Summer research in Dr. Gelabert's lab encompasses two MADE in SC projects in optical materials: synthetic methods and fluorescence study of ZnO nanoparticles, and discovery of new compounds using hydrothermal methods and thermodynamic calculations. Tamara Bright and Kameron Johnson are undergraduate research fellows working with Dr. Gelabert.
ZnO is an important material used in sun protection, pigments and bacterial remediation. Ms. Bright is exploring nanoparticle synthetic methodologies using environmentally benign solvents, as well as incorporation of thermodynamic supersaturation data as a backdrop to the kinetic factors driving particle size and properties. Using ethanol/water mixtures as solvent, particles are then analyzed for particle size (left photo*), fluorescence emission and X-ray powder diffraction. [*Tamara Bright ('20) operating the Horiba Partica LA950 laser scattering analysis instrument.]
Mr. Johnson (right photo**) is examining phase space in the K-La-Zr-O quaternary system in the search for new rare earth compounds, for applications such as scintillation. In the hydrothermal synthetic method, solutions are first prepared with complexing agents for La3+ (ethylenediaminetetraacetate ion) and ZrO2+ (acetylacetone), with addition of KOH, followed by sealing in teflon-lined pressure vessels. After heating, products are separated, washed, then analyzed with compound optical microscopy, X-ray powder diffraction, and SEM. Specific conditions are chosen based on yield diagrams calculated with aqueous speciation software, a tool that can show the concentration and pH conditions, at reaction temperature, where stable binary compounds (zirconia and lanthanum hydroxide) are less likely to form in high yield. [**Kameron Johnson ('21) collecting X-ray powder diffraction data with the Rigaku Miniflex 600 diffractometer.]August 7, 2018