October 26, 2006

New probe will open windows to the molecular world

by Tim Crosby

CARBONDALE, Ill. -- A new piece of high-tech equipment paid for with a federal grant will greatly enhance Southern Illinois University Carbondale researchers' ability to study the structure of solid materials at the molecular level.

It's a probe that attaches to one of the University's nuclear magnetic resonance instruments located at Neckers Building. It will allow scientists to study materials that are in a solid state, which the University previously lacked the equipment to do.

Daniel J. Dyer, associate professor of chemistry and biochemistry, led a group of researchers who successfully petitioned the National Science Foundation to fund the equipment. They learned this summer that the NSF approved the $164,000 price tag for building and installing the instrument.

Dyer said the upgrade is key to pursuing the University's goal of becoming a top-75 publicly funded research institution. The goal is one of those included in Southern at 150: Building Excellence Through Commitment, the blueprint the University is following as it approaches its 150th anniversary in 2019.

"It's becoming pretty common for all major research universities to have a solid state NMR," Dyer said. "This is putting us right in line with other top facilities. It will allow researchers to do experiments they couldn't do before and it will be good for recruiting new faculty and good graduate students."

The custom-built piece will arrive sometime this academic year and physical science researchers — chemists, geologists, coal researchers, for example — will use it to examine the infinitely small structures that form solid materials. It will give researchers the opportunity to do many things, such as investigate ways to grow better industrial-use crystals or find ways to deliver drugs via ultrasound.

Nuclear magnetic resonance instruments use a powerful magnet and radio waves to examine the molecular structure of materials. Researchers place a sample in a tube running through the magnet, which modifies the spin of the nuclei in the sample. Radio waves pulsed by the probe at the bottom of the tube then "excite" the nuclei, which researchers then analyze as they "relax" following the radio wave.

Researchers can then analyze the amount of energy absorbed by the sample against the amount that passes through it in order to infer information about the type of nuclei present and their location within the molecule. This can tell them about the structure, strength and other characteristics of the material.

The University's NMR facility has been around since 1987 and SIUC now has three such instruments, said William C. "Bill" Stevens, director of the facility. The machines all are new or practically new, given the many electronic and other updates they have undergone. Currently, the machines work only with substances that are suspended in liquid and Stevens said the new equipment is an important addition to the University's research arsenal.

"This grant will completely open us up for playing a greater role for researchers in the University's Materials Technology Center and the Center for Advanced Friction Studies," said Stevens, referring to two major research centers on the SIUC campus. "It also will help researchers in any of the physical sciences.

"Not having a solid state capability here kind of stuck out like a sore thumb," Stevens said. "This really rounds out the package of what we can offer here."

Using a Web site and special software, researchers and students can use the facility from any computer. The person simply can deliver the sample they want tested to the facility and then gather and analyze data from the remote location.