Polymer Science Faculty Research


Inside Nanofibers: Molecular Scale Images and Electron Beam Induced Changes

Document Type

Conference Proceeding

Publication Date

Spring 3-16-2014


Electron micrograph images of CF2 groups, in electrospun nanofibers of polyvinylidene fluoride, appeared as rows of dots, separated by about 0.24 nanometers, along segments of molecules. The dots arise from the three times greater electron density of the CF2 groups than the CH2 groups. The polymer nanofibers contained crystals with the polymer chains aligned predominately along the axis of the fiber. A significant degree of long-range translational symmetry was maintained by extended segments of the polymer molecules. The molecules in the fibers contained a variety of non-planar zigzag conformations. A cross section of a nanofiber typically contained one or more crystals, each with its own polarization direction. The observed segments were comparable in scale with those considered in molecular dynamics calculations and crystal defect models.

Publication Title

Abstracts of Papers of the American Chemical Society