Energy Filtered TEM and Helium Ion Microscopy As Tools for Membrane Research

We explore the potential of  energy filtered transmission electron microscopy (Zeiss Libra 120) and helium ion microscopy (Zeiss Orion) in studying various polymer films and membranes. The energy filtered TEM including low eV imaging and standard three-window elemental mapping are coupled with electron energy loss spectroscopy, energy dispersive spectroscopy, and ultramicrotoming to provide structural information with high spatial and energy resolution including high resolution fluorine maps, sulfur maps, oxygen maps, carbon maps, and nitrogen maps in polymer films and mebranes. Helium ion microscope may be an ideal tool for membrane studies because of its high surface-specific and elemental-specific contrast as well as extraordinary depth of view compared to electron microscopes. Helium ions are considerablely less massive than gallium ions so that their damage to polymer films and mebranes are small. On the other hand, they are much more heavier than electrons, which means the helium ion microscopy is relatively free of diffraction effect and could provide unparalleled resolutions for polymer films and membranes without complicated sample preparation.