The scope and accessibility of sequence-controlled multiblock copolymers is demonstrated by direct "in situ" polymerization of hydrophobic, hydrophilic and fluorinated monomers. Key to the success of this strategy is the ability to synthesize ABCDE, EDCBA and EDCBABCDE sequences with high monomer conversions (>98 %) through iterative monomer additions, yielding excellent block purity and low overall molar mass dispersities (Ð<1.16). Small-angle X-ray scattering showed that certain sequences can form well-ordered mesostructures. This synthetic approach constitutes a simple and versatile platform for expanding the availability of tailored polymeric materials from readily available monomers.
Crystallinity is seldomly utilized
as part of the microphase segregation
process in ultralow-molecular-weight block copolymers. Here, we show
the preparation of two types of discrete, semicrystalline block co-oligomers,
comprising an amorphous oligodimethylsiloxane block and
a crystalline oligo-l-lactic acid or oligomethylene
block. The self-assembly of these discrete materials results in lamellar
structures with unforeseen uniformity in the domain spacing. A systematic
introduction of dispersity reveals the extreme sensitivity of the
microphase segregation process toward chain length dispersity in the
crystalline block.
Understanding the molecular level origin of chiroptical properties in enantiopure π-conjugated polymers is essential for tailoring these materials for application in organic light-emitting diodes and photonic devices. Here we have studied poly(9,9′-dialkylfluorene-alt-2,5-dialkoxyphenyl)s as prototypical copolymers to investigate their structure− chiroptical property relationship. The effect of a systematic variation of the location and configuration (S or R) of chiral and achiral side chains in the repeating units on the liquid crystalline ordering and its relationship to chiroptical properties were investigated. The results clearly indicate that enantiopure side chains on the fluorene units are critical for obtaining the cholesteric liquid crystalline ordering and thereby strong chiroptical properties in both absorption and photoluminescence in annealed thin films. Finally, solution-processed organic light-emitting diodes constructed from a liquid crystalline polymer show strong emission of circularly polarized light, demonstrating the potential application of these systems.
The scope and accessibility of sequence‐controlled multiblock copolymers is demonstrated by direct “in situ” polymerization of hydrophobic, hydrophilic and fluorinated monomers. Key to the success of this strategy is the ability to synthesize ABCDE, EDCBA and EDCBABCDE sequences with high monomer conversions (>98 %) through iterative monomer additions, yielding excellent block purity and low overall molar mass dispersities (Ð<1.16). Small‐angle X‐ray scattering showed that certain sequences can form well‐ordered mesostructures. This synthetic approach constitutes a simple and versatile platform for expanding the availability of tailored polymeric materials from readily available monomers.
The assembly of donor-acceptor molecules via charge transfer (CT) interactions give rise to highly ordered nanomaterials with appealing electronic properties. Here, we present the synthesis and bulk co-assembly of pyrene...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.