Investigation of Five Organic Dyes in Ethanol and Butanol for Two-Color Laser-Induced Fluorescence Ratio Thermometry

Abstract

In this article, we compare absorption and temperature-dependent fluorescence spectra of five organic dyes for 2c-LIF (two-color laser-induced fluorescence) thermometry in ethanol and butanol. The dyes fluorescein, eosin Y, rhodamine B, rhodamine 6G, and sulforhodamine 101 individually mixed in ethanol and butanol were studied at liquid temperatures of 25-65 • C. The self-absorption spectral bands are analyzed along with intensity ratios and the respective sensitivities for one-dye and two-dye 2c-LIF thermometry are deduced. For one-dye 2c-LIF, rhodamine B showed the highest sensitivity of 2.93%/ • C and 2.89%/ • C in ethanol and butanol, respectively. Sulforhodamine 101 and rhodamine 6G showed the least sensitivities of 0.51%/ • C and 1.24%/ • C in ethanol and butanol, respectively. For two-dye 2c-LIF, rhodamine B/sulforhodamine 101 exhibited the highest temperature sensitivities of 2.39%/ • C and 2.54%/ • C in ethanol and butanol, respectively. The dye pair eosin Y/sulforhodamine 101 showed the least sensitivities of 0.15%/ • C and 0.27%/ • C in ethanol and butanol, respectively.

Fluorescence Spectroscopy for Studying Evaporating Droplets Using the Dye Eosin-Y

“…The fluorescence spectra are shifted with increasing temperature towards higher wavelengths (from 554.0 nm to 568.6 nm). This spectral behavior is in agreement with the investigations reported by Mishra et al [ 20 ] in the temperature interval from 298 K–338 K. The integrated fluorescence intensity decreases by 19.8% with increasing temperature within the investigated temperature range (283 K to 413 K), see Figure 9 .…”

“…In the first step, the photo-physical properties of the mixtures are analyzed in a micro cell under various conditions using a spectrometric LIF setup. The present work extended the temperature sensitivity interval of the absorption and emission of Eosin-Y dissolved in ethanol in the literature (296 K–338 K, [ 20 , 21 ]) to 283 K–413 K. Furthermore, the single droplet investigations extend the knowledge regarding the measurement uncertainties of the LIF/Mie droplet sizing technique at ambient conditions and long droplet residence times, leading to a change in dye concentration as well as droplet deformation. These studies provide deeper insights into individual effects on the LIF signal supporting the error estimation of PDS.…”

“…A dye is typically added to a non-fluorescent liquid. Eosin-Y is a suitable dye for ethanol and water, as it shows high fluorescence quantum yield and low temperature sensitivity, which is advantageous for planar droplet sizing (PDS) [ 20 , 21 ]. The technique is based on the assumption, that the LIF-signal of a laser light illuminated droplet is approximately volume dependent (i.e., it is proportional to d 3 ) and the Mie-scattering signal is surface dependent (i.e., it is proportional to d 2 ) [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ].…”

Molecular Dynamics and Energy Transfer in Pure Aniline and Rh101+/Aniline Mixed Solution Measured by Ultrafast Spectroscopy

“…[5] Spectral analysis of absorption is regarded as the most common and competitive approach to identify the types of organic pollutants. [6,7] However, strong fluorescence cannot be clearly distinguished, and the complex energy transfer mechanisms of dyes still need to be investigated. Since energy transfer is the first step of chemical reactions, it plays a vital role in the contaminant treatment.…”

A Novel Approach for Measurement of Composition and Temperature of N-Decane/Butanol Blends Using Two-Color Laser-Induced Fluorescence of Nile Red

“…In case of a spectral variation of the fluorescence with varying mixture composition, this behavior could be utilized to determine the butanol concentration, e.g., in evaporating gasoline, diesel, or kerosene droplets. However, for other dyes such as Eosin Y or rhodamines, the emission spectra are similar when the dyes are dissolved in ethanol or butanol, respectively [ 31 ].…”