Tailoring the morphologies of PVDF nanofibers by interfacial diffusion during coaxial electrospinning

• Cross-section morphology of NFs are tailored by controlling Interfacial diffusion during coaxial electrospinning.
• Interfacial diffusion are regulated by the miscibility and the viscosity difference between the inner /outer solutions
• NFs with cross-section structures from the net-like to the hollow are prepared
• NFs have a high surface area, 40m2/g, showing a great potential for various applications.

The morphology regulation of nanofiber (NF) plays an important role in its applications. In the present study, a simple method to tailor the cross-section morphology of polyvinylidene fluoride (PVDF) NFs by controlling the interfacial diffusion during coaxial electrospinning is presented. By choosing a soft bad-solvent of PVDF to prepare a partially miscible inner solution, the regulation of the interfacial diffusion can be simplified into the adjustment of the viscosity difference between the inner and outer solutions. When the viscosity of the inner solution surpassed that of the outer solution, the diffusion direction changed from outer-to-inner to inner-to-outer, which leaded to the change in the cross-section morphology of resultant NFs from a net-like to a hollow structure. Water contact angle also showed the effect caused by the interfacial diffusion. BET surface area of the as-prepared porous PVDF NFs can reach up to 42 m2/g, which is almost the highest data ever reported in the literature for polymer nanofiber.

The cross-section morphologies of polyvinylidene fluoride (PVDF) nanofibers (NFs) are tailored by controlling the interfacial diffusion between the inner and outer solutions during coaxial electrospinning. The direction and strength of the interfacial diffusion can be adjusted by miscibility and viscosity difference of the two solutions. Finally the resultant NFs with cross-section morphologies from a net-like to a hollow structure are obtained. BET surface area of PVDF NF can reach up to 42 m2/g, which is almost the highest ever reported in the literature for polymer nanofiber.Figure optionsDownload as PowerPoint slide