1. Nanocamp June 27, 2012Chris Marin

2. What is a liquid?  All liquids:  have a definite volume  conform to the shape of container  are not compressible  are made up of atoms that aren’t in fixed places

3. What is a solid?  All solids:  have a definite volume  have a definite shape  are made up of atoms in fixed places

4. What is ice cream??  It has ice in the name, is it a solid?  Not quite! See how it took the shape of the glass?  Is it a liquid?  Not unless you wait to long!  It’s both!

5. Colloids  A colloid is one phase mixed into another.  Ice cream is both a foam, emulsion, and sol!

6. So what is ice cream?  In the above microscope image, A is air bubbles, C is ice crystals, F is fat, and S is a solution of liquid.  A big part of controlling ice cream’s texture is controlling how much air and ice are in the colloid.

7. nano-ice cream  We will be using liquid nitrogen to rapidly make ice cream  Normally, ice cream takes hours to make, but liquid nitrogen is extremely cold (-321 °F, or 77 K)  The change in temperature when the liquid nitrogen is poured in should be so rapid that the cream doesn’t have time to change to ice  Instead, tiny nanometer sized ice crystals should form, like snow does on a very cold day.  This should make our ice cream very very smooth!