Molar flux of a species is proportional to the negative gradient of concentration: J = −D ∇c, where D is the diffusion coefficient (m²·s⁻¹). The prototypical linear irreversible transport law for mass.
Molar flux of a species is proportional to the negative gradient of concentration: J = −D ∇c, where D is the diffusion coefficient (m²·s⁻¹). The prototypical linear irreversible transport law for mass.