12 membrane diffusion derive the concentration

Info icon This preview shows pages 11–14. Sign up to view the full content.

View Full Document Right Arrow Icon
Example 2.1.2: Membrane diffusion Derive the concentration profile and the flux for a single solute diffusing across a thin membrane. The analysis is the same as before leading to ( ) 2 1 2 z z 1 z 1 dz c d D j j A 0 = = + but the boundary conditions differ: 1 1 10 1 Hc c , z Hc c , 0 z = = = = where H is a partition coefficient (the concentration in the membrane divided by that in the adjacent solution e.g. Henry’s or Raoult’s law). Then the concentration profile becomes: ( ) z c c H Hc c 10 1 10 1 + = 10 c 1 c 10 c 1 c The solute is more soluble in the membrane than in the adjacent solution The solute is less soluble in the membrane than in the adjacent solution
Image of page 11

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon