화학공학소재연구정보센터
Journal of Applied Polymer Science, Vol.125, No.4, 2585-2594, 2012
The effect of solvent dielectric properties on the collection of oriented electrospun fibers
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 (Deitzel, J. M.; Kleinmeyer, J. D. et al. Polymer 2001, 42, 8163, Zussman, E.; Theron, A.; et al. Appl Phys Lett 2003, 82, 973, and Li, D. Wang, Y. L.; et al. Nano Lett 2003, 3, 1167). 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. This method has been experimentally demonstrated with other low-dielectric constant solvents and other common polymer, ceramic, and composite materials. Furthermore, it has been demonstrated that fibers electrospun from these solutions can be mechanically drawn to submicron dimensions (similar to 200500 nm) by controlling drum speed. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012