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Perylene tetracarboxylic bisimide (PTCBI) derivatives bearing oligosiloxane moieties were synthesized. At room temperature, the PTCBI derivatives bearing oligosiloxane chains exhibit a nanosegregated columnar phase in which crystal-like π-stacks are surrounded by a liquid-like mantle. These PTCBI derivatives are soluble in various organic solvents, and thin films can be produced by a spin-coating method. The PTCBI derivatives bearing polymerizable cyclotetrasiloxane rings show the liquid crystalline (LC) phases at room temperature. The spin-coated films of the LC PTCBI derivatives with cyclotetrasiloxane rings can be polymerized and insolubilized by exposure to the vapors of trifluoromethanesulfonic acid.
Liquid crystalline organic semiconductors are good candidates for organic transistors because the materials have properties that are beneficial compared with those of polymer materials. Liquid crystalline materials show good solution processability for the fabrication of uniform crystalline thin films. The novel liquid crystalline material 2-phenyl-7-decyl[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-10) exhibits a highly ordered liquid crystal phase, and has good solution processability and high thermal durability to use for creating transistor devices with high mobility, over 10 cm2 Vs−1, following thermal annealing.
Liquid crystals (LCs) have recently gained significant importance in organic photovoltaics (PVs). Power-conversion efficiency up to about 10% has reached in solar cells incorporating LCs. This review presents an overview of the developments in the field of organic PVs with LCs. Comprehensive details of LCs used in bilayer solar cells, bulk heterojunction solar cells and dye-sensitized solar cells have been given. An outlook into the future of this newly emerging, fascinating and exciting field of self-organizing supramolecular LC PV research is provided.
In this focused review, we provide an overview of our recent work on the design and synthesis of a new type of side-chain liquid crystal π-conjugated polymeric system associating regioregular poly(3-alkylthiophene) backbones with laterally pending π-conjugated mesogenic groups. Several polymeric architectures have been prepared based on different polymer backbone structures and various side groups, providing important insight into the relationships among the polymeric architecture, nano- and macroscale organization and charge transport properties in such self-organized multi-lamellar macromolecular systems.
A new type of porous crystal, metal–organic framework (MOF), has been recently utilized for the preparation of network polymers. The obtained network polymers possess highly controlled structures derived from the molecular organization of MOF crystal. This focus review emphasizes the significance of integration of flexible organic polymers and rigid MOFs to attain shaped network polymers and organic–inorganic hybrid networks.
Zwitterions are organic salts whose cation and anion are covalently bridged. In the Focus Review, I describe the potential utility of these zwitterions as building blocks for self-organizing materials, such as liquid crystals and block copolymers. Owing to the unique characteristics of zwitterions to form homogeneous mixtures with certain acids and lithium salts, their self-organization behavior can be tuned by addition of these compounds. In particular, these zwitterion derivatives are useful for constructing bicontinuous cubic liquid-crystalline assemblies with three-dimensionally continuous periodic minimal surface.
Amphiphilic C3-symmetric tris-ureas self-assemble into supramolecular hydrogels in aqueous solution. These supramolecular hydrogels were used as matrices for the electrophoresis of biopolymers (SUGE: SupramolecularGelElectrophoresis). A unique separation mode in comparison to that of SDS–PAGE was found during the electrophoresis of denatured proteins. Native proteins were separated on the basis of their isoelectric points and retained their activities. Large DNA fragments that previously had been separated only by pulsed-field gel electrophoresis were separated using a supramolecular hydrogel matrix and a typical continuous-field electrophoresis apparatus.
The facile control of the microdomain orientation in the liquid-crystalline block copolymer (LC-BCP) thin films has been realized by means of micropore extrusion and introducing polydimethylsiloxane (PDMS), instead of complicated processes or costly apparatus. In extrusion process, the alignment can be recovered via ultrasonicating the extruded BCP solution or as-placing upon long-time thermal annealing.
The true chiroptical measurements of optically anisotropic samples cannot be generally achieved with modern chiroptical spectrophotometers such as circular dichroism and circularly polarized luminescence based on polarization modulation techniques because of the coupling effect of the nonideal optics and the electronics with macroscopic anisotropies. Artifact signals related to the nonchiral phenomena are often much stronger than the chiroptical signals. Universal chiroptical spectrophotometer (UCS) and comprehensive chiroptical spectrophotometer (CCS) integrated into the Stokes–Mueller matrix analysis for optically anisotropic samples can be applicable for accurate chiroptical measurements for samples with macroscopic anisotropies.
We reviewed the recent progress in the development of micro/nanofibrillar scaffolds for biomedical applications. We demonstrated the significance and essential information on four different micro/nanofibrillar scaffolds: (1) solid micro/nanofibrillar scaffolds (2) hydrogel nanofibrillar network scaffolds based on bacterial cellulose, (3) hydrogel micro/nanofiber scaffolds based on partially precipitated PVA, and (4) hydrogel micro/nanofiber scaffolds based on cross-linked PVA. This review would guide researchers for selecting a proper scaffold suitable for their own purposes and developing more sophisticated scaffolds.
Self-assemble introduction of α-glucan contained block copolymer materials into the particular layer of the memory devices have been impressed by their excellent performance. Some newly reported MH-based copolymer literatures in electronic application are discussed in this focus review, including the electron-trapping mechanism of oligosaccharide MH, the relationships between chemical structures and their supramolecules, self-assembly morphologies and the memory device characteristics of electronic devices. As a perspective, the glucose-based block copolymer materials have a great potential to develop into the greener generation for advanced green electronics.
This review focuses on the recent developments on the photo-induced liquefaction and softening of azobenzene-based materials. The trans–cis photoisomerization of azobenzene units incorporated in molecular materials, polymers, and gels induces a variety of state changes such as solid–liquid, gel–sol, and glass–rubber transitions of those materials isothermally. Several novel applications such as reusable and environmentally friendly photoresists, reworkable adhesives, and self-healing materials can be expected using the photochemical liquefaction and softening.
Recent works revealed that protein and cell resistance of bioinert self-assembled monolayers originates in the physical barrier of the interfacial water. We review the history of the previous works that attempted to clarify the underlying mechanism and discuss prospects to apply the findings to design new biomaterials.
A chromatography-free procedure for the preparation of monodisperse monotosylated PEGs allowed for the preparation of 8- to 16-mers in relatively large quantities in good yields and purities and facilitates the investigation of PEG-based functional molecules such as structured PEGs, which had specific two-dimensional shapes. For example, the triangular molecule dehydrated at a lower temperature than linear compounds with a similar molecular weight and can suppress aggregation of proteins at high temperatures. It was also found that the introduction of an aromatic group in the PEG skeleton lowered the dehydration temperature.
Recent developments for nanowires fabricated from self-assembled π-conjugated polymers are reviewed. Particular attention is paid to advances in techniques for scalable production of highly ordered nanowires as well as their deposition and alignment in thin films and composites. The benefits of using π-conjugated polymer nanowires, rather than thin films, in electronic devices is examined. Devices investigated include organic field-effect transistors (OFETs), chemical sensors, and thermoelectric devices.
Amphiphilic block polymers having nitroxide radicals (TEMPO) self-assemble in water to form nanoparticles. This is a new nanomedicine that avoids the adverse effects of conventional antioxidants, which destroy the intracellular redox environment, and makes it possible to treat various oxidative-stress-related diseases such as cerebral or cardiovascular ischemia-reperfusions, Alzheimer’s disease and cancer. In addition, we have designed a gelation function in these materials and developed them as a material for anti-tissue adhesion agents and periodontal diseases. Additionally, we succeeded in enhancing cultured cell functions using an antioxidant biointerface.
Soft materials based on colloidal self-assembly in ionic liquids: fundamental studies on the colloidal stability in ionic liquids (ILs) are highlighted. Three different repulsive forces—electrostatic, solvation, and steric—are examined for their effectiveness to stabilize colloidal particles in ILs. An overview of recent studies on colloidal soft materials in the presence of ILs is also provided. Based on suspended states of colloid particles, two different soft materials—colloidal gel and colloidal glass—were prepared in ILs. Their functional properties, including ionic transport, rheological and optical properties, are discussed in relation to the microstructures of the colloidal materials.
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.
