Focus Review

We fabricated polymer brushes using a novel concept, which involves block copolymer segregation from the polymer region at the water interface. The resulting polymer brush is called a dynamic polymer brush because block copolymer segregation is a dynamic process that occurs at room temperature and is activated through contact with water. Dynamic polymer brushes undergo self-organization in the processes of self-assembly and self-healing (if destroyed). The concept and physical characteristics of dynamic polymer brushes are discussed in this review.

This focus review summarized current adhesives that are capable of macroscopic adhesion in seawater. The design strategies and performance of these adhesives were reviewed based on their bonding methods. Some future research directions and perspectives for under-seawater adhesives were discussed.

Various in situ measurement techniques have been applied to investigate changes in the three-dimensional structures and the physical properties of polyimides (PIs) generated at high pressures using a custom-built optical cell (up to 4,000 atm) or a diamond anvil cell (up to 80,000 atm). Moreover, the structural changes in the PI chain repeating units and interchain distances induced by the ultrahigh pressures were observed with WAXD, and they were compared with optical absorption, fluorescent and phosphorescent emission spectra, infrared absorption spectra, and refractive indexes observed under the same conditions.

Surface modification of carbon materials with polymers is useful for engineering surface properties and adding functionality to carbon materials. This review article describes processes for coating carbon materials with polybenzimidazoles and their applications.

In comparison to the ubiquity of their chalcogenic thiophene analogs, selenophene-incorporated conjugated polymers are relatively scarce in the organic electronics literature. However, this scarcity belies the tremendous utility of selenophene in high-performance optoelectronic materials. In this focus review, we discuss the key developments in selenophene-based conjugated polymer research from the early polyselenophene investigations, through the detailed study of regioregular poly(3-hexylselenophene), to the state-of-the-art donor-acceptor polymers that have enabled advancements in the performance and functionality of various optoelectronic devices. Finally, we end with our perspective on the future of this field.

This review outlines the research across the areas of polymer chemistry and cryobiology We discuss the solutions to problems in cryobiology from the viewpoint of polymeric materials science and the applications of polymer-based cryobiology for biomedical applications. We explain how the recent advances in polymer research have enabled the development of innovative polymeric cryoprotectants with novel mechanisms and the development of state-of-the-art methods for the intracellular delivery of substances, such as drugs, using a cryobiological technique called the freeze-concentration effect.

Recent advances in polymer informatics are reviewed, focusing on experimental research. Data-driven analyses, predictions, and suggestions are becoming more practical, despite the appropriate treatments of higher-order structures and process information acting as bottlenecks. After summarizing recent developments, future challenges in polymer informatics are discussed.

Intrinsically stretchable semiconducting polymer materials have been sought for meeting requirements in the development of wearable intelligent electronic devices. In this focus review, our recent progress in main-chain engineering for development of intrinsically stretchable n-type semiconducting materials is described. The topics include four strategies, namely, (i) a conjugation-break spacer approach, (ii) a block copolymer approach, (iii) an all-conjugated statistical terpolymer approach, and (iv) a sequence random copolymer approach, in which specially designed stress-relaxation units or sequences are incorporated along the main chains of naphthalene-diimide-based n-type semiconducting polymers.

As the performance of organic semiconductors has increased so has their molecular structure. In this focused review, we introduce the concept of synergistic catalysis, which involves the use of two or more catalysts with orthogonal reactivity to enable reactions that are not possible with the use of a single catalyst, to synthesize π-conjugated polymers. Synergistic catalysis allows for controlled polymerizations, room-temperature reactions, and/or polymerizations with greater regioselectivity, opening the door to more time-, labor-, cost-, and energy-saving synthetic methods.

We describe here the new concept of developing stimuli-responsive luminochromic materials based on frustrated element-blocks. We termed “frustrated” element-blocks as those that show a relatively larger degree of structural relaxation in the excited state but are structurally restricted. Enhanced sensitivity toward environmental changes and external stimuli can be observed.

This review focuses on the controlled radical polymerization of vinyl ether (VE) and the related self-assemblies. VE was long believed to be among the monomers that could not be radically homopolymerized. Under such circumstances, some groundbreaking polymerizations of VE have been discovered. Advances in research have made it possible to perform controlled radical polymerization with VE due to hydrogen bonds and/or cation-π interactions between VE monomers and the propagating radical. By using the resulting poly(VE)s, various functional polymers and nano-objects via polymerization-induced self-assembly can be obtained.

This focus review discussed our recent developments of unnatural glycopolymers based on polyoxazoline, protein–polymer conjugates, and protein stabilization. To develop new glycopolymers, a bicyclic monomer composed of glucosamine and 2-methyl-2-oxazoline (MeOx) was designed. This cationic ring-opening polymerization proceeded not by the mechanism for MeOx but by a new polymerization mechanism. This oligosaccharide has promise to be applied to a new glycomaterial owing to the polymer design. Additionally, protein conjugation and encapsulation by amphiphilic/fluorous chain-folding nanoparticles were investigated. Fluorous nature in random copolymers was useful for the protein conjugation and stabilization.

Among stimuli-responsive polymers, thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm) is the most widely investigated. PNIPAAm-based polymers can undergo appropriate changes in response to their external environment. In this focus review, recent advancements in the applications of stimuli-responsive polymers based on PNIPAAm in biomedical fields are summarized, with an emphasis on our own research. In particular, a summary of the design of polymers for application in the separation and purification of (bio)pharmaceutical products and controlled cellular uptake is provided.

Optically active polymers and supramolecules that form well-defined architectures are important materials with a wide range of applications. Amino acids and sugars are great candidates for the preparation of optically active functional materials because of their versatile structures and functional groups. In these chiral units, intra- and intermolecular noncovalent interactions play significant roles in the generation of smart functions. In this focus review, the author reviews his recent studies related to the fabrication and functions of chiral conjugated polymers and chiral supramolecules based on these natural chiral compounds.

Reverse osmosis (RO) membranes composed of polyamides and cellulose acetates are used as separation layers in pure-water production. However, improving the separation performance and antifouling properties of RO membranes is necessary. This focus review described the composite reverse osmosis membranes with optimal amounts of polyhedral oligomeric silsesquioxanes (POSS), which are cage-shaped, subnanosized molecules exhibiting organic–inorganic hybrid structures, showed improved water flux, NaCl rejection, antichlorine and antifouling properties, and mechanical strength.

The encapsulation of polymer chains into MOF pores is a powerful strategy for controlling polymer chain assemblies at the molecular level. In this focus review, recent developments of hybridization of conjugated polymers and MOFs are described. This approach can facilitate the study of the inherent optoelectronic properties of conjugated polymers. Furthermore, the formation of nanocomposites can provide unprecedented material platforms to accomplish nano-synergistic functions.

In this review, recent developments in data-driven approaches for structure-property relationships in polymer science based on statistical/informatics methods are introduced. A concept and some methods in data-driven science to obtain the desired properties and understand the mechanisms in polymeric materials are first explained. Additionally, various examples, such as the description of a single chain, phase separations, network polymers, crystalline polymers, and machine learning potential are introduced.

This paper outlines recent progress in various solution-processed fluorescent polymer tandem organic light-emitting diodes (OLEDs), white phosphorescent tandem OLEDs, and perovskite nanocrystal (NC) LEDs. Tandem OLEDs, which comprise multiple light-emitting units stacked in series through a charge-generation layer, have attracted considerable attention for display applications owing to their high efficiencies and long operational lifetimes. Metal halide perovskite NCs have also been considered promising light-emitting materials owing to their excellent optoelectrical properties.

Dispersibility and interfacial interactions are the important factors to exploit the high potential of nanocarbons for polymer/nanocarbon nanocomposites. However, carbon backbone with low reactivity has often cause agglomerations and defects from the interfaces. The use of surfactants and the surface modifications of nanocarbons have widely been conducted to improve these issues. This paper reviews recent advances in the design of polymer/nanocarbon nanocomposites, focusing on our research on the reinforcement effect of nanodiamond on polymer nanocomposites.