SIZE ANALYSIS OF SIMPLE AND COMPLEX-MIXTURES OF COLLOIDS IN THE SUBMICROMETER RANGE USING CAPILLARY HYDRODYNAMIC FRACTIONATION

The application of capillary hydrodynamic fractionation (CHDF) to mixtures of monodisperse particle samples is described. The particle size distribution of several polymer latexes with diameters ranging from 20 nm to 1000 nm was determined in less than 10 minutes using the fractograms obtained with the CHDF system. The distributions obtained were compared with those using electron microscopy. The reproducibility of the instrument is illustrated by successive analyses of several samples of different particle sizes. Capillary hydrodynamic fractionation is compared to two other fractionation techniques: hydrodynamic chromatography and sedimentation field flow fractionation. It is shown, using an example, that capillary hydrodynamic fractionation is sufficiently versatile to separate by size complex colloidal mixtures which have particles of different chemical composition and density.