Tunable wrinkle modes of core-shell polymer fibers in electrospinning

Wrinkled surfaces are commonly observed on ultrathin polymer fibers produced in electrospinning process. This paper is to formulate a continuum mechanics model to explore dependencies of surface wrinkling of electrospun core–shell polymer fibers enwrapped with hard cores upon the thickness and stiffness of the glassy shell and inner soft sol-gel layer. The study provides a rational basis of surface wrinkling in electrospun polymer fibers and the technical strategies to regulate the electrospinning process for producing ultrathin polymer fibers with tunable surface morphologies for broad applications (e.g., oil-water separation, tissue scaffolding, etc). (paper)