The DLS Method, or Dynamic Light Scattering, is a widely used technique for determining the particle size distribution of nanoparticles and colloids in...
DLS is primarily used to measure the hydrodynamic size distribution of nanoparticles and colloids suspended in a liquid, typically ranging from sub-nanometer to several microns. It also provides insights into particle aggregation and stability.
DLS works by measuring the fluctuations in light scattered by particles undergoing Brownian motion. Smaller particles move faster, causing more rapid fluctuations, which are analyzed to determine their diffusion coefficient and, subsequently, their size using the Stokes-Einstein equation.
Advantages include its non-invasive nature, ability to measure particles in their native environment, speed of analysis, and suitability for a wide range of sample concentrations. It is particularly effective for characterizing small particles.
Factors include sample concentration (too high causes multiple scattering), sample purity (dust can skew results), solvent viscosity, temperature, and the presence of high polydispersity (very broad size distributions).