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Wetting Behavior of Cerium Oxide Films Grown by Pulsed Laser Deposition • Daniel Li, UIUC • Advisor Dr. Jeremiah AbiadeNSF-REU Symposium • University of Illinois at Chicago • Chicago, IL • 8/1/2013 Daniel Li email@example.com
Purpose and Motivation Build upon research that investigate the intrinsic hydrophobic properties of REOs Robust, hydrophobic coating compatible with existing facilities Daniel Li firstname.lastname@example.org 15Azimi, Gisele, Rajeev Dhiman, Kwon Hyuk-Min, Adam T. Paxton, and Kripa K. Varanasi. "Hydrophobicity of Rare-earth Oxide Ceramics." Nature Materials 12.4 (2013): 315-20. Nature Publishing Group, 20 Jan. 2013.
Wetting Behavior • Water Contact Angle • Surface energy • Hydrophobicity and hydrophilicity Daniel Li email@example.com 9 Quéré, David. "Wetting and Roughness." Annual Review of Materials Research 38.1 (2008): 71-99. Review in Advance. Annual Review of Materials Research, 7 Apr. 2007.
Applications of Hydrophobic Materials • Waterproofing and Lubrication • Corrosion Prevention • Condensation • Self Cleaning Materials • Heat Transfer/Cooling Systems  http://geography.swansea.ac.uk/hydrophobicity/soil_hydrophobicity.htm http://meanderinglanes.blogspot.com/2010/09/rain-on-windshield.html Daniel Li firstname.lastname@example.org  http://www.aeconline.ae/qatar-s-deputy-prime-minister-to-inaugurate-world-2s-largest-district-cooling-24893/news-files/dc2_main.jpg  http://www.criticalend.com/wp-content/uploads/2009/03/balepsycho.jpg
Cerium Oxide Polymer Additives • Chemically Stable • High Adhesiveness • Thermal Transfer • Durability/Wear Resistance • Relatively Low Cost Hydrophobic Properties diminish substantially from thermal, mechanical, and chemical attack Daniel Li email@example.com [1,2] http://www.rustoleum.com/product-catalog/consumer-brands/neverwet/neverwet-kit/ http://www.netl.doe.gov/newsroom/features/12-2010.html
Pulsed Laser Deposition (PLD) Process1. Laser is focused onto a target in high vacuum or ambient gas2. Target material is vaporized and a plasma plume is created3. Gaseous target deposits onto substrate, thin film develops Thin Films • Thin = less than one micron (1000 nm) • Film = layer of material on a substrate Daniel Li firstname.lastname@example.org [1,2] http://tfy.tkk.fi/aes/AES/projects/prlaser/pld.htm
PLD Factors • KrFExcimer Laser Fluence • Target-substrate distance • Number of pulses and frequency • Deposition temperature • Basal and gas pressure Advantages:- stoichiometry is preserved- multiple targets allowable- easily controlled growth rateDisadvantages:- limited uniformity, requires small substrate Daniel Li email@example.com  https://rt.grc.nasa.gov/main/rlc/pulsed-laser-deposition-laboratory/
Experimentation Pulsed laser deposition of thin film cerium oxide (ceria) on Si at varying oxygen partial pressures and deposition temperature WCA measurements over time with and without UV irradiation (4 microliters, DI water) III. X-ray photoelectron spectroscopy (XPS) characterization Daniel Li firstname.lastname@example.org
PLD Thin Films • Controls • Cerium Oxides onto Silicon wafer • Target-Substrate Distance: 6.2 cmKrFExcimer Laser: • Wavelength: 248 nm (UV) • Laser Fluence 4.5 J/cm2, 22 kV, 500 mJ • 5000 Pulses at 5 Hz • Independent Variables • Oxygen Partial Pressure • 2 main Cerium oxidation states: +3, +4 • Temperature (RT, 300, 700 degrees Celsius) Daniel Li email@example.com  http://www.kruss.de/en/products/contact-angle/drop-shape-analysis-system
PLD Depositions Daniel Li firstname.lastname@example.org
WCA as a function of Deposition Temperature Oxygen Pressure(Torr) 3.0 E-2 5.0 E-2 No Oxygen Photo provided courtesy of Sin Pui Fu, UIC Daniel Li email@example.com
Oxygen Pressure(Torr) Daniel Li firstname.lastname@example.org
Retreatment of Previous Samples with UV over time Oxygen Pressure(Torr) Oxygen Pressure(Torr) Resistance to UV: smaller drop in WCA Daniel Li email@example.com
UV Treatment of Room Temperature Samples over Time Oxygen Pressure(Torr) Daniel Li firstname.lastname@example.org
WCA over Time (after 120 minutes of UV Irradiation)Samples were kept in the dark Variation in recovery to pre- UV levels Daniel Li email@example.com
X-Ray Photoelectron Spectroscopy (XPS) Sample is irradiated by X-rays - emitted electrons are measured Useful for determining stoichiometry- oxidation states- empirical formula Daniel Li firstname.lastname@example.org
XPS Data 2.1 E-3 T, 700 C 7.5 E-3 T, 700 C • XPS analyzed valency of Ce ions at the surface • Ce(III)Oxide is present in higher amounts in higheroxygen pressures than Ce (IV) Oxide • Stoichiometry: cerium and oxygen is independent of temperature Daniel Li email@example.com
Conclusions and Discussion • Water contact angles vary initially but eventually increase and plateau to ~ 90 degrees over a week • UV treatment causes a significant drop in WCA but most samples recover to pre-UV levels • Samples that have been treated previously with UV have a greater resistance (smaller WCA drop) than those treated for the first time; likewise for recovering to pre-UV treatment levels • More observed uniformity in samples created at 700 degrees, though XPS indicates temperature has little effect on oxidation states Daniel Li firstname.lastname@example.org
Further Work • Run standard scan on pure cerium to determine remaining peak features; XPS of additional samples • Additional characterization of surface morphology with AFM and TEM • Ultra clean storage inbetween measurements to account for hydrocarbon contamination Daniel Li email@example.com
Acknowledgements • EEC-NSF Grant # 1062943 • Advisor Jeremiah Abiade • RiadAlzeghier • Jelani Hannah • Dr. Takoudis and Dr. Jursich • REU Staff Daniel Li firstname.lastname@example.org
References 1 Joanne Devalet al “Reconﬁgurable hydrophobic/hydrophilic surfaces in microelectromechanical systems (MEMS)” 2004 J. Micromech. Microeng. 14 91 2 Anand, Sushant, Adam Paxon, and Kripa K. Varanasi. "Enhanced Condensation on Lubricant-Impregnated Nanotextured Surfaces." American Chemical Society 6.11 (2012): 10122-0129. ACS Nano. Apr.-May 2012. 3 Cao, Liangliang, Andrew K. Jones, and Vinod K. Sikka. "Anti-Icing Superhydrophobic Coatings." Langmuir Letter (2009): n. pag. American Chemical Society, Sept. 2009. 4 Nakajima, Akira. "Design of Hydrophobic Surfaces for Liquid Droplet Control." Asia Materials 3.55 (2011): 49-56. Nature. NPG, 19 May 2011. 5 Liu, Kesong, and Lei Jiang. "Metallic Surfaces with Special Wettability." Nanoscale 3.3 (2011): 825-38. RSC Publishing, 11 Jan. 2011. 6 Crick, Colin R., and Ivan P. Parkin. "A Single Step Route to Superhydrophobic Surfaces through Aerosol Assisted Deposition of Rough Polymer Surfaces: Duplicating the Lotus Effect." Journal of Materials Chemistry 19.8 (2009): 1074-079 7 Cao, Feng, Zisheng Guan, and Dongxu Li. "Preparation of Material Surface Structure Similar to Hydrophobic Structure of Lotus Leaf." Journal of Wuhan University of Technology-Mater. Sci. Ed. 23.4 (2008): 513-17. Aug. 2008 8 Wong, Tak-Sing, Sung Hoon Kang, and Sindy K.Y. Tang. "Bioinspired Self-repairing Slippery Surfaces with Pressure-stable Omniphobicity." Nature.com. Nature Publishing Group, 21 Sept. 2011. Web. 08 July 2013. 9 Quéré, David. "Wetting and Roughness." Annual Review of Materials Research 38.1 (2008): 71-99. Review in Advance. Annual Review of Materials Research, 7 Apr. 2007. 10Fowkes, F. Contact Angle, Wettability and Adhesion, American Chemical Society, 1964 11 McCarthy, T. A Perfectly Hydrophobic Surface, J. Am. Chem.Soc., 2006, 128, 9052. 12Tanford, C. “The Hydrophobic Effect, Wiley. 1973 13 Young, Thomas. "An Essay on the Cohesion of Fluids." Philosophical Transactions of the Royal Society of London (1776-1886) 95.1 (1805): 65-87. Royal Society Publishing. 14Giovambattista, N., Debenedetti, P. G. & Rossky, “Enhanced surface hydrophobicity by coupling of surface polarity and topography. Proceedings of the National Acaddemy of Sciences. USA 2009, 106 no.36, 15Azimi, Gisele, Rajeev Dhiman, Kwon Hyuk-Min, Adam T. Paxton, and Kripa K. Varanasi. "Hydrophobicity of Rare-earth Oxide Ceramics." Nature Materials 12.4 (2013): 315-20. Nature Publishing Group, 20 Jan. 2013. 16 Adachi, G., Imanaka, N. & Kang, Z. C. Binary Rare Earth OxidesCh. 2 (KluwerAcademic, 2004). 17K.Tsukuma, M. Shimada, “Strength, Fracture Toughness and Vickers Hardness of CeO2 Stabilized Tetragonal ZrO2 Polycrystals,” Journal of Materials Science, 20 (1985), 1178-1184. 18 Beie, H.-J., and A. Gnörich. "Oxygen Gas Sensors Based on CeO2 Thick and Thin Films." Sensors and Actuators B: Chemical 4.3-4 (1991): 393-99. 19 M. F. Stroosnijder, V. Guttmann, T. Fransen, J. H. W. de Wit, “Corrosion of Alloy 800H and the Effect of Surface Applied CeO2 in a Sulfidizing Oxidizing Carburizing Environment at 700 degree-C”, Oxidation of Metals, Vol. 33, Nos. 5/6, 1990 20Patsalas, P., S. Logothetidis, and C. Metaxa. "Optical Performance of Nanocrystalline Transparent Ceria Films." Applied Physics Letters 81.3 (2002): 466. 21 A.E. Hughes, J.D. Gorman, P.J.K. Patterson, R. Carter, Surface Interfacial Analysis 1996, 24, 634-640 22 Mohandas, E., G. Balakrishnan, and S. Tripura Sundari. "A Study of Microstructural and Optical Properties of Nanocrystalline Ceria Thin ﬁlms Prepared by Pulsed Laser Deposition." Elsevier(2010): 2520-526. Science Direct. Thin Solid Films, 10 Dec. 2010. 23 Jiang, Keren. "Fabrication and Catalytic Property of Cerium Oxide Nanomaterials."Chemistry Thesis (2011): 1-73. University of Nebraska- Lincoln, Jan. 2011. 25 Martínez, L., E. Román, J.l. De Segovia, S. Poupard, J. Creus, and F. Pedraza. "Surface Study of Cerium Oxide Based Coatings Obtained by CathodicElectrodeposition on Zinc." Applied Surface Science 257 (2011): 6202-207. Questions? Daniel Li email@example.com
Atomic Force Microscopy: Cerium (IV) oxide on Si No oxygen, 200 degrees C Roughness: 4.61 nm WCA: 95 degrees 5 E-2, 200 degrees CRoughness: 4.91 nmWCA: 44 degrees • PLD process doesn’t seems to yield different surface morphologies • Very different water contact angles Images provided by Sin-Pui Fu, UIC Daniel Li firstname.lastname@example.org
XPS DataCerium 7.5 E-3, 700 C 2.5 E-3, RT 2.1 E-3, 700 C Stoichiometry:7.5 E-3 torr at 700 C Ce:O 15:1 2.1 E-3 torr at 700 C Ce:O 32:1 Intensity A.u. Binding Energy eV Daniel Li email@example.com