[alexwlewis]

I am a product designer at uni and i am looking for a chemical that could sustain at constant temperature approximately  10 degrease C. Being activated though a method such as a low electrical current. The outside influence of heat wouldn't exceed 50 degrease C. I am looking to be-able to reuse this at least 200 times.

An alternative would be reusable cold packs I would like to know how they work, the chemicals that are used and how long they work for. any other information on this would be helpful to.

I would also like to know where freon would be applicable for this situation as I am not a chemist. Are there chemicals which stay at a temperature that is constant whilst there are outside temperature influences.

Any information on chemical cooling would be relevant to my research.

thanks peeps

[Chymysta]

This is not the appropriate forum for this question, but there are a lot of references out there for constant temperature baths. It really depends on how long you need the temperature to stay at 10 degrees.

One good reference is Chemistry is Not Voodoo http://chem.chem.rochester.edu/~nvd/reactionnotes2.html. They say:

Temperature Control

Synthetic organic experiments are conducted at temperatures ranging from -90 degrees to 200 degrees Celcius. It is important to know how to achieve and maintain the correct temperature for a reaction, especially over long time periods. Temperature should be monitored with a low-temperature alcohol thermometer.
Low Temperature Cooling Baths

Cryocool: If you have access to one, a cryocool can maintain a reaction at a set temperature (typically -40 to 20 degrees) for a long period of time.
Ice/Salt: -15 to -5 degrees
Dry Ice/Acetonitrile: -40 degrees
Dry Ice/Acetone: -78 degrees
Liquid Nitrogen/Dichloromethane: -92 degrees
See also: The Complete List http://www2.bc.edu/~hoveyda/cool.html on the Hoveyda Group website.

[DemonicAcid]

Another good resource is the slush temperature of various solvents. Slush baths can help you maintain a temperature for long periods of time with only minimal maintenance.

http://www.chem.unl.edu/dbb/useful%20info%20links/slush%20bath.pdf

[alexwlewis]

Thanks for the help guys. will have a look into all areas