# Fick's Law

1. Apr 25, 2007

### chemeguy

I've been doing tons of research on Fick's Law. I understand how to derive it and what its used for. I just need to see an example of it being used.

I need to use this equation to separate water from an alcohol and aromatic component.

Any help is greatly appreciated.

2. Apr 25, 2007

### sicjeff

Which version of this equation are you using? Do you have any known diffusivities? Are you deriving through Navier-Stokes?

3. Apr 25, 2007

### chemeguy

I know that I'll be needing to use it for a pervaporation membrane. Here is a site that I've found useful and I'm sure I need to use these equations.

http://www.cheresources.com/pervaporation.shtml

I just need help on how to start doing it, it seems that I'm having too many unknowns. I'm not sure if I need to look at experimental data and use the thickness in the equation and if I need to calculate the vapor pressure. I'm given thermal conductivity, specific heat, heat of vaporization, and specific gravity of the components.

I'm just lost and don't know where to start.

4. Sep 20, 2009

### Stefanie

Hi, I have a problem in finding solution to the Fick's 2nd Law. I know how is it being derive from the 1st Law but had no idea how to go on from there on.

Is there anyone that can teach me? I'm totally new in this and needed for my project.

5. Sep 20, 2009

### Mapes

Hi Stefanie, welcome to PF. Fick's Second Law is a very common partial differential equation, and its solution should be described in most books on PDEs (it's also called the diffusion equation). Incropera and DeWitt's Fundamentals of Heat and Mass Transfer and Baluffi's Kinetics of Materials also describe solutions, since this PDE arises in heat and material diffusion problems, respectively.

6. Sep 22, 2009

### Stefanie

Thanks for the references :)

7. Jul 11, 2011