We derive by computer simulation the radial distribution functions of water confined in a silica pore modeled to reproduce MCM-41. We perform the calculations in a range of temperatures from ambient to deep supercooling for the subset of water molecules that reside in the inner shell (free water) by applying the excluded volume corrections. By comparing with bulk water we find that the first shell of the oxygen-oxygen and hydrogen-hydrogen radial distribution functions is less sharp and the first minimum fills in while the oxygen-hydrogen structure does not significantly change, indicating that the free water keeps the hydrogen bond short range order. The two body excess entropy of supercooled water is calculated from the radial distribution functions. We connect the behavior of this function to the relaxation time of the same system already studied in previous simulations. We show that the two body entropy changes its behavior in coincidence with the crossover of the relaxation time from the mode couplin.

Structural properties and fragile to strong transition in confined water / De Marzio, Margherita; Camisasca, Gaia; Conde Maria, Martin; Rovere, Mauro; Gallo, Paola. - In: THE JOURNAL OF CHEMICAL PHYSICS. - ISSN 0021-9606. - 146:8(2017). [10.1063/1.4975624]

Structural properties and fragile to strong transition in confined water

Camisasca Gaia;
2017

Abstract

We derive by computer simulation the radial distribution functions of water confined in a silica pore modeled to reproduce MCM-41. We perform the calculations in a range of temperatures from ambient to deep supercooling for the subset of water molecules that reside in the inner shell (free water) by applying the excluded volume corrections. By comparing with bulk water we find that the first shell of the oxygen-oxygen and hydrogen-hydrogen radial distribution functions is less sharp and the first minimum fills in while the oxygen-hydrogen structure does not significantly change, indicating that the free water keeps the hydrogen bond short range order. The two body excess entropy of supercooled water is calculated from the radial distribution functions. We connect the behavior of this function to the relaxation time of the same system already studied in previous simulations. We show that the two body entropy changes its behavior in coincidence with the crossover of the relaxation time from the mode couplin.
2017
computer simulation; mesoporous material; magnetic ordering
01 Pubblicazione su rivista::01a Articolo in rivista
Structural properties and fragile to strong transition in confined water / De Marzio, Margherita; Camisasca, Gaia; Conde Maria, Martin; Rovere, Mauro; Gallo, Paola. - In: THE JOURNAL OF CHEMICAL PHYSICS. - ISSN 0021-9606. - 146:8(2017). [10.1063/1.4975624]
File allegati a questo prodotto
File Dimensione Formato  
De Marzio_structural-properties_2017.pdf

solo gestori archivio

Tipologia: Versione editoriale (versione pubblicata con il layout dell'editore)
Licenza: Tutti i diritti riservati (All rights reserved)
Dimensione 813.09 kB
Formato Adobe PDF
813.09 kB Adobe PDF   Contatta l'autore

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1291678
Citazioni
  • ???jsp.display-item.citation.pmc??? 1
  • Scopus 24
  • ???jsp.display-item.citation.isi??? 19
social impact