Issue 36, 2011

A study of freezing–melting hysteresis of water in different porous materials. Part II: surfactant-templated silicas

Abstract

The freezing–melting hysteresis of water in mesoporous silicas MCM-48, MCM-41 and SBA-16 has been studied by NMR cryoporometry. The hysteresis in MCM-48 was found to exhibit nearly parallel branches, matching type H1 hysteresis that had been observed earlier in controlled pore glass. The same type of hysteresis is observed in two of three different-sized MCM-41 under study (a pore diameter of 3.6 and 3 nm), superimposed with a secondary, extremely broad, type H3 hysteresis. No hysteresis was found in the smallest MCM-41 with a pore diameter < 3 nm. Finally, water in SBA-16 exhibits type H2 hysteresis with the freezing branch being essentially steeper than the melting one, which is attributed to a pore blockage upon freezing, similar to what we observed earlier in Vycor porous glass. The data were analyzed using the model of curvature-dependent metastability of a solid phase upon melting; the validity of this model has been discussed.

Graphical abstract: A study of freezing–melting hysteresis of water in different porous materials. Part II: surfactant-templated silicas

Article information

Article type
Paper
Submitted
10 Jun 2011
Accepted
21 Jul 2011
First published
11 Aug 2011

Phys. Chem. Chem. Phys., 2011,13, 16358-16365

A study of freezing–melting hysteresis of water in different porous materials. Part II: surfactant-templated silicas

O. Petrov and I. Furó, Phys. Chem. Chem. Phys., 2011, 13, 16358 DOI: 10.1039/C1CP21902B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements