Applications in Asymmetric Flow Field Flow Fractionation (AF4) have been growing in number since its commercialization approximately 15 years ago. When coupled with online detectors such as multi-angle liight scattering detectors (MALS) and PALS (phase analysis light scattering detectors), molar mass distributions, size distributions, and even charge distributions can now be measured. AF4 can help confirm results determined by classical techniques such as SEC-MALS, and in cases of heavily branched material that becomes entangled in SEC packing material, fractionation by AF4 can result in improved size distribution analysis due to the nature of the fractionation method. Innovations such as hollow fibers have been developed to reduce sample and solvent requirements without loss of signal sensitivity. For sample types prone to entanglement or significant aggregation resulting from sample concentration during focusing steps, specialized channels such as the frit inlet channel have been developed to permit fractionation of these samples without a focusing step that typically is used during FFF methods. Examples of samples which do not fractionate well by SEC but were successfully fractionationated by FFF will be presented.

Advances in Asymmetric Flow Field Flow Fractionation (AF4) combined with MALS in the characterization of polymers in solution

253rd National Meeting (2017)

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