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Direct arylation polycondensation has been investigated to develop efficient synthetic methods of conjugated polymers for use in optoelectronic applications. The optimization of reaction conditions achieved high molecular weights and minimal structural defects in the recurring structures. The optimized direct arylation method has several advantages over conventional methods, e.g., fewer synthetic steps, and high-molecular-weight and high-purity polymer. The high-quality polymeric materials exhibited superior performance to those obtained using a conventional method when used in organic photovoltaics and field-effect transistors.
The liquid crystalline (LC) rod-like mesogens preferentially orient normal to the substrate plane due to the excluded volume effect (homeotropic alignment) in side-chain liquid-crystal (SCLC) polymers free-standing films. For in-plane alignment, a homeotropic orientation is unsuitable because the mesogens are in a direction opposite to the in-plane directions. This review focuses on new approaches to induce a random planar orientation in SCLC polymer systems by interface and surface molecular design utilizing a high-density polymer brush structure and surface segregation structures of block copolymers.
Interfacial morphologies and associated processes in multicomponent polymer systems, e.g., block copolymers (BCPs) and polymer blends, are examined using three-dimensional (3D) microscopies. Because of the rich structural information in 3D images, various new types of structural parameters, including chain conformation inside BCPs nanodomains, chain packing frustration in BCPs, Genus etc., can be obtained. The stability and interfacial dynamics are also discussed.
Recent advances in the study of active self-assembly utilizing biomolecular motors are reviewed. Various methodologies developed for demonstrating active self-assembly of biomolecular motors are discussed in detail with an emphasis on the morphological variations of the self-assembled structures.
Carboxylated poly(arylene ether ketone)s with hyperbranched and linear architectures were synthesized by the self-condensations of aromatic dicarboxylic anhydrides. A linear poly(arylene ether ketone) was obtained from an AB monomer, 4-phenoxyphthalic anhydride, while a hyperbranched poly(arylene ether ketone) was obtained using an AB2 monomer, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride. The method for the synthesis of the hyperbranched poly(arylene ether ketone) is notable because it provides a high ion-exchange capacity, above 7 mmol g−1, through a one-pot polycondensation.
10,10′-(1,4-Phenylene)bis(5,7,9-decatriynyl N-(butoxycarbonylmethyl)carbamate) 1 and its perfluorophenylene derivative 2 were synthesized. Upon UV irradiation, both of them showed excitonic absorption of polydiacetylene. In particular, 2 showed an absorption maximum at 743 nm, which was approximately 100 nm longer than that of conventional polydiacetylenes, and its solid-state polymerization scheme was investigated.
Organic–inorganic hybrid thin films containing [Ti4(μ3-O)(OiPr)5(μ-OiPr)3(O3PPh)3]·THF (TiOPPh) as element blocks were prepared via hybridization with the hydroxyl-substituted organic polymers (PVP, PSA, or PBE) by spin-coating. The hybrid thin films were characterized by AFM, DSC, and pencil hardness. The pencil hardness values of the PVP hybrid thin films were in the order 20 > 40 > 0 wt% and were dependent on the surface smoothness. When TiOPPh was reacted with excess ethanol, the core was retained. Therefore, the core of TiOPPh will be retained in the hybrid polymers.
A palladium (Pd) was confined within poly(N-isopropylacrylamide)-based hydrogel particles (GPs) with different sized hydrogel network. Nanosized Pd was loaded in the GPs via ligation to tertiary amine group in the GPs. The size of gel network was tuned varying the feed ratio of crosslinker. The catalytic efficacies of Pd-loaded GPs were significantly higher than those of commercially available Pd-loaded supports in Suzuki coupling reaction under aqueous condition. Using the smallest gel network, Pd-loaded GPs achieved the highest turnover number for the catalytic reaction, owing to protection of Pd from aggregation.
Hollow and solid fibers made of polyion complexes of chondroitin sulfate C (CS) and chitosan (CHI) were selectively fabricated using a coaxial two-phase microfluidic device. The selective fabrication was successfully achieved only by changing the solvent of the sheath flow that contained CS. Proteins and nanomaterials could be incorporated in both fibers by mixing them in the core flow, CHI-containing solutions. Results suggested the great potentials of microfluidic techniques for preparation of polysaccharide hollow and solid fibers.
