Water in mesoporous confinement

Author(s)
Wilfried Schranz, Viktor Soprunyuk
Abstract

The first mechanical relaxation measurements (f = 400 Hz) of water confined in microporous silica were performed more than 40 years ago. The authors reported a so called "capillary transition" (here denoted as P3) of water in the core of the pores and a second one at a lower temperature, which they called the "adsorbate transition" (P1 in present work) related to water near the surface of the pores. The capillary transition was identified with the freezing of water in the centre of the pores. However, even 40 years later, the origin of the adsorbate transition is not yet clear. One study relates it to the liquid-to-glass transition of the supercooled water in the pores, and another study to the freezing of the proton reorientations at the lattice defects. The present work shows the data from extensive dynamic mechanical analysis (DMA) measurements (f = 0.1 Hz-70 Hz) of water confined in mesoporous silica (d = 2.5, 5 and 10 nm), which are in favour of a liquidto- glass scenario.

Organisation(s)
Physics of Functional Materials
External organisation(s)
Erich Schmid Institute of Materials Science
Journal
Molecules
Volume
24
No. of pages
14
ISSN
1420-3049
DOI
https://doi.org/10.3390/molecules24193563
Publication date
10-2019
Peer reviewed
Yes
Austrian Fields of Science 2012
Materials physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/water-in-mesoporous-confinement(4c358aca-197e-468d-96e1-df43f5405ccc).html