Dr. Tasneem Siddiquee

Nanoparticles and Neutron Diffraction Offer Summer Research Participant New Challenges

Tennessee State University Professor Dr. Tasneem Siddiquee is an architect, but not in the usual sense. Rather than buildings, he designs molecules.

A chemist experienced in forming new molecular structures and studying how they react, Dr. Siddiquee said he was pleased to have the opportunity to participate in the 2009 Oak Ridge National Laboratory (ORNL)/Oak Ridge Associated Universities (ORAU) Historically Black Colleges and Universities (HBCU) and Minority Education Institutions (MEI) Faculty Summer Research Program at ORNL.

The program enabled him to broaden his academic credentials by exploring neutron scattering in a project led by ORNL's Dr. Andrew Christianson. Neutron scattering refers to techniques in which neutrons are used to study the structure and physical properties of matter; in this project, magnetic properties of materials.

The goal of the project is to add to the body of knowledge concerning nanoparticles, which are pieces of material so tiny that they exhibit physical and chemical properties that are different from the bulk sample of material.

"This project is looking at how magnetic properties are affected by the variation of nanoparticle sizes," Dr. Siddiquee said. "I worked on optimizing the yield, controlling the size and shape of the nanoparticles. Neutron scattering experiments and other measurements of magnetic properties are being performed on these particles."

When nanoparticles are better understood, new molecules having the shape of a container, or "cage," may be anchored to them for delivery in environmental cleanup or cancer therapy applications, Dr. Siddiquee said.

Molecules could be synthesized to "mop up" hazardous substances; however, depending on their physical properties, they may clump together and be rendered unable to do their jobs. Because nanoparticles maintain a slight chemical separation from one another, the cage molecules could be anchored to them and thus remain separated.

"Suppose you have a chemical hazard composed of molecules that are small enough to fit into these cage molecules," Dr. Siddiquee said. "You could have several cage molecules anchored to nanoparticles, which would serve to separate the molecules. All you would need to do is dump some of these modified nanoparticles into the waste, and the molecules anchored to them would take up the toxic materials.

"Next, you could filter these modified nanoparticles soaked with toxic materials. Then, you could release the toxic materials in a controlled chamber by chemical treatment or physical treatment; for example, heating and oxidizing, when appropriate."

Relative to cancer treatment, nanoparticles assembled with cage molecules could be used to carry and deliver cancer-healing drug molecules to destroy tumor cells with radiation therapy without harming the good cells, Dr. Siddiquee explained.

"Participation in this program has enhanced my professional development," Dr. Siddiquee said. "I have gained practical experience working with nanoparticles and neutron diffraction, which are new areas for me, and what I have learned will make me a better teacher and researcher."