CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

Cause of the fragile-to-strong transition observed in water confined in C-S-H gel

M. Monasterio ; Helén Jansson (Institutionen för bygg- och miljöteknik, Byggnadsteknologi) ; J. J. Gaitero ; J. S. Dolado ; S. Cerveny
Journal of Chemical Physics (0021-9606). Vol. 139 (2013), 16,
[Artikel, refereegranskad vetenskaplig]

In this study, the rotational dynamics of hydration water confined in calcium-silicate-hydrate (C-S-H) gel with a water content of 22 wt.% was studied by broadband dielectric spectroscopy in broad temperature (110-300 K) and frequency (10(-1)-10(8) Hz) ranges. The C-S-H gel was used as a 3D confining system for investigating the possible existence of a fragile-to-strong transition for water around 220 K. Such transition was observed at 220 K in a previous study [Y. Zhang, M. Lagi, F. Ridi, E. Fratini, P. Baglioni, E. Mamontov and S. H. Chen, J. Phys.: Condens. Matter 20, 502101 (2008)] on a similar system, and it was there associated with a hidden critical point of bulk water. However, based on the experimental results presented here, there is no sign of a fragile-to-strong transition for water confined in C-S-H gel. Instead, the fragile-to-strong transition can be explained by a merging of two different relaxation processes at about 220 K. (C) 2013 AIP Publishing LLC.

Nyckelord: band dielectric-spectroscopy, calcium silicate hydrate, neutron-scattering, temperature-dependence, cement pastes, tricalcium, silicate, dynamic crossover, glass-transition, mixtures, model



Denna post skapades 2013-12-17. Senast ändrad 2015-03-06.
CPL Pubid: 189484

 

Läs direkt!

Lokal fulltext (fritt tillgänglig)

Länk till annan sajt (kan kräva inloggning)


Institutioner (Chalmers)

Institutionen för bygg- och miljöteknik, Byggnadsteknologi

Ämnesområden

Fysik

Chalmers infrastruktur