"Applying conventional disciplines of chemistry to current and future issues."

Materials Science

graph based diagram

Chris Brazier's group searches for new electronic emission spectra of diatomic molecules. Recent work has concentrated on aluminum, boron, carbon, germanium, and silicon (SiB, AlB, AlC, and GeC). The molecules are produced by applying a high voltage discharge through a supersonic expansion into vacuum of the appropriate precursor gases diluted in helium. The expansion cools the molecular translational and rotational temperature to about 10 K while leaving them vibrationally and electronically excited. Visible or near UV light emitted by the excited molecules is analyzed by a high-resolution spectrometer and CCD camera to determine the characteristic transitions of the molecule. The spectra are then analyzed to determine the structure and potential energy curves of the molecule. The spectra also provide information about the distribution of valence electrons in the ground and excited states. Spectra recorded in such a controlled fashion can then be used to detect the molecules in more complex environments such as vapor deposition systems and flames.

a chemical reaction

Xianhui Bu's group seeks to develop CHPM with two different methods: (1) incorporation of enantiopure building blocks into the porous architecture; (2) use of enantiopure chiral additives to induce the absolute chirality of porous materials made of achiral building units. For chiral separation or asymmetric catalysis, crystalline homochiral porous materials (CHPM) have a great potential to achieve high efficiency because of their unique structural features such as high surface area. Porous materials are also of great interest as adsorbents for applications such as hydrogen storage and carbon dioxide sequestration. In their work, in addition to the control of geometrical features, they seek to introduce structural features such as open metal sites and charged frameworks to enhance host-guest interactions so that a higher storage density can be achieved.

relationship between crystal structre, physical properties and electronic structure
Shahab Derakhshan's group is devoted to design, synthesis and characterization of some novel solid state inorganic materials with desired physical properties for some specific applications. Accordingly their research activity is designed based on two different, albeit related categories namely energy related materials and magnetic materials. Due to the multidisciplinary nature of the field, their research program attracts a great deal of attention from Chemistry, Physics and Materials Science and Engineering communities. Their work is pushing forward the boundaries of our knowledge on the connections between crystal structure, electronic structure and physical properties of materials. This leads them to rationally design and produce the target functional materials. They can also perform chemical modifications to enhance physical properties when needed. The crystal structure (elemental composition, bonding characteristics and connectivity) determines the electronic structure, which in turn explains the physical properties. So our general focus will be devoted towards designing, synthesis, crystal structure determination, electronic structure calculations and physical property measurements of the following representative groups of materials.

digram showing a chemical reaction

Lijuan Li's group uses zero-valent metal centers, particularly electron-rich metal centers, to prepare potential molecular wires, polymeric systems or non-linear optical materials. Theses positively charged metal centers linked by bisphosphines have been found to exhibit special properties due to the phosphine linkers. They have also prepared metal organic frameworks with specific coordination mode, which exhibit special magnetic and photoluminescent properties.

system design schematic

Hadi Tavassol's research group focuses on fundamental understanding and design of chemical interfaces, especially in electrochemical systems. The group fabricates materials, specifically designed toward interfacial processes, which are essential in the system level performance of electrochemical devices, and mimic biological systems. Students in the group use in-situ characterization techniques to elucidate the interplay of materials and function. Tavassol group members prepare inter-layers, thin films, and molecular assemblies and employ advanced electrochemical and laser spectroscopy techniques to study energy devices and biological systems.

Tian research image 2

Fangyuan Tian's group focuses on designing and synthesizing highly ordered metal-organic frameworks (MOFs) on silicon substrate both with and without the aid of self-assembled monolayers (SAMs). Appropriate fabrication techniques are selected based on different surface binding moieties. Following surface anchored MOF thin film formation and characterization, nanostructured MOF-based devices are under development, including non-electronic micro-electro mechanical system (MEMs) and electronic devices that utilize MOF thin films as a dielectric layer. Integrate MOF thin films as an insulation layer on a silicon substrate or silicon/SAM system with fabricated source and drain will be the next goal.