Concentration effects in gel permeation chromatography with mixed eluents

Berek, Dušan; Bakos, D; Šoltés, Ladislav; Bleha, Tomáš

doi:10.1002/pol.1974.130120507

Cited by 33 publications

(6 citation statements)

References 10 publications

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“…The concentration effects for the oligomers and also for the excluded (high) polymer species are usually small or even negligible. The k c values depend also on the thermodynamic quality of eluent 94 and the correlation was found between the product A 2 M and k c where A 2 is the second virial coefficient of the particular polymer–solvent system (Section 2.2) and M is the polymer molar mass 95. At moderate c i values, the concentration effects may slightly contribute to the reduction of the band‐broadening effects in SEC because the retention volumes for species with the higher molar masses are more reduced than those for the lower molar masses.…”

Section: Problems Of Secmentioning

confidence: 99%

“…Similarly, k c values diminish for polymers with excluded molar masses. The dependence of V R on c i is co‐responsible for the mutual shifts of calibration dependences of log V h versus V R for chemically different polymers 94, 115. Increased viscosity of concentrated polymer solutions reduces diffusion rate of macromolecules and, consequently, it hinders mass transfer between the interstitial space and the pore volume.…”

Section: Practical Hintsmentioning

confidence: 99%

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Size exclusion chromatography – A blessing and a curse of science and technology of synthetic polymers

Berek

2010

J of Separation Science

152

126

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Size exclusion chromatography, SEC is one of the most popular methods for the separation of different kinds of macromolecules. This critical review gives concise information about macromolecules and their behavior in solution, basic understanding about principles, instrumentation, and application possibilities of SEC, and more in detail discusses drawbacks and pitfalls of the method with the emphasis on synthetic polymers. Selected practical advices are included to help enhance the quality of SEC results.

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Section: Problems Of Secmentioning

confidence: 99%

Section: Practical Hintsmentioning

confidence: 99%

Size exclusion chromatography – A blessing and a curse of science and technology of synthetic polymers

Berek

2010

J of Separation Science

152

126

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“…Another complicating factor in the quantitative evaluation of polymer–packing interactions by SEC is the concentration effect, that is, the dependence of elution volumes, V e , on the injected polymer concentration, c 2 . As reported,12,13 the slopes of linear plots of V e vs c 2 strongly depend on the thermodynamic quality of the eluent with respect to the polymer and become higher as the molar mass of the polymer increases, especially for good solvents. As usually found in the literature,11–24 the hydrodynamic volume of the polymer decreases as the injected polymer concentration increases making its V e higher than the one obtained at zero concentration, especially for polymers of high molar mass.…”

Section: Resultsmentioning

confidence: 66%

“…In addition, another factor affecting the quantitative evaluation of polymer–packing interactions in SEC, is the concentration effect, i.e., the dependence of the elution volume on the injected polymer concentration, especially for good solvents. This effect has been mainly interpreted on the basis of hydrodynamic factors 11–24. In this paper, the concentration effect has also been correlated with the preferential solvation phenomenon.…”

Section: Introductionmentioning

confidence: 99%

An Analysis of the Concentration Effects on Elution Volumes by Using the Preferential Solvation Parameter in Two SEC Packings

Garcı́a-Lopera

Gómez

Abad

et al. 2002

Macro Chemistry & Physics

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Size exclusion chromatography (SEC) elution behavior of different solvent/polymer systems has been analyzed from chromatographic, thermodynamic, and hydrodynamic points of view in two organic column packings based on polystyrene/divinylbenzene (PS/DVB) copolymer, μ‐styragel and TSK‐Gel HHR. Although both packings present similar chromatographic properties, some differences arise when eluting the same systems. The values of the adsorption distribution coefficients, Kp, have been correlated with the preferential solvation coefficient, λ (see Figure), for both packings, showing that those systems with lower and negative λ values (denoting higher preferential solvation of the polymer by the gel packing) are those with Kp > 1. In addition, the main goal has been to make use of the λ values to adequately interpret the dependence of the elution volumes on injected polymer concentration. In this regard, the experimental concentration effects have been completely explained by taking into account not only the conventional hydrodynamic factors but also thermodynamic aspects such as the preferential solvation phenomenon.Plot of the preferential solvation coefficient, λ, as a function of the volume fraction of polymer (2), ϕ2, at three hydrodynamic volumes, Vh = 106 (○ •); 107 (□ ▪), and 108 (▵ ▴) mL · mol−1 for the system THF/PBD/PS (μ‐styragel: empty symbols; TSK‐Gel HHR (solid symbols).magnified imagePlot of the preferential solvation coefficient, λ, as a function of the volume fraction of polymer (2), ϕ2, at three hydrodynamic volumes, Vh = 106 (○ •); 107 (□ ▪), and 108 (▵ ▴) mL · mol−1 for the system THF/PBD/PS (μ‐styragel: empty symbols; TSK‐Gel HHR (solid symbols).

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“…For polystyrene, eq 4 yields Ke= 8.135 x 10-2 cm 3 /g, compared to a measured value of 7.023 x 10-2 cm 3 /g. 21 ' 22 In any solvent the intrinsic viscosity of the particular polymer is given by the Mark-Houwink equation with appropriate constants (5) …”

Section: Theorymentioning

confidence: 99%

Effect of Solvent on Concentration Dependence of Hydrodynamic Volumes and GPC Elution Volumes

Mahabadi

Rudin

1979

Polym J

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ABSTRACT:The models of Yamakawa and Rudin were used to predict the effects of polymer concentration on hydrodynamic volumes of solvated macromolecules and on peak elution volumes in gel-permeation chromatographic (GPC) analyses. Both theories predict GPC behavior accurately for all systems of practical analytical interest. Yamakawa theory calculations predict that a concentration region may exist in which the polymer hydrodynamic volume may be greater in a poorer solvent than in a thermodynamically better solvent. This "cross-over" is noticeable for high molecular weight polymers at relatively high concentrations which are beyond the dilute region for which the theory was developed. Some GPC observations with porous glass packings are nevertheless in qualitative agreement with this prediction. Both models account for the effects of concentration, solvent choice, and polymer molecular weight on GPC column behavior.KEY WORDS Hydrodynamic Volume I Elution Volume I GPC I Gyration Radius I It is well known that the peak elution volume tends to increase with increasing concentration of a given polymer in the feed to GPC column sets. 1 -10 The concentration effect is more pronounced with polymers of narrow molecular weight distribution and higher mean molecular weight. The effect of concentration decreases as the thermodynamic quality of the GPC solvent deteriorates and is practically non-existent in theta mixtures.The concentration effect in GPC was explained as a consequence of the reduction of the effective hydrodynamic volume of solvated polymer coils with increasing concentration. A semi-empirical model has been discussed which can be used to correct for concentration effects in GPC. 11 This model has also been applied to universal calibration in GPC. 12 The theory did not fit experimental observations in theta solvents and a revision (herein-after referred to as the Rudin model) has been published which is less empirical and which appears to fit the elution behavior of polymers in all * On leave from Chemical Engineering Department, Arya-Mehr University of Technology, Tehran, Iran. GPC solvents. 9 ' 13 -16 The Rudin model seems to be the only one which has been used quantitatively to correct GPC data for concentration effects. It was of interest, therefore, to determine whether a model which is accepted as more "orthodox" in current polymer solution theory would also be applicable to this practical problem. In this article, we compare the Rudin model 13 with Yamakawa's 17 theory relating the concentration and effective hydrodynamic volume of solvated polymers. It will be shown that the two theories yield equivalent predictions under almost all conditions which are likely to be encountered in GPC analyses. The two deviate only in the case of very high molecular weight polymers at relatively high concentrations in very good solvents. The Rudin model is more convenient to use. The Yamakawa theory predicts that the dimensions of a high molecular weight polymer coil in a good solvent may be smaller than those in a...

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Concentration effects in gel permeation chromatography with mixed eluents

Cited by 33 publications

References 10 publications

Size exclusion chromatography – A blessing and a curse of science and technology of synthetic polymers

Size exclusion chromatography – A blessing and a curse of science and technology of synthetic polymers

An Analysis of the Concentration Effects on Elution Volumes by Using the Preferential Solvation Parameter in Two SEC Packings

Effect of Solvent on Concentration Dependence of Hydrodynamic Volumes and GPC Elution Volumes

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