Universal calibration for thermal field‐flow fractionation

摘要

AbstractExperiments have shown that the thermal diffusion coefficient of a polymer is independent of the sample's molecular weight. According to the relationship between the ordinary diffusion coefficient and polymer molecular weight, a universal calibration method for thermal field‐flow fractionation (FFF) has been created. This method has been examined experimentally by three polymers of different chemical composition with different molecular weight in three organic solvents. It is shown that this method is useful both in terms of calibrating a thermal FFF system with some readily available polymer standard, for use with unknown samples of known thermal diffusivity, and in terms of determining the thermal diffusion coefficient of the unknown sample under conditions where its molecular weight can be measured by other method