Sup2 - Rubber bands and entropic elasticity - UCSD NANO 134 - Darren Lipomi

Why do rubber bands heat up when you stretch them and cool down when you allow them to compress? This is a supplemental video on entropic elasticity and the direction of heat flow.

[@Xyzzzz138]

The way you started this video was hysterical. That intense look hahaha

[@edwardmacnab354]

the stretching is actually a compression . The molecules are compressed inwards along the length and compression of a gas , at least , produces heat . The total energy doesn't change . The energy of the molecules is distributed over a smaller area . Therefore the heat transfer per area is greater

[@deshdeepaksingh1182]

very helpful.. thank you

[@aniawo5119]

Thank you

[@napalguable]

Great lecture. 감사함다. ㅎㅎ

[@shuningyuan7469]

very good explanation

[@yoavmatia]

Beautiful and simple, and accurate! I am now convinced. You got me now to go over your entire playlist.
Please make more of your unique content.

[@djlipomi]

Thanks for the kind words and thanks for subscribing!

[@Dubstepforthewin101]

How might I calculate the temperature change in a rubber band due to entropy change? I'm trying to measure it, but I want a mathematic model to compare my real life results.

[@swampwiz]

I contend that what is going on is that here is some type of minor chemical reaction going on, with more hydrogen bonding in the stretched state than in the jumbled state. I don't think the statistical mechanics model works here.