Funded Research Projects

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14641/189

An index of publicly funded research projects conducted by Texas A&M affiliated researchers.

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Browsing Funded Research Projects by Funding Agency "Department of Energy"

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    Research Project
    Radioactive Powder Characterization Equipment for Enhanced Research and Teaching Capability
    Nuclear Engineering; TAMU; https://hdl.handle.net/20.500.14641/628; Department of Energy
    The objective of this proposal is to enhance the capabilities of the Texas A&M University (TAMU), Department of Nuclear Engineering, Fuel Cycle and Materials Laboratory (FCML). The FCML is a unique university facility established to study issues in the nuclear fuel cycle, including materials and chemical processing. It currently operates under the direction of Dr. Sean M. McDeavitt (Co-PI) with Drs. Delia Perez-Nunez and Luis H. Ortega (Co-PI, and PI) as laboratory manager and research engineer, respectively. Work carried out at the FCML has focused on the processing and characterizing of materials related to fuel development, waste management, and several other projects relevant to the DOE-NE mission. Current FCML equipment includes a JEOL 6400 SEM, two large and one small inert atmosphere gloveboxes, multiple uniaxial presses for pelletization (including two 12-ton hydraulic presses, a 40-ton programmable press, and a 90-ton hydraulic press) and a hot isostatic press. Multiple high temperature furnaces with Tmax ranging from 1000C to 2000C which may be configured for casting, diffusion couple studies, instrumented sintering, cold or hot pressing, and extrusion. Thermal property characterization capabilities include a Netzsch LFA 447 to measure thermal diffusivity, and a Netzsch STA 409 for simultaneous differential calorimetry and gravimetric analysis. The FCML has been approved for the handling, testing and characterization of radioactive materials (including small quantities of enriched uranium). A quality assurance plan is in place that is applicable for simple fuel fabrication operations, potential irradiation studies, or other work which requires more stringent validation protocols. This infrastructure upgrade request is designed to establish missing capabilities within the controlled area boundaries of the FCML. A challenge related to work with enriched powder and certain hazardous chemicals is that standard materials characterization tools are not as readily available without shipping to a national laboratory (if time and funding are available). Operations such as X-ray diffraction are currently available to FCML at user facilities on campus, but certain radioactive and hazardous powders (e.g., uranium and beryllium oxide powders) are not examinable anywhere on campus. Powders are very common precursors to the work carried out at the FCML. A thorough characterization of these powders is essential to obtaining a complete understanding of processing parameters during material development studies, as well as product verification and qualification. Therefore, an infrastructure improvement upgrade is proposed to assist in overcoming these challenges. The proposed equipment (Table 1) includes a Bruker D2 Phaser X-Ray Diffractometer (XRD) and a Micromeritics Sedigraph III Particle Size Analyzer (PSA) which are not currently available on campus for radioactive powders.
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    Research Project
    Studies of Reactive Amorphous Compounds and Surfaces: Their Pathways to Crystallinity and Surface Functionality
    Chemistry; TAMU; https://hdl.handle.net/20.500.14641/622; Department of Energy
    Mapping the pathway from amorphous to Crystalline There are many groups of compounds that do not form crystals. Yet they may have interesting properties such as porosity, ion exchange and proton conductivity. They are said to be amorphous with only short range order. If their structure were known it would allow chemists to better develop uses for these compounds. We have chosen to study two types of layered amorphous materials, that on heating for long periods approach crystalline structures. The first type of compounds are layered zirconium and tin phosphates, M(HPO4)2∙H2O, for short, ZrP and SnP. The crystallization is a slow process with the surface changing from highly disordered nanoparticles to single crystals. We have found that many compounds may be bonded to the POH groups that are on the surfaces of the layers. Our intention is to affix MOFs to the surfaces. MOFs are a combination of metals and organic compounds (Metal-Organic Frameworks) that exhibit ultra-high porosity and enormous internal surface areas. Many applications have been suggested but there is a problem with stability. We believe that MOFs bonded to our surfaces will be studier than the normally prepared MOFs. The crystallization of ZrP is a slow process with the surfaces changing as the crystallinity increases. This change is observed by the change in the sodium ion exchange curves as the particles become more crystalline. We propose to determine the changes in the MOFs made on the surfaces of ZrP from amorphous in increments to complete crystallinity. The tin compounds remain amorphous unless treated with 10-12 M H3PO4 and high temperatures (180o C). This provides us the opportunity to study the changes in the amorphous phases and how this effects the MOF structures. To aid in this endeavor we will team with Prof. Simon Billinge at Columbia University who is an expert in determining structures of non-crystalline materials. A second group of compounds are the phenyl phosphonates of Zr and Sn and their mixed derivatives such as Zr(O3PC6H5)2-x(HPO4)x. All these compounds are nanoparticles from as small at 10 nm to start and micron sized when near crystalline. Surely the surfaces can be prepared as different by degrees so that the MOFs or other reactive compounds may have their structures controlled by the nature of the surface. We use a layer by layer process so that we can increase the porosity depending upon the number of layers added. Furthermore, mixed MOFs may be prepared by changing the ion charge or ligand from layer to layer. We envision a new strategy controlling the nature of the surface and the composition to produce more robust MOFs with applications as catalysts, proton conductors, electron donors, molecules for separation, and drug delivery.