SEPARATION AND CHARACTERIZATION OF POLYMERIC LATEX BEADS AND AGGREGATES BY SEDIMENTATION FIELD-FLOW FRACTIONATION

The high resolution separation and characterization of latex beads and their aggregates by sedimentation field-flow fractionation (SdFFF) are described here. Emphasis is placed on the principles of SdFFF, power programming and associated fractionating power, optimization strategies, determination of particle size distribution, and applications. Experimental results are provided on both narrow and broad latex distributions and on latexes having densities lower as well as higher than that of the aqueous carrier liquid. The separation of polystyrene latex particles whose diameters differ only 10% verifies the extraordinary resolving power of SdFFF. Aggregates of a 0.230 mum polymethylmethacrylate latex were resolved into eight cluster sizes (from singlets to octets) using SdFFF. Scanning electron microscopy was used as a complementary technique on collected fractions to verify elution sequence and particle size.