% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@ARTICLE{GonzlezGaitano:189818,
author = {González-Gaitano, Gustavo and Müller, Céline and
Radulescu, Aurel and Dreiss, Cécile A.},
title = {{M}odulating the {S}elf-{A}ssembly of {A}mphiphilic
{X}-{S}haped {B}lock {C}opolymers with {C}yclodextrins:
{S}tructure and {M}echanisms},
journal = {Langmuir},
volume = {31},
number = {14},
issn = {1520-5827},
address = {Washington, DC},
publisher = {ACS Publ.},
reportid = {FZJ-2015-02836},
pages = {4096 - 4105},
year = {2015},
abstract = {Inclusion complexes between cyclodextrins and
polymers—so-called pseudopolyrotaxanes (PPR)—are at the
origin of fascinating supramolecular structures, which are
finding increasing uses in biomedical and technological
fields. Here we explore the impact of both native and a
range of modified cyclodextrins (CD) on the self-assembly of
X-shaped poly(ethylene oxide)–poly(propylene oxide) block
copolymers, so-called Tetronics or poloxamines, by focusing
on Tetronic 904 (T904, Mw 6700). The effects are markedly
dependent on the type and arrangement of the substituents on
the macrocycle. While native CDs drive the formation of a
solid PPR, most substituted CDs induce micellar breakup,
with dimethylated β-CD (DIMEB) having the strongest impact
and randomly substituted CDs a much weaker disruptive
effect. Using native α-CD as a “molecular trap”, we
perform competitive binding experiments—where two types of
CDs thread together onto the polymer chains—to establish
that DIMEB indeed has the highest propensity to form an
inclusion complex with the polymer, while hydroxypropylated
CDs do not thread. 1D 1H NMR and ROESY experiments confirm
the formation of a soluble PPR with DIMEB in which the CD
binds preferentially to the PO units, thus providing the
drive for the observed demicellization. A combination of
dynamic light scattering (DLS) and small-angle neutron
scattering (SANS) is used to extract detailed structural
parameters on the micelles. A binding model is proposed,
which exploits the chemical shifts of selected protons from
the CD in conjunction with the Hill equation, to prove that
the formation of the PPR is a negatively cooperative
process, in which threaded DIMEBs hamper the entrance of
subsequent macrocycles.},
cin = {JCNS (München) ; Jülich Centre for Neutron Science JCNS
(München) ; JCNS-FRM-II / Neutronenstreuung ; JCNS-1},
ddc = {670},
cid = {I:(DE-Juel1)JCNS-FRM-II-20110218 /
I:(DE-Juel1)JCNS-1-20110106},
pnm = {6G15 - FRM II / MLZ (POF3-6G15) / 6G4 - Jülich Centre for
Neutron Research (JCNS) (POF3-623)},
pid = {G:(DE-HGF)POF3-6G15 / G:(DE-HGF)POF3-6G4},
experiment = {EXP:(DE-MLZ)KWS2-20140101},
typ = {PUB:(DE-HGF)16},
UT = {WOS:000353177200007},
pubmed = {pmid:25785814},
doi = {10.1021/acs.langmuir.5b00334},
url = {https://juser.fz-juelich.de/record/189818},
}