Macromolecular Rapid Communications最新文献

The illustration depicts vertically aligned polymer whiskers derived from advanced molecular architectures, with a potential for bio based synthesis. Arrows highlight applications in drones, aircraft, and automobiles, emphasizing how highly ordered crystalline fillers enable stronger, lighter, and more sustainable composite components for future mobility systems. More details can be found in the Research Article by Satoshi Okamoto and co-workers (DOI: 10.1002/marc.202500919).

Growing focus on health and quality of life is driving increasing demand for skin-like wearable sensors in human motion monitoring and healthcare. Unlike traditional e-skin, ionic skin utilizes a polymer network scaffold with mobile ions, effectively overcoming the issue of poor dispersion of conductive fillers in polymer matrices. As an ionic liquid with facile synthesis and low cost, 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl) forms strong interactions with both polymers and water molecules. Cellulose is a natural polymeric material with advantages such as low cost, environmental friendliness, and renewability. 2,2,6,6-Tetramethylpiperidinyl-1-oxyl (TEMPO)-oxidized cellulose nanofibrils (TOCNs) exhibit excellent biocompatibility. In this work, the TOCN-[EMIM]Cl ionic hydrogel was formed by mixing a TOCN dispersion with [EMIM]Cl ionic liquid, followed by Ca^{2 +} cross-linking. By adjusting the [EMIM]Cl content from 0 to 3 wt.%, the conductivity of the TOCN-[EMIM]Cl hydrogel increased from 9.43 × 10^-5 to 4.13 × 10^-4 S cm^-1. The obtained ionic skin exhibits high transparency, with a sensitivity of 2.11 kPa^-1, rapid response/recovery times (< 50 ms), and excellent cyclic stability (> 5000 cycles). Stable and distinguishable signal outputs have been achieved for human joint movements (wrist, elbow, and knee), demonstrating significant potential in flexible wearable sensors and health monitoring applications.

Over the last few years, 4D printing of liquid crystal elastomers (LCEs) has been explored to develop actuators with significant, reversible, and anisotropic shape changes upon external stimuli such as heat or light. Most reported ink formulations rely on photo-curable liquid crystal materials derived from high molecular weight (MW) main-chain macromers. Their rheological properties allow to program molecular alignment during direct ink writing. In contrast, formulations composed mainly of monoacrylate or diacrylate low MW mesogens are unsuitable for extrusion-based 4D printing as they fail to promote mesogen alignment during printing. This shortcoming restricts the range of chemical and physical compositions accessible to 4D printing. Here, we introduce a practical route for formulating 4D printable inks that integrate low MW mesogens. By adding an acrylate-ended macromer to the low MW constituents, these mixtures become suitable for direct ink writing. This enables the preparation of multi-functional actuators with digitally controlled director morphology and tailored properties, for example, stiffness and actuation strain, as well as light-responsive behavior when photoactive molecules are used. These results highlight the versatility of the method and suggest its potential compatibility with other functional low MW units, such as those responsive to electrical or pH stimuli.

Hydrogel-based flexible wearable devices and physiological electrodes have garnered increasing attention owing to their biocompatibility and comfort. However, accurate sensitivity for tiny deformation and low electrical conductivity are still limitations for ideal hydrogel sensors and electrodes. In this work, a multifunctional conductive polyelectrolyte hydrogel was prepared with cationic monomer 3- (methacryloylamino) propyl-trimethylammonium chloride, at the same time, polyphenolic compound tannic acid and glycerol were introduced to the hydrogel network to enhance the adhesion performance and environmental tolerance. The polyelectrolyte hydrogel showed low hysteresis (below 10%), good self-adhesion (∼50 kPa), excellent biocompatibility and antibacterial activity, satisfactory conductivity (8.5 mS m^-1), long-term stability (∼10 000 repeated cycles), wide strain sensing range (0.1%-100%), and accurate sensitivity even for human pulse monitoring. A flexible wearable device was designed for real-time monitoring of multiple movements and outdoor sports. In addition, a reusable self-adhesive electrode was designed based on the polyelectrolyte hydrogel for physiological signal monitoring, including electroencephalogram (EEG), electrocardiogram (ECG), and electromyogram (EMG). The electrode exhibited a superior signal-to-noise ratio, long-term stability, and sensitivity compared to traditional commercial electrodes. This study provides a promising material platform for long-term stable and accurate signal monitoring in flexible wearable electronics.

Platelets play a critical role in hemostasis and tissue repair; however, their short shelf life of approximately four days poses a major challenge to their supply. This limitation underscores the need for long-term storage alternatives. In this study, we developed and characterized platelet membrane-coated gelatin nanoparticles (PL-GNPs) as potential platelet substitutes. PL-GNPs were prepared by coating gelatin nanoparticles (GNPs) with platelet-derived membrane vesicles. Cryo-electron microscopy revealed the formation of a core-shell structure, and immunoblotting demonstrated that key platelet surface proteins, CD41 and CD61, were preserved on the PL-GNP surface in the same orientation as in platelets. The membrane coating improved the stability of the nanoparticles against collagenase-dependent degradation. Moreover, PL-GNPs bound effectively to fibrinogen, an essential interaction in thrombus formation, and retained this function even after one month of storage at 4°C. Collectively, these findings indicate that PL-GNPs recapitulate the critical structural and functional properties of native platelets and hold promise as a stable, long-term storable alternative to conventional platelet preparations for therapeutic use.

We present linear-viscoelastic characterization and elongational viscosity start-up data of 4 model polystyrene pom-poms and 2 model polystyrene combs. All 6 model systems have a self-entangled backbone, but unentangled side arms. Pom-poms consist of a linear backbone with one branching point with q arms at each end of the backbone. Analysis by the Enhanced Relaxation of Stretch (ERS) model shows that the elongational rheology of all model polymers is equivalent to that of polymer melts consisting of long linear chains diluted by short, unentangled linear polymer chains of the same chemistry. Strain hardening increases with increasing intrinsic dilution of the backbone by the arms. The comparison of the elongational viscosity data of pom-poms versus that of the combs with several branching points along the backbone chain suggests that the location of the unentangled side arms does not result in significant differences. At higher elongation rates, brittle filament fracture is observed, which is well described by the fracture criterion for linear melts and polymer solutions, thus confirming the self-dilution of the backbone chains of pom-poms and combs by unentangled side arms.

Poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) can readily form a ferroelectric phase and display distinctive polarization switching in electric fields. It is thus promising for advanced flexible electronics, e.g., bio-inspired actuators and wearable sensors, highlighting its substantial research value. The impact of processing conditions on the multi-level structures and polarization switching performance of them remains yet inadequately elucidated. In this paper, P(VDF-TrFE) films were fabricated via blade-coating and hot-pressing methods, respectively. Their structures and ferroelectric properties before and after post-stretching were systematically investigated. The hot-pressed films exhibit superior ferroelectric properties of advantageous polarization response over 10.0 µC/cm², lower coercive field (E_c), and notably rapid switching dynamics characterized by almost halved activation field (δ) owing to higher crystallinity (X_c) and less gauche defects in polar domains. On the other hand, stretching improves molecular orientation, therefore enhancing the Curie temperature (T_Curie) and switching dynamics in both films, but affects polarization response oppositely. The polarization response increases by 25 % in the blade-coated films due to a reduction of gauche defects, while it weakens in the hot-pressed films due to a critical 10 % decline in X_c. This work delineates the pathway for controlling the switching characteristics and provides fundamental theoretical guidance for developing high performance P(VDF-TrFE) films.

Open-shell organic radical semiconductors, distinguished by their unique electronic ground states, have attracted growing interest as alternatives to conventional closed-shell materials. However, their sensitivity to oxygen often leads to limited chemical and photothermal stability, hindering practical application. In previous work, we identified widespread open-shell diradical character in donor-acceptor semiconductors. In this study, we propose to fully introduce oxygen radicals into the backbone of polythiophene and other donor-acceptor materials, reported three open-shell poly(3,4-dioxythiophene radical) polymers, PTO₂-1/2/3, via a one-pot reaction under three different conditions. The synthesis was achieved through BBr₃ and HBr-mediated oxidation radical polymerization and demethylation using low-cost starting materials. The open-shell character of PTO₂ was systematically confirmed by various characterization techniques, including ¹H NMR, electron spin resonance, and MALDI-TOF mass spectrometry. Notably, PTO₂-2 exhibited a HOMO energy level of -5.42 eV and high electronic conductivity of 2.6 × 10^{- 2} S cm^{- 1}, demonstrating a new design strategy for non-doped organic semiconductive radical polymers. Furthermore, under 808 nm laser irradiation (1 W cm^{- 2}), PTO₂-2 heated from 28°C to 205°C within 60 s, showcasing outstanding photothermal conversion capability. This study provides a new platform for constructing low-cost, stable, non-doped open-shell polymers.

Novel Inverse Vulcanized Polymers (IVPs) with high refractive index and excellent transparency in the NIR are achieved exploiting the recently emerged Inverse Vulcanization (IV) process as a simple, green, efficient, and scalable synthetic method to upcycle elemental Sulfur, which is accumulating in the environment as a by-product of the oil and gas industry. Co- and ter-polymers with Sulfur content 50 or 60 wt% are prepared in quantitative yields utilizing different crosslinking aromatic comonomers bearing isopropenyl functionalities. To the best of our knowledge, for the first time, two novel diisopropenyl aromatics, namely 2,7-diisopropenylfluorene (DIF) and 2,8-diisopropenyldibenzothiophene (DIDBT), are designed, prepared in very high yields via a sustainable, facile, single-step Suzuki-Miyaura cross-coupling reaction, and explored as suitable crosslinking comonomers for the IV reaction. Subsequently, comonomer(s) nature, number of their functionalities, as well as Sulfur-to-comonomer(s) ratio are varied to address both the optical behavior and filmability of the ensuing IVPs, which are technologically relevant properties for their application and industrial scale-up. Crosslink density is nicely correlated with the experimental glass transition temperatures of the investigated systems. Synthesized IVPs are then employed to fabricate all-polymer distributed Bragg reflectors (DBRs) and imprinted optical components. Results pave the way for diverse applications of IVPs in advanced nanophotonics.