was observed for different parameters including polymer concentration, applied voltage, and needle to electrode distance.;Findings and conclusions. Observations of electrospinning of aqueous solutions of PEO at different concentrations yielded the following major conclusions: (1) As the concentration of the solution decreases, beaded fibers are formed. Further reduction in the concentration results in the generation of beads with spindle-like structures. This could possibly be attributed to the decrease in the viscosity of the polymer solution, and hence a decrease in the damping of the axis-symmetric disturbances along the jet surface. (2) Increasing the applied voltage and the traveling distance favors the formation of sphere-like structures with short tails. (3) Spheres of PEO were observed for the following test conditions: applied voltage = 30kV, gap = 0.23m and initial polymer concentration of 0.25% by weight.