COLL 157 |
| Josef F. Holzwarth, Physical Chemistry, Fritz-Haber-Institute, MPG, Faradayweg 4-6, D-14195 Berlin, Germany, S. Couderc, Physical Chemistry, Fritz-Haber-Institut, MPG, Faradayweg 4-6, D-14195 Berlin, Germany, Andrew Beeby, Department of Chemistry, University of Durham, South Road, Durham, DH1 3LE, United Kingdom, Ian P. Clark, Laser for Science Facility, Rutherford Appelton Laboratories, Chilton, Didcot Oxfordshire, OX11 0QX, United Kingdom, and Anthony W. Parker, Central Laser Facility, CLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX, United Kingdom. |
| Measurement of temperature changes in nanoliter volumes is a serious problem, especially if both high precision and nanosecond time resolution are required. Exploitation of the anti-Stokes fluorescence of laser-excited Rhodamine 101 dye offers a solution to the problem. We used a pulsed dye laser (bandwidth 20 ns) for time resolved measurements. The T-jump laser and the pulsed detection laser were aligned inside a 1 mm spot of a liquid sample. A DT=4 K caused 10% increase in fluorescence intensity. The detection was performed with a variable delay between 10 ns and 100 ms after the heating. We could observe special effects caused by shock-waves produced by the fast thermal expansion of the liquid sample. This new technique of time resolved anti-Stokes fluorescence measurements provides a convenient and precise tool to measure small temperature changes in nano-volumes of liquid samples under many different experimental conditions. |
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Colloidal and Molecular Electro-Optics
Division of Colloid and Surface Chemistry |