The research conducted at the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL) does more than contribute to a basic understanding of the world around us. It also helps to improve the environment, ensure national security, advance health care, and promote clean energy through real-world applications. The following research projects demonstrate the diversity of EMSL's scientific contributions.
HostDesigner and designer materials--Advanced computational methods developed by researchers in EMSL are being used to identify new molecular structures that can be applied to speed environmental cleanup and also provide benefits in areas including pharmaceuticals and industrial processes. Using these methods, scientists have designed a new "ligand" or receptor that targets the f-block metal ions, a group of metal ions present in radioactive waste. Experimental studies have shown that the "designer" diamide ligand is 10 million times more efficient at removing f-block metals from process waste than conventional diamide ligands.
The ligand design methodology has been automated in a new computer software program called HostDesigner. This program was created specifically for the discovery of molecules that bind with metal ions--an application that is crucial for environmental cleanup and other industrial processes in which the objectives are to detect and recover metals. "Our ability to design molecules tailored for specific applications will save time and money by focusing research efforts on the most promising ligand structures," said Ben Hay, creator of HostDesigner.
Engine Exhaust Aftertreatment System Based on Non-Thermal Plasma-Assisted Catalysis --Utilizing research at EMSL, scientists have developed an exhaust aftertreatment system based on non-thermal plasma-assisted catalysis for lean-burn diesel and gasoline engines. This system converts harmful oxides of nitrogen (NOx ) and particulate matter emitted from vehicle engines into components of clean air. In laboratory tests with a simulated gas mixture, this technology reduced the NOx by nearly 100 percent. Tests with actual diesel engines have achieved greater than 75 percent NOx reduction over a range of operating conditions and up to 50 percent particulate matter reduction. With the addition of an optional particulate filter, this system can reduce particulate emissions by up to 90 percent. The system performs well in the lean-burn conditions of energy-efficient diesel engines, where conventional three-way catalytic converters are inadequate. It also could easily be incorporated into existing vehicle tailpipe designs with few modifications and could be a retrofit option to decrease pollutants from older vehicles.
The system combines an electrically energized gas, or plasma, with specialized catalyst materials that selectively bring about important chemical reactions to reduce NOx. "This concept of using a non-thermal plasma to activate catalysis has existed only for about 7 or 8 years," said Chuck Peden, who leads interfacial chemistry and engineering research. "Today it is recognized as a potential commercial solution." See related story, PNNL honored for technology transfer.
BEADS (Biodetection Enabling Analyte Delivery System)--An automated system based on research conducted at EMSL purifies samples of soil, air and water. Called BEADS, for Biodetection Enabling Analyte Delivery System, it is being created for use in a biological warfare detector. BEADS cleans samples so that micro-organisms can be identified in places like food processing lines and water treatment plants. The system's sample preparation process can be used with existing detectors, which require a person to manually purify samples for identification. BEADS takes the person out of the process by using proprietary microfluidic systems and automated sample cleanup methods. It can be used in chemical, protein, nucleic acid or whole-cell detectors.
[photo of BEADS]
Computer-aided design of ligand architecture yields a dramatic enhancement of metal-ion affinity. The vectors on each oxygen atom, which indicate the direction required for optimal interaction with a metal ion, diverge in the conventional diamide structure (left) and converge in the computer-designed structure.
The Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time.