Dynamic Light Scattering

Exponential Business and Technologies Company

Bridging You and Nano

Particles suspended in liquids are in Brownian motion due to random collisions with solvent molecules. This motion causes the particles to diffuse through the medium. The diffusion coefficient, D, is inversely proportional to the particle size according to the Stokes-Einstein equation:

Where D is the diffusion constant, kB the Boltzmann’s constant, T the absolute temperature, ƞ0 the viscosity, d the spherical particle diameter. Photon Correlation Spectroscopy (PCS), also referred to as dynamic light scattering, is a technique used to determine the diffusion coefficient of small particles in a liquid. The coefficient is determined by accurately measuring the light scattering intensity of the particles as a function of time. Photon correlation spectroscopy is a proven technique for particle size analysis of sub nano meter to a few micron particles.

Typical Experimental Results:

dynamic light scattering

Particle size analysis of a particle in solution

Applications:

Brownian Motion	Contamination of Solution	Effect of Additives
Electrophoretic Light Scattering	Organic Mixtures	Particle Suspensions
pH Analysis	pH Titration	Photo Correlation Spectroscopy
Polishing Slurries	Sedimentation	Temperature Testing

For more information please read our application notes.

Instruments: Beckman Coulter Delsa Nano C Particle Analyzer

particle size Key Specifications:

Measurable Size Range	0.6nm – 7µm
Concentration Range	0.001% - 40%
Maximum Heating Temp	90°C
Maximum Cooling Temp	15°C below ambient temp
pH Range	1-13
Scattering Angle	15°, 30°, 160°
Size Cell Sample Requirements	0.9mL
Flow Cell Sample Requirements	0.7mL
High Concentration Cell Sample Requirements	1mL