Effect of Temperature on Particle Separation in Hollow Fiber Flow Field-Flow Fractionation

Ž . Abstract: Hollow fiber flow field-flow fractionation HF-FlFFF has been tested Ž . by varying the temperature 21]738C to increase separation speed with reduced lift forces. It has been experimentally shown that the separation time of 0.050]0.426-mm polystyrene latex standards can be reduced approximately by half, at 598C, compared to the separation at room temperature. In addition, the resolution for the separation of large diameter particles, which are often influenced by the lift forces, is greatly improved. It also has been found that the steric Ž inversion diameter can be possibly shifted to a larger diameter up to about 0.800 . mm at 738C. The steric retention of particles is observed to increase with temperature due to the decrease in hydrodynamic lift forces that is known to decrease with the viscosity of the carrier liquid. Q 1999 John Wiley & Sons, Inc. J Micro