Effect of core-shell micelle formation on the redox properties of phenothiazine-labeled poly(ethyl glycidy ether)-block-poly(ethylene oxide)

Ryohei Tsuda, Sayaka Kaino, Hisashi Kokubo, Shin Ichiro Imabayashi, Masayoshi Watanabe

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3 Citations (Scopus)


Redox properties of phenothiazine-labeled poly(ethyl glycidy ether)-block-poly(ethylene oxide) (PT-EGEn-b-EOm) are reversibly changed by core-shell micelle formation. In the temperature range higher than the critical micellization temperature (cmt), the anodic potential of PT group positively shifts and concomitantly its anodic current decrease, or levels off compared to those of the reference polymer PT-EOm without the thermo-responsive EGEn segment. The former alteration is caused by incorporation of hydrophobic PT groups into a core of the micelle and the latter by the decrease in the diffusion coefficient of PT groups due to formation of the core-shell micelles. The cmt value and the temperature-dependent alteration in the redox properties strongly depend on the polymer structure, especially the length of thermo-responsive EGEn segment. The electrochemically determined hydrodynamic radii of the polymer aggregates seem to be overestimated, compared to the values reported for the aggregates of other thermo-responsive polymers with similar molecular weights, implying the presence of electrochemically inactive PT groups in the copolymers having longer thermo-responsive segments.

Original languageEnglish
Pages (from-to)255-259
Number of pages5
JournalColloids and Surfaces B: Biointerfaces
Issue number1-2
Publication statusPublished - 2007 Apr 15



  • Critical micellization temperature
  • Hydrodynamic radius
  • Phenothiazine
  • Temperature dependence of redox response
  • Thermo-responsive block copolymer

ASJC Scopus subject areas

  • Biotechnology
  • Surfaces and Interfaces
  • Physical and Theoretical Chemistry
  • Colloid and Surface Chemistry

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