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Coaxial electrospun encapsulation of epoxy for use in self-healing materials


Correspondence to: Michael W Keller, Department of Mechanical Engineering, University of Tulsa, Tulsa, OK, USA. E-mail:


Epoxy was sequestered within a poly(vinyl alcohol) (PVA) shell using a coaxial electrospinning process resulting in fibers suitable for use in self-healing materials. Electrospinning equipment was designed and built including extensive development of the coaxial spinneret and optimization of the electrical field. Other parameters that were studied and controlled included the viscosity of the shell material and the interfacial tension between the shell and core material. The interfacial tension between the PVA solution and the epoxy was controlled by adding ethanol to the water solvent. A concentration of 8.5 wt% PVA in a combined ethanol and water solution (water:EtOH = 1:0.15) yielded a PVA solution that had interfacial tension and viscosity characteristics that were effective for coaxial electrospinning. The resulting coaxially electrospun fibers assumed a beaded fiber morphology. © 2012 Society of Chemical Industry