ACS Omega最新文献

Flexible textile-basedelectronic systems are emergingas promisingcandidates for next-generation wearable technologies due to theirmechanical compliance, lightweight nature, and seamless integrationinto garments. In this work, a metamaterial-inspired dual-band flexibletextile antenna based on a wool-felt substrate is presented for body-centricwireless applications. The proposed device is designed as a flexibleelectronic structure integrating coplanar waveguide (CPW) feedingwith symmetric square-ring resonators to enable compact size and dual-bandelectromagnetic functionality. The wool-felt substrate serves as afunctional textile material offering low density, high flexibility,and stable dielectric behavior under mechanical deformation. The fabricatedstructure exhibits an overall dimension of 40 × 52 mm², making it suitable for garment-integrated electronic systems. Experimentalresults demonstrate two impedance bandwidths of 3.11–3.70 GHzand 5.52–6.89 GHz (|S₁₁| < −10dB), covering sub-6 GHz 5G and ISM wireless communication bands. Theproposed flexible electronic system achieves measured gains of 1.81dBi and 4.35 dBi at the lower and upper frequency bands, respectively,with good agreement between simulated and experimental results. Mechanicalbending analysis confirms stable electromagnetic performance, withresonance shifts below 1%, indicating robust mechanical–electromagneticcoupling under deformation. Furthermore, specific absorption rate(SAR) analysis verifies compliance with international safety standardsfor on-body wireless operation. Owing to its combination of a functionaltextile substrate, compact architecture, and stable dual-band performance,the proposed wool-felt-based flexible antenna represents a promisingcandidate for wearable and body-centric electronic systems.

In this paper, acomprehensive review of the technologies and challengesassociated with hydrogen-blended natural gas (HBNG) systems is provided.The background, hydrogen production pathways, blending technologies,and implementation strategies of HBNG were systematically reviewed,while the effects of hydrogen addition on gas properties, pipelinetransportation systems, and end-use applications were critically examined.The results indicate that HBNG technologies are gradually evolvingfrom low-concentration feasibility studies toward high-hydrogen-ratioapplications. At elevated hydrogen blending levels, major technicalchallenges include hydrogen embrittlement of pipeline materials, leakageand explosion risks, combustion stability control, and determinationof hydrogen blending ratios. Besides, high hydrogen production costs,infrastructure retrofitting requirements, and the lack of harmonizedinternational standards continue to hinder large-scale deployment.Therefore, future implementation of HBNG technologies will requirebreakthroughs in material durability, technical standardization, accuratehydrogen concentration control, and end-use system adaptability, therebyproviding important support for the transition toward low-carbon andsustainable energy systems.

In the field of aluminum alloy protection, constructingdurablesuperhydrophobic coatings through a simple strategy is always a greatchallenge. Here, we report a functional coating with high mechanicalrobustness and superhydrophobic recoverability, composed of 1H, 1H,2H, 2H-perfluorooctyltriethoxysilane (PTES) bonded octyltrimethoxysilane-functionalizedtitanium dioxide nanoparticles (OTMS-TiO₂ NPs) and high-viscosityepoxy resin (EP). The coating combines a hierarchical micro/nanostructure,an EP adhesive interface, and a surface enriched with fluorinatedand alkyl functionalities. The synergy between the hierarchical roughnessand the low-polarity surface chemistry enables excellent water repellency.After 100 cycles of sandpaper abrasion or tape peeling, the coatingretained its superhydrophobic water repellency, with WCA values remainingabove 160°. The newly exposed surfaces preserved sufficient hierarchicalroughness and low-surface-energy components to sustain superhydrophobic.Even after continuous water flow impact or stirred sand-slurry abrasionfor 48 h, the superhydrophobicity of the coating does not show significantdegradation (WCA > 150°). In addition, the coating shows greatstability in strong acidic (pH = 2) or strong alkaline (pH = 12) environments.More importantly, when the coating encounters mechanical damage, corrosionby 36.5 wt % HCl, or complete contamination by industrial oil/paint,its superhydrophobic properties can be quickly restored through asimple sandpaper rubbing treatment. This easily prepared superhydrophobiccoating with both recoverability and excellent robustness providesnew technical support for protecting aluminum alloy.

The viscoelastic and adhesive properties of food wastematerialsare critical factors influencing the efficiency of mechanical separationprocesses in waste management. This study investigated the moisture-dependentrheological behavior─specifically storage modulus in both shear(G′) and compression (E′)modes, alongside the loss factor (tan δ)─of various foodwaste types, categorized as solid-like (steamed rice, banana pulp,raw meat) and paste-like (mashed banana, ketchup, mashed steamed rice,yogurt). These properties were correlated with adhesion strength onaluminum and high-density polyethylene (HDPE) surfaces using 90°peel tests. Results identified specific moisture-induced viscoelastictransitions for different materials. Steamed rice demonstrated a sharpincrease in tan δ at a critical moisture range, indicative ofstarch gelatinization. Material-specific correlations revealed thathigher tan δ (more viscous behavior) closely corresponds tostructural softening and enhanced interfacial adhesion within individualpaste-like materials, with consistently stronger adhesion observedon aluminum foil compared to HDPE sheets. However, carbohydrate-richpastes showed increased adhesion at very low moisture levels. Thesefindings highlight the significant impact of moisture-dependent rheologicalproperties, where tan δ serves as a critical within-materialtransition indicator for identifying localized risk of clogging, screenblinding, and material agglomeration in processing equipment. Thestudy underscores the importance of considering material-specificviscoelastic behavior and surface interactions in optimizing wasteprocessing technologies and suggests potential benefits of moisturecontrol and material selection in equipment design, as well as thestrategic implementation of source separation for problematic wastefractions, particularly those exhibiting high tan δ and highviscoelasticity.

This work presents an engineered single-plasmid, dual-pigmentwhole-cellbiosensor for simultaneous colorimetric detection of Pb(II) and Hg(II).To address the challenge of signal interference in cocontaminatedenvironmental samples, a Pb(II)-responsive PbrR regulatory moduledriving indigo biosynthesis (blue, 620 nm) and an Hg(II)-responsiveMerR module driving deoxyviolacein biosynthesis (purple, 570 nm) wereintegrated into Escherichia coli TOP10.The orthogonal decoupling of the two pigment pathways, combined witha unified 10 h induction protocol, enables independent chromogenicreadout of both metals from a single cultivation. Dose-response assaysafforded a broad linear dynamic range for Pb(II) of 0.977–2000μM (R² = 0.9503) with a limit of detection (LOD)of 0.977 μM, alongside nanomolar sensitivity for Hg(II) witha linear range of 0.244–250 nM (R² = 0.9800) andan LOD of 0.244 nM. A two-dimensional cross-concentration matrix experimentfurther demonstrated that the two detection channels maintain distinguishabledose-dependent responses under coexposure conditions, with crosstalkremaining within an acceptable range. Robust performance was retainedin spiked surface water and seawater matrices, yielding Pb(II) LODsof 0.244 μM (surface water) and 0.488 μM (seawater), andHg(II) LODs of 0.488 nM (surface water) and 0.977 nM (seawater). Thesedetection limits approach or fall below relevant environmental regulatorythresholds, including the Class III surface-water standard for Hg(II).This self-contained, instrument-free pigment-based approach enablesnaked-eye discrimination of both metals in a standard microplate assay,offering a low-cost, high-throughput screening platform that complementsstandard instrumental methods for on-site environmental monitoringand emergency pollution response.

Chemical reductionof graphene oxide is considered to be the mostpromising method for the large-scale, fast, and low-cost productionof graphene in solution. Despite its importance, there is a lack ofstudies regarding this process, the detailed description of whichwould allow for optimization in terms of both time and cost. Moreover,a rapid and real-time method for monitoring the reaction could furtheroptimize the procedure. The aim of this work is to study the kineticsof the chemical reduction of graphene oxide using ascorbic acid asa green reducing agent. For this purpose, the reduction reaction ismonitored by measuring both the UV–vis spectra and the electricalconductance of the reaction solution, which increases as the reductionof graphene oxide proceeds. An accurate mathematical model of thereaction kinetics is proposed. Excellent agreement between the experimentaland simulated curves was obtained using an uncoupled system of first-orderdifferential equations for each reactant. The electrical monitoringof the reaction progress is validated by comparing the reduced grapheneoxide concentrations obtained by the two methods, with no significantdifferences.

Developing shapedcatalysts for the low-temperature selective catalyticreduction (SCR) of NO_x often results insevere physical detachment and efficiency loss. Building on our previousdevelopment of highly active nitrate-incorporated V₂O₅–WO₃/TiO₂ powder catalysts, weinvestigated the effect of SiO₂ as a structural binderfor coating these catalysts onto glass fiber sheets. Coatings with0–30 wt % SiO₂ were prepared and evaluated. Theaddition of 10 wt % SiO₂ significantly improved catalystdispersion, coating uniformity, and mechanical adhesion, successfullypreventing the structural degradation typically observed under highlyhumid operating conditions. Consequently, the SiO₂-containingcatalyst demonstrated enhanced physical stability, maintaining consistentNO_x removal efficiencies for at least80 h, whereas the SiO₂-free coating showed progressivedeactivation due to physical peeling. The optimized catalyst (10 wt% SiO₂, 4 wt % V₂O₅) achieved a 98.7%NO_x removal efficiency at 180 °Cunder dry conditions and 95.2% in the presence of 10 vol % H₂O. These findings clearly demonstrate that SiO₂ acts asan exceptionally robust structural binder, effectively bridging thegap between highly active fundamental powders and macroscopicallystable industrial applications.

Flexible, freestandingelectrodes with high mechanical robustness,electrical conductivity, and electrochemical performance are highlydesirable for wearable energy storage devices. Herein, a hierarchicalpolyaniline/partially oxidized graphene/cellulose nanopaper (PANI/po-Gr/CNP)electrode was developed by integrating redox-active PANI, conductivepo-Gr, and mechanically robust cellulose nanofibers (CNFs). PANI-coatedCNFs were first prepared via in situ polymerization, followed by incorporationof po-Gr nanosheets. We vacuum-filtered and dried the resulting hybridsuspension to fabricate a freestanding PANI/po-Gr/CNP electrode. Comparedwith the po-Gr-free PANI/CNP electrode, the optimized PANI/po-Gr/CNPelectrode increased electrical conductivity from 0.16 to 1.85 S·cm^–1 while maintaining a comparable tensile strength (∼42MPa). In a three-electrode configuration, the optimized electrodedelivered an areal capacitance of 2.74 F·cm^–2 at 5 mV·s^–1, corresponding to volumetricand gravimetric capacitances of 342.5 F cm^–3 and572.7 F·g^–1 (based on the combined mass ofPANI and po-Gr), respectively. The assembled symmetric supercapacitordelivered an areal energy density of 58.08 μWh·cm^–2 and a volumetric energy density of 7.26 mWh·cm^–3, while retaining 81.0% of its initial capacitance after 10,000 charge–dischargecycles. These results show that combining CNFs, PANI, and po-Gr enablesa freestanding electrode with a favorable balance of mechanical robustness,electrical conductivity, and electrochemical performance, offeringa promising platform for flexible, wearable supercapacitors.

Accurate multistepprediction of nitrogen oxide (NOx) emissionsis essential for combustion perception and optimization in utilityboilers. Under deep peak-shaving conditions, frequent operating conditiontransitions induce mixed operating data, strong variable coupling,and progressive error accumulation, restricting the long-horizon stabilityof conventional models. To address these issues, a gated residualfusion framework was constructed by using data from a 300 MW circulatingfluidized bed (CFB) boiler. A preprocessing strategy integrating rollingsignal denoising, correlation analysis, and Random Forest rankingselected 30 variables from 162 candidates. iTransformer and TimesNetwere coupled to extract complementary dynamic representations, andsequence decomposition fusion, parallel fusion, and gated residualfusion were compared. In the proposed architecture, the dominant NOxevolution is captured by the iTransformer backbone, while the TimeNetresidual branch provides correction for local deviations that areinsufficiently represented by the backbone. Compared with standaloneVMD-iTransformer and VMD-TimesNet, RMSE was reduced by 73.99% and78.37% at step 1 and by 39.86% and 49.51% at step 6, respectively.Compared with eight baseline models, the proposed model achieved thebest average performance, with RMSE, MAE, MAPE, and R² values of 3.2228 mg/m³, 1.8930 mg/m³, 5.2338%, and 0.9185. Results demonstrate peak recovery, abruptchange tracking, and long-horizon stability.

Cultivated kelps are a scalable marine feedstock forrenewablepolymers, but regional aquaculture supply chains lack engineeringbenchmarks for the alginate yield and quality. Here, we apply a lower-hazardcitrate-based process to quantify bioplastics-relevant alginate metricsacross cultivated northeast Pacific kelps from commercial farms inBritish Columbia (Canada) and Alaska (USA). Ten blade biomass samplesspanning five species were screened. Two samples failed to undergophase separation after extraction and centrifugation, indicating biomass-dependentextractability as a process risk. For the remaining eight feedstocks,yields ranged from 11.95 to 26.11% (dry weight). Weight-average molarmass (M_w) ranged from 36.6 to 623 kDa,with 7/8 samples exceeding 400 kDa. Uronic acid composition spannedM/G = 0.14–1.38, with variation in G/M block compositions (blockfractions and block lengths) relevant to cross-linking. Multivariateanalysis resolved dominant gradients linking the uronic acid compositionand molar mass distributions. The studied kelps were evaluated inthe context of known seasonal, tissue-specific, and environment-driveneffects and climate-related stressors that can alter productivity.Collectively, these results provide a regional benchmark for lowerhazard alginate production from cultivated kelps and an engineeringscreening framework to support consistent feedstock selection forscalable manufacturing of alginate-based films, coatings, and relatedbio-based materials.