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• Carbon Nanopipes for
Nanofluidic Devices and In-situ Fluid Studies
The processes that govern fluid processes in pipes are well
understood for diameters in the range of micrometers and
above. As the diameters diminish (e.g. in the range of a few
nanometers), the role of surface tension and capillarity is
has been seen to change, as well as their dependence on
material properties. Thus, the expected promise of Carbon
nanotubes in technological applications is in urgent need of a
well-documented basic understanding of such forces, especially
since no consistent experimental data have been collected so
far. The PI has obtained a lot of results in the determination
of the liquid/vapor distribution in nanotubes, interaction of
the fluids with the nanotubes walls as well as the effect of
the hydrothermal treatment on the carbon nanotubes. On that
basis, he offers to develop an experimental program that will
explore as thoroughly as possible the various aspects of phase
interfacing in a number of nanotube situations. The special
case of the newly developed closed nanotubes will be examined.
Fluid behavior, Chemical modification, metallization, and
opening of the nanopipes will be also investigated using
bipolar electrochemistry. Then, the experimental work will be
supplemented by modeling based on parallel molecular dynamics
simulations. Such work should offer a precious set of data for
the elaboration of a model based on precise experimental
observations. For more information, please click here.
• Carbide Derived Carbon
The research focus is on the discovery of new methods for
synthesis of carbon coatings on the surface of
silicon-carbides and nanoporous materials with tunable pore
size. This research will allow the comparison of different
techniques for the extraction of metals from carbides. The
comparison will then make it possible to increase our
understanding of carbon growth mechanisms. The coatings
developed as a result of this research will find uses in new
protective coatings for sensors and tools, intermediate thin
films for further chemical vapor deposition of diamond,
molecular membranes for sensors, et al. Porous materials will
be used for hydrogen storage, methane storage, gas separation,
water desalination, and other applications.
Click here for more information.
• Phase Transformations in Ceramics and Semiconductors
Under Contact Loading
Phase transformations occurring in materials under high
pressures are important for a wide range of problems in
materials science and engineering. Most of the results in this
area have been obtained using various sophisticated
high-pressure cells. In this project, the solid-state phase
transformations and amorphization under high non-hydrostatic
pressures using a combination of hardness indentation tests
with Raman spectroscopy will be studied. Micro-Raman
spectroscopy is probably the only method that allows the
non-destructive phase analysis of materials to be conducted
within seconds with a spatial resolution in the order of 1
micrometer on a non-prepared surface of the material or under
the surface. Preliminary experiments have demonstrated
metallization due to closing of the band gap and consequent
formation of metastable phases upon decompression in Si and Ge.
For the first time, metastable phases were unambiguously
observed in hardness impressions and for some of these phases
Raman spectra have not been published before. The data
obtained will be used to confirm experimentally that the
hardness level of many brittle materials depends on the stress
(deformation) needed to initiate the phase transformation and
supply evidence that metallization of semiconductors is a
deformation induced, not a 'pressure' induced phenomenon. TEM
with SAD and EELS, micro-XRD and micro-FTIR will be used as
supplementary techniques for phase analysis.
Hardness indentation tests combined with Raman spectroscopy
will be used to analyze a variety of semiconductors and
ceramics. The use of this technique will allow us to
demonstrate the high-pressure metallization of diamond. This
technique will also be used to find other new high-pressure
phases in ceramics (carbides and nitrides) and semiconductors
that have been theoretically predicted, but not yet obtained.
The success in solving this problem is likely to catalyze
rapid advances in high-pressure research, and make it a
routine technique which is accessible to almost every material
scientist. The project is structured in order to ensure that
the basic science developed in this project will lead to
achievement of long term goals of practical significance with
applications in indentation testing, ductile regime machining,
nanopatterning of surfaces, surface quality control and
tribology.
• Manufacturing of Drug Nano-dispersions and
Nano-particles by Mechanochemical Synthesis
The research objective of this effort is to develop a
manufacturing process for drugs and other organic compounds
known as ‘mechanochemical synthesis’ (MCS). Drug
nanoparticles manufactured by MCS are expected to exhibit
significantly improved pharmacological properties which will
increase the effectiveness of many important pharmaceutical
treatments. This research will contribute to the advancement
of materials nanomanufacturing by developing a MCS process
for organic compounds with low melting points, and is driven
by a documented need within the pharmaceutical industry. The
development and optimization of a nanomanufacturing process
and exploration of the underlying responsible phenomena will
be addressed. In particular, this project will establish
conditions for ensuring high reproducibility and develop the
control strategy/equipment for production. The analytical
and nanoscale manufacturing experience of a team from Drexel
University will be combined with the mechanochemical
synthesis and equipment design experience of iCeutica Inc.,
presenting an opportunity to promote collaboration with
industry, fostering a better understanding amongst industry
and university scientists, and potentially leading to
scientific breakthroughs and technological accomplishments
in the fields of manufacturing research. The proposed study
will have a strong educational component, building on the
existing strengths of the A.J. Drexel Nanotechnology
Institute in research and education. Activities within this
project will be integrated into existing NSF-supported RET
and REU programs.
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