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Dynamic mechanical analysis of supercooled water in nanoporous confinement
- Autor(en)
- Viktor Soprunyuk, Wilfried Schranz, Patrick Huber
- Abstrakt
Dynamical mechanical analysis (DMA)(f = 0.2.100Hz) is used to study the dynamics of confined water in mesoporous Gelsil (2.6nm and 5nm pores) and Vycor (10 nm) in the temperature range from T = 80K to 300 K. Confining water into nanopores partly suppresses crystallization and allows us to perform measurements of supercooled water below 235K, i.e., in water's so-called no man's land', in parts of the pores. Two distinct relaxation peaks are observed in tan δ around T
1 ≈ 145K (P
1) and T
2 ≈ 205K (P
2) for Gelsil 2.6 nm and Gelsil 5 nm at 0.2Hz. Both peaks shift to higher T with increasing pore size d and change with f in a systematic way, typical of an Arrhenius behaviour of the corresponding relaxation times. For P1 we obtain an average activation energy of E
a = 0.47 eV, in good agreement with literature values, suggesting that P
1 corresponds to the glass transition of supercooled water. The observation of a pronounced softening of the Young's modulus around 165K (for Gelsil 2.6 nm at 0.2 Hz) supports the conjecture of a glass-to-liquid transition in the vicinity of P
1. In addition we find a clear-cut (1/d)-dependence of the calculated glass transition temperatures which extrapolates to T
g(1/d = 0) = 136 K, in agreement with the traditional value of water.
- Organisation(en)
- Physik Funktioneller Materialien
- Externe Organisation(en)
- Technische Universität Hamburg-Harburg (TUHH)
- Journal
- Europhysics Letters
- Band
- 115
- Anzahl der Seiten
- 7
- ISSN
- 0295-5075
- DOI
- https://doi.org/10.1209/0295-5075/115/46001
- Publikationsdatum
- 08-2016
- Peer-reviewed
- Ja
- ÖFOS 2012
- 103015 Kondensierte Materie
- Schlagwörter
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/d408bea0-363b-442e-a858-ebf3cbd6454d