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This work presents a simple strategy to prepare 3D printable and tough ionogels that can adjust to arbitrary topography. Inks for direct ink writing were prepared by dispersing cellulose nanocrystals in an aqueous solution of polyvinyl alcohol. After printing, the ink underwent a freeze-thaw process to form soft and stretchable hydrogels. Further reshaping and solvent exchange with deep eutectic solvents led to geometrically complex and tough ionogels for wearable sensors.

Complex formation of pendant lysine residue-containing zwitterionic random copolymer with copper (II). To remove excess copper in the body, a copolymer (P(MPC/LysA)) comprising 2-(methacryloyloxy)ethyl phosphorylcholine (MPC) and l-lysinylacrylamide (LysA) was synthesized via controlled radical polymerization. The copolymer exhibited a zwitterionic structure under physiological conditions due to the pH-independent neutral charge of MPC. The LysA residues were found to form a complex with copper (II) ion (Cu²⁺) under neutral-basic conditions, with two pendant l-lysine residues forming a complex with one Cu²⁺ molecule. P(MPC/LysA) has potential for use in removing excess Cu²⁺ in the body by forming water-soluble aggregates with Cu²⁺ at physiological pH.

In this paper, the construction of a hierarchical supramolecular structure comprising reduction-responsive DNA microspheres and semi-artificial glycopeptide-based micro-asters was described. Such a unique hierarchical supramolecular structure was obtained through molecular assembly of three oligonucleotides and a semi-artificial glycopeptide in a single thermal annealing process under aqueous conditions in the presence of Mg²⁺.

Our recent studies on high-performance semiconducting polymers are reviewed. In the first part of this article, the correlations between semiconducting polymer structures and charge transport properties in thin film transistors are described. The second part of this report summarizes our recent results on the near-infrared emission properties of carefully designed semiconducting polymers.

By taking advantage of the green benefits of multi-component reactions, adhesive polymers were designed and synthesized essentially using bio-based compounds as building blocks. Specifically, phenylpropanoids were selected as a green and photo-responsive chemical units. Synthesized bio-based adhesive polymers showed facile adhesion properties against quartz plates and the adhesion behaviors were altered by photo irradiation, probably owing to the [2 + 2] self-cycloaddition of the phenylpropanoid-derived vinyl moieties.

In this Focus Review, we summarize our new strategy to create electroresponsive soft materials using electroresponsive dopants. Dopants can change the property of the LC material only with a minute amount and do not need to have an LC property by itself, allowing a simple molecular design. Based on this new concept, we developed cholesteric displays with rewritable color memory functions and quick color modulation functions. We also utilized this concept to create new columnar LC systems and realized multiresponsive columnar LC materials.

3D printable hydrogel inks were prepared by incorporating carbon nanotubes (CNT) in a low-concentrated, thermoreversible poly(N-acryloyl glycinamide) hydrogel. After adding the photoinitiator and N-acryloyl glycinamide monomer, the printed inks were further crosslinked into strong, elastic hydrogel networks. The hydrogels based on preliminary cell viability experiments are considered for bioscaffold applications.

Radical copolymerization of lithium p-styrenesulfonate (LiSS) was investigated using acrylamide (AAm) as the comonomer in the presence of various salts as additives. The addition of lithium chloride promoted the polymerization reactivity of LiSS, while the addition of lithium bromide and sodium bromide suppressed the copolymerization of LiSS and AAm and completely prevented the spontaneous homopolymerization of AAm. The interactions between lithium cations and functional groups in the monomers and polymers that benefit the copolymerization reactivity is discussed.

This focus review described recent research on cinnamate-based polymers. Polyesters derived from hydroxycinnamic acid showed characteristic ultraviolet response behavior. The mechanism of photodeformability and found that polyesters derived from 3-hydroxycinnamic acid are deformed by photoexpansion. By using dimers of bioproduced cinnamates, polyimides and polyamides were synthesized. The biobased polyimides and polyamides were found to exhibit high transparency, mechanical strength, and good chemical modification properties due to the cyclobutane main chain and carboxylic acid side chains, which are not present in other high-performance polymers.

A newly discovered nanostructure (island-nanomatrix structure) is introduced based on previous studies on the structure of natural rubber. Effects of the proteins and phospholipids that form the nanomatrix on the mechanical properties of natural rubber are described using a model island-nanomatrix structure of natural rubber. Furthermore, a synthetic cis-1,4-polyisoprene with island-nanomatrix structure is prepared; its mechanical properties are similar to those of natural rubber.

Atomic molecular dynamics simulations of the complexation of plasmid DNA in the presence of two types of cationic peptides clear the mechanism of plasmid DNA condensation for gene delivery systems.

Inspired by mussel adhesion, polydopamine ultrathin films were formed at silicone oil/water interfaces even in neutral solutions. The MCF-7 cells successfully adhered to the oil/water interface without aggregation during cell growth. The interfacial wrinkles were induced by changes in the oil volume and the compressive stress, and the MCF-7 cells adhered to the oil/water interface and were arranged along the wrinkles. The polydopamine interfacial films provide new opportunities to investigate the relationships between toughness and patterns for tissue engineering and regenerative medicine.

Polymer gels containing an iridium complex in their compartmentalized nanodomain structures were designed. Novel Ir-containing vinyl monomers were first synthesized and then incorporated into homogeneously dispersed thermoresponsive nanodomains via living radical polymerization. The product gels exhibited immediate color change by sensing ammonia in a thermoresponsive manner, and catalyzed the N-alkylation reaction. These findings strongly supported the importance of the incorporation of organometallic complexes into the nanodomain of hydrogels for the further development of a novel soft material exhibiting selective molecular recognition abilities and catalytic reactions.

We have developed innovative new phosgenation reactions and their special reaction systems with the key objective of “safe application” to organic synthesis. This focus review summarizes our recent studies on in situ photo-on-demand phosgenation reactions of alcohols and amines for synthesizing polycarbonates, polyurethanes, and their precursors such as chloroformates, carbonate esters, and diisocyanates, in batch reaction systems, which are preferable for laboratory or small-scale industrial syntheses.

The transparent and flexible photocatalytic films composed of titanium oxide, organophosphonate-modified polysilsesquioxane, and poly(bisphenol A-co-epichlorohydrin) were prepared. The effects of hydroxy group ratio and organic substituent on phosphorus atoms in these films were evaluated by appearance and photocatalytic ability. Film using anchoring layer with APPS-low was formed large cracks, while films with other anchoring layers were formed no cracks. However, all films were formed small cracks after a 10-day durability test. All films showed photodegradation ability of methylene blue, photoinduced hydrophilicity, and photocatalytic bactericidal effects on Escherichia coli.

Two-dimensional sheet-shaped poly(methyl methacrylate) (2d-PMMA) with crosslinking only in the two-dimensional direction was synthesized via planar polymerization of MMA monomer in montmorillonite (MMT) nanolayers by using γ-ray irradiation, and the samples obtained were characterized by size-exclusion chromatography with a multiangle light scattering (SEC-MALS) and atomic force microscopy (AFM). Our results provided experimental proof that the desired sheet-like polymer was attained and the obtained samples were appropriately characterized, augmenting the previous reports.

Atomic force microscopy (AFM)-based nanomechanical characterization techniques have been extensively used to investigate the mechanical properties and mechanisms of polymeric materials. This technique enables direct visualization of the micromechanical properties of material surfaces and is referred to as the AFM nanomechanics technique. This review article discusses the application of this technique to studying polymer composites with a specific focus on the significant advances made in tracking the microscopic deformation behavior and visualizing the microscopic stress distribution of materials.

Statistical structural analysis was conducted for ternary blends of copolymers composed of two monomers chosen from acrylonitrile, α-methylstyrene, and styrene. Blending parameters, such as the composition and blending fraction of the component copolymer, were predicted by regularized regression analysis of ¹H NMR data. Regression models were constructed with the dataset for copolymers and binary blends to predict the blending parameters for ternary blends. The composition and blending fraction were predicted with high accuracies

We propose a method for analyzing the morphology of polymer blends with nanometric resolution using scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopic imaging in the low energy-loss region (5–30 eV). Furthermore, we employed medium-voltage (200 kV) and high-voltage (1000 kV) STEMs at different temperatures to compare the extent of electron-beam damage. This comparison highlighted the utility of the ultra-high voltage electron microscope for suppressing thermal damage and analyzing thicker samples.