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Monolithic stationary phases with a longitudinal gradient of porosity
Autoři | |
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Rok publikování | 2017 |
Druh | Článek v odborném periodiku |
Časopis / Zdroj | Journal of Separation Science |
Citace | |
www | http://dx.doi.org/10.1002/jssc.201700048 |
Doi | http://dx.doi.org/10.1002/jssc.201700048 |
Klíčová slova | hypercrosslinking; polymer monoliths; polymers; porosity gradient; size-exclusion chromatography |
Popis | The duration of the hypercrosslinking reaction has been used to control the extent of small pores formation in polymer-based monolithic stationary phases. Segments of five columns hypercrosslinked for 30-360 min were coupled via zero-volume unions to prepare columns with segmented porosity gradients. The steepness of the porosity gradient affected column efficiency, mass transfer resistance, and separation of both small-molecule alkylbenzenes and high-molar-mass polystyrene standards. In addition, the segmented column with the steepest porosity gradient was prepared as a single column with a continuous porosity gradient. The steepness of porosity gradient in this type column was tuned. Compared to a completely hypercrosslinked column, the column with the shallower gradient produced comparable size-exclusion separation of polystyrene standards but allowed higher column permeability. The completely hypercrosslinked column and the column with porosity gradient were successfully coupled in online two-dimensional liquid chromatography of polymers. |