Focus Review in 2018

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.

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.

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.

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.

Intracellular structures and function are tightly interwoven. Recapitulation of such intracellular microenvironments may enable novel biomimetic material synthesis and bioanalysis. Cell-inspired microanalysis platforms can be constructed by combined top-down microfabrication and bottom-up molecular self-assembly. Microcompartments of phase-separated aqueous solutions also play a critical role in biological processes. The biphasic microdroplets provide a unique analytical platform that conventional homogeneous bulk environments fail to achieve.

This review summarizes the recent advances in surface-coated single-walled carbon nanotubes as near-infrared nanometer-sized photoluminescent emitters for single-particle imaging and tracking applications in complex biological environments. It is focused on demonstrating surface coating identification, excitation strategies comparison, and long-term single-nanotube tracking inside the brain extracellular space in the live brain tissue.

Highly sensitive and rapid biosensing on a three-dimensional polymer platform. Increasing sensitivity and decreasing assay time are two of the most crucial goals in the development of biosensing devices. We have developed three-dimensional (3D) nanospherical and microfiber structure for biosensing devices aimed at highly sensitive and rapid immunoassays. The system having polystyrene microfiber of 3D structure paired with vacuum pump pressurization to induce bulk flow enables an efficient and rapid immunoassay. Because it takes advantage of the increased amount of immobilized antibody on 3D structure and of the accelerated propagation of antigens by flowing through the microfiber.

Our recent studies on the development of conjugated polymer synthesis via direct arylation polycondensdation (DArP) are summarized. Based on an appropriate molecular design and adjustment of the catalytic system for DArP, a variety of conjugated polymers, such as low-band-gap polymers with the strong acceptor moieties and regioregular poly(3-hexylselenophene) are successfully synthesized. These results demonstrate potential and utility of DArP as an alternative conjugated polymer synthesis methodology.

Theoretical models for thermo-sensitive hydrogels in pure water and in mixed solvent of water and methanol, and for thermo-sensitive copolymer in water are developed based on the concept of cooperative hydration of thermo-sensitive water-soluble polymers. The high-temperature collapse in water and the reentrant volume phase transition in water/methanol mixtures of poly(N-isopropylacrylamide) gels, and the phase behavior of statistical random copolymers of N-isopropylacrylamide and N,N-diethylacrylamide are theoretically studied.

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.

This review focuses on recent developments in the study of photosensitive engineering plastics based on reaction development patterning (RDP). RDP is a method of forming a fine pattern by promoting the reaction between carboxylic acid derivatives in a polymer chain and nucleophiles in a developer selectively at the exposed or unexposed area. Since engineering plastics such as polyimide and polycarbonate inherently have carboxylic acid derivative groups, RDP can impart photosensitivity to various polymers, including commercially available engineering plastics. Both positive- and negative-tone patterns can be formed by using RDP.