Unusual sensitivity of closed-loop phase behavior to chain size and distribution

Sung Wook Hwang, Eunhye Kim, Changhak Shin, Jung-Hyun Kim, Du Yeol Ryu, Soojin Park, Taihyun Chang, Jin Kon Kim

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

An anionically polymerized polystyrene-block-poly(n-pentyl methacrylate) (PS-b-PnPMA) was fractionated by interaction chromatography (IC), and the closed-loop phase behavior of the mother block copolymer and its fractions with different chemical compositions was investigated by depolarized light scattering and polarized optical microscopy. With increasing elution time the average chain size (or the average molecular weight) of the block copolymer decreased slightly, and the average chemical composition changed steadily from a PS volume fraction of 0.583 to 0.403, thereby producing five fractions collected over the different ranges of elution time. This is caused by the difference of relative interaction strength between the stationary phase and the PnPMA chains of PS-b-PnPMA, in which PnPMA chains tend to be adsorbed onto the stationary phase while PS chains behave oppositely. Over the range of accessible temperatures studied (110-250°C) a variety of phase transitions were observed, including fully ordered state, a closed-loop (consisting of the lower disorder-to-order transition and upper order-to-disorder transition), and fully disordered state. The original, unfractionated block copolymer was disordered over the entire temperature range. The variety of observed phase transitions obtained from the fractionated block copolymers is assumed to be governed by the sensitivity of the closed-loop phase behavior to average chain size, average chemical composition, and the compositional broadness.

Original languageEnglish
Pages (from-to)8066-8070
Number of pages5
JournalMacromolecules
Volume40
Issue number22
DOIs
Publication statusPublished - 2007 Oct 30

Fingerprint

Phase behavior
Block copolymers
Methacrylates
Polystyrenes
Phase transitions
Chemical analysis
Chromatography
Light scattering
Optical microscopy
Volume fraction
Molecular weight
Temperature

All Science Journal Classification (ASJC) codes

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

Cite this

Hwang, Sung Wook ; Kim, Eunhye ; Shin, Changhak ; Kim, Jung-Hyun ; Ryu, Du Yeol ; Park, Soojin ; Chang, Taihyun ; Kim, Jin Kon. / Unusual sensitivity of closed-loop phase behavior to chain size and distribution. In: Macromolecules. 2007 ; Vol. 40, No. 22. pp. 8066-8070.
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abstract = "An anionically polymerized polystyrene-block-poly(n-pentyl methacrylate) (PS-b-PnPMA) was fractionated by interaction chromatography (IC), and the closed-loop phase behavior of the mother block copolymer and its fractions with different chemical compositions was investigated by depolarized light scattering and polarized optical microscopy. With increasing elution time the average chain size (or the average molecular weight) of the block copolymer decreased slightly, and the average chemical composition changed steadily from a PS volume fraction of 0.583 to 0.403, thereby producing five fractions collected over the different ranges of elution time. This is caused by the difference of relative interaction strength between the stationary phase and the PnPMA chains of PS-b-PnPMA, in which PnPMA chains tend to be adsorbed onto the stationary phase while PS chains behave oppositely. Over the range of accessible temperatures studied (110-250°C) a variety of phase transitions were observed, including fully ordered state, a closed-loop (consisting of the lower disorder-to-order transition and upper order-to-disorder transition), and fully disordered state. The original, unfractionated block copolymer was disordered over the entire temperature range. The variety of observed phase transitions obtained from the fractionated block copolymers is assumed to be governed by the sensitivity of the closed-loop phase behavior to average chain size, average chemical composition, and the compositional broadness.",
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Hwang, SW, Kim, E, Shin, C, Kim, J-H, Ryu, DY, Park, S, Chang, T & Kim, JK 2007, 'Unusual sensitivity of closed-loop phase behavior to chain size and distribution', Macromolecules, vol. 40, no. 22, pp. 8066-8070. https://doi.org/10.1021/ma071314a

Unusual sensitivity of closed-loop phase behavior to chain size and distribution. / Hwang, Sung Wook; Kim, Eunhye; Shin, Changhak; Kim, Jung-Hyun; Ryu, Du Yeol; Park, Soojin; Chang, Taihyun; Kim, Jin Kon.

In: Macromolecules, Vol. 40, No. 22, 30.10.2007, p. 8066-8070.

Research output: Contribution to journalArticle

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T1 - Unusual sensitivity of closed-loop phase behavior to chain size and distribution

AU - Hwang, Sung Wook

AU - Kim, Eunhye

AU - Shin, Changhak

AU - Kim, Jung-Hyun

AU - Ryu, Du Yeol

AU - Park, Soojin

AU - Chang, Taihyun

AU - Kim, Jin Kon

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N2 - An anionically polymerized polystyrene-block-poly(n-pentyl methacrylate) (PS-b-PnPMA) was fractionated by interaction chromatography (IC), and the closed-loop phase behavior of the mother block copolymer and its fractions with different chemical compositions was investigated by depolarized light scattering and polarized optical microscopy. With increasing elution time the average chain size (or the average molecular weight) of the block copolymer decreased slightly, and the average chemical composition changed steadily from a PS volume fraction of 0.583 to 0.403, thereby producing five fractions collected over the different ranges of elution time. This is caused by the difference of relative interaction strength between the stationary phase and the PnPMA chains of PS-b-PnPMA, in which PnPMA chains tend to be adsorbed onto the stationary phase while PS chains behave oppositely. Over the range of accessible temperatures studied (110-250°C) a variety of phase transitions were observed, including fully ordered state, a closed-loop (consisting of the lower disorder-to-order transition and upper order-to-disorder transition), and fully disordered state. The original, unfractionated block copolymer was disordered over the entire temperature range. The variety of observed phase transitions obtained from the fractionated block copolymers is assumed to be governed by the sensitivity of the closed-loop phase behavior to average chain size, average chemical composition, and the compositional broadness.

AB - An anionically polymerized polystyrene-block-poly(n-pentyl methacrylate) (PS-b-PnPMA) was fractionated by interaction chromatography (IC), and the closed-loop phase behavior of the mother block copolymer and its fractions with different chemical compositions was investigated by depolarized light scattering and polarized optical microscopy. With increasing elution time the average chain size (or the average molecular weight) of the block copolymer decreased slightly, and the average chemical composition changed steadily from a PS volume fraction of 0.583 to 0.403, thereby producing five fractions collected over the different ranges of elution time. This is caused by the difference of relative interaction strength between the stationary phase and the PnPMA chains of PS-b-PnPMA, in which PnPMA chains tend to be adsorbed onto the stationary phase while PS chains behave oppositely. Over the range of accessible temperatures studied (110-250°C) a variety of phase transitions were observed, including fully ordered state, a closed-loop (consisting of the lower disorder-to-order transition and upper order-to-disorder transition), and fully disordered state. The original, unfractionated block copolymer was disordered over the entire temperature range. The variety of observed phase transitions obtained from the fractionated block copolymers is assumed to be governed by the sensitivity of the closed-loop phase behavior to average chain size, average chemical composition, and the compositional broadness.

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