We have found that water in pores smaller than about 15 nm in diameter shows anomalous properties, including higher thermal expansion coefficient and reduced mobility. Detailed examination of the structure and properties of the pore fluid using molecular dynamics has revealed that the water is strongly affected only within about 6 Å of the pore wall. The effects observed in larger pores can be explained as a volume average of the thin layer of surface-affected liquid with the rest of the liquid in the pores (which exhibits the same behavior as bulk liquid).
Relevant papers:
“Thermal Expansion and Viscosity of Confined Liquids”, S. Xu, G.C. Simmons and G.W. Scherer, pp. 85-91 in Dynamics of Small Confining Systems, Mat. Res. Soc. Symp. Proc. Vol. 790, eds. J.T. Fourkas, P. Levitz, M. Urbakh, K.J. Wahl (Materials Res. Soc., Warrendale, 2004), P.6.8.1-7
“Evidence of anomalous thermal expansion of water in cement paste”, J.J. Valenza and G.W. Scherer, Cement Concr. Res. 35 (2005) 57-66
“Molecular Mechanisms Causing Anomalously High Thermal Expansion of Nanoconfined Water”, S.H. Garofalini, T.S. Mahadevan, S. Xu, and G.W. Scherer, Chem. Phys. Chem. 9 (2008) 1997 – 2001
“Thermal Expansion of Confined Water”, S. Xu, G.W. Scherer, T.S. Mahadevan, and S.H. Garofalini, Langmuir, 25 [9] (2009) 5076–5083
“Transport of Water in Small Pores”, S. Xu, G.C. Simmons, T.S. Mahadevan, G.W. Scherer, S.H. Garofalini, Carlos Pacheco, Langmuir 25 [9] (2009) 5084-5090
“Molecular Dynamics Investigation of Solution Structure between NaCl and Quartz Crystals”, M.B. Webb, S.H. Garofalini, and G.W. Scherer, J. Phys. Chem. C 115 (40) 19724–19732