Labs and instruments

Dynamic Light Scattering (DLS)

Graz University of Technology

Dynamic Light Scattering (DLS) is a widely used technique for measuring the size distribution of small particles, macromolecules, or polymers in suspension or solution. It is based on analyzing temporal fluctuations in the intensity of scattered light caused by the Brownian motion of particles. These fluctuations are mathematically processed using an autocorrelation function (ACF), where smaller, faster-diffusing particles lead to a more rapid decay in signal. DLS is also referred to as photon correlation spectroscopy or quasi-elastic light scattering, and measurements can be performed in either the time domain or frequency (spectral) domain. Beyond size determination, DLS is also used to investigate the behaviour of complex fluids, concentration-dependent aggregation, and temperature effects on particle dynamics.

Litesizer 500 – Particle Size and Zeta Potential Analyzer
The Litesizer 500 (Anton Paar) is an optical analyzer for determining the size distribution, diffusion coefficient, and zeta potential of particles in solution or dispersion. It uses dynamic light scattering (DLS) to measure the hydrodynamic radius of particles based on their Brownian motion, covering a size range from below 1 nm up to several micrometrs. By applying an electric field, it measures zeta potential via electrophoretic light scattering (ELS), providing insight into particle surface charge and colloidal stability.
The instrument includes precise temperature control from 0°C to 90°C, enabling thermal stability studies, temperature-dependent diffusion measurements, and pH titrations under defined thermal conditions.
It is suitable for a wide variety of sample types, including proteins, surfactant micelles, polymer assemblies, and inorganic nanoparticles.

Capabilities:
• Particle size and size distribution via DLS
• Zeta potential via ELS
• Diffusion coefficient determination
• Temperature-controlled measurements (0–90°C)
• Real-time transmittance monitoring

Sample Types:
• Aqueous or non-aqueous dispersions
• Protein solutions
• Micellar systems
• Colloidal nanoparticles

Contact: Heinz Amenitsch
Tel: +43 (316) 873 – 32145

More information on the Instrument’s webpage.