Synthesis and Self-Assembly
of Thiophene-Based All-Conjugated
Amphiphilic Diblock Copolymers with a Narrow Molecular Weight Distribution
In Young Song
Jinseck Kim
Min Jeong Im
Byung Joon Moon
Taiho Park
10.1021/ma300771g.s001
https://acs.figshare.com/articles/journal_contribution/Synthesis_and_Self_Assembly_of_Thiophene_Based_All_Conjugated_Amphiphilic_Diblock_Copolymers_with_a_Narrow_Molecular_Weight_Distribution/2510767
A series of amphiphilic poly(3-hexylthiophene-<i>b</i>-3-(2-(2-{2-[2-(2-methoxy–ethoxy)-ethoxy]-ethoxy}-ethyl))thiophene)
(P(3HT-<i>b</i>-3EGT)) polymers was synthesized via a nickel-catalyzed
quasi-living polymerization. Size exclusion chromatograms (SEC) revealed
that the molecular weight distributions of the <b>P3HT</b> blocks
in the block copolymers were comparable with those of the polystyrene
standard (monodisperse). <sup>1</sup>H NMR spectra revealed that the <b>P3HT</b> and <b>PEGT</b> units in the block copolymers were
well-defined and did not form compositionally mixed regions at the
boundary between the blocks and the highly regioregular <b>P3HT</b> units. The correlations among the block ratio, the amphiphilicity,
and the self-assembled nanostructures of the block copolymers in thin
films and in solution were examined. Differential scanning calorimetry
(DSC) and X-ray diffraction (XRD) studies revealed that the crystallinity
of the <b>BP93</b> composed of 93 mol % <b>P3HT</b> blocks
was higher than the crystallinity of the <b>P3HT</b> alone due
to the packing effects caused by repulsion among the hydrophobic hexyl
and hydrophilic ethylene glycol oligomer side chains. A long relaxation
time was required to observe the ordering among <b>P3HT</b> blocks
in the <b>BP26</b> composed of 26 mol % P3HT blocks, suggesting
that self-assembly could occur if induced on the molecular level.
We demonstrated that the molecular-level self-assembly of <b>BP26</b> (at dilute concentrations) via a slow dialysis method produced highly
ordered polymer vesicles 200–250 nm in size under thermodynamic
control. The size could be tuned via competitive hydrophobic interactions
using polystyrene. In contrast, kinetic control via a rapid precipitation
method yielded 5–20 nm micelles.
2016-02-20 18:38:10
ethylene glycol oligomer side chains
Narrow Molecular Weight DistributionA series
XRD
DSC
P 3HT
regioregular P 3HT units
Size exclusion chromatograms
BP 26
PEGT
P 3HT blocks
SEC
Differential scanning calorimetry
1 H NMR spectra
block copolymers