![]() These complex mixtures of species were analyzed to investigate the retention and particle interaction behavior under different AF4 experimental conditions, such as the mobile phase. ![]() Furthermore, different emulsions were mixed with inorganic species used as additives in cosmetics and coatings such as TiO2. ![]() Additionally a low particle size shoulder was observed for SdFFF indicating bimodality in the reactor very early during the polymerization reaction. The calculated radii values were 5 nm larger for SdFFF measurements for each analyzed sample against the corresponding AF4 values. SdFFF has additional separation capabilities with a much higher resolution compared to AF4. Results indicated differences between AF4 and DLS results due to DLS taking hydration layers into account, whereas both AF4 and SdFFF were coupled to MALLS detection, hence not taking the hydration layer into account for size determination. The obtained particle sizes were compared against batch-mode dynamic light scattering (DLS). Asymmetrical flow field-flow fractionation (AF4) and sedimentation field-flow fractionation (SdFFF), coupled to a multidetector system, multi-angle laser light scattering (MALLS), ultraviolet (UV) and refractive index (RI), respectively, were used to investigate the evolution of particle sizes and particle size distributions (PSDs) as the polymerization progressed. An acrylic emulsion polymerization was conducted, continuously sampled from the reactor and subsequently analyzed to determine the particle size, radius of gyration in specific, of the latex particles throughout the polymerization reaction. As model systems, a pure acrylic emulsion and emulsions containing titanium dioxide were prepared and analyzed. In this study, different FFF techniques were used for the fractionation and analysis of polymer emulsions/latexes. Makan, Ashwell C Spallek, Markus J du Toit, Madeleine Klein, Thorsten Pasch, Haraldįield flow fractionation (FFF) is an advanced fractionation technique for the analyses of very sensitive particles. Copyright 1998Academic PressĪdvanced analysis of polymer emulsions: Particle size and particle size distribution by field-flow fractionation and dynamic light scattering. For many classes of particles, resolution of the MALS/FFF combination far exceeds that of TEM measurements. The MALS/FFF combination provides unique advantages and precision relative to FFF, photon correlation spectroscopy, and CHDF techniques used alone. The latter has proven most useful when combined with MALS to provide accurate differential number fraction size distributions for a broad range of particle classes. At that time, fractionation of particles was achievable by capillary hydrodynamic chromatography (CHDF) and field flow fractionation (FFF) methods. The great success, in the past decade, of on-line multiangle light scattering (MALS) detection combined with size exclusion chromatography for the measurement of polymer mass and size distributions suggested, in the early 1990s, that a similar attack for particle characterization might prove useful as well. The very best characterized polystyrene latex sphere standards have been measured extensively using transmission electron microscope (TEM) images of a large subpopulation of such samples or by means of the electrostatic classification method as refined at the National Institute of Standards and Technology. ![]() The acid test for any particle sizing technique is its ability to determine the differential number fraction size distribution of a simple, well-defined sample. Submicrometer Particle Sizing by Multiangle Light Scattering following Fractionation
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