Determination of pore volume distribution from size exclusion chromatography data

Jeřábek, Karel

doi:10.1021/ac00285a022

Cited by 84 publications

(32 citation statements)

References 10 publications

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“…Although nitrogen adsorption measurements reveal the presence both of 100-nm diameter macropores and 1-3-nm diameter micropores in dry MN-200 [10], the pore size in the swollen polymer under the conditions used for HPLC could be different. From the standpoint of practical usage, SEC should be more informative for the characterization of an LC packing [8,26,27]. In this work the pore size distribution in MN-200 was determined by using a cylindrical pore model.…”

Section: Pore-size Distributionmentioning

confidence: 99%

Investigation of the properties of hypercrosslinked polystyrene as a stationary phase for high-performance liquid chromatography

et al. 1999

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SummaryThe mechanical rigidity, swelling properties, adsorption selectivity, and chromatographic performance of hypercrosslinked polystyrene (mainly MN-200 or Purosep-200; Purolite, UK) have been studied to evaluate the use of the material as a stationary phase for reversedphase high-performance liquid chromatography (RPHPLC). By use of inverse size-exclusion chromatography (SEC) this adsorbent, with a high specific 2 1 surface area of 1500 m g was found to have a biporous structure with micropores of ca 1-2 nm and macropores ca 100 nm in diameter. The polymer does not change its volume significantly on changing water for organic solvents. The retention increments for methylene and phenyl groups were calculated and indicated that the mechanism of retention on the hypercrosslinked polystyrene involves re-re interactions and strong hydrophobic interactions. The column performance of the hypercrosslinked polystyrene was found to be acceptable, with reduced plate height increasing very slowly as the linear velocity of the mobile phase increased to high values (up to 20-45 cm min-1). Columns containing hypercrosslinked polystyrene were evaluated for the separation of phenols, dialkyl phthalates, and polyaromatic compounds. On-column preconcentration of trace organic compounds from aqueous media is possible. With smaller particles of hypercrosslinked polystyrene becoming available, this material can be regarded as an alternative to alkylsilica as a hydrolytically stable column-packing material for RPHPLC.

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Section: Pore-size Distributionmentioning

confidence: 99%

Investigation of the properties of hypercrosslinked polystyrene as a stationary phase for high-performance liquid chromatography

et al. 1999

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“…the ion-exchanger, as the stationary phase in a liquid chromatography column, and measures elution volumes of solutes with a characteristic molecular size. Then, under the considered assumptions: (a) a simple geometric model can describe the pore system, and (b) the pore system can be treated as a discrete set of fractions with simple pores of a single size, the mathematical treatment of the data provided by the ISEC analysis provides information on pore volume distributions [6,7,32].…”

Section: Fig2 Isec Morphological Pattern Of the Gel-phasementioning

confidence: 99%

“…Up to date, the only procedure employed to characterize the morphology of ion-exchangers in the swollen state is the Inverse Steric Exclusion Chromatography (ISEC), based on modeling the microporous structure as a set of discrete volume fractions with different characteristic polymer chain densities [6,7]. The ISEC technique is appropriate to assess the catalytic behavior in chemical reactions, since it is based upon the swelling of ion-exchangers in water, for water was found to be the most suitable solvent in terms of reducing enthalpic interactions between polymer and solute [8], despite a number of industriallyinteresting reactions take place in water-free environment.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Activity and Accessibility of Acidic Ion-Exchange Resins in Liquid Phase Etherification Reactions

et al. 2015

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Although macroreticular acidic ion-exchange resins have been widely used as catalysts in the industrial world for decades, their catalytic behavior is still far from being completely understood at a molecular level. Several characterization techniques coexist, which provide information about their properties. Only few of these techniques give an actual picture of their working-state features when swollen in anhydrous polar reactive media such as in etherification processes, where they are extensively used. The inverse steric exclusion chromatography technique, based on modeling the micropores structure, or gel-phase, as a set of discrete volume fractions with a characteristic polymer chain density, constitutes an appropriate procedure to assess the morphology of ion-exchangers in the swollen state. Present work proposes an empirical model to correlate the properties of the volume fractions with their catalytic activity in the etherification reaction rates of isobutene by addition of C1 to C4 linear primary alcohols. Sixteen different macroreticular acidic ion-exchange catalysts, both commercial and lab-made, have been used, which differ in acid capacity, sulfonation type, cross-linking degree and swollen-phase volume fractions distribution. Experimental reaction rates have been expressed as a sum of contributions of each individual volume fraction. The contribution of each polymer volume fraction corresponds to the product of the catalyst acidity, the characteristic volume fraction within the gel-phase of the catalyst, and a specific turnover frequency (TOF) of that fraction. Accessibility of the reacting alcohol, expressed in terms of the Ogston coefficient, has been also included in the empirical dependency equation presented in this work.

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“…Organic solvent-swollen state was investigated using THF as the mobile phase and n-alkanes and polystyrenes as the standard solutes. Details of the experimental procedure and data treatment were reported elsewhere [28][29][30][31].…”

Section: Inverse Steric Exclusion Chromatography (Isec)mentioning

confidence: 99%

“…Nanostructure of CF4, R402, R425, R402MeI, R425MeI: assessment with ISEC ISEC provides detailed information on the swollen-state morphology of crosslinked polymers [28][29][30][31]. It is based on the analysis of the elution behaviour of standard solutes with known effective molecular size flowing through a column filled with the investigated material under conditions where the chromatographic process is influenced by steric (entropic) effects only.…”

Section: Swelling Behaviour: Specific Absorbed Volume (Sav) Analysis mentioning

confidence: 99%

Cross-linked poly-4-vinylpyridines as useful supports in metal catalysis: micro- and nanometer scale morphology

Giammatteo

Tauro

D’Archivio

et al. 2007

Journal of Molecular Catalysis A: Chemical

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Determination of pore volume distribution from size exclusion chromatography data

Cited by 84 publications

References 10 publications

Investigation of the properties of hypercrosslinked polystyrene as a stationary phase for high-performance liquid chromatography

Investigation of the properties of hypercrosslinked polystyrene as a stationary phase for high-performance liquid chromatography

Catalytic Activity and Accessibility of Acidic Ion-Exchange Resins in Liquid Phase Etherification Reactions

Cross-linked poly-4-vinylpyridines as useful supports in metal catalysis: micro- and nanometer scale morphology

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