Fick’s laws are two principles that describe the phenomenon of diffusion, which is the spontaneous net movement of atoms, molecules, ions, or other particles from regions of higher concentration to regions of lower concentration. These laws were formulated making an analogy between the transport of matter and the flow of heat as described by Fourier’s law. Fick’s laws serve as the basic mathematical framework for modeling mass transport processes in porous media, such as the ingress of moisture or aggressive ions into concrete, the migration of contaminants through soil, or the diffusion of gases through building materials. They quantify how concentration gradients drive diffusive flux and how those concentrations evolve with time, enabling engineers to predict long-term durability and performance of infrastructure under environmental exposure.
- Fick's First Law: Steady-state Diffusion
- Fick's Second Law: Non Steady-state Diffusion
