Colloid and Polymer Science

, Volume 292, Issue 8, pp 1757–1774

Novel thermoresponsive block copolymers having different architectures—structural, rheological, thermal, and dielectric investigations

  • Konstantinos Kyriakos
  • Dionysia Aravopoulou
  • Lukas Augsbach
  • Josef Sapper
  • Sarah Ottinger
  • Christina Psylla
  • Ali Aghebat Rafat
  • Carlos Adrian Benitez-Montoya
  • Anna Miasnikova
  • Zhenyu Di
  • André Laschewsky
  • Peter Müller-Buschbaum
  • Apostolos Kyritsis
  • Christine M. Papadakis
Original Contribution

DOI: 10.1007/s00396-014-3282-0

Cite this article as:
Kyriakos, K., Aravopoulou, D., Augsbach, L. et al. Colloid Polym Sci (2014) 292: 1757. doi:10.1007/s00396-014-3282-0
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Abstract

Thermoresponsive block copolymers comprising long, hydrophilic, nonionic poly(methoxy diethylene glycol acrylate) (PMDEGA) blocks and short hydrophobic polystyrene (PS) blocks are investigated in aqueous solution. Various architectures, namely diblock, triblock, and starblock copolymers are studied as well as a PMDEGA homopolymer as reference, over a wide concentration range. For specific characterization methods, polymers were labeled, either by partial deuteration (for neutron scattering studies) or by fluorophores. Using fluorescence correlation spectroscopy, critical micellization concentrations are identified and the hydrodynamic radii of the micelles, rhmic, are determined. Using dynamic light scattering, the behavior of rhmic in dependence on temperature and the cloud points are measured. Small-angle neutron scattering enabled the detailed structural investigation of the micelles and their aggregates below and above the cloud point. Viscosity measurements are carried out to determine the activation energies in dependence on the molecular architecture. Differential scanning calorimetry at high polymer concentration reveals the glass transition of the polymers, the fraction of uncrystallized water and effects of the phase transition at the cloud point. Dielectric relaxation spectroscopy shows that the polarization changes reversibly at the cloud point, which reflects the formation of large aggregates upon heating through the cloud point and their redissolution upon cooling.

Keywords

Block copolymers Thermoresponsive Structural investigations Mechanical properties Thermal behavior Dielectric properties 

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Konstantinos Kyriakos
    • 1
  • Dionysia Aravopoulou
    • 2
  • Lukas Augsbach
    • 1
  • Josef Sapper
    • 1
  • Sarah Ottinger
    • 1
  • Christina Psylla
    • 1
  • Ali Aghebat Rafat
    • 1
  • Carlos Adrian Benitez-Montoya
    • 3
  • Anna Miasnikova
    • 3
  • Zhenyu Di
    • 4
  • André Laschewsky
    • 3
    • 5
  • Peter Müller-Buschbaum
    • 1
  • Apostolos Kyritsis
    • 2
  • Christine M. Papadakis
    • 1
  1. 1.Physik-Department, Fachgebiet Physik weicher Materie/Lehrstuhl Physik funktioneller MaterialienTechnische Universität MünchenGarchingGermany
  2. 2.Physics DepartmentNational Technical University of AthensAthensGreece
  3. 3.Institut für ChemieUniversität PotsdamPotsdam-GolmGermany
  4. 4.Jülich Centre for Neutron Science (JCNS), Forschungszentrum Jülich GmbH, Outstation at MLZGarchingGermany
  5. 5.Fraunhofer Institut für Angewandte PolymerforschungPotsdam-GolmGermany

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