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Transmission electron microscopy with automated image analysis (TEM/AIA) was used to characterize the three-dimensional morphology and anisometry of carbon black aggregates. Individual carbon black aggregates were imaged at multiple goniometer angles, and their three-dimensional aggregate structure was modeled, yielding greatly enhanced morphological information. Aggregate size distributional properties were determined at multiple goniometer orientations for N300 and N600 series grades of varying aggregate structure levels. Aggregate projections were found to exhibit statistical decreases of 10 to 25% in area and perimeter with rotation. Decreases in other morphological parameters, including non-dimensional shape parameters, were also observed. In general, higher structure grades (aggregates) were found to display larger relative changes in morphological parameters with rotation than lower structure grades. Ramifications for conventional TEM/AIA and void-volume/polymer occlusion capacity measurements are addressed. Further analysis includes an assessment of aggregate anisometry on the TEM sample grid and new insights into the three dimensional nature of carbon black aggregate structure.

Raman spectra of laser heated carbon blacks provide information on the dynamics of the graphitization process. Continuous wave and pulsed-laser heating is used. It is shown that two ordering mechanisms of distinctly different reaction rates are present during the heat treatment. The dominating mechanism, during the initial stages of graphitization, is characterized by a very fast rate. The rate during the later stages of the process, after the initial first couple of seconds, is orders of magnitude slower.

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A three-dimensional modeling technique is used to characterize the structure of carbon-black aggregates. The relative positions of individual particles in aggregates are determined using transmission electron microscopy (TEM). Data are acquired from two-dimensional projections taken with the aggregates at two different orientations with respect to the electron beam. Computerized aggregate models are generated using data from TEM projections in our reconstruction algorithm. Inspection of these models shows that their projections very closely replicate the TEM micrographs. Quantitative analysis of the aggregate models reveals that aggregates generally exhibit anisotropy, in the form of a reduction of aggregate breadth, or “flatness,” in one direction. The flat sides tend to align preferentially, along the plane of the TEM sample grid. The dimensions for each aggregate with respect to its best-fitting plane of flatness are determined, and are related through a “flatness index.”