Center for Functional Nanomaterials Seminar

Functional materials with exciting novel properties are often disordered, posing challenges to structural characterization. The conventional laboratory X-ray powder diffraction breaks down when the material is nanocrystalline or amorphous. Atomic pair distribution function (PDF) calculated from synchrotron X-ray total scattering, on the other hand, is the tool of choice for studying local structure of disordered materials. In the beginning part of my talk, I will introduce PDF technique, and its applications on extracting structural details of emerging two-dimensional nanomaterials. Despite the ubiquitous importance of nanoparticles in the modern scientific and technological materials landscape, it is notoriously difficult to find an experimental answer to questions as simple as "do bonds get weaker or stronger in a nanocluster compared to the bulk", yet the answer to these questions is critical to understanding properties such as catalytic activity or optical response. I will present our recent work on examining size dependence of lattice dynamics of cadmium selenide quantum dot nanoparticles via high resolution inelastic X-ray scattering (HERIX). Finally, I will summarize my research progress in applying synchrotron X-ray techniques in studying pharmaceutical soft materials [6-8] and conclude the talk with future plans.