Development of Image Analysis Techniques for Epoxy Fillers

Peter Montoya, Cory Gibson, Caitlin Taylor, Sarah House, Brittany Muntifering

Sandia National Laboratories

Fillers are often incorporated into epoxies to change various material properties. In this work, we focus on glass micro-balloons (GMBs), which are hollow glass spheres filled with gas. Optical microscopy and Scanning Electron Microscopy (SEM) were utilized to image the size distribution and wall thicknesses of GMBs both as-received and already embedded in an epoxy. As-received GMBs were imaged by sprinkling onto carbon tape. GMBs already embedded in epoxy were measured by cross-sectioning and polishing a piece of epoxy. The areal density was also quantified in the GMB filled epoxy. Various image analysis techniques were explored for rapid quantification of the size distribution using both image sets. Size distributions from the as-received and embedded GMBs were compared to each other and to the manufacturer values. Energy Dispersive X-ray Spectroscopy (EDS) was utilized to confirm the GMB composition. SEM was found to produce higher-contrast images than optical microscopy in all cases. Wall thicknesses could only be accurately measured in cross-sectional SEM and could not be resolved using optical microscopy.

Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.