Recent content by Sascha_K

You are awesome dude. Not only have you helped me with understanding this (heretofore) seeming contradiction of how dialysis membranes work, but you also helped resolve a friendly argument with a co-worker. Physic forums is awesome, thanks to people like you! :)

Using a 10 cm long dialysis tube, I roughly estimate that the diameter of the pore would need to be in the vicinity of 0.2 to 0.3 mm

I now have another question: At what pore size will the surface tension fail and allow water to leak out of the bag? Or at least, what are the appropriate equations for calculating such a problem.

So essentially the surface tension is holding the water inside the bag until it is placed in the buffer, upon which the surface tension is no longer applicable (surface tension of water against air is 71.97 dyn/cm at 25 C)

Aha! I see! Thanks for clearing that up for me!

The way I think about it, the dialysis membrane basically has holes in it of a given size which keep molecules larger than the holes from moving out. My question is, since the pore size of the tubing is always bigger than the size of water molecules, why doesn't water leak out of the dialysis...