(600m) Comparative Analysis of the Structure and Chemical Nature of Carbon Blacks and Diesel Soot

Diesel
particulate matter (DPM) in the atmosphere is considered a major cause of
environmental problems such as change in the atmospheric heat balance and
interference with photosynthesis [1], as well as of many adverse health effects
related to the respiratory system [2]. Structural analysis and chemical
characterization of the DPM aggregates are important to improve the fundamental
understanding about the relationship with their oxidation from diesel
particulate filters (DPFs) [3]. This is a highly challenging problem due to the
complex structure of the heavy fuel-derived carbonaceous materials [4]. Therefore,
studies on detailed structure and chemical analysis of carbonaceous materials,
as well as the correlations between various structural properties are lacking.

In
this work, structure and chemical nature of ten commercially available carbon
black materials and diesel engine soot are investigated using X-ray Diffraction
(XRD) and In Situ- XRD studies, Nitrogen
sorption studies, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy
(TEM), Fourier Transform Infrared (FT-IR) spectroscopy, Raman spectroscopy, and
Energy Dispersive X-ray (EDX) spectroscopy (see Figure for examples). On the
structural side, we have studied the nature of aggregates, morphology and size
of the primary particles, orientation and spatial distribution of the crystallites
having the graphitic structure, total surface area, pore size distribution and
pore volume. On the chemical side, we have studied the elemental composition by
EDX spectroscopy and molecular vibrations by FT-IR. Furthermore, the chemical
activity of these samples is studied using Thermo Gravimetric Analysis (TGA) under
an oxidative environment. Our comprehensive study has revealed some novel and
unique correlations between the structure and chemical nature of the carbon
blacks and diesel soot.  

References:

(1)   van Setten, B.A. A. L., Makkee, M., and
Moulijn, J.A., Catalysis
Reviews: Science and Engineering, 2001, 43(4), 489-564.

(2)   Dockery,
D.W., Cunningham, J., Damokosh, A.L., Neas, L.M., Spengler, J.D., Koutrakis,
P., Ware, J.H., Raizenne, M., and Speizer,
F.E., Environmental Health Perspectives, 1996, 104,
500-505.

(3)   Ishiguro,
T., Takatori, Y., and Akihama,
K., Combustion and Flame, 1997,
108, 231-234.

(4)   Apicella,
B., Barbella, R., Ciajolo,
A., and Tregrossi, A., Chemosphere, 2003,
51, 1063-9.

(5)   Muller,
J.O., Su, D.S., Jentoft R.E., Wild U., and Schlogl, R., Environmental Science & Technology,
2006, 40, 1231-1236.