Donor-node-acceptor (D-n-A) systems based on perylene bisimide (PBI) have emerged as versatile platforms for organic electronics and quantum materials. In this architecture, a non-conjugated node, typically an imide nitrogen, breaks conjugation between the donor and acceptor, spatially separating the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) on the two components. This decoupling renders p- and n-type doping independent and precisely controllable, thereby overcoming the fundamental limitations of conventional conjugated polymers. This review systematically summarizes the recent progress in D-n-A systems from small molecules to functional polymers. In PBI dyads and triads, node-induced exciton coupling enables tunable photophysics, whereas molecular conformation controls the competition between fluorescence and symmetry-breaking charge separation. The cascade energy-level alignment in the D-n-A₁-n-A₂ architectures yields long-lived charge-separated states by spatially separating the radical ion pair. Covalent linking of stable radicals (TEMPO, TTM) to PBI or naphthalene bisimide (NBI) via nodes allows efficient photoinduced intersystem crossing and the formation of quartet states (S=3/2), promising for molecular qubits. In the polymer domain, D-n-A polymers with a small fraction of PBI acceptors exhibit photoenhanced hole transportation, serving as hole-transporting layers for photodetectors. Bipolar polymers with a D:A ratio of approximately 1:1 demonstrate ambipolar charge transport and storage and have been successfully applied in flexible supercapacitors, lithium-ion batteries, and multicolor electrochromic devices. Finally, the outlook highlights future directions: precise control of donor-acceptor coupling, optimization of polymer morphology, translation to stable solid-state systems, and multifunctional integration of electrochemistry with spin quantum properties.

Non-compressible hemorrhage arising from torso, junctional, or intracavitary injuries remains a major cause of preventable trauma-related mortality owing to anatomically difficult-to-access bleeding sites, rapid high-pressure blood flow, and the limitations of conventional hemostatic approaches. Injectable polymeric hemostats enable minimally invasive delivery into narrow or irregular wound tracts and conformal adaptation to complex wound geometries, representing a promising strategy for effective hemorrhage control. This review summarizes the recent advances in three classes of injectable polymeric hemostats, including hydrogels, gelable powders, and expandable hemostatic materials, with particular emphasis on material design strategies, hemostatic mechanisms, and performance characteristics. Current challenges and future perspectives are also discussed, providing insights to guide the rational design and clinical translation of advanced polymeric hemostats for safer and more effective management of non-compressible hemorrhage.

Achieving optimal active-layer morphology in organic solar cells (OSCs) without volatile additives is critical for long-term operational stability. This study introduces a rational molecular design strategy utilizing chalcogen-engineered two-dimensional (2D) side chains to intrinsically regulate non-fullerene acceptor (NFA) packing. We synthesized three novel NFAs, BTP-OTh, BTP-STh, and BTP-SeTh, to systematically decode the impact of heteroatomic polarizability on device performance. The incorporation of highly polarizable selenium atoms in BTP-SeTh effectively enhances the local dielectric constant (ε_r) and suppresses the exciton binding energy (E_b) through intensified dielectric screening. Consequently, deploying BTP-SeTh as a morphology-regulating ternary component in the D18/L8-BO system yields an exceptional power conversion efficiency (PCE) of 20.58% via an entirely additive-free fabrication process. This work establishes chalcogen-substituted 2D side chains as a robust molecular blueprint for developing high-performance, intrinsically stable, and additive-free organic photovoltaics.

The development of high-performance ionotronics is currently hindered by the fundamental trade-off between mechanical robustness (high modulus and toughness) and functional reliability (low hysteresis and high elasticity). Conventional toughening mechanisms that rely on sacrificial bonds inevitably introduce significant energy dissipation and irreversible creep, leading to fatal signal drifts in long-term applications. Herein, we report a synergistic spring-entanglement network that achieves simultaneous optimization of the modulus, recovery, and extensibility via topological modulation. By utilizing a click-chemistry-derived covalent framework as a stiff athermal spring, the elastomer achieved a skin-like modulus (approximately 1 MPa) and near-zero hysteresis (<0.51%). The strategic integration of ultra-high-molecular-weight polymer entanglements introduces topological constraints that function as non-dissipative stress delocalisers, facilitating a fracture strain of 142% without compromising the instantaneous restorative force. This architecture maintains low hysteresis and high elasticity over 10000 cycles, ensuring impeccable signal fidelity and negligible baseline drift in multimodal sensing. This synergistic topological design provides a robust foundation for reliably stable human-machine interfaces and precision ionotronics.

All-polymer solar cells (all-PSCs) have attracted increasing attention owing to their unique advantages, including excellent operational stability and mechanical flexibility. However, the development of high-performance all-PSCs remains constrained because commonly used polymer donors usually suffer from lengthy synthesis and high production costs. Polythiophenes (PTs), which have simple structures and low-cost synthesis, are promising donor candidates for all-PSCs. Nevertheless, the application of PTs in all-PSCs has been hindered by their mismatched energy levels and unfavorable active layer morphology. Herein, two new PTs with a fluorinated polymer backbone and branched alkyl chains, namely P3T2F-DT and P3T2F-DP, were designed and synthesized for high-performance all-PSCs. Fluorination downshifted the highest occupied molecular orbital (HOMO) energy levels, whereas the delicate design of the alkyl chain branching point further modulated the aggregation characteristics and donor-acceptor miscibility. When blended with the polymer acceptor PY-DT-X, P3T2F-DT exhibited improved polymer crystallinity and formed a well-developed fibrillar network in the blend film. Consequently, the all-PSC based on P3T2F-DT achieved a power conversion efficiency (PCE) of 15.64% with a fill factor (FF) of 76.02%, both of which represent the highest reported values for PT-based all-PSCs to date. This work provides a feasible molecular design strategy for PT donors for all-PSCs and demonstrates the great potential of PTs for high-performance, low-cost solar cell modules on an industrial scale.

Perhydropolysilazane (PHPS) is a silicon-nitrogen backbone polymer widely utilized as a ceramic precursor; however, a deep understanding of its molecular structure has been hindered by the complex and highly branched architecture. This work presents a systematic and quantitative investigation into the molecular structure of PHPS by integrating advanced characterization techniques, including multidimensional nuclear magnetic resonance spectroscopy (¹H-/ ²⁹Si-/ ¹⁵N-NMR), gel permeation chromatography with multi-angle light scattering and differential viscometry (GPC-MALS-Vis), and molecular simulations. Through multidimensional NMR analysis, five fundamental structural units (―SiH, ―SiH₂, ―SiH₃, ―NH, and ―N) were identified, with no detectable ―NH₂ groups. A dual-nucleus quantification strategy based on ¹H- and ²⁹Si-NMR enabled the precise determination of the molar ratios of these structural units. Building upon these results, two structural parameters—branching degree (D_b) and number of cyclization (N_c)—were introduced to quantitatively characterize the network topology of PHPS. Subsequently, three-dimensional molecular models were constructed via density functional theory (DFT) simulations to reveal the micro-conformations of the polymer. This study establishes a robust characterization framework that reveals the fine structure and network topology of PHPS, thereby providing a significant theoretical foundation and technical support for structural tailoring and performance optimization to meet the demanding requirements of integrated circuits, functional coatings, and advanced functional materials.

Organic dyes, as a typical class of persistent pollutants in aquatic environments, pose potential threats to ecosystem safety and public health. Poly(ionic liquid)s (PILs) can provide charge repulsion and MXene can offer interlayer nanochannels, making them ideal candidates for fabricating high-efficiency separation membranes. In this study, composite membrane materials with asymmetric and symmetric structures were facilely constructed by loading coatings of PILs-modified two-dimensional transition metal carbides (MXene, Ti₂C) at various loadings onto polypropylene microfiltration membranes, overcoming the drawbacks of poor stability of pure PIL membranes and severe interlayer stacking of neat MXene membranes, with the aim of achieving efficient separation of dye molecules. Methyl orange, methyl red, methylene blue, and rhodamine B were selected as model dyes to systematically evaluate the separation performance of the as-prepared composite membranes. The results showed that the PILs/MXene composite membranes exhibited excellent rejection performance for the four model dyes, with rejection rates exceeding 99% at higher loading levels (e.g., AM-3/SM-3) while maintaining a high water flux (up to 58.36 L·m^–2·h^–1·MPa^–1). The charge interaction between dyes and the membrane surface, as well as the size effect of dye molecules, were key factors that significantly affected the rejection efficiency of the membranes. In addition, the composite membrane displayed favorable operational stability in aqueous environments, demonstrating its application potential in the purification of industrial dye wastewater. This work provides new insights for the development of PILs/MXene composite membranes for dye wastewater purification, meanwhile, the simple membrane fabrication method also endows it with considerable potential for industrial scale-up.

The photovoltaic performance of organic solar cells is critically determined by the multiscale morphology of their bulk heterojunction active layers, whose formation is strongly influenced by solution processing conditions. Therefore, understanding the drying kinetics of blade-coated films is essential for rational morphology regulation and scalable device fabrication. In this study, we established a simultaneous in situ grazing-incidence wide-angle X-ray scattering/grazing-incidence small-angle X-ray scattering/ultraviolet-visible (GIWAXS/GISAXS/UV-Vis) platform to monitor in real time the molecular stacking behavior, mesoscale structural evolution, and optical property changes of blade-coated PTB7-Th:PC₇₁BM blend films during film formation. Synchronized measurements correlate lamellar ordering, mesoscale structure development, and optical response on a common temporal axis. The results show that these events occur over closely related stages of solvent evaporation. Furthermore, the effect of shearing speed on film formation was systematically investigated. Among the examined conditions, a shearing speed of 28 mm/s yielded the most favorable combination of molecular ordering and phase-separated structures, leading to the best device performance. This study provides a versatile multimodal in situ approach for elucidating the film-formation kinetics of solution-processed organic photovoltaic active layers and offers useful guidance for optimizing scalable coating processes.

A propylene-based elastomer (PBE) and calcium phthalate (CaPh) were selected to modify polypropylene (PP) via melt blending. The prepared PP blends exhibited excellent impact toughness and crystalline properties owing to the synergistic effects of PBE and CaPh. The dispersed PBE phase in the PP matrix acted as numerous stress concentrators, initiated shear banding, and impeded the crack propagation. The impact strength of the PP/PBE blends progressively increased with increasing PBE content. CaPh functioned as a β-nucleating agent and effectively induced the formation of a high content of β-crystals in PP. The DSC results indicated that CaPh exhibited high nucleation efficiency, acting as a heterogeneous nucleating agent to improve the crystallization of PP and PBE. With the incorporation of 15 wt% PBE and 0.05 wt% CaPh, the content of β-crystals reached 87.1% and the impact strength of PP enhanced to 50.9 kJ/m².

The skin-core morphology and the crystallinity in aramid fibers critically influence their mechanical properties. In this study, Kevlar 29 and Kevlar 49 fibers were embedded in epoxy and cut along the longitudinal direction, and the cross-sections were characterized by using confocal Raman spectroscopy. The degrees of crystallinity in the skin and the core regions were determined quantitatively, and the crystallinity profiles along the radial direction were obtained for both fibers. The results showed that the crystallinity at the fiber surface was relatively low, which increased quickly into the fiber and approached a higher plateau value at the fiber center. The Kevlar 49 exhibited a steeper increase in the skin region than Kevlar 29, and a more uniform distribution in the core region with a higher degree of crystallinity.

A novel synthetic method towards recyclable polyesters rich in double bonds is highly desirable yet remains a considerable challenge. α-Ethylidene-δ-vinyl-δ-valerolactone (EVL), a lactone derived from CO₂ and butadiene, is an attractive intermediate for the production of sustainable and functional copolymers. However, its anionic ring-opening polymerization (ROP) is significantly impeded by undesired conjugate addition of the tiglate groups. This study presents the chemoselective and controlled ring-opening copolymerization (ROCP) of EVL with α-(1-(alkylthio)ethyl)-δ-vinyl-δ-valerolactones (ATEVL), which are derivatives of EVL and thiols, utilizing 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as the catalyst. Conducted at temperatures ranging from –20 °C to 20 °C, the copolymerizations achieved 100% ROP selectivity with an initial EVL monomer content of less than 40 mol%. The resulting polyesters have number average molecular weights (M_n) between 3.8 and 11.0 kg/mol, low dispersities (Đ=1.15–1.28), and preserve intact conjugated double bonds. The obtained copolymers can be modified by Michael addition and light-induced thio-ene click reactions to produce polyesters with various functional groups. A transparent polyester network was formed upon UV-induced crosslinking, exhibiting considerable shear strength and fluorescence properties, making it a promising candidate for use as a fluorescent photocuring adhesive. This method provides a convenient approach to achieve the chemoselective ROCP of EVL, enabling the synthesis of linear CO₂-based polyesters with numerous sites for post-polymerization modification.

Recently, polymer-based room temperature phosphorescence (RTP) materials have emerged as a research focus owing to their excellent mechanical strength, flexibility, and processability. Herein, a series of poly(vinyl alcohol) (PVA)-based films exhibiting multicolor afterglow emission were fabricated and characterized by using seven naphthalene carboxylic acid derivatives (Nap-nCOOH) as guests. Both the number and substitution position of carboxyl groups in Nap-nCOOH significantly influenced the afterglow color and duration. With an increasing number of carboxyl groups at the α-position of the naphthalene ring, the doped system showed a gradual red-shift of afterglow emission, along with a continuous decrease in RTP lifetime. Moreover, the 1,4,5,8-naphthalenetetracarboxylic acid doped PVA films exhibited unique excitation-wavelength-dependent and time-dependent multicolor afterglow emission, and also displayed concentration-dependent behavior. As an example, the 2-naphthoic acid doped PVA film (2-NapCOOH@PVA) could dynamically switch RTP off or on in response to water or heat stimulation. 2-NapCOOH@PVA₀₅₈₈ exhibited higher water sensitivity than 2-NapCOOH@PVA₁₇₉₉, demonstrating the superior water resistance of PVA films with higher degrees of polymerization and alcoholysis. Subsequently, the potential applications of these PVA-based films were verified in screen printing, information storage and encryption.

A novel synergistic structure (GNS-LDH) was synthesized by modifying graphene with Ni/Fe layered double hydroxide hybrids via hydrothermal method, which have successfully constructed high-performance acrylonitrile butadiene styrene (ABS) nanocomposites in terms of strength, toughness, and smoke toxicity safety through solution blending technology. The composites exhibited excellent mechanical properties, with a tensile strength of 46.23 MPa, elongation at break of 5.78%, and flexural strength of 53.16 MPa. In terms of flame retardancy, the heat release rate of the composites was reduced by 33.2% and the total heat release was reduced by 12.3% with the addition of 2.0 wt% GNS-LDH. Moreover, the generation of toxic gases, such as CO, CO₂ and HCN, during the combustion process was effectively suppressed, and the smoke generation rate was significantly reduced. The comprehensive performance of this ABS nanocomposite based on GNS-LDH in terms of enhancement and toughening, flame retardancy, smoke suppression, and reduction in toxicity has surpassed that of many similar materials reported in the current literature, which provides a new way of thinking for the design and development of high-performance protective materials.

Although silicon is a promising anode material for high-energy-density lithium-ion batteries, the huge volume change during the cycling leads to collapse of the electrode structure and fast degradation, particularly for the high-mass-loading electrodes. This has severely hindered its practical application. Here, a crosslinked polymer gel electrolyte is developed for high-mass-loading Si electrode. The gel electrolyte was fabricated by in situ polymerization method using methyl methacrylate and N,N′-methylenebisacrylamide as the monomer and crosslinking agent, respectively. It forms hydrogen bonds with hydroxyl groups on the surface of silicon anode to fix silicon particles and shows high oxidative stability to be compatible with high voltage cathode. With such gel polymer electrolyte, a high-mass-loading Si anode at 3.5 mg·cm^–2 achieves a largely improved cycling stability, with a high reversible capacity of 1462.4 mAh·g^–1. Furthermore, full cells using the high-mass-loading Si anode and LiNi_0.8Co_0.1Mn_0.1O₂ cathode demonstrate exceptional cycling performance with a high capacity retention of 75.8% after 1000 cycles at 1 C, and stable cycling even at a high temperature of 60 °C. Our findings provide an effective strategy to promote the practical application of high-mass-loading Si anode for high energy density lithium ion batteries.

Thermal runaway-induced safety issues have seriously hindered further development of lithium-ion batteries (LIBs). As a key component of LIBs, high-performance electrospun nanofiber separators (ENSs) with high-temperature self-closing functions can prevent safety issues caused by thermal runaway in LIBs. In this study, a sandwich-structured high-temperature self-closing polyacrylonitrile/polyurethane//adding cetyltrimethylammonium bromide to the poly(butylene succinate) (PAN/PU//CPBS) ENS (CPC ENS) was efficiently fabricated using free-surface electrospinning technology via material selection and structural design. A high-melting-point polyacrylonitrile-based ENS served as the intermediate layer, providing its thermal stability, while a low-melting-point polybutylene succinate-based ENS served as the outer layer, endowing it with a high-temperature self-closing function. To enhance its performance, CPC ENS was modified with polydopamine and loaded with porous structured UiO-66 rich in active sites, resulting in a high-performance self-closing UiO66@PDA@CPC ENS. The results showed that UiO66@PDA@CPC ENS had an excellent electrolyte uptake rate (740.7%±20.6%) and wettability (8.3°±0.3°), while maintaining good thermal stability at 160 °C. Furthermore, after 100 cycles at 0.5 C, the assembled battery maintained a discharge specific capacity of 139.6 mAh/g, with a capacity retention rate of 92.4%. Meanwhile, the surface of the lithium sheet had a flat morphology, indicating that UiO66@PDA@CPC ENS had superior long-term cycling stability, thus demonstrating its enormous potential as a high-performance and safe LIB separator.

Passive anti-icing approaches utilizing icephobic surfaces present innovative solutions that require minimal energy, are simple to maintain, and are environmentally sustainable, garnering considerable interest. However, icephobic surfaces may encounter challenges related to environmental adaptability, which diminishes their durability. To mitigate this issue, we developed soluble polydimethylsiloxane covalent adaptable networks (PDMS CANs) for low-modulus icephobic coatings with intrinsic self-repairing capability. These soluble PDMS CANs were synthesized from diol-terminated PDMS, which underwent dynamic end-cross-linking through dioxaborolane linkages. The end-linked structure enabled dissolution in solvents such as ethyl acetate. Once the solvent was removed, the dynamic cross-linked networks re-formed. This feature made PDMS CANs suitable for processing methods such as solution casting or coating. The cross-linking density of the CANs could be modified by varying the chemical formulation. The effects of cross-linking density on mechanical properties, self-repairing capability, and icephobic performance were examined. To further enhance deicing performance, silicone oil was incorporated into the PDMS CANs as a lubricant. The relationship between icephobic performance and oil content was explored. The optimal ice adhesion strength, achieved at an oil content of 40 wt%, was approximately 7.1 kPa at –10 °C. The coatings demonstrated good durability throughout icing-deicing cycles. This study highlights the potential of self-repairing, low-modulus elastic coatings based on CANs for large-area deicing applications.

Nonreciprocal chiroptical response, a phenomenon arising from light-matter interaction by the coupling of linear optical effects, attracts rapidly increasing attention to advance fundamental chiroptical theory and develop high-performance optical devices. Herein, we fabricated a chiral polyurethane system with tunable apparent all-angle nonreciprocal chiroptical response, where can be further controlled by modulating the content of doped small molecules within the polyurethane film. Building on these observations, we investigated the origins of the angle-dependence and nonreciprocal chiroptical responses, and proposed a plausible mechanism to explain the emergence of this apparent circular dichroism (CD) signal. Furthermore, we utilized achiral helical polyacetylene to regulate the response wavelength. Our research establishes a clear relationship between polyurethane structure and apparent all-angle nonreciprocal chiroptical response, providing new insights into the connection between chiral materials and linear optical materials.

Integrating photoresponsive components into superhydrophobic surfaces remains a challenge because functional species often disrupt the hierarchical micro/nanostructures required for superhydrophobicity. In particular, intrinsically hydrophilic polyoxometalates (POMs) are difficult to incorporate into low-surface-energy systems without compromising their structural integrity and wetting performance. Herein, a fluoropolymer porous coating of phosphomolybdic acid (FPPC@PMA) was fabricated via a high-internal-phase emulsion (HIPE) templating strategy, enabling the simultaneous immobilization of hydrophilic POMs and construction of a hierarchical porous fluoropolymer framework. The resulting FPPC@PMA coating exhibited excellent superhydrophobicity with a water contact angle of 152° and remarkable mechanical durability in sandpaper abrasion and tape-peeling tests. Owing to the redox activity of PMA, the composite also displays a sensitive and reversible photochromic response upon ultraviolet irradiation, suggesting its potential applications in ultraviolet (UV) monitoring and information encryption. Molecular dynamics simulations further elucidated the interfacial interactions between the polymer matrix and phosphomolybdic acid clusters, providing theoretical insights into the structural stability of the composite system. This work offers an effective strategy for integrating hydrophilic photoresponsive species into superhydrophobic architectures while maintaining their structural integrity and functionality.

Heat-, light-, and humidity-responsive materials were fabricated via chemical design and cold drawing processing. The crystallizable polyether/polyester diols were first reacted with isophorone diisocyanate (IPDI), followed by chain extension with azobenzene units. The synthesized polyurethanes exhibited ductile behavior and drawing-induced orientation when the soft segments possessed high crystallinity. Upon heating or UV irradiation, the oriented polyurethane strips underwent bending, whereas the pristine strips did not. Under humid conditions, both oriented and pristine polyurethane strips containing poly(ethylene oxide) (PEO) soft segments bent, albeit in opposite directions. In contrast, polyurethane strips with polycaprolactone (PCL) and polytetramethylene ether glycol (PTMEG) soft segments showed no response to humidity, regardless of whether they were stretched. Mechanistic investigations revealed that the temperature increase resulting from the photothermal effect of the azobenzene moieties is the main reason for light-induced actuation, which differs from that in many other azobenzene-based materials. The entropic elastic energy stored during stretching is released upon UV irradiation, heating, or humidification to drive the bending deformation. This work presents a strategy for constructing multi-stimuli- responsive materials via molecular design and post-processing, highlighting the synergy between functional moieties and microscopic structures, which holds great significance for the development of advanced intelligent materials.

Polyurethane (PU) foams are extensively utilized in various industries owing to their lightweight, excellent thermal insulation, and robust mechanical properties. However, their widespread use generates significant quantities of waste, which poses serious environmental and disposal challenges. In this study, rigid PU foam was effectively depolymerized via microwave-assisted glycolysis, using 2-methyl-1,3-propanediol (MP-diol) as the glycolysis agent and sodium hydroxide (NaOH) as the catalyst. The depolymerization process was systematically optimized by varying the reactant ratio, catalyst concentration, reaction temperature, and microwave power. The resulting oligomeric product (PUF-O) was characterized by physical, chemical, and spectroscopic analyses. Subsequently, a series of polyester polyols (PEs) was synthesized by partially and fully replacing neopentyl glycol with an oligomeric product in formulations containing adipic acid and phthalic anhydride. These PEs further reacted with commercial polyisocyanates to form polyurethane coatings. Characterisation was conducted to analyse the optical, mechanical, chemical, and anticorrosive properties of the cured films were characterized. The PUF-O-based polyols exhibited performance comparable to those synthesized using conventional raw materials, demonstrating the feasibility of incorporating recycled PU foam into high-performance coating systems. This work not only provides a sustainable strategy for recycling PU waste but also offers a viable route to value-added products.

Thermo-responsive pressure-sensitive adhesives (PSAs) offer significant potential for advanced wound care but face challenges in achieving simultaneously robust physiological adhesion and controllable, atraumatic removal. This study introduces silicone-contained pressure-sensitive adhesive (SiPSA), the adhesive platform synthesized by crosslinking thermo-responsive poly(ethylene glycol-co-siloxane) (PEG-Si) with trimethylol-propane triacrylate and chitosan tackifier. SiPSA exhibits dual-temperature-triggered debonding, delivering exceptional adhesion on skin at 37 °C (180° peel strength=211 N/m), while enabling rapid, on-demand detachment via either heating to 60 °C (72.7% adhesion reduction) or cooling to 0 °C (82.5% adhesion reduction). Critically, SiPSA maintains robust interfacial bonding under high-humidity conditions, adhering effectively to moist skin and bleeding wounds, and retaining significant peel strength even after absorbing 20 vol% water, a key advantage for exudative wound management and aqueous environments. Comprehensive biocompatibility tests confirmed its non-irritating and clinically safe profile. Compared to conventional dressings, SiPSA uniquely integrates high-strength physiological adhesion with programmable, painless removal through distinct thermal stimuli, significantly enhancing patient comfort and clinical utility. These results highlight SiPSA as an advanced material for medical care, providing reliable adhesion modulation, excellent performance in wet settings, and favorable patient compliance.

Polyethylene (PE) and polypropylene (PP) are widely used in commercial lithium-ion battery (LIB) separators owing to their high mechanical strength and chemical stability. However, both polymers suffer from poor high-temperature tolerance, low porosity, and inadequate electrolyte wettability, making it difficult to reconcile electrochemical performance with safety under thermal stress. Developing advanced lithium-ion battery separators is therefore crucial for achieving high efficiency, safe LIBs. This study presents a boehmite/polyacrylonitrile (BM/PAN) composite nanofiber separator fabricated by electrospinning and systematically examines how BM loading affects separator microstructure and electrochemical behavior. Compared with commercial PP separators, the BM/PAN composites exhibit a unique three-dimensional interconnected fiber network, together with markedly improved wettability, thermal stability and electrochemical properties. The optimal formulation contains 4 wt% BM (denoted PAN-BM-4) exhibited an outstanding wettability with electrolyte uptake of 692.5% with the porosity of 80.7% and electrolyte contact angle of 25.5°, ensuring rapid electrolyte infiltration and efficient ion transport. It also displayed a higher mechanical property with tensile strength of 7.9 MPa and elongation at break of 27% (cf. 6.5 MPa and about 45% for pure PAN), indicating enhanced structural integrity. Meanwhile, such PAN-BM-4 separator demonstrates an excellent thermal stability with negligible shrinkage at 200 °C and a residual mass of 57.6% at 800 °C, effectively mitigating the thermal-runaway risk of conventional separators. Moreover, as to the electrochemical performance, this unique PAN-BM-4 separator showed an ionic conductivity of 3.31 mS/cm, more than six times that of commercial PP, and the electrochemical stability window exceeding 5.5 V (versus Li⁺/Li) and a Li⁺ transference number (t_Li⁺) of 0.42, substantially higher than PP (0.28) and pure PAN (0.34), reflecting enhanced selective Li⁺ transport. Besides, in half-cell testing, the PAN-BM-4 separator delivers an initial discharge capacity of 140.6 mAh/g at 0.5 C with 88.3% capacity retention after 100 cycles. In summary, this work establishes a viable materials-design strategy and experimental framework for next-generation LIB separators that simultaneously achieve high ionic conductivity, superior thermal stability and favorable interfacial compatibility.

Preparing poly(lactic acid) (PLA) composites with balanced stiffness toughness has been a research focus in recent years. In this study, we designed a segmented copolymer containing unsaturated carbon–carbon double bonds, polycaprolactone-r-polylactide (PCL-r-PLLA). This copolymer was then blended with PLA via an in situ crosslinking reaction. The torque curves and Fourier transform infrared spectroscopy (FTIR) spectra confirmed the occurrence of branching and crosslinking reactions within the PLA/PCL-r-PLLA composites. Tensile tests indicated that the PLA/PCL-r-PLLA composites exhibited excellent performance with balanced toughness stiffness. The elongation at break of the PLA/PCL-r-PLLA composites increased to approximately 116%, which is approximately 25 times that of neat PLA, while the tensile strength decreased by only 20% compared to neat PLA. In addition, the scanning electron microscope (SEM) images indicated that the diameter of the dispersed PCL phase was close to the wavelength of visible light; therefore, this composite exhibited good transparency. Shear deformation and matrix cavitation have been identified as primary toughening mechanisms. This work presents an effective strategy for fabricating transparent PLA composites with a balanced stiffness–toughness performance. This would broaden their applications in transparent packaging.

The co-nonsolvency of polymers in binary mixtures of individually good solvents remains mechanistically controversial, despite extensive research over several decades. Recent theoretical analyses based on ternary solution thermodynamics suggest that the orientation of tie lines in the polymer solvent composition plane serves as a decisive signature to distinguish between preferential interaction-driven and solvent cosolvent attraction-driven mechanisms, yet direct experimental verification of this prediction has remained elusive. Here, we report the quantitative experimental determination of tie line orientations in a poly(N-isopropylacrylamide) water-methanol system through direct measurement of solvent partitioning between coexisting liquid phases. Our experimental results reveal that all measured tie lines consistently exhibit positive slopes in the polymer concentration and methanol fraction composition planes, unambiguously indicating preferential enrichment of the better solvent in the polymer-rich phase. This observation provides direct experimental evidence supporting the preferential interaction-driven mechanism and establishes tie line orientation as a robust practical experimental observable for elucidating co-nonsolvency phenomena. These findings validate theoretical predictions within the Flory-Huggins framework and bridge the gap between the mean field theory and experimental reality, offering a definitive methodology that should broadly applicable to other polymer systems exhibiting similar phase separation behavior.

Polymer-based scintillating materials hold considerable promise for a broad range of applications. However, their development has been constrained primarily by the intrinsically low exciton harvesting efficiency. Herein, we harness a host-guest energy transfer strategy to overcome this limitation. Through a simple radical polymerization, thermally activated delayed fluorescence units bearing a C＝O/N resonance structure are embedded into a pyridine-containing copolymer framework. Using pyridine groups with high triplet energies as the host matrix effectively suppresses aggregation-caused quenching and maintains efficient reverse intersystem crossing process of luminescent thermally activated delayed fluorescence unit for high exciton harvesting. The resulting material exhibits intense photoluminescence and radioluminescence emission at 492 nm. Line-pair and modulation transfer function analyses further validate that the scintillator delivers a spatial resolution of 13.3 lp/mm and a detection limit of 390 nGy/s. X-ray imaging experiments demonstrate that the material can clearly resolve complex internal structures of diverse specimens, confirming its potential for industrial non-destructive testing. This work presents a flexible, high-resolution organic scintillator and paves the way for its deployment in multi-scenario X-ray imaging.

Various phase structures can be formed by rubber and rigid particles in a polymer. Which is more beneficial to the impact toughness and rigidity, as well as their balance. This has been unclear until now. In this study, polymer composites with typical three-phase structures, that is, hard core-soft shell particles, soft core-hard shell particles, and two types of separated particles, were studied theoretically. The calculated results indicate that the soft core-hard shell structure is the best for enhancing the modulus in these three-phase structures, whereas the hard core-soft shell structure is the worst. On the other hand, both core-shell structures are beneficial for enhancing toughness, whereas the two types of particle-separated structures are not. These theoretical results are supported by the experimental results for polypropylene (PP), ethylene-propylene-diene monomer (EPDM) rubber, and SiO₂ composites.

Self-healing polyurethane (PU) elastomers will greatly extend the service life of key components, reduce maintenance costs, and promote sustainability. However, dense hydrogen bonds cannot quickly recover after stretching, causing permanent deformation, while high-temperature and long-duration curing are required for their crosslinking. Therefore, dual crosslinked networks are designed herein to achieve self-healable, high-resilience and UV-curable polyurethane-urea elastomers (PUU-SS-Zn), using polycarbonate diol (PCDL) as the soft segment for entropic elasticity, cystamine (Cy) as a chain extender for disulfide bonds and urea-linked hydrogen bonds, 2-hydroxyethyl acrylate (HEA) as end-capping groups for rapid UV-curing, ZnCl₂ for metal coordination bonds. The resultant elastomers are UV-cured within 100 s, exhibit a transmittance >92%, tensile strength of 11.8 MPa, and elongation at break of 2423%. More importantly, it achieves nearly 100% resilience at 500% strain within 5 s, realizes 99.6% resilience at 1000% strain within 5 min, and maintains 90.2% after multiple cycles. Surface scratches disappear within 30 min at 60 °C, and the self-healing efficiency reaches 93% after 8 h at 80 °C. This self-healable, high-resilience and UV-curable polyurethane-urea elastomer shows great application potentials in flexible sensors and wearable devices.

The performance of polyimide (PI) nanocomposites is strongly dependent on both the matrix structure and degree of filler dispersion. This study compares the efficacy of mechanical mixing versus in situ polycondensation as methods for incorporating Fe₂O₃ and Al₂O₃ nanocrystalline particles into PI matrices with varying flexibility of macrochains that have different dianhydride fragments based on either pyromellitic acid (PMDA) or 1,3-bis(3′,4-dicarboxyphenoxy)benzene acid (R), with the same diamine: 4,4′-oxydianiline (ODA). Comprehensive characterisation using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) confirmed the chemical and crystalline structures of the polymers and the inorganic fillers, respectively. Scanning electron microscopy (SEM) analysis demonstrated that the in situ method provided significantly more homogeneous particle distribution within the matrix, reducing the agglomeration observed with mechanical mixing. This facilitated adding more filler into the PIs, which in turn enhanced key properties of the materials. For example, a semi-flexible-chain PMDA-ODA-based composite with 7 wt% of Fe₂O₃ prepared in situ exhibited a 19% increase in rigidity relative to the host polymer. In contrast, the mechanically mixed counterpart demonstrated only a 6% increase in Young’s modulus relative to the matrix. Meanwhile, the tensile strength of the in situ prepared composite is approximately the same as that of the corresponding matrix polymer, whereas for the mechanically mixed composite it decreases by about 20%. For Al₂O₃-containing composites, materials based on the flexible-chain R-ODA exhibit higher thermal stability than those based on the semi-flexible PMDA-ODA, which is attributed to better accommodation of local inhomogenieties and more efficient heat dissipation. The work establishes the correlation between the synthesis approaches and the properties of PI-based composites, which is essential for the development of new materials with optimized thermal and mechanical characteristics for advanced engineering applications.

Waterborne polyurethanes (WPUs) are increasingly valued for their low volatile organic compound emissions but suffer from poor water resistance and weak mechanical properties. Herein, a strategy based on covalent self-crosslinking combined with ionic crosslinking was proposed to construct a PU elastomer with excellent water resistance and antibacterial activity. This film exhibited dramatically enhanced tensile strength (12.7 MPa) and toughness (43.0 MJ/m³), far exceeding those of non-crosslinked and single-crosslinked PU films. Notably, the chain segments with C＝O and N―H bonds assembled into hard-phase regions, enabling efficient energy dissipation through the rupture and reformation of reversible H-bonds. This WPU can serve as a recoverable, solvent-free adhesive, achieving lap shear strengths of 2.69 MPa (glass). Moreover, the excellent water resistance of WPU materials ensures a sustained high adhesion strength under wet conditions. In addition, the chlorinated film demonstrated satisfactory cytocompatibility and antibacterial efficiency. This high-performance and sustainable PU material holds great promise for biomedical applications.

The development of conductive hydrogels with stretchability, adhesiveness, self-healing, antibacterial and ionic conductivity is crucial for wearable electronic devices such as motion and health monitoring sensors and flexible generators. In this study, a novel multifunctional conductive hydrogel with high conductivity, excellent stretchability, antibacterial property, antifreeze and moisture retention, as well as self-healing and self-adhesive capabilities was successfully prepared by introducing the dynamic redox reaction between phenolic hydroxyl groups and Fe³⁺ through the addition of tannic acid (TA) to the acrylic acid (AA)-based hydrogel system, and the addition of LiTFSI. This material not only has good mechanical flexibility (tensile strength of 0.3048 MPa and elongation at break of 1657%), but also stable electrical properties (conductivity of 1.47 S·m^–1). The excellent antibacterial and self-healing properties also endow it with long-term stability in complex environments. The triboelectric nanogenerator (PTFL-TENG) constructed with this hydrogel can achieve an open-circuit voltage of approximately 100 V, with excellent and stable output performance, capable of providing self-powering ability for small electronic devices and enabling signal transmission. In addition, the self-powered sensor assembled with PTFL hydrogel can respond quickly and accurately to deformation and transmit electrical signals, demonstrating high sensitivity and good repeatability. Based on its comprehensive performance, this hydrogel has broad application prospects in flexible wearable sensors, intelligent medical monitoring, and self-powered systems.

Polypropylene (PP) can be toughened by adding elastomers or constructing core-shell structures, although the toughening efficiency of both approaches is limited. Herein, a synergistic dual-phase toughening method is proposed by introducing high-density polyethylene (HDPE) into ethylene-propylene rubber (EPR) and isoprene rubber (IR) composite systems. This resulted in an HDPE@EPR core-shell particle structure alongside finely dispersed IR particles. Interfacial tension promotes adhesion between the EPR shell and IR, concurrently reducing the size of the IR domains and interparticle spacing of the rubber phase. By optimizing the HDPE content, a loading of 15 phr resulted in a well-defined core-shell morphology with minimized IR domains. This enables the fabrication of a PP alloy exhibiting exceptional low-temperature impact toughness (35.8 kJ/m² at –20 °C) and an optimal strength-toughness balance. However, surpassing the optimal HDPE content triggers IR particle aggregation, because the thinned EPR shell fails to fully encapsulate the HDPE core, while interfacial tension-driven repulsion facilitates this process. Finite-element simulation results demonstrated a significant synergistic toughening effect between the HDPE@EPR core-shell particles and IR particles. Under low-temperature impact loading, stress and strain are concentrated at the core-shell interface and around the IR particles, which effectively inhibits rapid crack propagation, thereby significantly enhancing the low-temperature toughness of the material. This dual-dispersed phase design strategy offers a promising pathway for the development of high-performance PP composites for demanding low-temperature applications.

Phase equilibria were investigated in uncured mixtures composed of an epoxy oligomer, polysulfone, and tetraethoxysilane. Pairwise interaction parameters were calculated and binodal curves were constructed. The mutual diffusion coefficients of the components were determined and the influence of tetraethoxysilane on the diffusion processes in both binary and ternary systems was examined. Phase diagrams of the binary and ternary systems were established using optical microscopy and dynamic light scattering, and the boundary compositions corresponding to the single-phase region were identified.

Conductive hydrogels with high mechanical strength, good adhesion, and high sensitivity are highly demanded for wearable electronics. A multifunctional hydrogel based on 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and acrylic acid (AA) was synthesized via free-radical polymerization. The system incorporates dynamic hydrogen bonds from guanine–cytosine (G–C) base pairs and homogeneously dispersed carbon nanotubes (CNTs) modified using a dual-ionic liquid strategy. Short-chain (C₄) and long-chain (C₁₂) imidazole-based ionic liquids act synergistically to exfoliate and stabilize CNTs, facilitating uniform dispersion and strong interfacial bonding. Owing to the continuous conductive pathways formed by the CNTs, the hydrogel exhibited enhanced electrical conductivity with a gauge factor of 5.61, together with excellent short-term cyclic stability and responsiveness for monitoring dynamic human motions. The combination of covalent cross-linking, reversible hydrogen bonding, and reinforced nanofillers endows the hydrogel with high stretchability, good adhesion (5.5 kPa), and superior fatigue resistance, showing great potential for use in flexible wearable bioelectronics.

Despite extensive research, understanding the formation process of microporous polymer membranes remains an open question. Despite computational advances, all-atomic mechanistic studies of phase separation remain challenging. This study employed all-atom molecular dynamics (MD) simulations to investigate the non-solvent-induced phase separation (NIPS) process in poly(vinylidene fluoride) membrane formation. The simulated microstructure was consistent with that of the experimental ultrafiltration membranes, both exhibiting cylindrical through-pores with well-defined pore walls and symmetrically connected structures. MD simulations further reveal key parametric effects: increasing the polymer concentration reduces the phase separation rate, with the pore volume decreasing to 50.29% of the initial value at four times the original concentration. Conversely, increasing the system temperature accelerated phase separation, with the pore volume reaching 111.23% of the original value at a 60 K temperature increase. The analysis of the interaction energy, diffusion coefficient, and atomic concentration provided mechanistic insights into these observations. These MD simulations enabled atomic-level visualization of the NIPS process, capturing intermediate states that are difficult to observe in conventional experiments and elucidating the formation mechanism of microporous polymer membranes. This not only provides a theoretical basis for preparing highly permeable, highly selective microporous polymer membranes but also offers technical support for optimizing membrane fabrication processes.