A simple approach to electrospinning has been developed that enables the collection of polymer, ceramic, and multiphase composite fibers, in quantity, with a high degree of spatial orientation. It has been demonstrated that a careful choice of solvent effectively eliminates the onset of the characteristic "bending" instability that is commonly associated with the electrospinning process. This allows collection of spatially oriented submicron electrospun fibers on a rotating drum without the need for elaborate mechanical or electrostatic manipulation of the electrospinning jet and/or collection target. Fibers have been electrospun from a series of model polyethylene oxide/CHCL3 solutions with a range of conductivities. The experimental data confirms theoretical predictions that the onset of the bending instability is a function of the available "free" charge in the solution, which in turn is strongly influenced by the dielectric constant of the solvent. The results show that fiber orientation becomes random as the conductivity increases, indicating the need for the surface charge density to exceed a critical threshold in order for the bending instability to initiate. Furthermore, it has been demonstrated that fiber diameter can be effectively controlled by controlling drum take-up speed. This method has been experimentally demonstrated with other low dielectric constant solvents and other common polymer, ceramic, composite materials.
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