Characterization of ultrafine coal fly ash particles by energy-filtered TEM.
In this study, energy-filtered transmission electron microscopy is demonstrated to be a valuable tool for characterizing ultrafine coal fly ash particles, especially those particles encapsulated in or associated with carbon. By examining a series of elemental maps (K-edge maps of C and O, and L-edge maps of Si, Al, Ti and Fe) recorded using the three-window method, considerable numbers of titanium and iron species with sizes from several nanometres to submicrometre were shown to be present, typically as oxides dispersed in the carbonaceous matrix. Crystalline phases, such as rutile and iron-rich oxide spinel, were also identified from electron diffraction patterns and high-resolution TEM images. Information about these ultrafine coal fly ash particles regarding their size, morphology, elemental composition and distribution, and crystalline phases, which has not been available previously in conventional ash studies, should be useful in toxicological studies and related environmental fields.
Chen
Y
Y
Consortium for Fossil Fuel Science/Department of Chemical and Materials Engineering, University of Kentucky, 533 South Limestone Street, Lexington, KY 40508-4005, USA.
Shah
N
N
Huggins
F E
FE
Huffman
G P
GP
Dozier
A
A
D000393:Air Pollutants / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D003031:Coal / Q000032:analysis*; D060729:Coal Ash; D007501:Iron / Q000032:analysis; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D052638:Particulate Matter; D014025:Titanium / Q000032:analysis
D000393:Air Pollutants; D003031:Coal; D060729:Coal Ash; D052638:Particulate Matter; D002244:Carbon; D014025:Titanium; D007501:Iron