Recently, the field of nanoscience and nanotechnology has provided a driving force in the
development of various high-resolution microscopy techniques in order to learn more about
nanomaterials using a beam of highly energetic electrons to probe objects on a very fine scale [145–147].
Among various electron microscopy techniques, SEM is a surface imaging method, fully capable of resolving different particle sizes, size distributions, nanomaterial shapes, and the surface morphology of the synthesized particles at the micro and nanoscales [10,117,137,148,149]. Using SEM, we can probeInt. J. Mol. Sci. 2016, 17, 1534 7 of 34 the morphology of particles and derive a histogram from the images by either by measuring and counting the particles manually, or by using specific software . The combination of SEM with energy-dispersive X-ray spectroscopy (EDX) can be used to examine silver powder morphology and also conduct chemical composition analysis. The limitation of SEM is that it is not able to resolve the internal structure, but it can provide valuable information regarding the purity and the degree of particle aggregation. The modern high-resolution SEM is able to identify the morphology of nanoparticles below the level of 10 nm.