Supercritical drying of aerogel: In situ analysis of concentration profiles inside the gel and derivation of the effective binary diffusion coefficient using Raman spectroscopy

Klima T, Quiño J, Quiño J, Rühl M, Klima T, Ruiz F, Will S, Bräuer A (2016)

Publication Language: English

Publication Status: Published

Publication Type: Journal article

Publication year: 2016

Journal

Journal of Supercritical Fluids Elsevier

Publisher: Elsevier

Book Volume: 108

Pages Range: 1-12

DOI: 10.1016/j.supflu.2015.10.011

Abstract

We here experimentally visualize in situ temporally and spatially resolved composition and concentration fields developing inside silica aerogels during the supercritical drying process. For the extraction of the pore liquid ethanol we used supercritical carbon dioxide. The evolution of the composition profiles inside the gel was measured via one-dimensional Raman spectroscopy. The composition profiles were converted into concentration profiles using an equation of state. The evolution of the concentration fields shows that ethanol is continuously transported out of the gel. On the contrary CO2 is first transported into and at later drying times (before the depressurization) out of the gel structure. The binary diffusion coefficient was derived as a function of the composition and found to vary by two orders of magnitude for different stages of the drying process. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.

Authors with CRIS profile

Tobias Klima Erlangen Graduate School in Advanced Optical Technologies (SAOT) Jaypee Quiño Erlangen Graduate School in Advanced Optical Technologies (SAOT) Martin Rühl Erlangen Graduate School in Advanced Optical Technologies (SAOT) Stefan Will Lehrstuhl für Technische Thermodynamik (LTT) Andreas Bräuer Erlangen Graduate School in Advanced Optical Technologies (SAOT)

Involved external institutions

KEEY Aerogel SAS FR France (FR)

How to cite

APA:

Klima, T., Quiño, J., Quiño, J., Rühl, M., Klima, T., Ruiz, F.,... Bräuer, A. (2016). Supercritical drying of aerogel: In situ analysis of concentration profiles inside the gel and derivation of the effective binary diffusion coefficient using Raman spectroscopy. Journal of Supercritical Fluids, 108, 1-12. https://doi.org/10.1016/j.supflu.2015.10.011

MLA:

Klima, Tobias, et al. "Supercritical drying of aerogel: In situ analysis of concentration profiles inside the gel and derivation of the effective binary diffusion coefficient using Raman spectroscopy." Journal of Supercritical Fluids 108 (2016): 1-12.

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