ACS Applied Polymer Materials最新文献

Extraction sockets are prone to bacterialcolonization,which causesalveolar bone resorption and refractory infection. However, conventionalbiomaterials cannot eliminate pathogenic bacteria and modulate theoral immune microenvironment at the same time. Herein, we constructeda structurally tailored hydrogel (HAQM) with in-network bactericidalactivity to achieve mild photothermal synergistic sterilization. Mildhyperthermia (∼42 °C) increases bacterial membrane fluidityand strengthens the contact-killing performance of the hydrogel. Invitro and in vivo biological assays verify its outstanding antibacterialactivity, particularly against oral obligate anaerobes, with an antibacterialefficiency reaching 95%. Transcriptomic analysis reveals that thehydrogel destabilizes bacterial membranes, disturbs bacterial metabolicpathways, and suppresses bacterial envelope repair. Benefiting fromits interconnected porous architecture and redox-responsive activity,the hydrogel mitigates inflammatory response and promotes M2-typemacrophage polarization. This multifunctional integrated platformprovides an innovative and clinically translatable therapeutic strategyfor the repair of infected oral bone defects.

Epoxy resin is widely used as a thermosetting material,but itsinherent flammability, brittleness, and high dielectric loss limitits applications. In this work, three P/Si-containing flame retardants,namely, DEDP, DEDO, and TMDO, were synthesized via addition reactionsusing DOPO and DPPO as the P-containing moieties and DEMPhSiO andTMDVSiO as the Si-containing moieties. A series of EP/DEDP, EP/DEDO,and EP/TMDO formulations were prepared by incorporating these flameretardants at phosphorus loadings of 0.15, 0.25, and 0.5 wt % intoDGEBA in the presence of DDS as the curing agent, and their propertieswere systematically evaluated. The results showed that low loadingsof DEDP, DEDO, and TMDO endowed the epoxy thermosets with excellentflame retardancy, improved mechanical performance, and reduced dielectricconstant and loss while maintaining good optical clarity and moisturerepellence. For example, compared with pure EP (LOI = 22%; DC = 3.8at 1 MHz), EP/DEDP-0.25P at only 0.25 wt % phosphorus loading achieveda UL-94 V-0 rating, an LOI of 28%, and a dielectric constant of 2.9at 1 MHz (a 23.7% reduction relative to that of pure EP), along with37% and 65% increases in tensile and impact strength, respectively.Similarly, EP/DEDO-0.5P and EP/TMDO-0.5P achieved UL-94 V-0 ratingsand LOI values of 28% and 29%, respectively, with dielectric constantsof 3.3 at 1 MHz (a 13.2% reduction relative to pure EP), along withincreases of 100% and 109.1% in tensile strength and 74% and 191%in impact strength, respectively. Furthermore, decreases of 33.3%and 34.7% were observed in the PHRR and THR, respectively, and theaverage CO₂ yield decreased from 5.1 to 4.4 kg/kg, whereasthe average CO yield increased from 0.32 to 0.39 kg/kg during conecalorimetry analysis of EP/DEDP-0.5P. These findings offer an effectivestrategy for designing multifunctional and high-performance epoxythermosets.

Aramidnanofiber (ANF) aerogels are promising candidatesfor thermalprotection and structural applications; however, their practical implementationremains substantially constrained by the intrinsic trade–offbetween mechanical robustness and fire–resistant functionality.In this study, a mechanically robust, highly hydrophobic, and fire–resistanthybrid aerogel was developed using a green high–pressure homogenizationprocess coupled with in situ polysiloxane cross-linking.Through the construction of a rigid–flexible interpenetratingnetwork, the resulting aerogel overcomes the inherent fragility associatedwith conventional physical entanglements while achieving an ultralowdensity of 4.62–9.48 mg cm^–3, pronouncedsuperelasticity (96.7% height recovery and 79% modulus retention after100 cycles), and excellent fire resistance (LOI = 33). Notably, theaerogel exhibits remarkable structural and functional integrity followingcombustion because in situ ceramization convertsthe polysiloxane network into a thermally stable Si–O–Si/Si–Cbarrier, enabling retention of 92% of its compressive strength whilepreserving substantial surface hydrophobicity, as evidenced by a watercontact angle of 132.7° even after direct flame exposure. Todemonstrate its practical applicability to fire–prone oil–spillscenarios, the aerogel displays synergistic adsorption and flame–retardantperformance in simulated burning oil spills, with a high absorptioncapacity of 60–180 g g^–1 and rapid self–extinguishingbehavior (<30 s). These findings establish a versatile design strategyfor engineering multifunctional aerogels that integrate mechanicalresilience, fire safety, and post–combustion structural integrity.

Owing to their excellent thermal stability and mechanicalproperties,colorless polyimides are key materials for modern optical devices.However, the preparation of colorless and transparent polyimide materialsvia conventional polycondensation approaches often involves complicatedmonomer design and tedious, energy-intensive reaction processes, leadingto elevated production costs and thus limiting their scalable manufactureand broader applications. Here, we report a facile polycondensationapproach based on the mild, regioselective Friedel–Crafts hydroxyalkylationmechanism, featuring reaction-enhanced reactivity of intermediatesfor the preparation of soluble, colorless, and transparent polyimides.The reaction system employs symmetric linear molecules containingtwo central imide groups flanked by two N-ethyl-4-anisoleterminals as monomers, which react with benzaldehyde derivatives bearingpara-electron-withdrawing groups, using methanesulfonic acid as thecatalyst. The resulting polyimides, featuring triphenylmethane andalkyl spacer groups in their backbones, retain the outstanding thermalstability characteristic of conventional polyimides, with a 5% weightloss temperature (T_d,5%) higher than 410°C, and exhibit outstanding transparency (T₅₀₀ > 83%, T₄₀₀ > 77%, andabsorptionedge λ₀ < 350 nm). This polycondensation methodfor synthesizing colorless polyimides can overcome many challengesassociated with conventional processes and offers additional opportunitiesfor the production and application of colorless polyimide materials.

Functionalized nanocellulosehas been strategically employedinbiobased materials to overcome intrinsic limitations by modulatingthe interfacial interactions and broadening their application potential.In this study, pectin-based nanocomposites were prepared by incorporatingpristine, TEMPO-mediated oxidized, or EPTMAC-cationized cellulosenanofibers (CNFs), and the influence of these surface functionalizationstrategies on interfacial interactions and macroscopic propertieswas investigated. Chemical functionalization significantly influencedthe supramolecular forces within the nanocomposites and their interfacialdynamics with the polyelectrolyte matrix, particularly at the highesttested loading (10 wt %). Crystallinity, morphology, mechanical performance,thermal stability, and water affinity were all influenced by CNF surfacechemistry. Films containing oxidized CNFs showed higher surface hydrophobicity,indicating stronger structural organization and reduced availabilityof hydrophilic groups. In contrast, cationic CNFs resulted in lowermechanical resistance and thermal stability. The observed behaviorsindicate that interfacial interactions in the nanocomposites arisefrom the combined contributions of electrostatic interactions, chemicalfunctionality, steric effects, and structural organization. Overall,the results demonstrate that CNF surface chemistry serves as a tunabledesign parameter for tailoring nanocomposite performance, contributingto the development of materials aligned with circular economy principles.

Photocurable, 3D-printable conductive hydrogels holdgreat promisefor personalized wearable sensors and flexible bioelectronic devices.However, current systems still face challenges in simultaneously achievingprintability, mechanical robustness, electrical conductivity, andinterfacial adhesion. In this study, an ionically conductive hydrogelsystem based on poly(vinyl alcohol) (PVA), polyacrylamide (PAM), tannicacid (TA), and glycerol (Gly), denoted as PATG, was fabricated bydigital light processing (DLP) 3D printing. The hydrogel exhibitedexcellent mechanical properties, including a fracture strain of 480%,a tensile strength of 271 kPa, and a tensile toughness of 550 kJ m^–3. It also achieved a compressive toughness of 90 kJm^–3 at 90% compressive strain and maintained structuralstability after 100 compression cycles. Furthermore, the PATG hydrogelshowed an electrical conductivity of 1.082 S m^–1 and a segmented linear response over 0–480% tensile strain,with a maximum gauge factor of 13.73. Benefiting from its stretchabilityand ionic conductivity, PATG enabled reliable monitoring of jointmotion, finger bending, and Morse code input, while its adhesion andantibacterial properties support skin-attached wearable applications.As a flexible electrode, PATG recorded electrocardiogram (ECG) andelectromyography (EMG) signals with signal-to-noise ratios (SNRs)of 32.62 and 14.73 dB, respectively, showing signal acquisition capabilitycomparable to that of commercial electrodes under the tested conditions.This work provides a multiple-network strategy for constructing personalizedhydrogel-based wearable devices.

Recirculating cooling water systems (RCSs) are essentialfor industrialthermal management, yet their reliance on continuous water circulationand evaporation-induced makeup water imposes substantial water andenergy burdens. Here, we report a passive interfacial cooling strategyby integrating polytetrafluoroethylene nanofibrous, porous membranes(PTFE NPMs) into the cooling unit of an RCS. Owing to the intrinsicallylow surface energy of PTFE and the interconnected micro/nanoporousfibrous architecture, the membranes exhibit robust superhydrophobicity,antiwetting stability, and efficient vapor permeability. This hierarchicalinterface promotes rapid outward diffusion of water vapor from hotwater while suppressing liquid-water retention and penetration, therebyaccelerating evaporation-diffusion-mediated heat dissipation withoutexternal energy input. Meanwhile, the tortuous hydrophobic nanochannelsfunction as selective mass-transfer barriers, enabling vapor escapewhile preventing the intrusion of droplets, particulates, and contaminants,which is beneficial for maintaining circulating-water purity and reducingwater consumption. In a 300 s cooling test, a conventional RCS cooleda copper disk to 47.5 °C with an average cooling rate of 0.588°C s^–1, whereas the PTFE-NPM-integrated systemreduced the temperature to 44.5 °C and increased the coolingrate to 0.651 °C s^–1. This work demonstratesa membrane-enabled, energy-free cooling enhancement strategy for sustainableRCSs and provides a materials platform for water-saving industrialthermal management.

Interfacial solar evaporation has emerged as an energy-efficientapproach for seawater desalination. Nevertheless, the practical applicationof conventional solar evaporators remains constrained by their strongdependence on sunlight, resulting in markedly reduced evaporationperformance under cloudy conditions or at night. To address this limitation,a dual-energy-driven composite membrane capable of operating undereither solar or electrical energy input was developed in this workfor continuous all-weather desalination. The membrane was designedwith a sandwich-structured architecture, in which a carbon fiber layerserved as the conductive intermediate layer, while the outer layersconsisted of Ketjenblack and MAH-grafted SEBS fabricated through asolution casting process. By integrating photothermal and electrothermalconversion within a single membrane, the composite membrane exhibitedefficient water evaporation performance under different energy-inputconditions. Under one-sun irradiation, the evaporation rate reached2.789 kg m^–2 h^–1, and under anexternal voltage of 3.5 V, the evaporation rate reached 3.768 kg m^–2 h^–1. In addition, the membranedemonstrated strong environmental tolerance toward complex water environments,including dye-containing solutions as well as strongly acidic andalkaline media. This work provides a practical strategy for developingdual-energy-responsive evaporation systems for continuous freshwaterproduction under variable environmental conditions.

In recent years,flexible, wearable, and implantablechemical sensorsand biosensors have become crucial in biomedical engineering. Theseflexible devices enable the noninvasive, real-time monitoring of biochemicalmarkers in biofluids, from blood to the most accessible ones thatenable noninvasive monitoring (sweat, tears, saliva, and interstitialfluid) as indicators of the health status. In their development, polymer-basedhydrogels have emerged as the material of choice and have recentlystarted to attract increasing attention due to advantages in termsof biocompatibility, surface area, and chemical tunability. Here,we provide an overview of the structural polymers according to theirnature (natural vs synthetic), giving a special focus on the use ofconductive polymers. Then, we discuss the strategies to integratethe bioreceptor to provide the hydrogels with the necessary selectivitytoward biomarker detection. Finally, we go through emerging trendswhere hydrogels are employed in smart formats beyond the simple performanceof the detection. As an overall, the integration of polymer-basedhydrogels with advanced bioreceptor strategies and smart functionalitiesis driving the development of next-generation wearable and implantablebiosensors, paving the way for noninvasive, continuous, and personalizeddiagnostics.

This study presents a systematic investigation into tailoringinterphasearchitecture in hierarchically toughened epoxy systems using multilayerpoly(ether imide) (PEI) films as ductile interlayers. Processing parameters,including PEI film thickness (60 and 120 μm), volume fraction(20–50%), and cure cycle (first dwell temperatures of 120–180°C), were varied to optimize fracture toughness. Single-edgenotched bending (SENB) tests, coupled with microscopic analyses, revealedthat fracture toughness is governed by the interplay between interphasemorphology and the relative thickness of the PEI layer compared tothe plastic zone size. Microscopic analysis showed that low cure temperaturesreduce gradient interphase formation, leading to weak interfaces,enabling high energy dissipation, while higher temperatures yieldstrong interfaces with reduced crack tortuosity and hence brittlefracture. A critical crack tortuosity threshold (∼1.8) wasidentified, beyond which crack deflection and delamination dominateover microstructural mechanisms. Interphase thickness and particlesize distribution were governed by diffusion-driven phase separation.In thinner epoxy cavities, PEI saturation occurred quickly, reducingthe diffusion gradient and limiting interphase growth, in agreementwith predictions from Fick’s law. These findings demonstratethat fracture toughness in PEI–epoxy systems is controlledby the interplay of intrinsic mechanisms (plastic deformation, particledebonding) and geometric mechanisms (crack deflection, tortuosity).Controlling both through process design enables toughness improvementsbeyond that of pure PEI, providing a framework for developing next-generationdamage-tolerant materials.