Thermal diffusion

What is thermal diffusion?

Thermal diffusion, also known as the Soret effect, is a phenomenon that occurs when there is a temperature gradient in a system. It is the movement of molecules or particles from a region of higher temperature to a region of lower temperature due to the difference in their kinetic energy.

In a system with a temperature gradient, the molecules or particles in the region of higher temperature have more kinetic energy and move faster than those in the region of lower temperature. As a result, the faster-moving molecules or particles will tend to diffuse toward the region of lower temperature, while the slower-moving molecules or particles will tend to diffuse toward the region of higher temperature. This process continues until the temperature gradient is reduced or eliminated, at which point the system reaches a state of thermal equilibrium.

Thermal diffusion can occur in various types of systems, including gases, liquids, and solids. It plays an important role in many natural and industrial processes, such as the convection of heat in the Earth's atmosphere and the separation of isotopes in nuclear reactors.