Skip to main content
Critical Evaluation of Electron Microscopy of Ionomers
Macromolecules (1980)
  • William MacKnight, University of Massachusetts Amherst
Electron microscopy has been used to examine the morphology of four ionomers. The transfer
theory of imaging, which has been overlooked in previous ionomer studies, has been used to interpret the
images of both solvent-cast and microtomed thin films. Solvent casting was found to produce a number of
interesting artifacts but no useful information about ionic domains. Microtomed sections of a copolymer of
ethylene and methacrylic acid, sulfonated polypentenamer, and sulfonated polystyrene contained no preparative
artifacts but showed no distinct domain structure even in the ionomers neutralized with cesium, probably
because of film thickness problems. Microtomed sections of sulfonated EPDM, however, contain 300-nm
phase-separated regions. Osmium tetraoxide staining of these EPDM sections showed domains averaging
less than 3 nm in size primarily inside these regions. Unfortunately, the section thickness prohibits an accurate
determination of the size distribution or the detailed shape of these domains and hence the selection of the
most appropriate model of domain structure.
  • Critical Evaluation,
  • Electron,
  • Microscopy,
  • Ionomers
Publication Date
Citation Information
William MacKnight. "Critical Evaluation of Electron Microscopy of Ionomers" Macromolecules Iss. 14 (1980) p. 795 - 801
Available at: