Advances in field-flow fractionation for polymer analysis

Recent advances in the application of field-flow fractionation (FFF) to polymer analysis are reviewed. Thermal FFF (ThFFF), which is traditionally applied to polymers dissolved in organic solvents, has been expanded to ultra-high molecular weight polymers and gels, where the low-shear environment of the FFF channel leads to unparalleled accuracy. ThFFF has also been applied to particle suspensions in both aqueous and non-aqueous liquids. Refinements in our understanding of thermal diffusion have augmented applications of ThFFF to copolymer analysis, while the use of solvent mixtures had led to greater flexibility and an expanded molecular weight range. The use of flow FFF for polymer characterizations has increased with advances in instrumentation, including specially designed inlets that reduce analysis time and stainless steel channels that tolerate elevated temperatures and organic carrier liquids.