The Department of Chemistry invites you to its departmental seminar Monday, Sept. 19, at 4:10 p.m. in Fulmer Hall, room 201.
Dr. Di Wu from the Gene and Linda Voiland School of Chemical Engineering and Bioengineering will present, Probing the Energetics of Interfacial Interactions and Structural Stability of Materials.
Abstract: During the past few decades, advances in surface chemistry and material sciences at the molecular level are shaping our world by playing crucial roles in balancing global scale energy crisis and critical environmental concerns. However, systematic investigations into the energetics of molecule – material interactions and the intrinsic stability of materials are rarely carried out.
In this talk, I demonstrate how thermochemistry reveals crucial energetic insights into surface phenomena and materials chemistry related to carbon dioxide capture and sequestration, heterogeneous catalysis, and environmental remediation. First, I present the thermodynamic complexity of carbon dioxide capture on metal – organic framework (MOF) sorbents with builtin and grafted nucleophilic functional groups (-OH and -NH2). These studies reveal that carbon dioxide adsorption on functionalized MOFs is a complex process involving multiple thermodynamic factors reflecting changes in surface phase and structure, chemical bonding and degree of disorder as temperature and gas loading vary. These fundamental insights may help optimize the design, synthesis and application of MOF-based carbon dioxide sorbents. I also explore the energetics of interaction and competition between small molecules (water, simple and complex organics) and inorganic materials, including calcite, silica, zirconia, uranium compounds, zeolites and mesoporous frameworks, at interfaces and in nanopores. Combined with spectroscopic, diffraction, electron microscopic and computational techniques, the energetics of gas/liquid – solid interactions can be correlated with specific bonds, molecular configurations and nanostructures. Though the energetics evolves continuously from weak association to strong bonding to classical capping, distinct regions of rapidly changing stepwise energetics often separate the different regimes. These phenomena are closely related to the properties of inorganic material surfaces (hydrophobicity and acidity/basicity), to the framework architectures, and to the chemical nature of adsorbate molecules. Moreover, I summarize some of our very recent results on the structure and thermodynamic stability of uranium compounds, including UO3, U2O7, UO4, U(v) metal urinates, UTa3O10, and uranothorite. The implication in nuclear waste forms and actinide environmental chemistry is discussed. These thermodynamic insights directly probed using calorimetric methodologies may reinforce our understanding of complex interfacial interactions as well as the specific structure – stability relations for materials relevant to energy sustainability and environment remediation.
