With the arrival of summer, a subject that comes up again is pykrete, an ice “that “never” melts. Also called indestructible ice, 24-hour ice or even eternal ice, it is much sought after by those who want to enjoy a beach or Carnival, for example, and need to keep drinks cold for a long time outside the fridge, in a cooler or styrofoam box. .
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But what is this pykrete? Basically, it’s ice with cotton. That simple. And the preparation is not at all complicated, precisely because it only involves the two ingredients (cotton and water). The amount is up to you, based on what you intend to do with that ice—namely, how big it should be.
How to make pykrete, the “eternal” ice
First, you need to choose the container, and then cover the bottom with the cotton. Then, add the water until the cotton is soaked well. Close the container with the lid and leave it in the freezer until it becomes rigid. If you don’t have one, it’s worth covering with a plastic film. The important thing is to leave it closed, so that the material remains clean, without contamination. Afterwards, just unmold and that’s it.
Although it’s a good option to keep your drinks cold, you have to understand that you shouldn’t put the pykrete in the glass, because of the cotton. Therefore, the “eternal ice” must not come into contact with the drink directly, only with the cans, bottles, etc.
What makes pykrete more durable?
If you think that science might have an answer to this improved resistance that pykrete has, you are absolutely right. Everything happens because of an effect called composite. This means that water and ice maintain their properties individually, and when mixed, they behave differently.
In this case, the water is responsible for ensuring the structure, while the cotton enhances certain properties, thus making the ice solid for longer. In practice, it is as if the cotton created a thermoprotective layer, that is: it preserves the low temperature, so that the water refreezes itself while returning to the liquid state.
Although pykrete is most often used as ice with cotton wool, other materials also play a reinforcing role. Originally, it was used in World War II-era construction to replace steel that was in short supply, and was made from ice and sawdust.
Source: Wired, Homify