Journal
JOURNAL OF SUPERCRITICAL FLUIDS
Volume 108, Issue -, Pages 1-12Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.supflu.2015.10.011
Keywords
Aerogel; Supercritical drying; Diffusion coefficient; 1D Raman spectroscopy; In situ measurements; Mass transport; Pore diffusion
Categories
Funding
- German Research Foundation (Deutsche Forschungsgemeinschaft - DFG) [BR 3766/4-2]
- Erlangen Graduate School in Advanced Optical Technologies (SAOT)
Ask authors/readers for more resources
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
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available