Release Date: March 20, 2007
|NETL Joins Forces with Medical School to Develop CO2 Sorbents|
A nanotechnology currently used to prevent infection in medical implants and to prepare microcapsules for drug delivery may also help ease concerns about global warming.
To investigate this possibility, a novel collaboration has been formed linking a medical school and the Department of Energy’s National Energy Technology Laboratory (NETL).
Medical research may not seem to have much in common with fossil energy research, but it turns out that the medical school’s nanotechnology research has potential to be of great value to the NETL as it focuses on ways to use the nation’s fossil energy resources without causing harm to the environment.
Researchers at NETL, the only national laboratory devoted to fossil energy research and development, are collaborating with scientists at two universities to take a technology developed for medical purposes and use it to remove carbon dioxide from fossil-fuel combustion gases.
NETL has a history of developing sorbents, materials fixed into forms that will remove various chemicals from the gases produced by combustion of fossil fuels – coal, oil and natural gas. Some of the sorbents take advantage of amines to remove carbon dioxide. Amines, which resemble ammonia, are chemical compounds that contain nitrogen as the key atom.
The NETL researchers prepare the amine sorbents by a process that deposits the amines on the substrate (base on which the active material is deposited). The more consistently uniform the deposition is, the more effective the sorbent is at removing the carbon dioxide. The challenge is to discover ways to obtain the highest degree of uniformity.
That’s where the university researchers come in.
The technology is called electrostatic layer-by-layer self-assembly, or LBL. It is used to treat surfaces of medical implants to prevent infections to the patients, or to deliver precise doses of medicine. It is regarded as the most promising method to prepare multilayer nanocoatings of controlled thickness and composition.
The procedure involves repetitive sequential dipping of a substrate into solutions of oppositely charged polyelectrolytes. Each layer of the solid sorbent produced by the LBL process can have a uniform thickness on the order of 1 to 2 nanometers. A nanometer is a billionth of a meter, or a fraction of the diameter of a human hair. The LBL process provides a novel approach to immobilizing large amounts of amine compounds, a process having the potential to produce highly efficient, multi-functional, solid sorbents, containing perhaps 100 times more of the amines than are deposited by the technology being used now.
This research collaboration requires the complementary strengths of all three parties: NETL researchers are expert at developing solid sorbents for fossil energy applications; the WVU researcher has nanotechnology and bioengineering expertise to apply chemicals to different surfaces; and the University of Pittsburgh researchers have expertise in reactor and process design, modeling, and scaleup.
What makes this unique collaboration possible is NETL’s University Research Initiative, a program that teams NETL researchers with university professors and students at WVU, Pitt, and/or Carnegie Mellon. NETL started the research initiative to strengthen the relationships between the national laboratory and the three universities.
According to Carl Bauer, director of NETL, “The University Research Initiative is an important new program we’ve designed to enhance NETL’s research capabilities while helping to produce the next generation of fossil energy researchers. This establishes relationships with university professors who might not otherwise be aware of the fossil energy research needs, and it brings some of the brightest university undergraduate students into our laboratories to become familiar with NETL research needs, as well as letting them get to know our research staff and our research facilities.”
The terms of the initiative require that at least two of the universities identify research projects that are appropriate to NETL’s mission, and that the university researchers must agree to do at least part of the research at NETL labs.Gray, NETL’s collaborating scientist on the project, explains that this particular research is valuable to all parties: “We’re excited about taking medical technology used in biological systems and using it in different industrial systems for carbon dioxide capture. For the universities, this is a branching out – an alternative use for the nanotechnology they’re doing now. This new application has challenges for them. They work in less than micron [a micron is a millionth of a meter] size, and we’re working at 100 microns and up. We have to see how much coverage of the substrate we can get, and how deep into the pores the material will go. In the immobilization process we’ve been using at NETL, because of the random distribution of the chemicals on the porous structure, deposition might not be uniform. We hope with this we will use less chemical and get more uniform deposition.”
WVU’s Dr. Li says the universities benefit from developing the technology. “In biomedical school, we focus on biomedical innovation and patient care. Right now we use this technology to make microcapsules for targeted drug delivery and to make nanocoatings for infection preventions, especially for orthopedic-device associated infection. It is very exciting that this technology may find its first application in energy. We are very happy to team up with McMahan L. Gray, Badie I. Morsi and Wen-Ching Yang. NETL’s University Research Initiative makes this research possible.”
Discussing the versatility of the deposition technology, he adds, “In general there’s no limit on the size or shape of the substrate. The substrate can be organic or inorganic.”
The project is scheduled for a year, with potential extensions for up to two more years.