The Potential for the Shape Separation of Rodlike Particles Using the Field Flow Fractionation

The potential for the shape separation of rodlike particles using the field flow fractionation (FFF) technique will be discussed in this presentation. FFF has been generally used for the size separation of micro/nano particles or macromolecules. FFF also can be applied to the shape separation of rodlike particles, such as gold nanoparticles and single-walled carbon nanotubes. However, the underlying principle for the separation mechanism is actually that of size separation (diffusivity difference). There have been studies that predicted shape-specific separation possibility based on excluded volume effect [Phelan & Bauer (2009) Chem. Eng. Sci. 64:1747-1758] and entropic trapping [Beckett & Giddings (1997) J. Colloid Interface Sci. 186:53-59]. Recent studies also proposed flow conditions which may induce shape separation due to the lift-hyperlayer mode [Alfi & Park (2014) J. Sep. Sci. 37: 876–883] and pole-vault rotation. The explanation of current experimental results using those theories and the prediction of new separation designs will be presented.