Variance analysis of dynamic light scattering data.

Area of Science:

• Materials Science
• Physical Chemistry
• Nanotechnology

Background:

• Dynamic Light Scattering (DLS) is a standard technique for nanoparticle sizing.
• DLS relies on analyzing the correlation function of scattered light intensity.
• Limitations exist in DLS, prompting the search for alternative methods.

Purpose of the Study:

• Introduce a novel particle sizing method as an alternative to DLS.
• Develop a technique that bypasses the need for a correlator.
• Validate the performance of the new method against DLS.

Main Methods:

• The proposed method utilizes the variance (VAR) of the scattered light signal.
• It analyzes the behavior of VAR as a function of sampling time (Δt).
• The correlation time (τc) is recovered using a wide range of sampling times, enabling hydrodynamic diameter calculation via the Stokes-Einstein relation.

Main Results:

• The variance (VAR) method demonstrated comparable performance to DLS in simulations.
• The technique was validated on both monodisperse and narrow polydisperse samples.
• Experimental results on polystyrene spheres and perovskite nanoparticles confirmed the method's efficacy across different setups.

Conclusions:

• The novel VAR method offers a viable alternative to DLS for nanoparticle sizing.
• This technique eliminates the requirement for a correlator, simplifying the measurement process.
• The method provides accurate particle size determination with an analytical error bar expression.