(5/12) Now, please look at above pictures showing how water freezes, when it contains some particle. In this experiment, we chose “red colored ink” as the particle. Please just pour a droplet (0.1 ml) of water-soluble ink (PILOT INK-30) into 500 ml of water prepared in a bowl to be placed in a home freezer (-18°C). After 2-3 hrs, you will see that inks are concentrated in the middle of ice crystal. Note that if inks are excessive, the result is not visible, although this phenomenon inevitably occurs. Ice crystal growth only consumes water molecule, and that any materials other than water are excluded from the ice phase to be concentrated. This phenomenon is called “freeze-induced concentration (FIC)”, a fundamental problem of the freezing storage techniques as it alters texture of any water-containing materials, like foods and tissues. (->next) (->page1) (->home) |
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