Gel chromatography: The effect of temperature on partitioning

Chitumbo, K.; Brown, Wyn

doi:10.1016/s0021-9673(01)91514-6

Cited by 7 publications

(3 citation statements)

References 15 publications

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“…It is well-established that the heat of mixing of hydrogen-bonding solutes and water is typically exothermic (i.e., solubility decreases with increasing temperature as does the swelling of hydroxylic gels. 33,34 The differences in slope are less pronounced with the gels as would be anticipated since the cross-links restrict the volume available to the polymer chains.…”

Section: Resultsmentioning

confidence: 95%

Decay time distributions from dynamic light scattering for aqueous poly(vinyl alcohol) gels and semidilute solutions

Fang¹,

Brown²

1990

Macromolecules

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Dynamic light scattering has been used to obtain decay time distributions for permanent poly(viny1 alcohol) (PVA) gels and the corresponding semidilute solutions by Laplace inversion of the autocorrelation functions. The gels were prepared from aqueous solutions of the narrow distribution polymer by cross-linking using glutaraldehyde. The PVA concentration range extends up to 7 % w/v; parallel measurements were made on the gel and corresponding solution as a function of temperature between 3 and 55 O C . Two main relaxational modes typified the PVA solutions, both relaxation rates being diffusive. The fast relaxation characterizes the diffusive motions in the transient gel formed by interpenetration of molecular domains. The slow mode is considered to derive from "clusters" or (groups of chains) having a size that depends on concentration and only slightly on temperature. Formation of the permanent gel resulted in disappearance of the slow mode, and the gels were characterized by single-exponential correlation functions. At a given concentration, the polymer-polymer correlation length of the gel was almost twice that characterizing the transient network in the solution in spite of a very low cross-linking level (~1%). In both systems the diffusion coefficient is linearly dependent on concentration. At high cross-linking density the correlation length shows a marked decrease.

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Section: Resultsmentioning

confidence: 95%

Decay time distributions from dynamic light scattering for aqueous poly(vinyl alcohol) gels and semidilute solutions

Fang¹,

Brown²

1990

Macromolecules

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show abstract

“…where Kp is the distribution coefficient for solute-gel interactions and AH°the standard enthalpy change (8). It suggests that the solute-gel matrix interactions are exothermic or the solvent-gel matrix interactions are endothermic (6). Prior to concluding the effect of column temperature on retention volume, one should consider what other variables would affect retention volume if the column temperature of the SEC unit is raised.…”

Section: Resultsmentioning

confidence: 99%

“…The retention volume fluctuation caused by room temperature variations may be assumed to be small (3), but no systematic studies of the effects of column temperature variations on molecular weight values have been reported for SEC systems. Previous studies of this type involved separation by polymer size at high temperature (3) and the effect of temperature on partitioning (5,6). 0003-2 7 00/80/035 2-1625S01.00/0…”

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confidence: 99%