(9/12) The red-colored ice experiment evoked us a gel experiment. If you boil 50 ml of water containing 0.25 g of agarose powder for 10 sec, and put 3 ml of it into a vessel after cooling (~60 degC), it will create a small 0.5%-agarose gel (left photo). Then, let us observe what happens in this gel after freezing with an ordinary fridge. The right photo is the result. As you can see, the gel structure is destroyed by the frozen storage, and leaked water comes out from the gel concomitantly to the thawing (movie, R&B are AFP). This implies that the gel lost the water-holding property by collapsion of polymer network. Within the forzen gel, the FIC phenomenon (page 7) will also occur to generate a block of ice, whose size becomes larger with time. This will squeeze the polymer network to be damaged, leading to the observed collapsions of the gel structure. (->next) (->page1) (->home) |
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