IEC 40 |
| Gamal Khalil1, Gregory D. Phelan1, Kimberly S. F. Lau1, Brenden Carlson1, Larry R. Dalton2, Martin Gouterman1, and Jim Callis1. (1) Department of Chemistry, University of Washington, Seattle, WA 98105, (2) Departments of Chemistry, University of Washington and University of Southern California, Bagley Hall 202D, Seattle, WA 98195-1700 |
| Since the classic work of Weissman and Crosby, rare earth complexes have attracted many researchers. Europium complexes, in particular, have been investigated as laser materials, electroluminescent devices, biological indicators, and temperature sensors. As temperature sensors, these europium chelates can correct for temperature problems in pressure sensitive paints, monitor excessive friction over a surface, detect a boundary between laminar and turbulent flow, allow for early measurement of structural failure, and be used in micro air vehicle wind tunnel and insect flight mechanism studies. Beta-diketonates are commonly used, and easily synthesized as ligands for europium chelates, producing highly luminescent complexes. Lifetime methods have shown to provide reliable and accurate measurements of temperature sensitivity for these luminescent-based, europium chelate temperature sensors. In this paper, the ligand, matrix, and concentration effects of various europium beta-diketonate complexes in polymer matrices were studied as a function of temperature. Results to date have shown that the environment indeed plays an important role in the temperature sensitivity of europium complexes. Further studies are needed to determine how the number and type of ligands affect temperature sensitivity. However, it has been seen that while conserving concentration, varying the types and amounts of ligands does affect temperature sensitivity, photodegredation, and mean lifetime. Changes in the type of polymer matrix used with the europium chelate also affected the temperature sensitivity and mean lifetime of the temperature sensor. In comparison to polycarbonate, the fluoroacrylic polymer, FIB, seemed to show the most changes in sensitivity and lifetime, while varying the concentration of a single complex. With this variation in concentration, changes were very constant. Temperature sensitivity results showed an increase in intensity with an increase in concentration, while the mean lifetime of the sensors actually increased with a decrease in concentration. These concentration results were also comparable between the different polymers. |
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General Papers in Advanced Materials and Nanotechnology (sponsored by Advanced Materials & Nanotechnology Subdivision)
1:30 PM-5:24 PM, Sunday, March 23, 2003 Convention Center -- Room 394, Oral
Division of Industrial and Engineering Chemistry |