Project Overviews

I. Processing Biomaterials for Improved Biocompatibility. An NIH Bioengineering Research Partnership.

Funding: National Institutes of Health/National Institute of Biomedical Imaging and Bioengineering; private industry; V. K Rasmussen Foundation and South Carolina Sustainable Universities Initiative; USC Vice President for Research.

Collaborators: Clemson University, the Medical University of South Carolina, Thar Technologies Inc.

Synopsis: The overall goal for this Bioengineering Research Partnership is to develop a new treatment process that results in clean, sterile, and functional biomedical devices. This project will provide the necessary basis for evaluating CO2-based cleaning and sterilization, and determining if the technology is more effective, less expensive, and more benign than technology based on steam, ethylene oxide, hydrogen peroxide, or radiation. The research is broadly applicable to the manufacture of biomaterials, implants, and prostheses. The research will support the development of the next generation of biomaterials (e.g. for tissue engineering) that are not compatible with current methods of sterilization and cleaning. This process should minimize property changes incurred with irradiation, the commonly used method of sterilization for polymeric medical devices. It will also eliminate the need for toxic sterilants such as ethylene oxide, which tends to reside in polymeric materials.

II. Hydrogen Production from Chemical Hydrides.

Funding: U.S. Department of Defense; U.S. Department of Energy; private industry

Synopsis: This project investigates all aspects of the novel gas/solid chemical reaction between steam and chemical hydrides that liberates pure hydrogen gas. The aim of this project is to gather fundamental kinetic, chemical, catalytic, and thermodynamic data on the reaction so that sufficient information is known to evaluate this technology rigorously for its potential as a means of delivering hydrogen to automotive fuel cells. In this project we will also evaluate and develop new catalysts and promoters to enhance the rate and controllability of the reaction, and we will use the fundamental data to support reactor design and evaluation for potential hydrogen delivery systems. The experimental and theoretical characterization of the byproducts will help answer the critical question of utilization and disposition of water in the reaction system, which has a profound effect on the mass efficiency.

This project derives from the recent discovery at the University of South Carolina that, by vaporizing water prior to contact with NaBH4, hydrogen yields in excess of 90% may be obtained without the need for a catalyst. Furthermore, other chemical hydrides, notably lithium aluminum hydride (LiAlH4), also react favorably. Thermodynamic considerations show that, in principle, the heat liberated by the reaction is more than sufficient to vaporize the stoichiometric water required for the steam. Thus, there is the possibility of developing a hydrogen reactor/delivery system that is autothermal (i.e. energy efficient) at steady state, that produces pure hydrogen in 100% yield, that requires no catalyst, that does not involve strongly caustic solutions, and that uses a minimum of water. Furthermore, the solid reaction products should be nearly free of water, which in the long term will facilitate recycling and regeneration to the hydride.

III. Green Electrochemistry in Ionic Liquids I: Low Temperature Oxidation of PCBs.

Funding: National Science Foundation, U.S. Department of Energy

Synopsis: The objective of this project is to demonstrate environmentally acceptable methods for complete oxidation of chlorinated solvents for environmental remediation. The active oxygenation species is the superoxide ion, generated in an aprotic room temperature ionic liquid using a suitable cathode. We conduct low-temperature oxidation of wastes via electrochemical generation of superoxide ion in novel ionic liquid solvents. Low-temperature oxidation of waste solvents provides a much-needed alternative to high temperature waste incinerators, whose use is greatly complicated by regulatory requirements and locating suitable sites. Ionic liquids are non-volatile and non-flammable, and should minimize the problems of secondary solvent waste and separation of products from solvent.

IV. Green Electrochemistry in Ionic Liquids II: Low Temperature Oxidation of Alcohols.

Funding: National Science Foundation

Synopsis: This project promotes discovery of economical and sustainable routes to selective organic oxidation involving the superoxide ion (O₂·-). In particular, this research program utilizes electrochemical means to generate O₂·- in highly conducting, non-volatile Room Temperature Ionic Liquids (RTIL) solvents. Subsequent oxidation of selected organic substrates also takes place in the RTIL at near-ambient conditions. RTILs are potentially environmentally-benign reaction solvents for conducting this electro-organic chemistry. We hypothesize that electrochemical formation of superoxide and subsequent reactions can be optimized by choosing the most appropriate ionic liquid (IL), and then controlling the electrical and transport properties of the RTIL solvent. The scientific objectives of this project are to identify reaction products and measure intrinsic kinetics of selected organic reactions involving O₂·-, and determine how these are affected by conductivity and viscosity of the RTIL, partial pressure of the gaseous reactants, and solubility of the solid reactants and products in the RTIL. Furthermore, a novel membrane reactor design increases current efficiency in the electrolysis of oxygen. The novel reactor employs a thin polymer membrane to separate the anode and cathode compartments. Present commercial processes may require organic solvents, expensive catalysts, or even phosgene in the synthesis of these intermediates. Thus, there is strong motivation for better, sustainable approaches to manufacturing these intermediates.

V. Enhanced Undergraduate Engineering Education: The Research Communications Studio.

Funding: National Science Foundation

Collaborators: USC College of Liberal Arts; USC College of Education; Departments of Mechanical and Electrical Engineering

Synopsis: Engineering colleges in research-intensive universities are expanding opportunities for undergraduates to conduct research with a faculty member’s group. However, research on student cognitive development is urgently needed to identify modes of mentoring and instruction that are effective in improving student learning, retention, and performance. Effective structures are needed for linking undergraduate research to the institution’s educational objectives and program outcomes. Undergraduate students who are engaged in research-based learning typically do not develop metacognitive awareness of their own learning and research processes. This project will develop a flexible model for integrating undergraduate research into the engineering curriculum and for strengthening undergraduates’ cognitive skills through a mentored program of research and communications within small groups. In this model, called the Research Communications Studio (RCS), small groups of three to five undergraduate students meet under the mentorship of communications faculty and engineering graduate students. The RCS sessions and related instruction focus strongly on the students’ communications tasks, as assigned by their research directors. The studio sessions enhance inquiry-based learning by making principles of research and communications explicit and by engaging students in reflection on those experiences. This approach builds students’ metacognitive awareness, enabling them to become self-directed learners. The project is guided by three hypotheses related to the effect of studio methods of instruction on 1. Quality of learning; 2. Retention and enrollment; 3. Cognitive development, self-directed learning, and team participation. The program evaluation component will furnish data to test the effectiveness of the RCS model, especially the use of communications, in cognitive development through research-based learning.