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Under an idealized reaction condition for A + B → product in a diluted solution, Smoluchovski suggested that the molecular flux at the infinite time limit can be calculated from Fick's laws of diffusion yielding a fixed/stable concentration gradient from the target molecule, e.g. B is the target molecule holding fixed relatively, and A is the ...
Both species A and B will typically be diffusing but diffusiophoresis is distinct from simple diffusion: in simple diffusion a species A moves down a gradient in its own concentration. Diffusioosmosis , also referred to as capillary osmosis, is flow of a solution relative to a fixed wall or pore surface, where the flow is driven by a ...
The rate of diffusion N A is usually expressed as the number of moles diffusing across unit area in unit time. As with the basic equation of heat transfer, this indicates that the rate of force is directly proportional to the driving force, which is the concentration gradient. This basic equation applies to a number of situations.
Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical potential.
The difference of concentration between the two areas is often termed as the concentration gradient, and diffusion will continue until this gradient has been eliminated. Since diffusion moves materials from an area of higher concentration to an area of lower concentration, it is described as moving solutes "down the concentration gradient ...
Diffusion force caused by a concentration gradient - all particles tend to diffuse from higher concentration to lower. Electrostatic force caused by electrical potential gradient - cations like protons H + tend to diffuse down the electrical potential, from the positive (P) side of the membrane to the negative (N) side.
Atomic diffusion across a 4-coordinated lattice. Note that the atoms often block each other from moving to adjacent sites. As per Fick’s law, the net flux (or movement of atoms) is always in the opposite direction of the concentration gradient.
With respect to molecular diffusion, dispersion occurs as a result of an unequal concentration of the introduced material throughout the bulk medium. When the dispersed material is first introduced into the bulk medium, the region at which it is introduced then has a higher concentration of that material than any other point in the bulk.