On the existence of two theta points for polymers in binary mixtures

Dondos, Anastasios; Benoît, H.

doi:10.1002/pol.1969.110070502

Cited by 53 publications

(10 citation statements)

References 15 publications

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“…As already reported (Ref. 26), in polystyrene/benzene/methanol system the polymer exhibits two different theta points at 25°C due to the preferential adsorption which changes the analytical conlposition in the interior of the coil: the theta intermolecular appears at a volume fraction of methanol, 42 = 0.22 and the theta intramolecular appears at 42 = 0.255. Dondos et al (Refs.…”

Section: Theta Conditionssupporting

confidence: 66%

Specific interactions in dilute polymer solutions

Simionescu

Ioan²,

Ioan³

et al. 1995

Macromolecular Symposia

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Section: Theta Conditionssupporting

confidence: 66%

Specific interactions in dilute polymer solutions

Simionescu

Ioan²,

Ioan³

et al. 1995

Macromolecular Symposia

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“…Figure9. The viscosity constant vs. A2 for Na-PAMS in aqueous NaCl solutions and for TBA-PAMS in organic media.…”

mentioning

confidence: 99%

Chain Characteristics of Poly(2-acrylamido-2-methylpropanesulfonate) Polymers. 1. Light-Scattering and Intrinsic-Viscosity Studies

Fisher¹,

Sochor²,

Tan³

1977

Macromolecules

116

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“…1,4 The correct characteristic ratio could not be obtained at the temperature defined by A 2 ϭ0 in the presence of a preferential sorption. 23 In the present experiment, the PMMA chain in pure tertbutyl alcohol was found to collapse completely within 90 min after quenching for M ϭ1.22ϫ10 7 and within 30 min for M ϭ4.1ϫ10 6 . For PMMA in the mixed solvent tert-butyl alcoholϩwater͑2.5 vol %͒, the chain collapse process was observed over periods of hours to weeks depending on the temperature and the molecular weight.…”

Section: Discussionmentioning

confidence: 87%

Solvent effect on single-chain collapse of poly(methyl methacrylate) in tert-butyl alcohol

Nakamura

Sasaki

Nakata

2003

The Journal of Chemical Physics

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Kinetic and static properties of the coil-globule transition of poly͑methyl methacrylate͒ ͑PMMA͒ in pure tert-butyl alcohol were determined by static light scattering and compared with those of PMMA in the mixed solvent tert-butyl alcoholϩwater͑2.5 vol %͒ in order to examine the effect of water on the chain collapse. The measurements were carried out for the molecular weight M ϫ10 Ϫ6 ϭ4.1 and 12.2 in the concentration range of 0.6ϫ10 Ϫ4 -2.6ϫ10 Ϫ4 g/cm 3 , and the mean-square radius of gyration ͗s 2 ͘ was determined as a function of the time after an abrupt decrease of temperature.PMMA chains collapsed to equilibrium globules within 90 min after quenching for M ϭ1.22 ϫ10 7 and within 30 min for M ϭ4.1ϫ10 6 . Chain aggregation due to phase separation became noticeable after the collapse of the chain because of an increase of observed molecular weight. For PMMA in the mixed solvent tert-butyl alcoholϩwater͑2.5 vol %͒, the chain collapse process has been observed for periods from hours to weeks depending on the molecular weight and temperature, and the chain aggregation was negligibly small in the chain collapse process. The expansion factor ␣ 2 ϭ͗s 2 ͘/͗s 2 ͘ 0 obtained for fully collapsed chains in pure tert-butyl alcohol was represented by the theoretical prediction ␣ 3 Ϫ␣ϪC(␣ Ϫ3 Ϫ1)ϭB(1Ϫ /T)M 1/2 with the coefficients of Bϭ0.0179 and Cϭ0.054. For PMMA in the mixed solvent, the coil-globule transition curve has been expressed by the same equation with Bϭ0.0164 and Cϭ0.049, close to the above values. The small amount of water in the mixed solvent caused a drastic slowdown in the chain-collapse rate but had little effect on the coil-globule transition curve.

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On the existence of two theta points for polymers in binary mixtures

Cited by 53 publications

References 15 publications

Specific interactions in dilute polymer solutions

Specific interactions in dilute polymer solutions

Chain Characteristics of Poly(2-acrylamido-2-methylpropanesulfonate) Polymers. 1. Light-Scattering and Intrinsic-Viscosity Studies

Solvent effect on single-chain collapse of poly(methyl methacrylate) in tert-butyl alcohol

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