ACS Omega最新文献

{"title":"Characterization and Nanoparticle Immobilization of a Thermotogaceae Esterase Active on Aromatic and Aliphatic Esters","authors":"Pietra Bruna Barbosa Bento,&nbsp;Dnane Vieira Almeida,&nbsp;Iara Ciancaglini,&nbsp;Ellen K.B. Roman,&nbsp;João Renato Carvalho Muniz,&nbsp;Roberta Albino dos Reis,&nbsp;Fabio Marcio Squina,&nbsp;Wanius Garcia","doi":"10.1021/acsomega.6c05063","DOIUrl":"https://doi.org/10.1021/acsomega.6c05063","url":null,"abstract":"<p>Esterases are a classof enzymes that catalyze the hydrolysis ofcarboxylic ester bonds and are widely utilized in the food, pharmaceutical,and detergent industries. In this study, we report the identificationand comprehensive characterization of a novel esterase (TbEst) fromthe <em>Thermotogaceae</em> family, a group of thermophilicbacteria. The predicted three-dimensional structure of TbEst displaysa classical α/β-hydrolase fold with a conserved Ser-His-Aspcatalytic triad. TbEst was cloned, heterologously expressed, and purifiedvia a multistep chromatographic protocol. The melting temperatureof TbEst at pH 8.0 was 78 °C, confirming its thermostability.Furthermore, TbEst exhibited activity against p-nitrophenyl acetate,confirming its esterase activity, with optimal performance at pH 8.0and 50 °C. Notably, TbEst exhibited catalytic activity towardbroad aromatic and aliphatic esters, reinforcing its versatility fordiverse biotechnological applications. Furthermore, the present studydescribes the successful nanoscale immobilization of TbEst onto Ag/AgClnanoparticles (TbEst@Ag/AgCl-NPs) via a facile photochemical route.TbEst@Ag/AgCl-NPs were highly stable, with different geometries includingspherical and cubic; it was crystalline in nature, and had a meandiameter of 100 nm. Notably, TbEst retained its catalytic activityupon nanoscale immobilization onto Ag/AgCl-NPs. Furthermore, nanoscaleimmobilization conferred enhanced thermostability and significantlyprolonged the active lifetime of the bioconjugate compared to thefree enzyme. The data described here should provide a useful basisfor future research and biotechnological applications of esterasesand nanoimmobilized esterases.</p>","PeriodicalId":22,"journal":{"name":"ACS Omega","volume":"11 41","pages":"62944–62954"},"PeriodicalIF":5.2,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149222064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Eco-Friendly Ethyl Cellulose Coating for Molded Kraft Paper Food Packaging with Multifunctional Barriers and Promising Recyclability","authors":"Supattra Klayya,&nbsp;Phattharasaya Rattanawongkun,&nbsp;Uraiwan Intatha,&nbsp;Patcharee Pripdeevech,&nbsp;Nan Meng,&nbsp;Emiliano Bilotti,&nbsp;Han Zhang,&nbsp;Nattakan Soykeabkaew","doi":"10.1021/acsomega.6c05004","DOIUrl":"https://doi.org/10.1021/acsomega.6c05004","url":null,"abstract":"<p>This study presents an eco-friendly, PFAS-free moldedkraft paperbowl coated with ethyl cellulose (EC) to improve water, oil, and thermalresistance while retaining fiber-recovery potential. Kraft paper (K)was hot-press molded into bowls and dip-coated with EC solutions.Among the tested conditions, three cycles of 10 wt % EC (K/10EC-D3)produced a continuous coating (∼45 μm) with sufficientcoverage over the three-dimensional molded geometry. The EC coatingincreased dry tensile strength by 25%, increased the water contactangle to 70°, reduced Cobb120 water absorptiveness to 2.46 g/m², and achieved the highest grease resistance (Kit 12). Importantly,wet mechanical testing demonstrated that K/10EC-D3 retained substantiallyhigher tensile strength and modulus after 30 min of water exposureat both 23 and 95 °C, confirming effective short-term protectionagainst moisture-induced mechanical deterioration. Under simulatedfood-service conditions, the coated bowls maintained structural integrityduring exposure to hot water, tea, oil, and greasy foods, as wellas microwave heating and freeze–thaw–microwave cycling.Overall migration remained below the EU regulatory limit of 10 mg/dm² for all tested food simulants. Laboratory-scale repulpingand solvent-assisted washing enabled effective fiber recovery, withEC removal verified by FTIR and SEM. These findings demonstrate thatEC dip coating can provide multifunctional barrier performance andshort-term wet mechanical stability to three-dimensional molded kraftpaper while maintaining promising fiber-recovery potential for sustainablePFAS-free food packaging.</p>","PeriodicalId":22,"journal":{"name":"ACS Omega","volume":"11 41","pages":"62919–62935"},"PeriodicalIF":5.2,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Light-Activated ZnO Sensor for NO2 Detection at Room Temperature","authors":"Ailyn Estévez,&nbsp;Joana Pimenta,&nbsp;Andoni Beriain,&nbsp;Noemí Pérez","doi":"10.1021/acsomega.6c04616","DOIUrl":"https://doi.org/10.1021/acsomega.6c04616","url":null,"abstract":"<p>Nitrogen dioxide (NO₂) is a pollutant gasthat causesdeterioration of the air quality. This work provides a promising approachto efficiently detecting NO₂ at room temperature usinga chemiresistive sensor based on a zinc oxide (ZnO) ink on top ofan interdigitated electrode (IDE). We propose a high-performance andlow-cost gas sensor composed of aluminum electrodes printed on a flexiblesubstrate using thermal printing. Unlike other gas sensors, the ZnO-basedsensor works under ambient conditions and artificial light from fluorescentlamps, with no need for a dedicated light source. Changes in the sensorresistance are measured for low concentrations of NO₂ gasadsorbed on the ZnO surface, showing a linear increase in resistancewhen the concentration of NO₂ increases from 0.1 to 1 ppm.The advantages of this sensor are high sensitivity, fast responsetime, full recovery, good selectivity, stability over time, low powerconsumption and low cost.</p>","PeriodicalId":22,"journal":{"name":"ACS Omega","volume":"11 41","pages":"62815–62823"},"PeriodicalIF":5.2,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zwitterionic Coatings for Urinary Catheters: Current Progress, Design Principles and Translational Challenges","authors":"Chenghao Yao,&nbsp;Zhengda Wang,&nbsp;Sixu Yan,&nbsp;Shuai Zhang","doi":"10.1021/acsomega.6c07621","DOIUrl":"https://doi.org/10.1021/acsomega.6c07621","url":null,"abstract":"<p>Catheter-associated urinary tract infection (CAUTI) isone of themost common healthcare-associated infections and remains a major causeof morbidity, catheter blockage, and repeated device replacement duringlong-term catheterization. This narrative review examines the interfacialprocesses that contribute to urinary catheter failure, including proteinadsorption, microbial adhesion, biofilm formation, encrustation, andswarming-associated blockage, and evaluates how zwitterionic surfacecoatings may address these challenges. Drawing primarily on urinarycatheter-specific studies, together with adjacent zwitterionic biomaterialsliterature where relevant to catheter design, this review synthesizescurrent coating strategies with emphasis on protein repellence, lubrication,biocompatibility, multifunctionalization, interface-specific designrequirements, architectural trade-offs between hydrogel-like and brush-likecoatings, and approaches to improve coating durability. The reviewalso considers translation, including interim human evidence for zwitterion-treatedurinary catheters, while recognizing that these data remain conference-reportedand product-specific. Overall, zwitterionic coatings should be viewednot as a single antifouling solution, but as a versatile biomaterialsplatform for engineering multifunctional, durable, and clinicallytranslatable urinary catheters. However, their long-term stability,resistance to complex biofilm and encrustation processes, and clinicalefficacy require further validation. To define these remaining validationneeds, the review compares PC-, SB-, and CB-based systems, stratifiesevidence by model and duration, reports quantitative coating datawhere available, and identifies validation requirements across theproduct lifecycle.</p>","PeriodicalId":22,"journal":{"name":"ACS Omega","volume":"11 41","pages":"62340–62356"},"PeriodicalIF":5.2,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Fluorescent Aptamer Sensor Based on Cu-TCPP/rGO for Homogeneous Screening of G-Quadruplex Ligands","authors":"Guozhen Chen,&nbsp;Jiaxin Li,&nbsp;Jianbin Zheng","doi":"10.1021/acsomega.6c02294","DOIUrl":"https://doi.org/10.1021/acsomega.6c02294","url":null,"abstract":"<p>Single-stranded human telomeric DNA can fold into G-quadruplexes,structures composed of stacked G-quartets. Ligands that target G-quadruplexDNA have received considerable attention because of their potentialanticancer activity. We developed a Förster resonance energytransfer (FRET) system to identify drugs that stabilize G-quadruplexeswith human telomeric DNA in a homogeneous medium using Cu-4,4,4,4-(Porphine-5,10,15,20-tetrayl)tetrakis (benzoic acid)/reduced graphene oxide (Cu-TCPP/rGO) as fluorescencequencher. Fluorescein-tagged human telomeric G-rich DNA (F-GDNA) exhibitedsignificant fluorescence quenching upon adsorption onto the Cu-TCPP/rGOsurface, with fluorescence recovery observed when the ligands werebound to the G-quadruplexes. The ligand stabilized formation of G-quadruplexeswas further confirmed using circular dichroism (CD) spectroscopy.Notably, flavonoids and anthraquinones derived from traditional Chinesemedicines promoted G-quadruplex formation within the GDNA. The combinedresults of fluorescence and CD spectroscopy indicate that the proposedFRET-based methodology serves as a cost-effective, facile, and efficienttool for screening G-quadruplex ligands. This approach has significantpotential for application in the identification of telomerase-targetinganticancer drugs.</p>","PeriodicalId":22,"journal":{"name":"ACS Omega","volume":"11 41","pages":"62533–62543"},"PeriodicalIF":5.2,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Activator Modulus on the Performance, Reaction Products, and Microstructure of Biomass Power Plant Ash-Based Alkali-Activated Binders","authors":"Shujie Zhao,&nbsp;Yian Chen,&nbsp;Tian Ma,&nbsp;Ming Xia","doi":"10.1021/acsomega.6c08056","DOIUrl":"https://doi.org/10.1021/acsomega.6c08056","url":null,"abstract":"<p>Biomass power plant ash (BPPA) is an emerging solid wastewithconsiderable potential for resource utilization, whereas its low reactivitylimits its direct application as a cementitious precursor. In thisstudy, BPPA was blended with ground granulated blast furnace slag(GGBFS) to develop an alkali-activated binder for potential mine backfillingapplications. The effects of activator modulus (<em>n</em>(SiO₂)/<em>n</em>(Na₂O)) on the freshand hardened properties were systematically investigated through slump,setting time, and compressive strength tests. The phase evolution,reaction products, thermal characteristics, and microstructural developmentwere analyzed by X-ray diffraction (XRD), Fourier transform infraredspectroscopy (FTIR), thermogravimetry-differential scanning calorimetry(TG-DSC), and scanning electron microscopy (SEM). The results showthat increasing the activator modulus decreased the slump and prolongedthe setting time. The compressive strength exhibited a nonmonotonicdependence on activator modulus, with a modulus of 1.4 achieving thehighest 28-day compressive strength value of approximately 5.0 MPaunder the investigated conditions. Microstructural analyses revealedthat an appropriate activator modulus enhanced precursor dissolutionand promoted the formation of calcium/sodium aluminosilicate hydrate-typereaction products, resulting in a more compact binder matrix. In contrast,excessive activator modulus reduced the availability of free OH^– and increased the viscosity, which hindered precursordissolution and weakened reaction product development. The strengthdevelopment was therefore governed by the balance between precursordissolution and gel precipitation. This study provides insights intoactivation chemistry regulation for the high-value utilization ofBPPA and the design of sustainable alkali-activated binders for usein potential mine backfilling applications.</p>","PeriodicalId":22,"journal":{"name":"ACS Omega","volume":"11 41","pages":"63781–63791"},"PeriodicalIF":5.2,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149222027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multifunctional AgNPs@Chitosan-g-C3N4-OH Nanocomposite: Efficient Catalytic Reduction of Nitro Pollutants, Antibacterial and Antioxidant Applications","authors":"Aakhila Banu A,&nbsp;Abhishek Kumar,&nbsp;Channabasaveshwar V Yelamaggad,&nbsp;Bhari Mallanna Nagaraja,&nbsp;Alejandro Bugarin,&nbsp;Siddappa A. Patil","doi":"10.1021/acsomega.6c04143","DOIUrl":"https://doi.org/10.1021/acsomega.6c04143","url":null,"abstract":"<p>A ternary nanocomposite comprising silver nanoparticlesanchoredon glutaraldehyde-cross-linked chitosan supported on hydroxyl-functionalizedgraphitic carbon nitride (AgNPs@CS-g-C₃N₄-OH)was synthesized via in situ reduction of silver in a stepwise method.Structural and physicochemical characterization confirmed successfulformation of the material. HR-TEM analysis showed uniformly distributed,quasi-spherical AgNPs with a lattice fringe spacing of ∼0.22nm, corresponding to the (111) plane of crystalline silver. XPS revealedAg(0) as the dominant species, while ICP-MS determined the silverloading to be 0.84 wt %. BET analysis indicated a mesoporous structurewith surface areas of 10.75 and 7.04 m² g^–1 for CS-g-C₃N₄-OH and the Ag-loaded composite,respectively. The nanocomposite exhibited excellent catalytic activityin NaBH₄-mediated reduction reactions. Conversion efficienciesof 99.79%, 97.91%, and 95.93% were achieved for 4-nitrophenol, metronidazole,and nitrofurantoin within 8, 6, and 2.5 min, respectively. The reactionsfollowed pseudo-first-order kinetics with rate constants of 0.9871,0.9819, and 0.9774 min^–1, and half-lives of ∼0.70min. Antibacterial studies showed strong activity against <em>Aeromonas hydrophila</em> and <em>Enterococcus faecalis</em>, with inhibition zones up to 16.45 ±0.35 mm and 17.10 ± 0.70 mm at 500 μg mL^–1. The MIC₅₀ values were 28.45 and 13.40 μg mL^–1, respectively. The material also exhibited moderateantioxidant activity with an IC₅₀ of 104.6 μg mL^–1 and 71.09% scavenging efficiency.</p>","PeriodicalId":22,"journal":{"name":"ACS Omega","volume":"11 41","pages":"62700–62716"},"PeriodicalIF":5.2,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149222053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Process-Intensified Pb(II) Removal from Complex Matrices Using an Ultrasound-Assisted Magnetic Fe3O4@γ-Chitosan–Gallic Acid Nanocomposite","authors":"Banpot Klinpratoom,&nbsp;Pattareeya Chaisaowong,&nbsp;Phitchan Sricharoen,&nbsp;Jintapat Nateewattana,&nbsp;Woravith Chansuvarn,&nbsp;Tanutta Amnuaywattanakul,&nbsp;Paisan Kanthang,&nbsp;Anchana Kuttiyawong,&nbsp;Sakchai Laksee,&nbsp;Wilasinee Kingkam,&nbsp;Titiya Meechai,&nbsp;Prawit Nuengmatcha,&nbsp;Kawin Lertlaokul,&nbsp;Nunticha Limchoowong","doi":"10.1021/acsomega.6c03761","DOIUrl":"https://doi.org/10.1021/acsomega.6c03761","url":null,"abstract":"<p>A magnetically recoverable Fe₃O₄@γ-chitosan-gallicacid (Fe₃O₄@Chi-GA) nanocomposite was engineeredas a sustainable bioadsorbent for Pb(II) removal from complex environmentaland consumer matrices. The material was synthesized via sequentialsurface functionalization of Fe₃O₄ nanoparticleswith γ-chitosan and gallic acid, introducing abundant oxygen-and nitrogen-containing functional groups to enhance metal bindingaffinity. Comprehensive characterization (FTIR, XRD, TG/DTG, TEM,EDS, DLS, and BET) confirmed successful fabrication and favorablephysicochemical properties. Ultrasound-assisted adsorption was employedto intensify mass transfer and reduce equilibrium time. The operatingconditions governing Pb(II) adsorption were optimized through responsesurface methodology (RSM) employing a central composite design (CCD).At the optimized conditions of 0.02 g adsorbent, 50 °C, 10 minof sonication, and pH 5, an equilibrium adsorption capacity (<em>q</em>_e) of 16.91 mg g^–1 was obtained.Equilibrium data were most appropriately fitted by the Langmuir model,which yielded a maximum adsorption capacity (<em>Q</em>_max) of 19.72 mg g^–1 and indicated predominantlymonolayer adsorption. Moreover, the pseudo-second-order model provideda strong fit to the kinetic data (<em>R</em>² =0.9861), implying that chemical interactions contributed substantiallyto the adsorption process. Thermodynamic analysis further revealedthat Pb(II) uptake was spontaneous and endothermic. Importantly, thenanocomposite demonstrated rapid magnetic separation, structural stability,and reusability over six cycles with minimal performance loss. Applicationto real samples, including beverages, cosmetic products, and wastewater,resulted in Pb(II) removal efficiencies of 75.92–85.40%, highlightingrobustness against matrix interference. These findings demonstratethe potential of Fe₃O₄@Chi-GA as an efficient,reusable, and scalable adsorbent for ultrasound-enhanced heavy metalremoval in complex systems.</p>","PeriodicalId":22,"journal":{"name":"ACS Omega","volume":"11 41","pages":"62632–62651"},"PeriodicalIF":5.2,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149222060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal History Effects on DSC Kinetic Analysis of DGEBA–DICY Epoxy Curing","authors":"Paulo E. Ferreira,&nbsp;Baltus C. Bonse,&nbsp;João G. R. Poço","doi":"10.1021/acsomega.6c02244","DOIUrl":"https://doi.org/10.1021/acsomega.6c02244","url":null,"abstract":"<p>The curing behavior of diglycidyl ether of bisphenolA (DGEBA)epoxy resin with dicyandiamide (DICY) was evaluated using differentialscanning calorimetry (DSC) and standard industrial kinetic methods.Melt-extruded powder samples were analyzed at heating rates of 5–20°C min^–1, under isothermal conditions from180 to 210 °C, and through combined isothermal–dynamicexperiments to assess residual curing. The Borchardt–Danielsmethod yielded apparent activation energies that depended on the heatingrate, ranging from 177 ± 2 kJ/mol to 127 ± 4 kJ mol^–1. The ± values correspond to the confidence limitsreported by STARe for the numerical fit and should not be interpretedas measures of experimental reproducibility. A peak-based Kissingeranalysis resulted in an apparent activation energy of about 108 kJmol^–1, whereas the isothermal Arrhenius analysisyielded approximately 84 kJ mol^–1. Both values hadrelatively wide confidence intervals because of the limited numberof experimental conditions. The nonextruded reference sample, analyzedat 10 °C min^–1, showed a lower reaction enthalpy(89.45 versus 118.54 J g^–1) and a higher peak temperature(234 versus 203 °C) than the extruded material. This suggeststhat melt processing changed the initial state of the formulation.However, the DSC results alone do not allow us to determine whetherthis was mainly due to better dispersion, partial dissolution of DICY,or some early-stage reaction during processing. The glass-transitiontemperature increased with conversion but remained well below theisothermal curing temperature, indicating that classical vitrificationwas not observed. The linear relationship between ln(A) and <em>E</em>_a (R2 &gt; 0.99) is interpreted as a correlationbetween the fitted Arrhenius parameters and may reflect both changesin the material and covariance between the parameters. Overall, thekinetic values obtained here should therefore be regarded as protocol-dependentphenomenological descriptors rather than intrinsic mechanistic constants.</p>","PeriodicalId":22,"journal":{"name":"ACS Omega","volume":"11 41","pages":"62564–62571"},"PeriodicalIF":5.2,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microwave-Treated Structural and Network Changes in Filled Industrial EPDM Waste: Effects of Particle Size and Exposure Time","authors":"Begüm Uzunbayir,&nbsp;Bahadir Uyulgan,&nbsp;Orçun Saf","doi":"10.1021/acsomega.6c04739","DOIUrl":"https://doi.org/10.1021/acsomega.6c04739","url":null,"abstract":"<p>Ethylene–propylene–diene monomer (EPDM)compoundsused in automotive sealing systems contain permanent cross-links andhigh amounts of fillers and process oils, which complicate their recycling.This study examined the effects of particle-size fraction (≤125and ≥125 μm) and microwave exposure time (60–180s at 600 W) on the structural response of a highly filled industrialEPDM waste. Apparent sol fraction and apparent cross-link densitywere used as comparative indicators, supported by ATR-FTIR, XPS, TGA,and SEM analyses. The fine fraction treated for 60 s showed the lowestapparent cross-link density (0.72 × 10^–4 mol/cm³), corresponding to an apparent reduction of 17.11% relativeto untreated ground EPDM. Longer exposure is increasingly favoredby network-forming responses, particularly in the coarse fraction,demonstrating competition between network loosening and secondarycross-linking. XPS showed changes in sulfur-containing surface environments,while ATR-FTIR revealed no appreciable shifts in the principal EPDMbands. TGA and SEM showed clear differences between the particle-sizefractions. In revulcanized compounds containing 10 phr recycled EPDM,tensile strength remained within 7.71–8.32 MPa, and none ofthe recycled formulations differed significantly from the referenceC-EPDM. Microwave treatment had a significant overall effect on tensilestrength (<em>p</em> = 0.014), but only the treated fine fractiondiffered from its untreated counterpart (<em>p</em> = 0.046);elongation at break did not differ significantly. Surface roughnessand Shore A hardness remained broadly comparable. Overall, microwaveexposure produced competing particle-size- and time-dependent networkresponses, indicating a narrow processing window for the controlledmodification of highly filled industrial EPDM waste.</p>","PeriodicalId":22,"journal":{"name":"ACS Omega","volume":"11 41","pages":"62838–62851"},"PeriodicalIF":5.2,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}