Dr. Marcus Bond instructs students on Southeast’s single crystal diffractometer.

The equipment will enhance Southeasts structural science capabilities and be used by students and faculty in chemistry, physics, agriculture and historic preservation.

The application process itself is extremely competitive, with only 20 to 25% of submitted grants funded in a given year, said Dr. Marcus Bond, professor of chemistry and co-principal investigator on the grant. So, receiving a major NSF award here is a pretty big deal.

Principal investigator on the grant is Dr. Sarah Shaner, assistant professor of chemistry. Co-principal investigator along with Bond is Dr. Margaret Peggy Hill, professor of physics. Collaborators on the grant include Dr Mike Aide, professor of agriculture, and Dr. Steven Hoffman, professor of history and coordinator of Southeasts Historic Preservation Program.

PXRDs create diffractogram fingerprint patterns like this one calculated from the MOXAMC structure using the Cambridge Structural Database program Mercury.

Powder X-ray diffractometers allow researchers to analyze the structure of unknown materials and perform materials characterization in such fields as chemistry, metallurgy, mineralogy, forensic science, archaeology, physics, and biological and pharmaceutical sciences. Samples for the PXRD are typically made by grinding solids into a powder to make thousands of very small crystals, creating a unique diffraction pattern for each chemical compound, a fingerprint if you will, Bond said. The powder diffraction pattern can be measured quickly, and the X-ray diffraction pattern fingerprint matched against a library of known diffraction patterns to identify the solid material. A PXRD is used primarily to identify rapidly the identity and composition of a sample.

Bond says the powder X-ray diffractometer will complement Southeasts current single crystal X-ray diffractometer (SCXRD), which is used to determine the detailed arrangement of atoms in small single crystals of newly discovered compounds.

This positions Southeast, he said, to become a major center for X-ray diffraction and structural science.

A powder X-ray diffractometer will enhance the capabilities of Southeast’s single crystal diffractometer, pictured here.

X-ray diffraction has been very important to the development of science since the technique originated in 1914, he said.

Most of what we know about molecular structure has come from X-ray diffraction, he said. X-ray diffraction has led to the discovery of a range of important crystal structures, from simple structures of salt, water and ice to the double helical structure of DNA to the structure of the ribosome, the macromolecular machine that transcribes the information from messenger RNA and assembles amino acids into proteins, Bond said. Knowing the structure allows us to understand the large-scale properties of materials. Once you know the structure of diamond, you understand why it is so hard. Once you know the structure of ice, you understand why it floats. Once you understand the structure of DNA, you understand how genetics are inherited.

The technique is frequently used in the pharmaceutical industry.

Knowing the structure, pharmaceutical chemists can find ways to alter the structure to improve drug activity or develop new drug activity, he said.

The PXRD will be housed in the Department of Chemistry and Physics in Rhodes Hall and is expected to be operational by fall 2020. While the PXRD will be used by chemistry students at all levels, it also will be used by a range of Southeast students, including non-traditional users in agriculture, geosciences, historic preservation and anthropology. It also will be used in courses for STEM pre-service high school teachers, providing them with research experience they can share with their students.

This is an instrument that is often used in industry and academic research, Shaner said. Providing the opportunity for Southeast students to be trained to use the PXRD instrument and analyze data will make them more competitive as they apply for jobs or graduate school.

Southeast students in CH187 explored crystallography and redetermined and submitted a plot of a molecule to a database.

Shaner said she plans to use the PXRD in her research to analyze potential catalyst materials prepared in her lab to determine if they are useful in converting solar energy and water into hydrogen, which can be used as a fuel. Hill intends to use it in her research that focuses on materials with interesting magnetic properties. Bond says the PXRD will assist him in his research to establish the purity of new compounds and to track solid state transformations or reactions over time.

We will solicit broader use from anybody working with solid materials that they need to identify, Bond said. This could be in forensics, soil science, historic preservation and other areas.

*The opinions, findings, and conclusions or recommendations expressed as part of this project are those of the authors and do not necessarily reflect the views of the National Science Foundation.