Gel-Permeation Chromatographic Observation of Solvent-Solute Interaction of Low-Molecular-Weight Compounds

Cazes, Jack; Gaskill, David R.

doi:10.1080/01496396908052234

Cited by 29 publications

(1 citation statement)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The increase in the apparent heterogeneity index and the tailing of the low molecular weight fraction of PBCHS may be explained also by the same phenomena; 1. e., strong solvent interaction can result in lower permeation into the stationary phase, hence lower retention As Ouano et ál.53 have pointed out, the same behavior has been observed with other polymers containing highly polar groups, such as polyols. 54 The difference of solvation between compounds of similar size and shape may be an element in their separation.55,56 Horta57 has given a theoretical prediction on the influence of the solvation on the fractionation of polymers by GPC. However, the solvation alone can not be the explanation to all the incompatibility processes observed in the literature.…”

Section: Resultsmentioning

confidence: 99%

Gel permeation chromatography of poly(N-vinyl-3,6-dibromocarbazole). Universal calibration, nonexclusion effects, and incompatibility

Barrales‐Rienda¹,

Gómez²,

Horta³

et al. 1985

Macromolecules

View full text Add to dashboard Cite

Nonexclusion effects in the GPC of poly(N-vinyl-3,6-dibromocarbazole) ) in tetrahydrofuran, at 25 "C, using cross-linked polystyrene (PS) as the gel phase, are analyzed by use of the universal calibration method. The first point in order to determine such nonexclusion effects is to use values for the hydrodynamic volume and the elution volume truly representative of the samples. We show that an adequate set of average magnitudes is the weight-average intrinsic viscosity of the sample, the viscosity-average molecular weight, and the elution volume defined as the viscosity average by means of vv, = log {J3?,(V)[l(P1v] dVJ('/OAL), where H,( V) represents the relative weight of the normalized chromatogram for sample i at elution volume V , a is the exponent in the Mark-Houwink equation for the system under study, and A, is the coefficient of the linear term in the log M vs. V calibration of GPC valid for samples constituted of monomolecular species. The early elution of PVK-3,6-Br2 in THF, as compared with PS standards, can be represented by the equationwhere V , is the retention volume, V,, the interstitial volume, V , the solvent volume within the gel, KD the distribution coefficient for steric exclusion, which is given by KD = -A log ([TIM) + B (A and B are constants), and K is a distribution coefficient for solute-gel interactions. The values of K , found in the present system are gelow unity, and their molecular weight dependence can be represented by -In K, -X,, where X, is the degree of polymerization of the polymer molecule in the mobile phase. In the formulation of Dawkins this corresponds to incompatibility between eluted polymer (2) and gel (3), and -In K,/X, = @3(l + x23), where @3 is the volume fraction of the gel in the stationary phase and ~2 3 the polymer-gel interaction parameter per polymer repeating unit. The compatibility of PVK-3,6-Br2 with PS in THF solution is studied by determining the phase-separation diagram of the ternary system THF (1) + PVK-3,6-Br, (2) + linear PS(3), from which a value of xB at the plait point is determined. The equilibrium distribution of solute polymer (2) between the mobile phase and the gel is treated thermodynamically as a problem in preferential sorption in a ternary system (selective adsorption or desorption of 2 by 3 from the 1 + 2 solution). The result of this thermodynamic treatment is -In K,/X, = b3(l + g23 -g12 -g13), which is similar to the one given by Dawkins, but now it includes the additional contribution of the polymersolvent and gel-solvent interaction parameters g,, and g13. These g,'s and the x,,'s defined on the basis of chemical potential are connected through xi, = g,, -(1 -@,)(dg,,/d@,). The value of gl, + g13 can be of the order of unity so that (1 -g12 -g13) can approximately cancel. This expression gives thus the conditions under which K, can be unity or differ from unity depending on the balance of the interaction parameters. IntroductionAs has been recognized for a long time, steric exclusion from a theoretical point of view is the only...

show abstract

Section: Resultsmentioning

confidence: 99%

Gel permeation chromatography of poly(N-vinyl-3,6-dibromocarbazole). Universal calibration, nonexclusion effects, and incompatibility

Barrales‐Rienda¹,

Gómez²,

Horta³

et al. 1985

Macromolecules

View full text Add to dashboard Cite

show abstract

Rationalisation of the sizes of small molecules in gel permeation chromatography

Lambert

1970

J. Appl. Chem.

View full text Add to dashboard Cite

Published data on the sizes of small molecules measured by gel permeation chromatography are reconsidered after subjecting them to a recalculation procedure which gives molecular sizes in consistent units. Almost half the results are rejected as being unreliable. A set of molar volume values for n‐alkanes is recommended as a standard which should be used to calibrate gel permeation chromatographs irrespective of operating conditions. Molar volumes of some simple gases are given.

show abstract

Review of gel permeation chromatography

Lambert

1971

Brit. Poly. J.

View full text Add to dashboard Cite

Gel permeation chromatography (g.p.c.) with organic solvents is of immense value in the characterisation of plastics and resins. Topics revie wed here are column packings and packing techniques, instrumental features, theories of the separating process and of instrumental dispersion, the use of g.p.c. to measure molecular size and hydrogen bonding, the applications of g.p.c. to low molecular weight polymers, applications to high molecular weight polymers, work on glass beads (as opposed to organic beads) and high resolution g.p.c.

show abstract

Gel-Permeation Chromatographic Observation of Solvent-Solute Interaction of Low-Molecular-Weight Compounds

Cited by 29 publications

References 6 publications

Gel permeation chromatography of poly(N-vinyl-3,6-dibromocarbazole). Universal calibration, nonexclusion effects, and incompatibility

Gel permeation chromatography of poly(N-vinyl-3,6-dibromocarbazole). Universal calibration, nonexclusion effects, and incompatibility

Rationalisation of the sizes of small molecules in gel permeation chromatography

Review of gel permeation chromatography

Contact Info

Product

Resources

About