Understanding Lubricants on the Nanoscale H' Taub, University of MissouriColumbia, DMR0411748

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Understanding Lubricants on the NanoscaleH.
Taub, University of Missouri-Columbia,
DMR-0411748
Alkane molecules are the principal
constituents of commercial lubricants such as
engine oils. Our current research deals with
what makes alkane films good lubricants. For
example, at the microscopic level, how do the
molecules orient themselves on a solid surface
and do they form uniformly thick liquid films
i.e., wet the surface?
Just below the bulk melting point, we have
observed an unusually soft solid phase only a
single molecule thick in which the rod-shaped
molecules are oriented perpendicular to a solid
surface.
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12 ?m
Upon heating, the monolayer patch spontaneously
transforms into small three-dimensional liquid
droplets rather than wetting the surface in a
film of uniform thickness.
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Our studies using Atomic Force Microscopy of
alkane films have revealed unexpected features of
the structure and morphology of alkane films on
the nanoscale.
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Understanding Lubricants on the NanoscaleH.
Taub, University of Missouri-Columbia, DMR-0411748
Education Two graduate students (Armand Diama
and Haiding Mo), two undergraduates (Matthew
Simpson and William Danchus), two postdoctoral
fellows (Mengjun Bai and Sven Trogisch), and a
Visiting Professor (Klaus Knorr, Universität des
Saarlandes, Germany) conducted research supported
by this NSF Award. The photo shows Danchus and
Diama at an international conference where they
reported on neutron scattering from alkane
films. Dr. Bai is continuing our AFM studies
of alkane films. Diama received his Ph.D. in
2006 and will return to the Ivory Coast to join
the faculty of the National University. Simpson,
a recipient of a Goldwater Scholarship, is
planning to enter medical school. Dr. Mo is now a
postdoctoral fellow at Brookhaven National
Laboratory, and Dr. Trogisch has an industrial
research position in Germany.
Societal Impact Alkane molecules are the
principal constituents of commercial lubricants.
A microscopic understanding of the structure and
dynamics of very thin alkane films could lead to
the development of better and more durable
lubricants in applications ranging from computer
hard drives to automobile engines.