Structural properties of ice in confinement

Abstract Water confined in nanoscale exhibits unique structural properties compared to the bulk phase. The effects of confinement of water in carbon nanopores were investigated in this study using differential scanning calorimetry (DSC), dielectric spectroscopy (DS), and neutron diffraction (ND). The ice was confined in slit-shaped pores of activated carbon fibers (ACF) and cylindrical-shaped porous system (ordered carbon mesoporous structure - CMK-5) of different inner diameter. Melting behaviors of the confined ice were studied using DSC and DS methods, while ND technique was used to determine the structure of nanoconfined ice. ND measurements for D 2 O in different carbon nanopores were taken in a temperature range of 300 to 100 K. The results of the DS and ND studies showed the existence of hexagonal ice, Ih, and cubic ice, Ic at temperatures below the pores melting point. We have found that the content of confined hexagonal and cubic ice phases depend on the type of porous materials used in the confinement. Our results of the confined ice in the carbon nanopores revealed the features of stacking disordered ice I sd formed by disordered hexagonal and cubic ice layers, which has been recently reported in the literature.