Fabricaiton of Hierarchically Structured Helical Micro/Nanofibrous Nonwovens and Its Mechanism Study

Electrospinning and melt blowing are the most commonly used technologies to produce micro/nanofibrous nonwovens. Helical fibers resembling plant tendrils in micro/nanoscale have been of increasing interest because of their unique characteristics. The introduction of helical structures into the micro/nanofibrous nonwovens finds potential applications in fields such as micro/nanoscale sensors, filtration materials, and oil sorbents. The three-dimensional structure of the helical fibers can provide the nonwovens larger specific surface area, larger porosity, and better mechanical properties in terms of resiliency and flexibility. In this study, we report the fabrication of micro/nanoscale helical fibers by electrospinning and melt blowing. Two kinds of polymer, an elastomeric component and a rigid component, are combined in the electrospinning and melt-blowing processes to produce helical fibers. A Core-shell spinneret is used in electrospinning. While during melt blowing, a swirl-die is adopted. Due to the different shrinkages displayed by the two components, helical fibers with three-dimensional spiral shape are formed after electrospinning and melt blowing. This work can provide a promising technique for producing micro/nanofibrous materials with helical fiber morphology.