6533b7d8fe1ef96bd126b545

RESEARCH PRODUCT

The Fractal Approach to Secondary Mechanisms in SEC

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Abstract Size‐exclusion chromatography (SEC) is one of the most used experimental techniques to characterize polymers in solution; it has been applied to interpret the elution behaviour of many polymer‐solvent systems in five types of column packings. The experimental data have revealed that the classical universal calibration is not accomplished. Deviations from a unique curve are a consequence of two effects: entropic (exclusion by size) and enthalpic (binary and ternary interactions between solvent, polymer, and gel), which results in secondary mechanisms accompanying the main “ideal” SEC separation mechanism. Therefore, three approaches of building a calibration curve have been compared in this work: (i) the classical universal calibration based on the elution of tetrahydrofuran (THF)‐polystyrene (PS) system as reference; (ii) the specific or proper calibration curve made with standards of the sample under study; and (iii) the fractal calibration. The understanding of the secondary mechanisms has been...