SPLITT FRACTIONATION SERIES
In this study, two Gravitation SF (GSF) channels were connected in a series (Tandem GSF) to obtain a separation into three subpopulations and to improve the fractionation efficiency (FE) of the fraction-b in the full-feed depletion (FFD) mode. Separation into more than two subpopulations requires repeated SF operations. JO - Bulletin of the Korean Chemical SocietyĪB - SPLITT Fractionation (SF) provides separation of sample into two subpopulations. T2 - Bulletin of the Korean Chemical Society TI - Size-sorting of Micron-sized Particles using Two Gravitational SPLITT Fractionation (GSF) Connected in a Series (Tandem GSF) The FE's measured for the fraction-2b are 64% in average, which is about 20% improvement from those obtained in a single channel FFD-GSF at the same conditions. The FE's measured for the fraction-2a are still good with the average value of 92%. When two GSF channels were connected so that the flow stream emerging from the outlet-b of the channel-1 is fed directly into the channel-2, all three FE's measured for the fraction-1a were high with the average value of 99%, indicating it contains almost purely the beads smaller than dc. Also no clear trends were observed between the FE and the sample-feeding flow rate, indicating higher sample-feeding rate can be used to increase the samplethroughput without losing resolution. No particular trends were found between FE and dc, indicating the performance of FFD-GSF does not change with dc in the range where tested. The FE's of the fraction-a are higher than 84% with the average of about 91%, while those of the fraction-b are lower than 60% with the average of about 43%. The measured FE's of the fraction-b are much lower than those of the fraction-a in all cases. In a single channel FFD-GSF operation, the fraction-a contained mostly the beads smaller than the cutoff diameter (d_c), while the fraction-b contained beads smaller than dc as well as those larger than d_c, as expected. The strategies needed for measuring particle properties other than size and size distribution are discussed.SPLITT Fractionation (SF) provides separation of sample into two subpopulations. It is shown how particle size distributions are obtained for a variety of particulate materials in both size ranges. For background, the mechanism of FFF is described in two parts, one applicable to particles over 1μm diameter and the other relevant to submicron size particles ranging down to 1nm size. The unique features contributing to the effectiveness of FFF include high resolution, relatively high speed, adaptability to different types and sizes of particles, and the ability to collect narrow fractions for further characterization by microscopy and other techniques. While FFF is a relatively new technology for particle characterization, it is one of the most versatile and powerful techniques now available for characterizing particle populations. This article provides an overview on the use of field-flow fractionation (FFF) for particle size analysis and for the characterization of other particle properties such as density, porosity, and the thickness of adsorbed layers.
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