Dynamic Light Scattering Particle Size Analyzer Nicomp N3000

Dynamic light scattering (DLS) is the preferred method for particle size analysis of nanoparticles. DLS is a fairly easy technique for many samples. Prepare the sample to the proper concentration, place a cuvette into the instrument, set  measurement parameters and generate the result. The basic size range for DLS is 0.3 nm – 10 µm, depending on the sample.  

Basic Principles 
 
The sample is placed in a cuvette where the particles experience Brownian motion. Smaller particles move faster than larger particles. 

The cuvette is placed in the instrument where it is illuminated by a laser. The scattered light due to the Brownian motion is captured on a detector at a specific angle. The time signature of the scattered light is used to create an autocorrelation function that decays more rapidly for smaller particles and more slowly for larger particles. The translational diffusion coefficient (D) is determined from the autocorrelation function. The Stokes-Einstein equation is then used to calculate the particle radius R.