Thermal Field-Flow Fractionation with Quintuple Detection for the Comprehensive Analysis of Complex Polymers

Abstract

With a constantly increasing complexity of macromolecular structures, advanced polymer analysis faces new challenges with regard to the comprehensive analysis of these structures. Today it goes without saying that comprehensive polymer analysis requires selective and robust fractionation methods in combination with a set of information-rich detectors. Thermal field-flow fractionation (ThFFF) has proven to be a powerful technique for the fractionation of complex polymers as well as polymer assemblies. In the present study, ThFFF is coupled to a set of five detectors to simultaneously provide quantitative information on a number of important molecular parameters, including molar mass, molecular size, chemical composition, molecular topology, intrinsic viscosity, and normal and thermal diffusion coefficients. The five-detector setup includes a triple detector device (multiangle light scattering (MALS), differential refractive index (dRI), and differential viscometer (dVis)) that is coupled to an ultraviolet (UV) detector for dual concentration detection and an online dynamic light scattering (DLS) detector. Triple detection consisting of MALS, dRI, and dVis provides information on molar mass, molecular size, and molecular topology. Dual concentration detection offers compositional analysis from a combination of UV and dRI detectors, whereas DLS provides information on diffusion coefficients and hydrodynamic radii. The power of this novel quintuple detector ThFFF (ThFFF-QD) is documented for three important fields of application, namely, the comprehensive analysis of (1) linear and star-shaped polymers, (2) hydrogenated and deuterated polymers, and (3) block copolymer self-assemblies. These applications highlight the novel approach of determining the most relevant molecular parameters, including Mark−Houwink and conformation plots, simultaneously in a single experiment.

Impact of Electron Beam Irradiation on Thermoplastic Polyurethanes Unraveled by Thermal Field-Flow Fractionation

“…[25][26][27][28][29] Details on the basic separation principle are given elsewhere 21,30 and in the supporting information (SI, section 1). FFF is usually coupled to a series of detectors (MALS, dRI, UV, online dynamic scattering or offline FTIR), [31][32][33][34][35] though, the analysis of the separation itself contains already useful information. This is because the measurement of the retention ratio R (void time over retention time) at given field strength allows the determination of the physicochemical parameter describing the response to the force field.…”

Field‐flow fractionation for nanoparticle characterization

“…The value of the ratio of the gyration diameter measured by MALS and the hydrodynamic diameter (or also the hydrodynamic and gyration radii), called shape factor, provides information on the shape, or even on the structure of the analyte. Some typical values of the shape factor for NPs are shown at the top right of Figure 2 [16,33,35,36]. This ratio is usually used for a morphological -Hydrodynamic diameters measured for MWCNT, and 11-350 nm for PLC-MWCNT complex); concentrations determined The fractal dimension structural parameter is defined as the log/log ratio between the molar mass and the gyration radius; and shape factor as the ratio between the gyration and hydrodynamic sizes (expressed either in diameters or in radii; e.g., d g /d h ).…”

Recent Advances in Separation-Based Techniques for Synthetic Polymer Characterization

“…Quintuple detector ThFFF was recently introduced and used for characterization of linear PS, three-arm star PS, deuterated PS and polybutadiene (PBD)- b -PS . The five detectors included MALS, DLS, DV, UV–vis, and DRI.…”