USING IONS TO PROBE IONIC LIQUIDS

Main Menu | News By Date | News By Supplier | News By Category | About Us

USING IONS TO PROBE IONIC LIQUIDS
17 May 2007 - DOE/Brookhaven National Laboratory

Scientists at the U.S. Department of Energy’s Brookhaven National Laboratory are using a very small and light ion, the electron, to study the structure and dynamics of ionic liquids and how those properties influence chemical reactivity.

Ionic liquids are made of positive and negative ions that pack so poorly together that they are liquids near room temperature. They offer extremely low volatility, non-flammability, new reactivity patterns, and the formation of separate phases that allow the easy separation of products, properties that make them safer to work with, easier to recycle, and less likely to pollute the atmosphere than traditional solvents.

Brookhaven chemist James Wishart and postdoctoral research associate Alison Funston use pulsed electron beams to initiate chemical reactions in ionic liquids, causing some of the ions to give up one of their own electrons. The isolated electrons can exist for hundreds of nanoseconds surrounded by solvent. Systematic variation of ionic liquid composition shows that solvated electron absorption spectra depend strongly on the structure of the ionic liquid and on the presence of functional groups such as hydroxyl groups.

While it takes only a few nanoseconds for electrons to become fully equilibrated (solvated) in ionic liquids, that is one thousand times slower than in most conventional solvents. During that time, the pre-solvated electrons are highly susceptible to capture by low concentrations of dissolved compounds. This can result in unanticipated reactivity patterns that have profound implications for uses of ionic liquids in radiation-filled environments such as the nuclear fuel cycle.

Wishart and Funston use electron scavengers to probe this reactivity and they measure ionic liquid solvation dynamics by following the laser-induced fluorescence of dye molecules that are sensitive to their surroundings. Viscosity is a key factor in all this work, and they have designed new, lower-viscosity ionic liquids to aid these studies.

http://www.bnl.gov

About: DOE/Brookhaven National Laboratory
Established in 1947 on Long Island, Upton, New York, Brookhaven is a multi-program national laboratory operated by Brookhaven Science Associates for the US Department of Energy (DOE). Six Nobel Prizes have been awarded for discoveries made at the Lab.

Brookhaven has a staff of approximately 3,000 scientists, engineers, technicians and support staff and over 4,000 guest researchers annually.

Brookhaven National Laboratory's role for the DOE is to produce excellent science and advanced technology with the cooperation, support, and appropriate involvement of our scientific and local communities. The fundamental elements of the Laboratory's role in support of the four DOE strategic missions are the following:

To conceive, design, construct, and operate complex, leading edge, user-oriented facilities in response to the needs of the DOE and the international community of users.

To carry out basic and applied research in long-term, high-risk programs at the frontier of science.

To develop advanced technologies that address national needs and to transfer them to other organizations and to the commercial sector.

To disseminate technical knowledge, to educate new generations of scientists and engineers, to maintain technical capabilities in the nation's workforce, and to encourage scientific awareness in the general public.

More News:
  • For May 2007
  • From DOE/Brookhaven National Laboratory
  • For Nanotechnology