Unsteady-State Interphase Diffusion
This Demonstration considers the mass transfer of a substance A between two immiscible solvents I and II. The concentration in both phases is plotted versus position for various values of the diffusion coefficients (in , and , time (in seconds), and Henry law constant (a dimensionless constant). When the concentration of A is continuous at the interface, which is not typical. The concentration profiles are solutions of the following diffusion equations and boundary conditions:[more]
for , ,
Using Laplace transforms, one can easily derive analytical expressions of the concentrations in phases I and II:
R. B. Bird, W. E. Stewart, and E. N. Lightfoot, Transport Phenomena, New York: Wiley, 1960.