title: Self-assembling semicrystalline polymer into highly ordered, microscopic concentric rings by evaporation.
abstract: A drop of semicrystalline polymer, poly(ethylene oxide) (PEO), solution was placed in a restricted geometry consisting of a sphere on a flat substrate (i.e., sphere-on-flat geometry). Upon solvent evaporation from the sphere-on-flat geometry, microscopic concentric rings of PEO with appropriate high molecular weight were produced via controlled, repetitive pinning ("stick") and depinning ("slip") cycles of the contact line. The evaporation-induced concentric rings of PEO exhibited a fibrillar-like surface morphology. Subsequent isothermal crystallization of rings at 40 and 58 degrees C led to the formation of multilayer of flat-on lamellae (i.e., spiral morphology). In between adjacent spirals, depletion zones were developed during crystallization, as revealed by AFM measurements. The present highly ordered, concentric PEO rings may serve as a platform to study cell adhesion and motility, neuron guidance, cell mechanotransduction, and other biological processes.
authors.affiliation: Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Myunghwan
authors.initials: M
authors.lastname: Byun
authors.forename: Suck Won
authors.initials: SW
authors.lastname: Hong
authors.forename: Lei
authors.initials: L
authors.lastname: Zhu
authors.forename: Zhiqun
authors.initials: Z
authors.lastname: Lin