Eur. Phys. J. E (2008) 27: 335-343
https://doi.org/10.1140/epje/i2008-10386-3

Regular Article

Stimuli-responsive poly(ethylene oxide)-b-poly(2-vinylpyridine)-b-poly(ethylene oxide) triblock copolymers and complexation with poly(acrylic acid) at low pH

¹ Department of Chemical Engineering, University of Patras, GR-26504, Patras, Greece
² Department of Chemistry, University of Patras, GR-26504, Patras, Greece
³ Institute of Chemical Engineering and High Temperature Chemical Processes, FORTH/ICE-HT, Patras, Greece

^* e-mail: bokias@chemistry.upatras.gr
^** e-mail: ct@chemeng.upatras.gr

Received: 16 July 2008
Revised: 26 September 2008
Published online: 6 November 2008

Abstract

The self-organization of the double hydrophilic triblock copolymer poly(ethylene oxide)-b-poly(2-vinylpyridine)-b-poly(ethylene oxide), PEO-b-P2VP-b-PEO, was investigated in dilute aqueous solution under several experimental conditions using turbidimetry, as well as static and dynamic light scattering. As a result of the temperature-sensitive properties of the end PEO blocks and the p H-responsive properties of the middle P2VP block, the formation of large star-like micellar nanostructures is observed at high p H, while at low p H, but in the presence of salt and at high temperature, flower-like micelles are formed. Moreover, the viscosimetric and dynamic light scattering studies at low p H revealed that micelle-like nanostructures are formed upon mixing the triblock copolymer with poly(acrylic acid), PAA, due to hydrogen bonding interpolymer complexation.