Project Report

The proposed research was suggested as a way to develop a comprehensive fundamental understanding of luminescent thin films constituted from well-defined ligand-capped lanthanide oxychlorides nanocrystals. Nano-indentation at Pusan National University was used to elucidate mechanical properties not only of the lanthanide oxychlorides nanocrystals thin films but also graphene composite films that had been prepared at the University at Buffalo. This opportunity provided me an unprecedented opportunity for personal growth and allowed me to acquire multidisciplinary expertise outside my native curriculum of chemistry. I was trained on an Agilent Nano Indenter G200. The Nano Indenter G200 uses an electromagnetic actuator, which allows for the measurement of Young’s modulus and hardness values of thin films, coatings, composite materials, and polymers. These measurements are acquired by analyzing the force versus displacement curve. Along with training on the Nano Indenter G200, I was introduced to the NanoSuite 6.0 Professional software to perform data analysis. Characterization of the nanoindentations was performed using a scanning electron microscope. All samples were previously prepared at the University at Buffalo. Each set of measurements included twenty sample points for three different areas of the samples. Preliminary data on an acrylic sheet standard resulted in a Young’s Modulus of ~5 GPa and a hardness of ~0.25 GPa, which is consistent with previous measurements done on acrylics and allowed for benchmarking of the apparatus. When graphene was added to the acrylic samples, the Young’s Modulus and hardness was reduced to ~4 GPa and ~0.18 GPa, respectively, perhaps due to the method of preparation. The Young’s Modulus and hardness of a steel sample coated with PEI (polyetherimide) was found to be ~5 GPa and ~0.4 GPa, respectively, with a slight deviations occurring at different sampling sites. Steel with a graphene/PEI coating showed a slight increase in Young’s Modulus to a value of ~ 5.5 GPa, whereas the hardness value decreased to ~0.35 GPa. A subsequent sample similar to that of the graphene/PEI on steel sample included an additional layer of graphene on top of the graphene/PEI layer had an increase in Young’s Modulus to ~5.7 GPa but no change in hardness. GdOCl nano-structured thin films deposited on Indium Tin Oxide (ITO) substrates were measured and found to have a Young’s Modulus of ~3.2 GPa and hardness of ~0.1 GPa. The GdOCl nanostructured thin films showed a coefficient of variation (COV) of ~18% most likely due to the inherent voids that occur between the nanocrystals constituting the film.

Agency
National Science Foundation (NSF)
Institute
Office of International and Integrative Activities (IIA)
Application #
1106371
Program Officer
Carter Kimsey
Project Start
Project End
Budget Start
2011-06-01
Budget End
2012-05-31
Support Year
Fiscal Year
2011
Total Cost
$5,700
Indirect Cost
Name
Kort Kenneth R
Department
Type
DUNS #
City
Buffalo
State
NY
Country
United States
Zip Code
14216