Fabrication of Octahedral Tantalum Cluster Film by Electrophoretic Deposition
October 1-6, 2017
The octahedral Ta6Br14.8H2O cluster, one of the [M6Li12La6]n- octahedrons (M= Nb, Ta; Li= halogen, La= halogen or chalcogen), exhibits interesting oxido-reduction properties in solution1. The application of the [Ta6Bri12]2+ cores has been potentially studied in biotechnologies2, optical devices3, photovoltaic cells4 and catalysis5. Originating from the expectation to block the UV and NIR light on low-emissivity window, the Ta6Br14.8H2O cluster thin film on ITO glass has been fabricated by electrophoretic deposition (EPD) process, a fairly rapid and low cost two-step process well-known for ceramic shaping, conductive surface coating and easily scalable to industrial level. The interesting characteristic has been recognized that the green [Ta6Bri12]2+ cores (adsorbing Ultra-Visible range) easily transfers to brown [Ta6Bri12]3+/4+ cores (absorbing near-infrared range) when dissolved in different solvents. Therefore, selecting the medium and optimizing the concentration of water in solvent to obtain the green homogeneous suspension with high dissolution is the main purpose of study. Considering the green color and transmittance of solution, as well as FE-SEM surface morphology of the green film, 0.02 mL H2O per mL acetone was selected as the optimal ratio to obtain the green transparent suspension and possibility to fabricate the green film by EPD process. However, the [Ta6Bri12]2+ green film has been essentially incorporated with poly vinyl pyrrolidone (PVP) in order to improve the dispersion of Ta6Br14.8H2O clusters inside the suspension and effectively prevent the performance of new [Ta6Bri12]3+/4+ clusters (brown-color) by oxidizing reactions.
 A. Vogler et al., Inorg. Chem., 1983, 23 (10), 1360.
 J. Knablein et al., J. Mol. Biol., 1997, 270, 1.
 S. Cordier et al., J. Inorg. Organomet. Polym., 2015, 25, 189.
 A. Renaud et al., Chemistry Select., 2016, 1, 2284.
 A. Barras et al., Appl. Catal. B: Environ., 2012, 123, 1
Nguyen Thi Kim Ngan, Adele Renaud, Stephane Cordier, Maxence Wilmet, Benjamin . Dierre, Fabien Grasset, Naoki Ohashi, and Tetsuo Uchikoshi, "Fabrication of Octahedral Tantalum Cluster Film by Electrophoretic Deposition" in "Electrophoretic Deposition VI: Fundamentals and Applications", Aldo R. Boccaccini, Institute of Biomaterials, University of Erlangen-Nuremberg, Germany Omer van der Biest, Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Belgium James Dickerson, Consumer Reports, USA Tetsuo Uchikoshi, National Institute for Materials Science, Japan Eds, ECI Symposium Series, (2017). https://dc.engconfintl.org/electrophoretic_vi/22