Field Flow Fractionation in Analysis of Polymers and Rubbers
Polymers and Rubbers
Published Online: 15 DEC 2009
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Ratanathanawongs Williams, S. K., Benincasa, M.-A. and Ashames, A. A. 2009. Field Flow Fractionation in Analysis of Polymers and Rubbers. Encyclopedia of Analytical Chemistry. .
- Published Online: 15 DEC 2009
Field-flow fractionation (FFF) was conceived by Calvin Giddings in 1966 as a separation and characterization method for macromolecules, colloids, and particulates. Like chromatography, sample migration is caused by differential interaction with a field acting along an axis orthogonal to that of the transport liquid. Unlike chromatography, where separation is achieved by solutes partitioning between mobile and stationary phases, separation in FFF arises from the distribution of sample components in fluid laminae flowing at different velocities in a single phase. The different flow velocities, described by a parabolic profile, arise from the high aspect ratio of the FFF channel. Different types of fields can be used in FFF as long as they interact with some physicochemical property of the sample. The FFF channel design makes it highly suited for analyses of fragile aggregates, high-molecular-weight polymers, and gels. In comparison with packed columns, shear rates in the channel and the probability of plugging the channel are low. The ability of thermal FFF to differentiate polymers and latexes of different bulk and surface compositions is unique among currently used separation techniques. The FFF family of techniques can provide a great deal of information about the sample but an initial time investment is often required for methods development.
In this article, the fundamental mechanism of FFF is shown at play in the separation and characterization of polymers and rubbers by the two techniques par excellence in this field: flow FFF and thermal FFF.
- field-flow fractionation;
- flow FFF;
- thermal FFF;
- water-soluble polymers;
- high molecular weight;
- ultrahigh molecular weight;
- chemical composition;
- thermal diffusion;
- diffusion coefficient;
- size exclusion chromatography