2.4. Characterization of the sheets
2.4.1. Scanning electron microscopy (SEM)
Images of sample surfaces and fractures were obtained
using a Philips XL-30 scanning electron microscope (USA)
for morphological analysis of the sheets. The samples were
coated with a
fine gold layer using a sputter coater model SCD 050 (BAL-TEC, USA) before obtaining the micrographs.