Freezing and Melting of Water Confined in Silica Nanopores

• Published in: Chemphyschem Vol. 9; no. 18; pp. 2651 - 2659
• Main Authors: Findenegg, Gerhard H., Jähnert, Susanne, Akcakayiran, Dilek, Schreiber, Andreas
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 22-12-2008; WILEY‐VCH Verlag
• Subjects: calorimetry; Chemistry Techniques, Analytical - methods; Freezing; Nanotubes; Phase Transition; phase transitions; Porosity; silica; Silicon Dioxide - chemistry; thermodynamics; Water - chemistry; water structure
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.200800616

In nanosized pores, liquid water can be thermodynamically stable down to temperatures well below the limit of homogeneous nucleation of bulk water (∼235 K). Studies of water in such pores therefore offer an opportunity to reveal the anomalous behavior of deeply supercooled water. Herein we focus on recent studies of the limits of freezing and melting of water in the cylindrical pores of ordered mesoporous silicas with pore diameters in the range of 2–10 nm, based on vapor sorption measurements, calorimetric studies, NMR spectroscopy and cryoporometry, and neutron diffraction studies.
In a tight spot: In nanosized pores, liquid water can be thermodynamically stable down to temperatures well below the limit of homogeneous nucleation of bulk water at about 235 K (see plot). Studies of water in such pores therefore offer an opportunity to reveal the anomalous behavior of deeply supercooled water.