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@ARTICLE{Kostyurina:906383,
author = {Kostyurina, Ekaterina and De Mel, Judith U. and Vasilyeva,
Alexandra and Kruteva, Margarita and Frielinghaus, Henrich
and Dulle, Martin and Barnsley, Lester and Förster, Stephan
and Schneider, Gerald J. and Biehl, Ralf and Allgaier,
Jürgen},
title = {{C}ontrolled {LCST} {B}ehavior and {S}tructure {F}ormation
of {A}lternating {A}mphiphilic {C}opolymers in {W}ater},
journal = {Macromolecules},
volume = {55},
number = {5},
issn = {0024-9297},
address = {Washington, DC},
publisher = {Soc.},
reportid = {FZJ-2022-01411},
pages = {1552–1565},
year = {2022},
abstract = {Amphiphilic polymers show a rich self-assembly behavior in
aqueous solutions. In experimental investigations
statistical copolymer or block copolymer architectures are
usually investigated, because of their ease of synthesis or
their structural analogy to surfactants. A copolymer
structure that links the two architectures are alternating
copolymers, which are easily accessible by polycondensation
reactions. Using alternating hydrophilic and hydrophobic
building blocks with varying length allows a systematic
variation between statistical and multi-block architectures.
We synthesized alternating amphiphilic copolymers as
polyesters using hydrophobic dicarboxylic acids (C4 – C20)
and hydrophilic polyethylene glycol (PEG) units (EG3 –
EG1000). Copolymers with long EG units were made accessible
with the help of a newly developed esterification process.
The solution properties of the amphiphilic copolymers
feature a lower critical solution temperature (LCST)
behavior in water, which can be systematically varied over a
wide range from 3 – 83°C by adjusting the lengths of the
Cn- and EGm–units. We find that the transition temperature
depends linearly on the hydrophobic unit length Cm and
logarithmically on the hydrophilic length EGn. In the
one-phase region the PEG copolymer coils are more compact
compared to the respective PEG homopolymers due to
hydrophobic interactions between the hydrophobic units
leading to loop formation. For shorter PEG-units the
copolymers form micellar structures consisting only of a few
copolymer chains. The micellar cores consist of hydrophobic
regions containing only a few dicarboxylic acid units,
embedded in a PEG-rich and water-poor matrix. The cores are
surrounded by a rather diluted corona of PEG chains. Further
decreasing the PEG unit length leads to the formation of
highly swollen gels consisting of networks of interconnected
micelles. These can self-assemble to form highly ordered
liquid crystalline cubic phases. The study demonstrates how
the structure of alternating amphiphilic copolymers can be
systematically varied to adjust thermal solution properties
such as the LCST over a wide range, as well as the
self-assembly properties varying between single chain,
micelle, gels and highly ordered lyotropic liquid crystals.},
cin = {JCNS-FRM-II / MLZ / JCNS-1 / JCNS-4},
ddc = {540},
cid = {I:(DE-Juel1)JCNS-FRM-II-20110218 / I:(DE-588b)4597118-3 /
I:(DE-Juel1)JCNS-1-20110106 / I:(DE-Juel1)JCNS-4-20201012},
pnm = {6G4 - Jülich Centre for Neutron Research (JCNS) (FZJ)
(POF4-6G4) / 632 - Materials – Quantum, Complex and
Functional Materials (POF4-632)},
pid = {G:(DE-HGF)POF4-6G4 / G:(DE-HGF)POF4-632},
experiment = {EXP:(DE-MLZ)KWS1-20140101},
typ = {PUB:(DE-HGF)16},
UT = {WOS:000772188000010},
doi = {10.1021/acs.macromol.1c02324},
url = {https://juser.fz-juelich.de/record/906383},
}