Category: Electron Optics Facility Featured

S-TEM Tomography Video

Screenshot of particles in a box with 500 nm scale bar
S-TEM Tomography of Li-ion Battery Cathode Particles

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Research by Stephen A. Hackney, Professor, Materials Science and Engineering, Michigan Technological University.

Imaging by Pinaki Mukherjee, Staff, Materials Science and Engineering, Engineer/Scientist, Applied Chemical and Morphological Analysis Laboratory (ACMAL).

Instrument: FEI 200kV Titan Themis S-TEM in ACMAL’s Electron Optics Facility.

Scale bar indicates 500 nm.

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Graphite exfoliation by supercritical carbon dioxide extraction

Wattanaprayoon Supercritical Carbon Dioxide
A schematic of graphite exfoliation by supercritical carbon dioxide.


Supercritical carbon dioxide is used to exfoliate graphite, producing a small, several-layer graphitic flake. The supercritical conditions of 2000, 2500, and 3000 psi and temperatures of 40°, 50°, and 60°C, have been used to study the effect of critical density on the sizes and zeta potentials of the treated flakes. Photon Correlation Spectroscopy (PCS), Brunauer-Emmett-Teller (BET) surface area measurement, field emission scanning electron microscopy (FE-SEM), and atomic force microscopy (AFM) are used to observe the features of the flakes.

Wattanaprayoon, Chaiyaporn, “Graphite exfoliation by supercritical carbon dioxide extraction”, Master’s Thesis, Michigan Technological University, 2011.