A recent article in Journal of American Chemical Society from researchers at the University of Bordeaux (France) shows graphene sheets visualized and measured with the SARFUS optical technique [1].
This characterization was done in the framework of negatively charged graphene layers preparation from a graphite intercalation compound by
dissolution in N-methylpyrrolidone. The dissolution is done spontaneously without sonication and yields to stable, air-sensitive solutions of laterally extended atom-thick graphene sheets and ribbons with dimensions over
tens of micrometers. Graphene sheets characterization by Sarfus yields height of 0.3nm, in good accordance with AFM analyses on mica which give the actual height of graphene (ca. 0.4nm).
SARFUS is a new optical characterisation tool at the nanoscale commercialised by NANOLANE (Montfort-le-Gesnois, France) that increases
the sensitivity of incoherent light optical microscopy to a point where it becomes possible to directly visualize nanometric films and isolated nano-objects with a standard optical microscope. Applications include for example rapid defect visualization of soft lithography, quality control of DNA biochips, direct visualization and measurement of nanolithography patterns, thin films and surface treatment studies, dynamic studies of crystallization and wetting applications, as well as direct behaviour and morphology characterization of nanotubes and nanowires. More information
about this technology are available at http://www.nano-lane.com.
[1] C.Valles et al, J. Am. Chem. Soc., 2008, 130 (47), pp 15802–15804
