Submicrometer Particle Sizing by Multiangle Light Scattering following Fractionation

Area of Science:

• Analytical Chemistry
• Materials Science
• Nanotechnology

Background:

• Accurate particle size distribution is crucial for material characterization.
• Traditional methods like transmission electron microscopy (TEM) and electrostatic classification have limitations in resolution and throughput.
• Advancements in chromatography and light scattering offered new avenues for particle analysis.

Purpose of the Study:

• To evaluate the efficacy of on-line multiangle light scattering (MALS) detection coupled with field flow fractionation (FFF) for particle sizing.
• To compare the performance of the MALS/FFF technique against established methods such as transmission electron microscopy (TEM), capillary hydrodynamic chromatography (CHDF), and photon correlation spectroscopy.
• To determine the ability of MALS/FFF to accurately measure differential number fraction size distributions.

Main Methods:

• Utilized field flow fractionation (FFF) for particle separation.
• Integrated on-line multiangle light scattering (MALS) detection for size analysis.
• Employed well-characterized polystyrene latex sphere standards for validation.
• Compared results with data obtained from transmission electron microscopy (TEM) and capillary hydrodynamic chromatography (CHDF).

Main Results:

• The MALS/FFF combination demonstrated the ability to provide accurate differential number fraction size distributions.
• This technique proved effective for a broad range of particle classes.
• The resolution and precision of MALS/FFF significantly exceeded that of FFF, photon correlation spectroscopy, and CHDF when used alone.
• For many particle types, MALS/FFF resolution surpassed that of TEM measurements.

Conclusions:

• The MALS/FFF technique is a powerful and precise method for determining differential number fraction size distributions.
• This approach offers significant advantages in resolution and accuracy over existing particle sizing techniques.
• MALS/FFF represents a valuable advancement for particle characterization, particularly for complex or polydisperse samples.