Functional gels exhibit unique properties that can be tuned by regulating their physical interactions and microstructures. However, quantifying the strength and fraction of these physical interactions and how they result in large-scale collective dynamical properties remains a significant challenge. From this perspective, we briefly review the theories and characterization method of light scattering on polyelectrolyte gels, with an emphasis on summarizing our efforts. In particular, we introduce our most recent work on an entirely new universality class of hierarchical gel dynamics for various types of physical gels, which is complementary to the light scattering studies on chemically crosslinked gels in the past five decades. By utilizing the hierarchical gel dynamics, we are able to extract the average bond binding energy of various physical bonds and the physical crosslinking density in the gels. Finally, we evaluated the advantages and limitations of the light scattering method and discussed the future perspectives in this field. It is anticipated that this perspective will facilitate the broad application of light scattering technique in the field of functional gels.

Phase-separated ionogels have emerged as a promising class of functional materials characterized by their unique thermodynamic behavior. In contrast to conventional polymer networks that rely on specific chemical structures, phase separation in these systems stems from the thermodynamic instability of polymer-solvent interactions. This mechanism allows precise control over material properties through a multiscale structural design. Ionic liquids (ILs), which serve as the dispersion medium, play a pivotal role in tuning the lower critical solution temperature/upper critical solution temperature (UCST/LCST) phase behavior of the corresponding ionogels owing to their tunable cation-anion combinations, polarity, and hydrogen-bonding capacity. These features not only facilitate the construction of thermally responsive ionogels but also provide a versatile platform for mechanistic studies. This review systematically explores the formation mechanisms of phase separation in ionogels, emphasizing the crucial influence of the physicochemical properties of ILs and categorizing the key driving forces behind phase separation. It further examined the distinctive effects of phase separation on the surface/interfacial properties, mechanical behavior, and electrical performance of ionogels, incorporating the latest research advances. Finally, the current challenges and prospective research directions for phase-separated ionogels were outlined.

Biofouling remains a critical challenge in medical devices, tissue engineering, and wound healing. The development of high-performance anti-biofouling materials is essential to ensure the long-term safety and functionality of biomaterials. Owing to their strong hydration capacity, excellent biocompatibility, and structural tunability, hydrogels show considerable promise for anti-biofouling applications. This review systematically elaborates on the fundamental hydration-mediated anti-biofouling mechanisms of hydrogels. These mechanisms primarily involve the formation of a stable hydration layer on the surface of the hydrogel materials, which acts as a physical and energetic barrier to prevent the initial adsorption of biomacromolecules. Two principal hydration mechanisms are discussed: hydrogen-bonding hydration, in which water molecules are strongly bound to hydrophilic moieties via hydrogen bonding, and ion-solvation hydration, which relies on the strong electrostatic interactions between water molecules and zwitterionic groups. Based on these underlying mechanisms, anti-biofouling hydrogels can be categorized into two major classes: hydrogen-bonding hydration-based polymer hydrogels and ion-solvation hydration-based polymer hydrogels. The first type of anti-biofouling hydrogel is constructed mainly from hydrophilic polymers such as poly(ethylene glycol) (PEG), acrylamide polymers, and peptide polymers. The second category includes pure zwitterionic polymer hydrogels, copolymerized zwitterionic polymer hydrogels, and mixed-charge polymer hydrogels. Finally, this review highlights the current biomedical applications and future trends of anti-biofouling hydrogels, including vitreous substitutes, postoperative anti-adhesion barriers, chronic diabetic wound dressings, and surface coatings, with the aim of providing theoretical guidance and strategic insights for the design of highly effective, durable, biosafe anti-biofouling hydrogels.

Damping polymers relying on significant internal friction in glass transition regions can suppress vibrations and noise; however, these materials generally exhibit a narrow damping breadth and severe mechanical instability. Natural damping tissues such as the skin and cartilage achieve high energy dissipation through the combination of viscous fluid and a 3D elastic skeleton. This binary structure inspired a high energy dissipation gel design strategy using synergistic viscoelastic scheme of confined chains and host network. Herein, we provide a comprehensive overview of recent advances in bio-inspired damping polymer gels. The structural designs and their corresponding performances are elucidated in this review. We anticipate that this review will motivate further exploration of design and applications of damping polymers.

Ionogels are a class of soft materials composed of ionic liquids and polymer networks. They possess many fascinating intrinsic properties (e.g., ionic conductivity, near-zero vapor pressure, and wide thermal and electrochemical operation windows) that make them promising for applications in ionotronics, sensors, energy storage devices, and flexible electronics. In addition to these intrinsic properties, ionogels can acquire additional functionalities (such as self-healing, shape memory, and adhesion) through structural design and the introduction of functional additives, thereby further expanding their application scope. This review focuses specifically on these additional functionalities of ionogels, elucidating their design strategies and applications and highlighting the current challenges and future opportunities in this rapidly developing field.

Direct-ink-writing (DIW) 3D printing has emerged as an indispensable advanced manufacturing technology in biomedical engineering owing to its material compatibility, structural precision, and multimaterial integration capabilities. By digitally programming hydrogel ink deposition, DIW 3D printing enables the controllable fabrication of high-performance hydrogel bioelectronic devices featuring complex 3D architectures, high-fidelity electrophysiological recording/stimulation, and mechanical compliance with soft tissues, thereby establishing a technological foundation for next-generation personalized medical electronics. This review systematically summarizes the recent progress in DIW-printed hydrogel bioelectronics, first elaborating design strategies for hydrogel inks that reconcile printability with functionality through synergistic engineering of rheological behavior, electrical conductivity, tissue adhesion, and biocompatibility. We comprehensively analyzed state-of-the-art wearable and implantable devices fabricated via DIW 3D printing, highlighting their advantages in electrophysiological monitoring, precision stimulation, and biosensing. Finally, we conclude by critically evaluating the current challenges and future directions, thereby establishing a framework for DIW 3D printing to become a foundational platform for customized biointegrated interfaces.

Ion-conducting soft polymers, encompassing hydrogels, ionogels, and organic mixed ionic-electronic conductors, have emerged as distinctive material platforms for neuromorphic electronics, fundamentally diverging from the rigid paradigms of silicon and metal oxides. By enabling volumetric ionic transport and intricate electrochemical interactions within mechanically compliant matrices, these materials offer a biologically inspired route for emulating synaptic plasticity, memory consolidation, and adaptive sensing. With artificial synapses serving as the cornerstone of neuromorphic architectures, this review highlights recent advances in four classes of polymer-based composites: ion-gated transistors, electrochemical random-access memory cells, nanofluidic memristors, and soft ionic synapses. We dissect the physical mechanisms underlying plasticity: electric double-layer gating, volumetric electrochemical doping, nanofluidic confinement, and distinct viscoionic relaxation effects stemming from the macromolecular nature of the host matrix. Emphasis is placed on the interplay between ionic dynamics and polymer structural evolution in shaping the device functionality, energy efficiency, and multimodal responsiveness. We identify the critical challenges in switching speed, hydrolytic stability, and large-scale integration while highlighting emerging opportunities at the interface of biology, soft robotics, and in-sensor computing. Ion-conducting polymers, by uniquely combining brain-like ionic signaling with soft-matter versatility, are expected to play a central role in the next generation of intelligent, bio-integrated systems.

Hydrogel-based self-floating catalytic materials have become a key interfacial platform in the field of solar-driven chemistry, effectively solving the difficulties of traditional powder catalysts in the aqueous phase, such as easy agglomeration, sedimentation, and limited mass transfer. In this study, the design strategy, structural properties, and interfacial advantages of these materials were systematically described, and the mechanisms of precursor mixing, in situ synthesis, and post-modification in regulating the distribution of active sites, gel structure formation, and multifunctional integration were analyzed. Through the construction of stable three-phase interfaces, the materials form a reaction microenvironment with a generalized enhancement effect. The structural design significantly improves the light trapping efficiency and carrier separation performance in photocatalytic processes and simultaneously strengthens the mass transfer process and local reactant concentration in peroxide activation reactions, establishing a synergistic system in which the adsorption, enrichment, and catalytic processes are tightly coupled. Successful applications in the fields of organic pollutant degradation, solar-driven chemical synthesis, and interfacial evaporation have demonstrated the wide applicability of this technology. By systematically combining the research progress in this field, this study aims to provide a theoretical basis for the development of efficient and stable interfacial catalytic platforms and promote the development of sustainable environmental remediation and energy conversion technologies.

Self-sustained continuous motion is a central functional objective in soft actuators and robotics. One key challenge lies in establishing a persistent, self-regulated deformation feedback in soft materials under external stimulation, which is ultimately rooted in their geometry and configuration. Here, based on a cylindrical hydrogel with fast, reversible, and anisotropic photoresponsiveness, we construct a series of hydrogel rings by twisting one end of the gel string and closing it into a loop. By regulating the built-in twist (Tw) and the resulting internal prestress, the rings adopt distinct configurations that give rise to multiple motion modes under light irradiation. Gel rings with relatively small Tw remain in quasi-flat configurations and display coupled rolling and spinning motions. As Tw increases, the rings undergo Michell’s instability and rapidly snap into a figure-of-eight configuration upon light irradiation, subsequently exhibiting irregular tumbling motions. At even larger Tw, the rings adopt “dough twist” configurations, showing persistent rolling under constant irradiation. Distinct motion modes arise from different actuation-deformation feedback loops established in hydrogels with distinct configurations and stress distributions. These results demonstrate not only the role of the configuration in governing locomotion, but also the potential of a single hydrogel system to achieve diverse motion behaviors through programming internal stresses.

Underwater camouflage materials can be hidden either from sight by being transparent or from sound by absorbing acoustic waves, but achieving both in one material remains challenging due to their distinct chemical designs. Here we decouple these conflicting properties using a hierarchically structured hydrogel featuring unique dual-scale bicontinuous microphase separation. By precisely integrating hydrophilic and hydrophobic units, we engineer three intertwined polymer-rich and aqueous phases spanning nano-to-micro length scales. This unique nanoconfinement preserves optical clarity by minimizing light scattering while facilitating ultrahigh broadband energy dissipation. Furthermore, the hydrogel’s acoustic impedance matches that of water, maximizing sound wave incidence into the material, where the propagating waves are scattered and attenuated through viscoelastic damping within the highly tortuous hydrophilic phases. A hydrogel film only 4 mm thick can absorb nearly 78% of incident sound energy. These findings highlight molecular-engineered hierarchical phase separation as a powerful strategy for developing advanced opto-acoustic soft materials.

Hydrogels have been widely used in tissue engineering and biomedical applications owing to their high water content and tunable functionality. Nevertheless, high water content and loosely cross-linked networks restrict the mechanical properties of hydrogels and their practical applications. Herein, we present a facile approach for designing strong and tough bacterial cellulose/poly(vinyl alcohol) (BC/PVA) double-network hydrogels involving immersing BC into PVA solutions and then freezing-thawing. The PVA chains encapsulate the BC nanofibers through hydrogen bonding interactions and chain entanglement, infiltrate the fibrous network, and thereby enhance the densification of the BC/PVA hydrogel. Concurrently, repetitive freeze-thaw cycles facilitate the regulation of PVA chain conformation and promote PVA crystallization, which increases the rigidity of the PVA segments. The resulted hydrogel demonstrates an exceptional tensile strength of (2.13±0.03) MPa, a remarkable toughness of (1.15±0.03) MJ·m^–3, and a high water content of up to 95%. Furthermore, the double-network hydrogels exhibit excellent biocompatibility. This study offers a practical strategy for the design of robust and tough hydrogels with potential utility in biomedical applications.

Polymer hydrogels with variable stiffness demonstrate immense practical application value, particularly when utilizing water as a trigger medium, which significantly expands their prospects in soft robotics, bioelectronics, and artificial muscles. However, existing water-induced stiffening hydrogel rely on ionic liquids and inorganic salts, posing leakage risks during prolonged use. Here, we proposed a strategy for mechanically strengthening hydrogel through water-induced phase separation. By designing a polymer matrix featuring hydrophilic oligomeric ethylene glycol methacrylate (OEGMA) and hydrophobic methyl methacrylate (MMA) moieties, this poly[methyl methacrylate-co-poly(ethylene glycol) methacrylate] [P(MMA_x-co-OEGMA_y)] hydrogel exhibited reversible stiffness switching across four orders of magnitude (from 1.88×10^–2 MPa to 201.63 MPa) upon water stimulation. This abrupt stiffness enhancement stemmed from strong hydrogen bonding between water molecules and hydrophilic OEGMA segments, facilitating spontaneous aggregation and phase separation of hydrophobic MMA segments. The resulting hydrophobic MMA domains formed dynamic physical crosslinking points, thereby enhancing the hydrogel's stiffness. Furthermore, the hydrogel exhibited a time-dependent, multi-stage stiffness enhancement during water swelling. As proof of concept, it was employed as a shape-memory component to explore its application in the controllable programming of multi-stage complex shapes, offering novel design insights for developing environmentally friendly, high-mechanical-performance smart hydrogel materials.

Compared to mechanical rheology, micro-rheology (µR) can probe the viscoelasticity of soft matter non-invasively with spatial resolution and broad temporal coverage; however, the measurement quality is undermined by interference from the structural and dynamic inhomogeneity of the tested media. Herein, gold nanorods are dispersed in tested media as tracer particles, and their diffusive dynamics are monitored by depolarized dynamic light scattering for the analysis of the rheological properties of the tested media, as the rotational/translational dynamics of tracers can be converted to shear modulus via the generalized Stokes-Einstein relation. Because of their strong optical scattering to the laser and the polarization of incident light, the contrast in the dynamics of gold nanorods over the media can be enhanced, rendering the fast and accurate measurement of rheological properties. The method was verified for applications in broad types of substrates, including ergodic systems such as polymer solutions, silica suspensions, non-ergodic gel systems, and biological fluids such as plasma. The critical experimental parameters, for example, tracer size and scattering angle range, are studied for their impact on the measurement quality, and they can be systematically optimized for feasible and practical applications of the developed µR method.

The rapid advancement of wearable sensors necessitates ionically conductive hydrogels that simultaneously exhibit high stretchability, damage tolerance, and reliable adhesion. However, achieving these properties in a single material remains a significant challenge. Herein, we report an ionically conductive polyoxometalate (POM)-based hydrogel (PAA/L-arg@SIW) fabricated by incorporating L-arginine (L-arg)-modified silicotungstic acid nanocomplexes (L-arg@SIW) into a poly(acrylic acid) (PAA) network as a multifunctional dynamic crosslinker. Strong electrostatic interactions and hydrogen bonding between rigid L-arg@SIW nanoclusters and flexible PAA chains generate a three-dimensional hard-soft synergistic network, in which dynamic crosslinks preferentially rupture and re-form under mechanical loading, thereby dissipating energy and suppressing crack propagation. Consequently, the hydrogel exhibits exceptional stretchability (fracture strain >1500%), high toughness (1483 kJ/m³), outstanding crack resistance (fracture energy up to 6.82 kJ/m²), and high ionic conductivity (0.15 S/m), along with robust adhesion to diverse substrates. Hydrogel-based sensors demonstrate high strain sensitivity (gauge factor (GF)=8.06), fast response, and excellent cyclic stability, enabling reliable monitoring of human motion and high-fidelity acquisition of electrocardiogram (ECG) and electromyogram (EMG) signals. This study presents an effective strategy for constructing high-performance ionically conductive hydrogels for wearable sensing applications.

Posture recognition technology plays a crucial role in health monitoring, motion analysis, and other related fields. However, traditional recognition devices are limited by a lack of comfort, stability, and environmental adaptability, which significantly restrict their performance and range of applications. In response, this study proposes a self-powered, strain-driven, intelligent posture recognition method based on a thermoelectric hydrogel. This approach enables high-precision posture recognition through simultaneous acquisition of dynamic strain signals from multiple joints. The proposed poly(vinyl alcohol) (PVA)/starch bi-network hydrogel, synthesized in a binary H₂O/glycerol solvent system, exhibited outstanding flexibility and tensile strength, allowing it to conform closely to joint movements and ensure wearing comfort. Simultaneously, the hydrogel generated stable electrical signals via the redox reaction of [Fe(CN)₆]^3–/4–, supporting continuous monitoring and data collection. Moreover, its self-powered nature allows effective joint strain signal acquisition, even in open environments. Using a machine learning algorithm that incorporates signal processing and analysis, the proposed method achieved a posture recognition accuracy of 96.82%. This study presents a novel technological route for posture recognition in wearable devices, demonstrating its strong application potential in real-time feedback for sports rehabilitation and performance analysis of athletes.

Nonlinear stress relaxation under step strain γ was examined for aqueous solutions of an end-associative telechelic polymer, hydrophobically modified ethoxylated urethane (HEUR) having hexadecyl groups at the two ends of the chain. At 20 °C where the end hexadecyl groups were in the molten liquid state, the solutions with the HEUR concentrations c=1 wt% and 5 wt% commonly exhibited strain-hardening at short time t and the strain-softening (damping) at long t. In the terminal relaxation zone at sufficiently long t, the nonlinear relaxation modulus G(t,γ) was found to obey the time-strain separability. These nonlinear features were discussed in relation to strain-induced changes in the associative network structure. In the aqueous HEUR solutions, aggregates of the precipitated end-groups should be stabilized by loops of dissolved HEUR backbones to form so-called flower micelles. At low c, most of those micelles would connect HEUR chains into a long linear sequence referred to as superbridge, thereby forming a sparse network. At higher c, those superbridges would become shorter to densify the network accordingly. Immediately after imposition of the large step strain, the flower micelles in the superbridge backbone would fuse each other to form a denser network thereby exhibiting the hardening. This micelle fusion would be more significant for longer superbridges to enhance the strain hardening at lower c. After this fusion, the micelles having liquid cores would be opened up because of the enhanced tension of the deformed superbridge, and then split to disconnect the superbridge if this tension overwhelms the micelle strength. This opening/splitting process possibly resulted in the partial breakage of the network and the corresponding softening. Finally, the surviving part of the network would relax on thermal dissociation of the remaining micelles thereby exhibiting the time-strain separable damping at long t. These features were semi-quantitatively described by a simple model that considered the strain-induced fusion followed by mechanical opening/breakage of the transient crosslinks.

The unique physiological barriers and rapid clearance of the ocular surface result in less than 5% bioavailability of topical drugs, forcing frequent high-dose administration, reducing compliance, and risking toxicity. Existing ophthalmic semi-solid formulations can delay clearance but often cause blurred vision and foreign body sensation due to high viscosity, limiting clinical use. In this study, a polysaccharide-based dual-dynamic crosslinked hydrogel (HC gels) was prepared via an in situ Schiff base reaction between aldehyde-functionalized hyaluronic acid and aminated carboxymethylcellulose under physiological conditions for sustained ocular drug delivery. By modulating the gelation kinetics, a controllable transition from a low-viscosity solution to a gel (15−384 s) was achieved. The in situ-formed gel dynamically adapts to the ocular surface during blinking, forming a thin, uniform, transparent layer that ensures conformal coverage, resists blinking and tear clearance, and significantly extends drug retention. In a rat model of uveitis, HC gels effectively alleviated inflammation via sustained dexamethasone release. Overall, HC gels provide a novel strategy for safe, effective, and sustained ocular drug delivery.

Aqueous zinc-ion batteries (AZIBs) are safe and cost-effective, making them ideal for large-scale energy storage and wearable electronics. Nevertheless, the advancement of AZIB technology faces constraints due to limited energy storage capability and degraded cyclability, primarily attributed to the absence of optimal cathode materials. In this study, two structurally similar but chemically different covalent organic framework materials (Aza-COF-1L and Aza-COF-2) were synthesized. Notably, Aza-COF-1L is easier to synthesize and features abundant pyrazine redox-active sites, a well-defined porous structure, and intrinsic stability. Consequently, Aza-COF-1L exhibited an electrochemical performance superior to that of Aza-COF-2. Aza-COF-1L achieved initial capacities of 368.58, 345.96, and 327.82 mAh·g⁻¹ at 0.1, 0.5, and 1 A·g⁻¹, respectively. After 800 cycles at 1 A·g⁻¹, Aza-COF-1L maintains a specific capacity of 136.38 mAh·g⁻¹. In contrast, Aza-COF-2 exhibited an initial capacity of 117.79 mAh·g⁻¹ at 0.1 A·g⁻¹, and its capacity significantly decreased during cycling. Additionally, the contribution of the C＝N pyrazine redox site in Aza-COF-1L to battery capacity during charging and discharging was experimentally analyzed. These results provide valuable guidance for the development of high-performance organic cathode materials for use in AZIBs.

Conductive hydrogel-based strain sensors, as key components of electronic skins, have garnered significant attention for the development of advanced human-machine interfaces and flexible electronics. However, their intrinsic limitations of large hysteresis and poor mechanical robustness pose significant challenges for achieving the high accuracy and long-term stability required for advanced sensing systems. Here, we achieve hysteresis suppression and structural stability by constructing a microphase-separated interlocking network within a 3D-printable poly(vinyl alcohol) (PVA)/conductive carbon black (CCB) hydrogel. The resulting conductive hydrogel strain sensor possesses low electrical hysteresis (0.82%) and high cycle stability (>1×10⁴ cycles), enabling real-time and precise monitoring of joint bending and muscle contraction. By converting finger motion into machine-learnable signal patterns, the sensor enables an identification system that decodes continuous strain signals into alphabetical information, offering a novel human-machine interaction modality. This work provides a promising conductive hydrogel platform with enhanced sensing fidelity and interaction capability towards intelligent human-machine interactions.

Polyurethane polymer grouting materials with rapid expansion and solidification characteristics have been widely applied for infrastructure repair and reinforcement. An accurate characterization of the chemical reaction process of the slurry is essential for investigating its grouting mechanism. However, the high concentration of isocyanate groups in such polymer systems causes a “flat-top phenomenon” in Fourier transform infrared (FTIR) spectroscopy, rendering it difficult to accurately determine the conversion rate. To address this issue, a real-time method for measuring the reaction conversion rates of slurry components was proposed. The polyol conversion rate was obtained by tracking the integral area changes of the C―O bond peak in the carbamate product relative to the internal standard. The total slurry volume was determined at different time intervals using light detection and ranging (LiDAR)-based point cloud scanning, from which the gas volume was estimated. Combined with the solubility curve of the physical blowing agent and ideal gas law, the conversion rate of the chemical blowing agent was calculated. The isocyanate conversion rate was indirectly inferred based on the measured polyol and chemical blowing agent conversions. This method was applied to a polyurethane grouting material used in an engineering project, and the time-resolved conversion curves of all components throughout the reaction were obtained. The results revealed a three-stage evolution: a slow initial increase, a rapid rise in the middle stage, and a gradual deceleration in the later stage. The foaming reaction proceeded consistently faster than the gelation reaction did. These findings provide a foundation for further research on the diffusion mechanisms of polyurethane polymer slurries.

Eco-friendly nanocomposites designed for gamma-ray shielding were developed by incorporating nano-magnesium ferrite (MgFe₂O₄ NPs) within low-density polyethylene (LDPE). This approach aims to create a lead-free, cost-effective, and environmentally sustainable shielding material. The LDPE nanocomposite was prepared using a melt blending technique. The incorporation of MgFe₂O₄ nanoparticles improved the radiation attenuation capabilities of the polymer matrix, offering a safer alternative to the traditional lead-based shields. The influence of MgFe₂O₄ NPs integration and gamma irradiation on the mechanical and thermal characteristics of LDPE/MgFe₂O₄ nanocomposites was systematically investigated. MgFe₂O₄ NPs were synthesized using the co-precipitation method and confirmed to have single-phase nanocrystalline spinel structures by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analyses. The results revealed that the optimal filler content was 15 wt% MgFe₂O₄ NPs, which improved the tensile strength (TS) from 7.55 MPa to 10.42 MPa (about 38% enhancement). The LDPE nanocomposite containing 15 wt% of NPs that was exposed to 100 kGy had the highest TS value (11.8 MPa), with an improvement of 56% compared with that of the unirradiated LDPE nanocomposite. The addition of MgFe₂O₄ enhanced the shielding performance of LDPE against gamma radiation, as indicated by the higher attenuation coefficients, lower half-value layer (HVL), and minimum mean free path (MFP). Increasing MgFe₂O₄ content, decreasing photon energy, and applying irradiation all contribute to enhancing the attenuation performance of LDPE nanocomposites. Furthermore, the incorporation of MgFe₂O₄ improved the thermal properties of the nanocomposites. TGA analysis showed that both gamma irradiation and MgFe₂O₄ addition enhanced the thermal stability of the LDPE. Among all samples, LDPE15-r100 exhibited the best performance, showing the highest degradation onset temperature (415.16 °C), the highest T50 (465.30 °C), and the largest residual mass at 600 °C (11.81%). These findings confirm that LDPE/MgFe₂O₄ nanocomposites are promising candidates for eco-friendly gamma-ray shielding applications, particularly when irradiated.

Liquid silicone rubber foam (LSRF) offers superior processability, high mechanical flexibility, and low thermal conductivity, which are of great significance for achieving long-term thermal insulation and fire resistance but remain challenging to achieve. We first prepared LSRF with excellent open-cell performance, achieving a water absorption rate of 242.5%, and then explored the advantages of flame-retardant solution impregnation in the open-cell structure. Meanwhile, the synergistic flame-retardant effect of kaolin (KL), glass powder (GP), and silica aerogel (AG) was investigated. When the composite formulation was LSRF/30KL10GP20AG, the material exhibited outstanding flame-retardant properties: the limiting oxygen index (LOI) reached 33.2%, an increase of 9% compared with unfilled LSRF, the vertical burning rating was V-0, and the water contact angle of the surface after combustion was 160.35°, meeting the superhydrophobic standard. At the same time, the sample LSRF/30KL10GP20AG showed a 49.6% reduction in peak heat release rate and an 83.8% reduction in total peak smoke production compared to LSRF. Under butane-flame impingement at 1300 °C, the flame-retardant LSRF maintained an intact structure for 120 s, with the backside temperature rising only to 219 °C, demonstrating excellent thermal insulation performance. In a high-temperature environment at 800 °C, the foam well retained its original cell structure and maintained volume stability, forming a dense, hard ceramicized carbon layer with a compressive strength of 2.69 MPa. The fillers were uniformly impregnated and distributed on the foam surface and cell walls, endowing the material with durable flame retardancy, low smoke generation, and minimal toxic gas release, effectively inhibiting the spread of flames during fires and enabling LSRF foam to be widely applied in the field of building flame retardancy.

Conductive elastomer composites (CEC) are widely used in flexible electronics, structural health monitoring, and aerospace applications. However, their resistive strain response often exhibits a shoulder peak effect, which undermines signal stability and measurement accuracy. In this study, the generation and suppression mechanisms of the shoulder peak effect were clarified by regulating hydrogen bonding interactions on the surface of nano-silica. Experimental results combined with molecular dynamics (MD) simulations demonstrate that in samples (OCV-260) fabricated with hydrophobic nano-silica (OB), the hydrophobic surface induces weak hydrogen bonding between conductive carbon black (CB) and OB. This interaction reduced the hysteresis area of the resistive-strain response by 78.84%, suppressed the adhesion-desorption migration of CB along silicone rubber (SR) molecular chains, and prevented sudden resistance spikes during unloading, thereby eliminating the shoulder peak effect. In addition, OCV-260 exhibited a 97.19% enhancement in the strain sensitivity coefficient (GF), a 53.20% extension of the monitoring range, and a rapid response time of 221 ms. Remarkably, no shoulder peak effect was detected, even after 1×10⁴ loading-unloading cycles. These findings offer a promising strategy and broad application potential for achieving long-term, precise sensing in CEC for aerospace, flexible electronics, and structural health monitoring.

Microvascular anastomosis is a fundamental technique in microsurgery, and the development of suitable cuff tubes is crucial for improving the surgical efficiency and long-term vascular patency. Polyimide, a high-performance polymer, offers excellent thermal stability, chemical resistance, and biocompatibility, making it a promising candidate for microvascular applications. In this study, we employed a dry-jet wet-spinning method using P84 polyimide to fabricate polyimide (PI) cuff tubes. The effects of bore fluid flowrate, dope flowrate, and take-up speed on the structural morphology and mechanical properties of the tubes were systematically investigated. Heat treatment was applied to optimize the mechanical performance. Heat treatment above the glass transition temperature significantly enhances the solvent resistance and mechanical strength without altering the chemical structure. The PI cuff tubes demonstrated negligible cytotoxicity and hemolysis, no genotoxic or immunogenic effects, and no systemic organ toxicity. In vivo implantation showed sustained vascular patency and no local inflammatory response for up to 90 days post-operatively. The fabricated PI cuff tubes possessed high structural integrity, tunable flexibility, ideal mechanical properties, excellent biosafety, and outstanding in vivo performance, suggesting their strong potential for future clinical translation in microvascular anastomosis and vascular graft applications.

This study simultaneously plasticizes and strengthens poly(vinyl chloride) (PVC) with structurally different ionic liquids (ILs), namely monomeric [Bmim]NTf₂, linear polymerized PImC₆NTf₂, and branched polymerized P(VIm-4)NTf₂. Notably, PImC₆NTf₂ exhibits the best performance. Dynamic mechanical analysis reveals that the glass transition temperature of PImC₆NTf₂/PVC composite film is lower than that of dioctyl phthalate (DOP)/PVC, indicating enhanced processability. Compared with neat PVC film, the 4% PImC₆NTf₂/PVC film exhibits 747.2%, 165.4%, and 49.1% increases in elongation at break, tensile strength, and Young’s modulus, respectively, along with a 27.4-fold rise in fracture energy. Additionally, the thermal stability, hydrophobicity, and wear resistance of PVC are also improved. These findings demonstrate the great potential of linear polymerized ILs as innovative PVC plasticizers.

Melt shear-induced crystallization of miscible poly(vinylidene fluoride)/poly(1,4-butylene succinate) (PVDF/PBSU) blends was investigated through a series of structural and morphological characterizations. By varying the shear rate and blend composition, we obtained two key findings regarding the γ-phase generation. First, the γ-phase fraction within the samples showed non-monotonic behavior, initially increasing and then decreasing with increasing shear rate ($ \dot{\gamma } $), indicating the existence of an optimal $ \dot{\gamma } $ value for maximizing γ-phase formation. Second, adding PBSU significantly enhanced shear-induced γ-phase crystallization, not only elevating the γ-phase fraction at the optimal $ \dot{\gamma } $ but also considerably broadening the effective $ \dot{\gamma } $ range to achieve a high γ-phase content. In contrast, PBSU did not promote γ-phase formation in untreated blends. These results highlight the synergy between the shear flow and PBSU addition in facilitating the polar γ-phase in PVDF. Finally, we constructed shear phase diagrams to depict the γ-phase crystallization within the parameter space of the shear rate/chain orientation and blend composition. It is speculated that melt shear primarily facilitates γ-phase nucleation through chain orientation, whereas PBSU enhances γ-phase growth after nucleation by promoting chain diffusion and/or hydrogen bonding interactions with PVDF. This study contributes to a deeper understanding of γ-phase crystallization under shear flow and provides a reference for regulating the polar phase of PVDF through direct melt processing.

Biodegradable polymer nanocomposites containing functional nanoparticles have attracted growing interest because interfacial phenomena can strongly influence macroscopic properties. In this study, ZnCoS nanoparticles were synthesized by a green microwave-assisted route and incorporated into a poly(lactic acid)/polyaniline (PLA/PANI) matrix at 1 wt%, 5 wt%, 10 wt%, and 20 wt% loadings. Dynamic light scattering indicated an average hydrodynamic diameter of 195.35 nm, suggesting partial aggregation in the dispersion. The ATR-FTIR spectra indicated nanoparticle-polymer interfacial interactions without evidence of chemical alteration of the polymer backbone. X-ray diffraction showed a non-monotonic crystallinity trend, with an initial decrease at low nanoparticle loading followed by an increase at higher loadings, consistent with heterogeneous nucleation. Thermal analysis showed improved thermal stability, with the char yield increasing from 4.30% for the neat PLA/PANI to 10.70% at 20 wt% ZnCoS, while the glass-transition and melting temperatures remained essentially unchanged. Dielectric and AC electrical measurements showed a frequency-independent conductivity plateau at low frequencies, followed by dispersive behavior at higher frequencies, consistent with hopping-type charge transport. At low ZnCoS loadings, interfacial charge trapping reduced the AC conductivity and dielectric loss, whereas higher loadings enhanced interfacial polarization and partially recovered the conductivity. The dielectric spectra showed clear Maxwell-Wagner-Sillars polarization and broad relaxation, indicative of a distribution of relaxation times, underscoring the key role of interfacial effects in the electrical response. Overall, the results clarify the nanoparticle-polymer interfacial contributions in biodegradable nanocomposites and support their relevance in functional and transient material systems.