[Zurück]

F. Handle, J. Füssl, S. Neudl, D. Großegger, L. Eberhardsteiner, B. Hofko, R. Blab, H. Grothe:
"The bitumen microstructure: a fluorescent approach";
Materials and Structures, 49 (2016), S. 167 - 180.

Five bituminous samples were carefully
studied by confocal laser scanning microscopy using
488 nmexcitation radiation and observing 500-530 nm
of emission. The images revealed the microstructure of
bitumen. The influence of the admixture of mineral
aggregates concerning the microstructure was tested.
For the minerals, no significant influence was found. For
understanding the origin of fluorescent signals, the
samples were separated into asphaltenes and maltenes
and analyzed with fluorescence spectroscopy. Although
former works have assumed the origin of fluorescent
emissions in bitumen to be found in the asphaltene
fraction, the asphaltenes produce little to no emissions,
but the maltenes exhibit strong fluorescence in the
observed spectral region. For deeper insight, fractionation
of the bitumina into the SARA fractions by
chromatographic columnseparationwas necessary. The
fluorescence spectra of these fractions were analyzed
and revealed the aromatics and resin phases to be the
only components capable of sufficiently intense fluorescent
emission. This is a strong argument for a
complex internal microstructure consisting of a mantle
of aromatics surrounding an inner core.

Bitumen, Microstructure, Photoluminescence spectroscopy, Optical microscopy

http://dx.doi.org/10.1617/s11527-014-0484-3

http://link.springer.com/article/10.1617/s11527-014-0484-3