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NanoFab Tool: Wyatt Technologies Dawn Heleos II Dynamic Light Scattering and Field Flow Fractionation System


Photograph of the Wyatt Technologies Dawn Heleos 2 Dynamic Light Scattering and Field Flow Fractionation system.

The Wyatt Technologies Dawn Heleos II dynamic light scattering and field flow fractionation system integrates several methods of field flow fractionation and light scattering to separate and measure nanoparticles in solution. The system can perform either hollow fiber flow field flow fractionation (HF5) or asymmetric flow field flow fractionation (AF4) to separate nanoparticle samples with highly polydisperse size distributions into sub-samples of nanoparticles of nearly uniform size. The system can measure the nanoparticle size distribution using simultaneous static and dynamic light scattering measurements on monodisperse sub-samples of nanoparticles. The system ensures repeatable results by allowing for automation and temperature control throughout the nanoparticle characterization process.


  • 24 bit analog to digital signal processing converters for maximum noise rejection without signal distortion of light scattering and auxiliary signals.
  • 120 mW gallium arsenide diode laser (658 nm wavelength) for increased signal-to-noise.
  • Multi-angle detector: 18 angle settings.
  • Molar mass range: 103 g / mole (daltons) to 109 g / mole (daltons).
  • Molecular and nanoparticle radius range: ˜ 0.5 nm to 500 nm.

Usage Information

Supported Sample Sizes

  • Nanoparticles in solution.

Typical Applications

  • Molar mass determination of nanoparticles and polymers.
  • Separation of polydisperse solutions.
  • Multi-angle static light scattering and dynamic light scattering measurements.
  • Differential refractive index (dRI) and ultraviolet determinations to measure sample concentrations.
  • Nanoparticle number densities.
  • Calculate polydispersity values.
Created May 19, 2014, Updated November 9, 2020