Environmental scanning electron microscope imaging examples related to particle analysis

Area of Science:

• Materials Science
• Analytical Chemistry
• Environmental Science

Background:

• Conventional scanning electron microscopy (SEM) faces challenges imaging uncoated, easily charged, or volatile samples.
• Surface charging and vacuum incompatibility limit SEM analysis for many particle types.

Purpose of the Study:

• To demonstrate the imaging capabilities of environmental scanning electron microscopy (ESEM) for difficult-to-image samples.
• To showcase ESEM's application in particle analysis, overcoming conventional SEM limitations.

Main Methods:

• Utilized environmental scanning electron microscopy (low vacuum or high pressure SEM).
• Examined various uncoated and volatile samples, including fly ash, fibers, uranium oxide, and filter-collected particulate matter.
• Applied ESEM to samples like polystyrene latex spheres and etched nuclear track-etch detectors.

Main Results:

• ESEM successfully imaged samples problematic for conventional SEM, such as oiled membranes and loosely mounted spheres.
• Eliminated surface charging issues common in high vacuum SEM, enabling analysis of previously incompatible specimens.
• Provided clear images of fly ash, fibers, uranium oxide, and particulate matter on filters.

Conclusions:

• Environmental SEM significantly expands imaging possibilities for challenging particle analysis.
• ESEM is a valuable tool for studying uncoated, volatile, and easily charged materials.
• The technique overcomes key limitations of conventional SEM, offering broader applications in materials and environmental science.