Particle Classroom Series

A Six-part Educational Webinar Series

1.) Introduction to Particle Analysis

If you're new to particle characterization, this is a webinar just for you! Dr. Jeff Bodycomb will discuss the basics of particles....why different size definitions will give you different results, various methods used to measure particles and why the method you use matters! This webinar will give you the knowledge you'll need to be the particle expert in your lab.

(00:01:00) Why Particle Size?
(00:05:26) The Basics
(00:10:19) Monodisperse vs. Polydisperse
(00:14:12) What does "Mean" mean?
(00:19:12) Number vs. Volume Distributions
(00:26:31) Methods of Analysis: Particle Measurement Methods*
(00:29:42) Sieves
(00:33:08) Sedimentation
(00:34:56) Microscopy (Manual, Automated, and Acoustic)
(00:38:05) Laser Diffraction

2.) The Basics of Laser Diffraction

Particle size analysis by laser diffraction offers many advantages. The technique is fast, reliable, and can be used for analyzing a wide range of particle sizes. In laser diffraction, an optical model is used to convert scattering data into a particle size distribution. This is a great introduction to someone who wants to understand the science behind the measurement.

(00:01:52) Why Particle Size?
(00:04:56) Core Principle
(00:07:53) Light (Interference and Path Length Difference)
(00:11:18) Fraunhofer Approximation
(00:13:44) Mie Scattering
(00:15:18) Refractive Index
(00:18:50) Mixing Particles and Comparison of Large & Small Particles
(00:23:48) Measurement Workflow
(00:26:54) How much sample? (Wet and Dry)
(00:39:16) Benefits of Laser Diffraction

3.) Refractive Index and Laser Diffraction

Modern laser diffraction particle analyzers use particle refractive index to accurately model the behavior of light inside of the particle. However, this presents the analyst with the challenge of choosing the correct value. In this Webinar, Dr. Jeff Bodycomb will discuss everything you need to know about refractive index.

(00:01:48) What do we mean by RI?
(00:03:56) Mie vs. Fraunhofer
(00:09:39) RI: Real Component and Imaginary Component
(00:17:58) Relative Refractive Index
(00:21:51) Practical Approach to Refractive Index
(00:26:58) What about Mixtures?
(00:31:05) Automation by Method Expert (Automated RI Computation)
(00:34:18) Results Discussion

4.) System Verification

Confirming the performance of a particle analyzer is a critical step in ensuring and proving data quality. Join Dr. Jeff Bodycomb as he discusses performance expectations, confirming system performance, and recommended practices.

(00:02:26) Calibration vs. Verification
(00:05:10) Monodisperse Standards
(00:08:48) Polydisperse Standards
(00:11:55) ISO 13320 (Real World Samples and Validation)
(00:14:48) Pass/Fail: Example: NIST 1003
(00:19:17) LA-960 and LA-950 Example Data
(00:24:09) Aqueous vs. Solvent
(00:26:03) Conclusions

5.) Sampling and Dispersion

The goal of a particle analysis is to understand the properties of a material, whether it is the size distribution of particles that are manufactured today or the size distribution of particles in the truck that just arrived. Naturally, a particle analyzer only encounters a tiny fraction of that material, the sample. In this webinar, Jeff discusses how to improve data quality by obtaining a representative sample and effectively disperse the sample to remove or prevent agglomerates.

(00:01:50) Measurement Error Sources
(00:03:04) Sampling Extraction: Good Sampling Practices
(00:07:30) Sampling Techniques (Coning & Quartering, Chute Riffling, Rotary Riffling)
(00:14:26) Sample Preparation: Dispersions
(00:16:48) Particle Wetting
(00:19:13) Effect of Surfactant Addition
(00:23:07) Particle Interactions
(00:25:30) Dispersion (Mechanical Energy & Ultrasonic Energy)
(00:28:13) Summary

6.) Laser Diffraction Method Development

Sample preparation and instrument setup are crucial parts of obtaining good data. Method development is thinking through and testing sample preparation and instrument setup to ensure optimal results. That is, variations due to sample preparation should be minimized.

Questions include: Should the sample be run in suspension or as a dry powder? What salts or surfactants are needed for the suspension? How much energy should be applied and how?