Simultaneous determination of the composition and temperature gradients in the vicinity of boiling bubbles in liquid binary mixtures using one‐dimensional Raman measurements

Abstract

The ability to transport large quantities of heat by nucleate boiling is reduced for mixtures compared to their pure components. To study the heat and mass transfer during the boiling process, a one-dimensional Raman spectroscopy setup was applied to measure, for the first time to the best of our knowledge, the composition and temperature gradients in the vicinity of single boiling bubbles of a mixture of acetone and isopropanol. A novel evaluation strategy allowed the simultaneous detection of the mixture composition and temperature from the C-H and the O-H Raman spectra. The composition gradients arise because of rectification effects, which cause unlike compositions in the gas and liquid phases. Heat transfer from the boiling bubble to the surrounding liquid induces temperature gradients. High temporal and spatial resolution measurements using an imaging spectrograph and an electron multiplying charge-coupled device camera revealed large composition and temperature gradients with similar shapes. The accuracy of the composition results was validated by a species conservation calculation.

Surfactant-free CO2-based microemulsion-like systems

“…A detailed description of the determination of R OH from the acquired raw Raman spectra is given in the ESI. † Temperature-, 21 composition- 22 or density 23 variations in the systems influence the development of the hydrogen bonding, and are therefore observable in the OH stretch vibration Raman spectrum of water and consequently influence R OH .…”

A fast and remote screening method for sub-micro-structuration in pressurized mixtures containing water and carbon dioxide

“…3, in water vapor the Raman signal of the water stretching vibration is a sharp narrow peak at 3660 cm -1 , because in the vapor phase the distance between the water molecules is too far to enable the formation of hydrogen bonds. [27,28] The same is true for very diluted water containing systems [29], in which also no hydrogen bonds can be formed.…”

Chemical Composition Monitoring in a Batch Distillation Process Using Raman Spectroscopy

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