Dynamic Light Scattering (DLS)

• DLS measures Brownian motion and relates this to the size of the particles.

• The larger the particle the slower the Brownian motion will be. Smaller particles are “kicked” further by the solvent molecules and move more rapidly.

• The velocity of Brownian motion is defined by a property known as the translational diffusion coefficient (D).

• The size of a particle is calculated from the translational diffusion coefficient by using the Stokes-Einstein equation:

d(H) – hydrodynamic diameter, D – translational diffusion coefficient, k – Boltzmann's constant, T – temperature, η - viscosity