Research articles

Bisphosphonate-bearing polymers formed stiff hydrogels in the presence of calcium and zinc ions. These hydrogels exhibited self-healing and stress-thinning properties. Crosslinking these polymers with zinc ions within water-in-oil emulsions yielded hydrogel nanoparticles.

Surface modification of liquid metal microparticles of the eutectic gallium–indium alloy afforded a liquid metal powder containing a small amount of organic components, which can be returned to the bulk liquid metal form by applying mechanical forces. Liquid metal–polymer composites with stimuli-responsive electrical conductivity were readily prepared by manual mixing of the liquid metal powder with polymer precursors. In addition, the liquid metal powder acted as a microwave absorber in the composite materials, thereby inducing microwave heating.

By using a water nanodroplet in a W/O miniemulsion as a nanoreactor, we prepared cellulose-based nanoparticles without chemical modifications such as crosslinking. Gelation of the MC aqueous solution in water nanodroplets was conducted by increasing temperature to create methylcellulose (MC) hydrogel nanoparticles (MC-H). Next, water evaporation from MC-H was performed to prepare MC xerogel nanoparticles (MC-X). The obtained MC-X showed high water resistance and suppressed release of substances due to the strong association of MC chains. In addition, MC-X could be embedded as a biomass-derived filler in the polymer film, maintaining its transparency.

Modification of terminal end groups of PEG altered its antigenicity. Polar terminal end groups effectively reduced recognition by both main-chain-specific and terminal-methoxy-specific anti-PEG IgG antibodies, whereas the nonpolar nC₄H₉ terminal end group was recognized by both types of anti-PEG IgGs. Based on these results, this study proposes a strategy for designing PEG chains that minimize recognition by anti-PEG antibodies and the resulting stable binding.

Double-hydrophilic diblock copolymers, PSB4_n-b-PGalM_m, comprising a polymethacrylate bearing galactose units and a polymethacrylate bearing sulfobetaine groups, exhibited unique miscibility inversions between dilute and concentrated regimes and between block copolymers and blends. These inversions were attributed to concentration-dependent χ_eff and solution-specific driving forces. Aqueous systems with periodically arranged zwitterionic and pyranose units represent a novel class of molecular assemblies resembling cell membranes, featuring arrays of zwitterions and glycocalyxes, and hold promise for the interfacial design of biomaterials.

In this study, a polymer blend with a salami structure with dimensions of several tens of microns was obtained by simultaneously polymerizing polymethacrylate and polyurethane. The methacrylate component of the polymer blend was co-polymerized with hydroxyethyl methacrylate (HEMA), which contains a hydroxyl group. The HEMA copolymerization increased the compatibility between the polyurethane and polymethacrylate regions. Consequently, the hard areas within the spherical domains decreased in size, accompanied by a decrease in the differences in composition and refractive index between regions.

A thermoresponsive coacervate enabling the sustained release of micelles and siRNA was developed using an appropriate blend of ABA/AB block copolymers. At room temperature, siRNA-loaded polyion complex (PIC) micelles were dispersed in solution. Upon mild heating ( ≈ 45 °C), they assembled into coacervate microparticles through a reversible phase transition. When maintained at 37 °C, the coacervates continuously and constantly release siRNA and micelles. Biological activities were evaluated using living cells, and cellular uptake and gene knockdown effects were confirmed. This concept highlights a coacervate-based depot platform for siRNA delivery system.

Divinyl ethers 1, 2, 3 and 4 caused ring-expansion cationic cyclopolymerization with a hemiacetal ester-incorporated cyclic initiator in conjunction with SnBr₄ to yield cyclic Poly(1), Poly(2), Poly(3) and Poly(4), respectively. High degree of cyclization of cyclopolymerization (>~98%) was necessary to obtain these macrocyclic cyclopolymers of well-defined structure quantitatively. The Tgs of these macrocyclic cyclopoly(divinyl ether)s were higher than those of the corresponding linear cyclopoly(divinyl ether)s.

Two-dimensional polymeric materials (2DPMs) with unique structural and functional properties are typically crosslinked for stability. Here, large-area noncrosslinked 2DPMs were exfoliated from lamellar films of poly(N-dodecyl acrylamide) (pDDA), which forms nanophase-separated lamellae via segregation of hydrophilic and hydrophobic segments. Poor-solvent exfoliation using hexane, ethyl acetate, or 2-propanol produced micrometer-scale monolayer nanosheets, whereas methanol dissolved the polymer. AFM and TEM confirmed nanosheet morphology, and spin-transferred films displayed dendritic or spiderweb-like networks dependent on solvent and centrifugal forces, offering a simple, scalable route to morphology-controlled noncrosslinked 2DPMs.

The rheological behavior of immiscible mixtures of microgel particle (MGP) dispersions and hydrophobically modified ethoxylated urethanes (HEUR) were investigated. Despite phase separation, mixing MGP and HEUR synergistically enhanced the modulus and altered relaxation behavior. Rheo-optical analysis revealed that HEUR localizes between MGPs, counterbalancing concentration fluctuations and inducing cooperative relaxation. Micromechanical modeling reproduced the observed behavior, highlighting stress coupling between phases as the key mechanism. This study provides insights into the viscoelastic properties of thickener mixtures, offering guidance for designing advanced formulations like cosmetics.

The enzymatic degradation of amorphous poly (ethylene terephthalate)(PET) films by a PET-degrading enzyme was analyzed using SAXS, WAXD, SEM, X-CT, and weight-loss measurements. FAST-PETase induced the emergence of hierarchical boring structures ranging from 10⁻⁵ m to 10⁻⁸ m on PET, revealing that enzymatic degradation proceeds through interfacial interactions within the evolving porous surface layer. This study contributes essential knowledge toward the sustainable use of plastics, responding to growing global concerns over microplastic pollution and the scarcity of fossil resources.

The biodegradable materials that can be used in heavy-duty applications were synthesized based on coprecipitation of modified natural rubber and cellulose. It was found that cellulose did not have a considerable effect on the morphology, or tensile strength of the samples but altered the degradation pathway and significantly accelerated the decomposition of the material in natural soil.

Nanofactories are artificial vesicles that shields the internal enzymes while allowing small substrates to permeate the membranes for catalytic reactions. A key challenge in nanofactories is achieving efficient enzyme encapsulation. The constructed self-assembled vesicles from a thermoresponsive peptoid-based block copolymer achieved a high enzyme encapsulation efficiency of more than 50%. It is hypothesized that this high performance stems from a temperature-induced coacervate-to-vesicle phase transition. The resulting enzyme-loaded vesicles acted as robust nanoreactors, protecting enzymes from external proteases, while exhibiting selective permeability of small molecules on the basis of physicochemical properties.

Analysis of wide-angle X-ray and neutron diffraction data has shown that the crystal structures of nylon-6 in both α and γ forms, as well as the iodine complex, are composed of statistically disordered arrangements of molecular chains. This composition can alternatively be described as the disordered slippages of sheet planes. The notion of stacking disorder within these sheets enables a logical interpretation of the transition mechanism among the three crystalline phases.

In this work, porous PBAT monoliths were fabricated via a solvent-based thermally induced phase separation (TIPS) method, and the pore morphology was tuned by adjusting the solvent ratio and polymer concentration. Furthermore, annealing treatment significantly enhanced the elasticity of the PBAT monoliths, reducing plastic deformation after 70% compression from 43 to 12%. Mechanistic analysis revealed that annealing improved defective crystals formed during phase separation, leading to enhanced structural integrity and mechanical performance.In this work, porous PBAT monoliths were fabricated via a solvent-based thermally induced phase separation (TIPS) method, and the pore morphology was tuned by adjusting the solvent ratio and polymer concentration. Furthermore, annealing treatment significantly enhanced the elasticity of the PBAT monoliths, reducing plastic deformation after 70% compression from 43% to 12%. Mechanistic analysis revealed that annealing improved defective crystals formed during phase separation, leading to enhanced structural integrity and mechanical performance.

The structure of interpolymer complex formed by poly(2-ethyl-2-oxazoline) and poly(methacrylic acid) by controlling the hydrogen bonds between the polymer chains by changing solvent pH or adding urea was investigated. The viscosity of solution containing the interpolymer complex was drastically increased in solvent with pH~12, then decreased at pH~13. This behavior can be explained by a model that the dimension of the complex was changed with a decrease of inter-polymer hydrogen bonds at high pH or urea concentration.

Poly(lactic acid) (PLA) copolymers incorporating main-chain thionoester linkages were synthesized via ring-opening copolymerization of lactide and thiocarbonyl lactide. These copolymers maintain thermal and aqueous stability while exhibiting rapid, stimulus-triggered degradation through selective main-chain scission in the presence of amines. Even minimal incorporation of thionoester units was sufficient to significantly reduce molecular weight, enabling tunable degradability. This modular approach could provide a straightforward strategy for designing PLA-based polymers with enhanced end-of-life degradability while preserving their desirable properties during use.

The introduction of imide groups into reactive oligomers containing long-chain aliphatic structures improved their compatibility with biphenyl-type epoxy resins. UV‒vis spectroscopy revealed the presence of intermolecular charge-transfer interactions between the biphenyl and imide groups. Cured epoxy blends containing the imide-based reactive oligomer exhibited smaller phase-separated structures than blends containing the imide-free reactive oligomer. It was found that the compatibility of the reactive oligomers influences the size of the phase-separated structures in the cured epoxy resins.

A decomposable and recyclable polymer consisting of polystyrene and trithiocarbonates was synthesized. The synthesized polymer decomposed by mixing with allylamine. The decomposition was due to the reaction between trithiocarbonate in the polymer and allylamine. The decomposition was evaluated by the indentation test and the spectroscopies (e.g., ¹H NMR). Following the decomposition, the recycling of the decomposed polymer was conducted via a thiol-ene reaction by shining UV light (λ =365 nm). The resultant recycled polymer showed as high mechanical strength as the original polymer before decomposition.

We report controllable protein adsorption onto crystalline assemblies of carboxylated cello-oligosaccharides synthesized via enzyme-catalyzed oligomerization. Under various pH and ionic strength conditions, significant adsorption of basic proteins onto negatively charged cello-oligosaccharide assemblies was observed. Notably, we found that acidic proteins were adsorbed onto the cello-oligosaccharide assemblies at an acidic pH, which was significantly enhanced under low ionic strength conditions. Our findings demonstrate the electrostatic control of protein adsorption onto cello-oligosaccharide assemblies through adjustments to their surface properties and solution parameters.