The region denoted by no man’s land in the temperature-pressure water phase diagram is still insufficiently explored and it is our intention to provide more data related to the thermodynamic properties of deeply supercooled water as well as the corresponding hydrogen bonding in it. In this presentation, the properties of water droplets (embedded in a liquid polymer matrix) consisting of ~ 100 to 1000 water molecules in the temperature range from 300 K to 120 K will be discussed. The presentation is organized as follows. The water droplets’ size measurements will be covered first. In our work, the hydrated electron absorption spectrum, as a function of water concentration in the polymer matrix, was measured using a nanosecond pulse radiolysis setup. The water droplets’ sizes were determined from the previously published relation between the absorption maximum and the water cluster size. The water droplets dispersity in the polymer matrix was also studied using electric conductivity measurements as a function of water concentration. The DSC measurements of the polymer Tg when the water droplets were (a) liquid and (b) frozen were used to corroborate the aforementioned results about water droplet size. Second, the heat capacity, freezing temperatures, and water cold crystallization data obtained using a DSC technique and corresponding to the temperature range from -150 0C to room temperature will be presented and analyzed. Finally, the Raman spectra of deeply supercooled water droplets will be presented and the hydrogen bonding in water droplets will be discussed.

On the deep supercooling of nano-sized water droplets dispersed in a polymer matrix

2019 Fall National Meeting

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