TY  - JOUR
A1  - Hildebrand, Viet
A1  - Heydenreich, Matthias
A1  - Laschewsky, Andre
A1  - Moeller, Heiko M.
A1  - Mueller-Buschbaum, Peter
A1  - Papadakis, Christine M.
A1  - Schanzenbach, Dirk
A1  - Wischerhoff, Erik
T1  - "Schizophrenic" self-assembly of dual thermoresponsive block copolymers bearing a zwitterionic and a non-ionic hydrophilic block
T2  - Polymer : the international journal for the science and technology of polymers
N2  - Several series of presumed dual thermo-responsive diblock copolymers consisting of one non-ionic and one zwitterionic block were synthesized via consecutive reversible addition-fragmentation chain transfer (RAFT) polymerization. For all copolymers, poly(N-isopropylmethacrylamide) was chosen as non-ionic block that shows a coil-to-globule collapse transition of the lower critical solution temperature (LCST) type. In contrast, the chemical structure of zwitterionic blocks, which all belonged to the class of poly(sulfobetaine methacrylate)s, was varied broadly, in order to tune their coil-to-globule collapse transition of the upper critical solution temperature (UCST) type. All polymers were labeled with a solvatochromic fluorescent end-group. The dual thermo-responsive behavior and the resulting multifarious temperature-dependent self-assembly in aqueous solution were mapped by temperature resolved turbidimetry, H-1 NMR spectroscopy, dynamic light scattering (DLS), and fluorescence spectroscopy. Depending on the relative positions between the UCST-type and LCST-type transition temperatures, as well as on the width of the window in-between, all the four possible modes of stimulus induced micellization can be realized. This includes classical induced micellization due to a transition from a double hydrophilic, or respectively, from a double hydrophobic to an amphiphilic state, as well as "schizophrenic" behavior, where the core- and shell-forming blocks are inverted. The exchange of the roles of the hydrophilic and hydrophobic block in the amphiphilic states is possible through a homogeneous intermediate state or a heterogeneous one. (C) 2017 Elsevier Ltd. All rights reserved.
KW  - RAFT polymerization
KW  - Block copolymer
KW  - Sulfobetaine methacrylate
KW  - Responsive polymer
KW  - LCST
KW  - UCST
KW  - Schizophrenic self-assembly
Y1  - 2017
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/46504
SN  - 0032-3861
SN  - 1873-2291
VL  - 122
SP  - 347
EP  - 357
PB  - Elsevier
CY  - Oxford
ER  -