CAMP Annual Report: Page 4
Professor Ahmadi and Professor Issen, in collaboration with the scientists from the US Department of Energy, are working to assess the safety of carbon dioxide sequestration in geological formation in addition to understanding hydraulic fracturing. As part of this project, computer models for gas-liquid flows in porous media, as well as in rock fractures, are being developed. In particular, the effect of variation of confining pressure on the effective permeability of fracture flows is being analyzed. The eventual goal is to implement the research findings into a computational code for modeling large scale geological reservoir simulations. In addition, a better understanding of hydraulic fracturing is expected to lead toward safe and sustainable production of shale based natural gas.
COLLOIDAL DISPERSIONS AND PROCESSING
Professor Devon Shipp and his team focus on the synthesis and study of hydrogel systems and novel degradable elastomers. Industrially-sponsored research projects leverage Professor Shipp's expertise in making polymers with well-defined molecular weights and chemical functionality for applications in ophthalmic and dental applications. The group has also developed novel degradable polymers, with Shipp and his students having demonstrated that linear and crosslinked polyanhydrides can be made using photoinitiated thiol-ene chemistry. This is a simple and effective method of making crosslinked structures that have surface degradation characteristics. Papers describing this work recently appeared in Chemical Communications, Macromolecules and ACS Applied Materials & Interfaces. This technology is expected to gain usage in many biomedical applications such as drug delivery, orthopedics, tissue engineering, scaffolds, and even lithography. Also Shipp’s group, in collaboration with Professor Sitaraman Krishnan (from Clarkson’s Department of Chemical and Biomolecular Engineering) has developed the first colloidal thiol-ene polymerizations. The process yields sub-micrometer to micrometer-sized particles very quickly and efficiently, and can be achieved using photoinitiation in a suspension polymerization. This research is published in ACS Macro Letters. Check out the following link. http://pubs.acs.org/doi/abs/10.1021/mz300358j
More information about Professor Shipp’s research activities can be found at www.clarkson.edu/~dshipp.
Professor S.V. Babu’s research group is continuing its fundamental investigations of various aspects of chemical-mechanical planarization (CMP) of metal and dielectric films. While continuing the development of more chemically active dispersions for low pressure planarization of InP, GaAs, InGaAs, Ge, Co, Mn, and Ru, and ensuring appropriate selectivity with respect to the underlying low-k dielectric films, they have also identified compositions that can minimize galvanic corrosion for Al/Co, Ru/Cu, Cu/Co and Cu/Mn layers. The investigation of Ge, Ru and InP was conducted collaboratively with IMEC, Belgium. Several results obtained while polishing InP, Ru, Co and Ge films and structures have been recently published. It was found that Ru films behave very differently depending on whether the underlying substrate is TiN or TaN.
The group is also investigating the planarization of dielectric (oxide, nitride, a-SiC, and poly-Si) films with controlled and variable selectivity which continues to be a topic of great interest. The investigation of controlled selectivity in material removal during the polishing of oxide, nitride, and poly-Si films has led to several fundamental discoveries. Several ceria and silica based compositions that yield a high nitride and low oxide polish rate and simultaneously a controllable poly-Si removal rate have been identified. It was shown that the presence of protonated functional groups of the additive is critical to suppress nitride removal to a few angstroms/min., since they can bind through strong hydrogen bonding to the nitrogen with unpaired electrons on the nitride surface. Both the stress and doping of the nitride film also play a critical role, while the ionic strength is an important parameter while polishing a-SiC films.
Aqueous and abrasive-free solutions of PDADMAC and PEI as well as several other polymers have been shown to polish poly-Si film at high rates with no oxide or nitride removal. The results were published in several recent papers. Some of these compositions were used to improve the surface finish of extreme UV lithography mask substrates. This work is continuing. Finally, Professor Panart Khajornrungruang of Kyushu Institute of Technology, Fukuoka, Japan; Professor Zifeng Ni of Jiangnan University, Wuxi, China and Professor Jun Li of Nanjing University of Aeronautics & Astronautics, Nanjing, China, are spending the current year as visiting research professors in Babu’s research group.
STATE-FUNDED RESEARCH PROJECTS
Seven research projects were supported by the Centers for Advanced Technology (CAT) Program of the Empire State Development Division of Science, Technology, and Innovation (NYSTAR) in the 2012 - 2013 fiscal year. Project titles and principal investigators are listed below for each research area.
Colloidal Dispersions and Processing
- Wetting Agents for Ophthalmic Applications -D. Shipp
- Dynamics and Electrophoretic Mobility of Nafion at Carbon, Mica, and Platinum Interfaces -S. Minko
- Development of Materials Systems and Tools to Study their Interactions for Printing Systems - S.V. Babu
- NY-Best Market Driven Research Program with GE Global (for electrochemical processes and microstructural analysis) -D. Roy
- Characterization of Filter Performance under Low-Pressure Operation -S. Dhaniyala and J. McLaughlin
- Petrographic and Chemical Analyses of Concrete Cores to Determine the Extent of Ettringite Formation, ASR and Chloride Induced Corrosion -S. Peethamparan
- Real-Time Structural Monitoring Platform for Wind Turbine Systems -K. Janoyan