@inproceedings{, author = {Ulrich, Hannah; Zigan, Lars}, title = {Application of Two Dye Two-Color Laser-Induced Fluorescence Spectroscopy on Droplets of Green Solvent Mixtures containing Water and Ethanol}, editor = {}, booktitle = {Proceedings of the 21st International Symposium on Application of Laser and Imaging Techniques to Fluid Mechanics 2024}, series = {}, journal = {}, address = {}, publisher = {}, edition = {}, year = {2024}, isbn = {978-989-53637-1-1}, volume = {}, number = {}, pages = {}, url = {https://www.lisbonsymposia.org/proceedings}, doi = {}, keywords = {Fluorescence ; droplet ; spray ; thermometry}, abstract = {In order to reach a higher sustainability, the utilization of green solvents is decisive in many technical applications. Water and ethanol substitute more complex solvents, showing advantages like ecologica l manufacturing, reusability or biodegradation. Both liquids are found in various industrial areas, ranging from a use as additives in biofuels, coolants or solvents for extraction in pharmaceutical, medical or food industries. Regarding these industrial processes, importa nt variable s are the liquid phase temperature and the composition in binary fluids The focus of this work is two dye two color laser induced fluorescence (2c LIF) measurements in ethanol, water and their mixtures. Liquid phase thermometry via 2c LIF requi res a selection of suitable fluorescence dyes regarding solubility, temperature sensitivity and the interaction among the dyes themselves. A mixture of a temperature sensitive and a temperature insensitive dye is used in order to reach a large change in si gnal ratio for thermometry. In this work, two dyes fluorescein disodium ( and sulforhodamine 101 ( as proposed by Chaze et al. Chaze et al. 2016) are analyzed regarding their absorption and emission behavior in various ethanol/water mixtures which are examples of "green solvents" The absorption spectra of the dissolved dye mixture are measured with a spectrophotometer at temperatures from 293 K to 343 K. Information on the temperature dependent absorption of the single dyes and reabsorption e ffects in ethanol/water mixture s is obtained. Additionally, the fluorescence of the mixtures is analyzed spectrally and by a n imaging system. Therefore, a fiber coupled spectrometer and a system with two sCMOS cameras equipped with a long distance ( mic roscope are applied for simultaneous detection of the signal of tempered solutions a monodisperse droplet chain. A study of small droplets with sizes below 50 μm are evaluated and the limit of the sp ectral detection system is determined and discussed. The application of the measurement technique to several solvent mixtures is investigated.}, note = {}, institution = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 10 - Institut für Thermodynamik, Professur: Zigan, Lars}, }