I have been experimenting with a hydrogel substance of nonsoluble polymers in a semi solid state, trying to achieve a cooling effect or freezing effect of the gel without having to refrigerate. Is there an alternative way, like by applying direct electricity on the gel or otherwise?
2007-06-14 02:17:45 · 4 answers · asked by donald k 1 in Science & Mathematics ➔ Physics
You can get semiconductor devices called Peltier effect devices. They are miniature heat exchangers. They are not instantaneous, but take a few minutes to heat and cool (one side is hot, the other cold).
They draw high currents - about 5 amps and up. They will not cool below 0 deg C. They are about 30mm x 30mm, and about 4mm thick. Two wires connect to them.
They are not terribly expensive - about $12-$20 depending on the wattage of the unit you choose. Google "Oatley Electronics" to see prices and details.
They should ideally be driven by an oscilator circuit capable of driving this current (running at 2kHz or up). However, they can be crudely used by connecting to a car battery. If you use a direct voltage, they will suffer thermal stress and not last their rated lifetime. Oatley Electronics (where I buy mine) have a kit for a suitable power supply which, from memory, runs at 3kHz.
2007-06-14 03:15:31 · answer #1 · answered by Anonymous · 0⤊ 0⤋
If it is in a closed container, take it someplace with a temperature that is lower than the freezing temperature. Another option would be to perform your experiment in an environment with a temperature that is colder than the freezing temperature.
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2007-06-14 10:39:22 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Look for some sort of anisotrophy which will allow 'fast' (i.e. thermally active) molecules flow in one direction and 'slow' molecules flow in the other âº
Doug
2007-06-14 09:24:38 · answer #3 · answered by doug_donaghue 7 · 0⤊ 0⤋
Create a true vacuum.
2007-06-14 09:25:28 · answer #4 · answered by Clown Knows 7 · 0⤊ 0⤋