Macromolecular Systems I & II           cmclogo.gif (7533 bytes)   

 

 

In this project, a lower phase containing dye (red food color, I think) and gelatin is covered with an upper phase containing either water or more gelatin (to suppress convection).  Then photos are taken over time to see how things progress.  This was done by Derek Dorman and Colleen Colson (AY 2002-3).  Main link:  http://macro.lsu.edu/psrgroup/PersonalPages/Derek%20Dorman/

Gel with Gel on top -- Day 1 Gel with Water on top -- Day 1
   
Gel with Gel on top -- Day 2 Gel with Water on top -- Day 2
   
Gel with Gel on top -- Day 7 Gel with Water on top -- Day 7
   
Gel with Gel on top -- Day 21 Gel with Water on top -- Day 21

What do we learn? 

  1. Diffusion is slow.
  2. Convection helps diffusion along (that's mostly why dye appears to diffuse so much faster in water).