Post-maceration
On the last day of processing, samples were quickly washed twice in
deionized water. Then, they were post-fixed in 2% OsO4in deionized water for 2 hours at 4 °C. After fixing, the samples were
dehydrated in an increasing ethanol series (70%, 80%, 90%, 95%),
with baths lasting 15 minutes each and, finally, absolute ethanol 4
times, also for 15 minutes each.
After dehydration, samples were taken to the Balzers CPD-030 critical
point apparatus using liquid CO2, where the material
remained in a dark container with silica gel to be kept dehydrated. With
the samples ready, the blocks were assembled. For this, a magnifying
glass fracture plane was established, with the material being positioned
on top of a drop of enamel at the base.
Finally, the sample was metallized with gold ions and analyzed using a
Jeol JSM-7401F 5V Scanning Electron Microscope. The importance of
coating the samples with metallic ions, such as gold, is emphasized
here, since it allows and/or improves the produced images. In addition,
by creating a conductive metallic layer on the sample, there is a
decrease in thermal damage, as well as an improvement in the electron
signals necessary for the topographic examination in the
SEM.13