Field-Flow Fractionation: A Versatile Technology for Particle Characterization in the Size Range 10-3 to 102 Micrometers

This article provides an overview on the use of field-flow fractionation (FFF)for particle size analysis and for the characterization of other particle properties such as density, porosity, and the thickness of adsorbed layers. While FFF is a relatively new technology for particle characterization, it is one of the most versatile and powerful techniques now avaiable for characterizing particle populations. The unique features contributing to the effectiveness of FFF include high resolution, relatively high speed, adaptability to different types and sizes of particles, and the ability to collect narrow fractions for further characterization by microscopy and other techniques. For background, the mechanism of FFF is described in two parts, one applicable to particles over 1 μm diameter and the other relevant to submicron size particles ranging down to 1 nm size. It is shown how particle size distributions are obtained for a variety of particulate materials in both size ranges. The strategies needed for measuring particle properties other than size and size distribution are discussed.