Techniques & Solutions for Particle Size Characterization

Summary

The video explains common particle sizing techniques and when to use them. It covers laser diffraction/static light scattering for fast distribution analysis (e.g., Saturn digitizer 2), dynamic image analysis for shape-aware sizing (Particle Insight), x-ray absorption sedimentation for dense slurries (Sedigraph 3Plus), electrical sensing zone (LZone 2) for high-resolution counts, and air-permeability analysis for packed powders (SAS). It also describes dynamic light scattering (DLS) and electrophoretic light scattering (ELS) for nano/submicron sizing and zeta potential (NanoPlus). Each method’s operating principle, measurement strengths, and typical application contexts are highlighted to help users choose the right instrument for R&D, QC, or production.

Takeaways

• 😀 Laser diffraction or static light scattering is the most common particle sizing technique, ideal for fast analysis of manufacturing processes.
• 😀 The Saturn Digitzer 2 uses a CCD detector and laser with 47.6 angles to capture scattered light for precise particle size determination.
• 😀 Dynamic image analysis directly captures images of particles in a liquid medium and uses specialized software to calculate particle dimensions and distributions.
• 😀 The Particle Insight system uses advanced software with 30 shape factors, making it suitable for applications where particle shape is as important as size.
• 😀 Sedimentation analysis, such as X-ray absorption, is used for high-concentration slurries to determine particle size and mass using Stokes' law.
• 😀 The Sedigraph 3 Plus provides high-resolution particle size distribution in the range of 0.1 to 3 micrometers, using X-ray absorption for sedimentation analysis.
• 😀 Electrical sensing zone (ESZ) technique measures the volume occupied by particles in low-concentration samples, providing high resolution and particle counting.
• 😀 The Lzone 2, using ESZ, offers accurate particle size analysis with a variety of orifice tubes, bringing precision to tabletop analysis and particle counting.
• 😀 Air permeability analysis determines particle size for powders with high density, measuring pressure drops across a packed bed of powder for sizing.
• 😀 Dynamic light scattering (DLS) is the go-to technique for submicron and nanoparticle sizing, measuring intensity fluctuations in scattered light due to Brownian motion.
• 😀 The Nano Plus system can measure particle size by DLS and Zeta potential by electrophoretic light scattering (ELS), useful for nanoparticle stability analysis.

Q & A

What is the main purpose of understanding particle size characteristics?

Understanding particle size is crucial for various elements of research, development, quality control, assurance, and production, especially in powder compaction or blending processes, to determine which techniques and instruments are best suited for specific applications.

How does laser diffraction work for particle sizing?

Laser diffraction, or static light scattering, determines particle size distribution by capturing scattered light data using the optical properties of particles suspended in a liquid medium. The Saturn digitizer 2 uses a CCD detector and a laser that moves at 14 different angles to capture scattered light from particles.

What is dynamic image analysis and how does it differ from laser diffraction?

Dynamic image analysis is a direct measurement technique that captures images of particles circulating in a liquid medium. Unlike laser diffraction, which measures light scattering, dynamic image analysis also considers particle shape and uses specialized software to calculate size distributions based on both dimensions and shape factors.

What is the primary use of the Particle Insight system?

The Particle Insight system uses dynamic image analysis with a high-definition camera to capture particle images. It’s ideal for applications where the particle shape, not just the diameter, is critical. The system employs 30 shape factors to analyze particles accurately.

What is sedimentation analysis and how is it used in particle size measurement?

Sedimentation analysis measures the terminal velocity of particles in a suspension using Stokes' law. This technique is used to determine the absolute mass and size of particles, especially in high-concentration slurries, with devices like the Sedigraph 3 Plus providing high-resolution distribution data.

How does the electrical sensing zone (ESZ) technique work?

The electrical sensing zone (ESZ) technique works by measuring changes in resistance as particles pass through an orifice separating two cells of electrolytic solution. It directly measures the volume occupied by particles, providing high-resolution particle size and count data, often used for low-concentration applications.

What type of particle size information can the LZone 2 provide?

The LZone 2 utilizes the electrical sensing zone technique to provide high-resolution particle size information, including both the size distribution and particle count, using a variety of orifice tubes to offer accurate measurements for tabletop particle size analysis.

What role does air permeability analysis play in particle size determination?

Air permeability analysis is used to determine the particle size of powders with high density. It works by measuring the pressure drops across a packed bed of powder, and devices like the Subve Auto Sizer (SAS) use this technique to report average particle size and a Fritsch number.

How does dynamic light scattering (DLS) help in nanoparticle characterization?

Dynamic light scattering (DLS) is used to characterize submicron or nanoparticle sizes by monitoring intensity fluctuations in scattered light, caused by particles in Brownian motion. This technique provides insights into nanoparticle suspension stability and size determination.

What is the Zeta potential, and how is it measured?

The Zeta potential refers to the electrical potential of particles in suspension that can influence their attraction or repulsion behavior. It is measured using electrophoretic light scattering (ELS), which determines the electrical potential and helps in understanding particle stability in suspensions.