Journal of Coatings Technology and Research最新文献

{"title":"Pulsating water jet for accelerated rain erosion of blade coatings: effects of process parameters and coating elasticity, with performance compared to whirling arm rig data","authors":"Zhiwei Wu,&nbsp;Nina Schuermann,&nbsp;Nezam Azizaddini,&nbsp;Claus Erik Weinell,&nbsp;Kim Dam-Johansen,&nbsp;Søren Kiil","doi":"10.1007/s11998-026-01327-4","DOIUrl":"10.1007/s11998-026-01327-4","url":null,"abstract":"<div><p>Pulsating water jets attract increasing attention for fast screening of rain erosion properties of wind turbine blade coatings. However, compared to natural rain erosion, the difference in experimental conditions adds significant uncertainty to the test results. The present work investigates the effects of impact velocity, exposure time, substrate type, coating elasticity, and impact frequency on the coating erosion process in a high-frequency pulsating water jet. Measurements were compared to data from a whirling arm rig, which, for decades, has served as the industrial standard. For four coating systems, it was shown that to initiate the erosion process, certain water jet threshold velocities are required. Furthermore, under high-frequency impacts, the effects of steel and glass fiber-reinforced epoxy resin substrates, relative to other process parameters, proved insignificant for the erosion process. For elastic coatings, the water jet erosion rate was notably affected by the impact frequency, with high-frequency impacts in the pulsating water jet resulting in a much faster erosion process in elastic coatings than in rigid (stiff) coatings. Variations in experimental conditions, especially the impact frequency, resulted in different coating failure sequences in the pulsating water jet and the whirling arm rig.</p></div>","PeriodicalId":619,"journal":{"name":"Journal of Coatings Technology and Research","volume":"23 5","pages":"2349 - 2363"},"PeriodicalIF":3.4,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11998-026-01327-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of influence factors on the leaching behavior of protected benzotriazole from active corrosion protection coatings","authors":"Pelin Duru,&nbsp;Malte Burchardt,&nbsp;Markus Jordan,&nbsp;Bernd Mayer","doi":"10.1007/s11998-026-01405-7","DOIUrl":"10.1007/s11998-026-01405-7","url":null,"abstract":"<div><p>Chromate-free corrosion inhibitors are important to establish non-toxic coating formulations for high strength aluminum alloys. A commercially sourced protected benzotriazole (BTA) based corrosion inhibitor was loaded into a 2K epoxy-amine matrix. The coating formulation was then systematically varied—inhibitor loading (IL), epoxy-to-amine ratio (EP:NH₂), filler type (FT), and filler amount (FA). In the formulation, BaSO₄ and TiO₂ were used as filler/pigments. The leaching behavior of BTA from free coating films was evaluated in de-ionized water. It was shown that the commercially sourced protected inhibitor could successfully be incorporated into the 2K epoxy-amine matrix and up to 77% of the inhibitor was released from the free films during the immersion in de-ionized water. The paint formulation impacted the leaching up to a factor of 9 with regards to the leached inhibitor fraction and up to a factor of 3 in terms of half time of leaching. FA had the most significant effect on overall inhibitor leaching.</p></div>","PeriodicalId":619,"journal":{"name":"Journal of Coatings Technology and Research","volume":"23 5","pages":"2365 - 2372"},"PeriodicalIF":3.4,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Behavior of sodium dodecyl sulfate in acidic environment","authors":"Florian Albrecht,&nbsp;Albert Rössler,&nbsp;Oliver I. Strube","doi":"10.1007/s11998-026-01312-x","DOIUrl":"10.1007/s11998-026-01312-x","url":null,"abstract":"<div><p>Whether sodium dodecyl sulfate (SDS) can be protonated in water under practically relevant acidities remains unclear because reported pK_a values for its conjugate acid, dodecyl hydrogen sulfate (DHS), vary widely. As SDS is widely used as an electrostatic stabilizer in waterborne coating formulations, clarification of its acid stability is of practical importance. SDS protonation was therefore examined by turbidity measurements, acid titration, and ¹H NMR spectroscopy. Solutions containing 0.025–0.50 mol L⁻¹ SDS remained fully transparent down to pH ≈ 0, with no turbidity or change upon heating to 45 °C. Titration with 1 M HCl showed a logarithmic pH decrease without buffer or equivalence points, indicating the absence of a measurable aqueous pK_a. In ¹H NMR spectra (0.10 mol L⁻¹ SDS), only ionic-strength-dependent shifts were observed, while integrals remained constant, confirming full solubility. Protonation, visible as line broadening and signal loss (~ 7%), occurred first at 1.26 mol L⁻¹ DCl, where samples became heterogeneous. These results demonstrate that SDS remains fully deprotonated and stable under practical-relevant pH conditions, while conversion to the poorly soluble protonated form occurs only under extremely acidic, high-ionic-strength environments.</p></div>","PeriodicalId":619,"journal":{"name":"Journal of Coatings Technology and Research","volume":"23 5","pages":"2341 - 2348"},"PeriodicalIF":3.4,"publicationDate":"2026-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11998-026-01312-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the effects of carbon black conductive network on the anti-corrosion performance of zinc-filled epoxy coatings","authors":"Amir Aminian,&nbsp;Hao Wu,&nbsp;Kim Dam-Johansen,&nbsp;Claus Erik Weinell,&nbsp;Jochen A. H. Dreyer","doi":"10.1007/s11998-026-01305-w","DOIUrl":"10.1007/s11998-026-01305-w","url":null,"abstract":"<div><p>The effects of a carbon black (CB) conductive network on the anti-corrosion performance of zinc-filled coatings were investigated using open circuit potential (OCP) measurements, electrochemical impedance spectroscopy (EIS), accelerated corrosion tests, and scanning electron microscopy (SEM). A percolated CB network formed when acetylene black content exceeded 2.7 vol.% in the dry film. To examine its effect on corrosion performance, 55, 66, and 75 wt.% zinc were incorporated into two formulations containing 3.6 and 4.5 vol.% CB. At 55 and 66 wt.% zinc, severe corrosion occurred because the CB network increased coating porosity, while the zinc level was insufficient to counteract this effect. In contrast, increasing zinc content to 75 wt.% significantly improved performance. SEM cross sections after 30 days of salt spray exposure showed that no corrosive species reached the coating-metal interface in the 75 wt.% zinc and 3.6 vol.% CB sample. This result was consistent with EIS data, which revealed increased low-frequency impedance after 30 days due to pore sealing by zinc corrosion products. Rust creep tests further confirmed that this coating exhibited the lowest rust creep, even compared to the 85 wt.% zinc-rich reference coating.</p></div>","PeriodicalId":619,"journal":{"name":"Journal of Coatings Technology and Research","volume":"23 5","pages":"2319 - 2328"},"PeriodicalIF":3.4,"publicationDate":"2026-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11998-026-01305-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydroxy silicone oil-modified loess-based molecular sieve/chitosan composite films","authors":"Yufeng Wang,&nbsp;Haobin Hu,&nbsp;Lipeng Wang,&nbsp;Yanyu Wang","doi":"10.1007/s11998-026-01286-w","DOIUrl":"10.1007/s11998-026-01286-w","url":null,"abstract":"<div><p>Films were prepared using chitosan and loess-based P-type molecular sieves as the primary raw materials, with modifications made using potassium diformate, hydroxy silicone oil, and other additives. Following a reaction under specific conditions and subsequent drying, an LMSC-film (loess-based molecular sieves and silicone oil-modified chitosan film) was obtained, exhibiting antibacterial, bactericidal, moisture-retaining, and biodegradable properties. The structural and physicochemical characteristics of the film were systematically analyzed. The results demonstrated that the modified film possessed a denser internal structure and a more compact surface morphology, along with an increased crosslinking degree. Notably, its thermal stability and hydrophobicity were significantly improved, achieving a maximum water contact angle of approximately 76°. Evaluations of mechanical properties revealed substantial enhancements: The modified film maintained high flexibility even after prolonged exposure to air, and its susceptibility to hardening and brittleness was reduced. Additionally, its water loss rate in ambient conditions was markedly lower, and it exhibited excellent aging resistance. Due to these favorable properties, the LMSC-film showed promising applications as a wound dressing to accelerate wound healing and related immune responses. It also holds potential as an edible antimicrobial coating to inhibit microbial proliferation and extend food shelf life. This study provides novel insights and methodologies for the development of advanced antimicrobial materials.</p></div>","PeriodicalId":619,"journal":{"name":"Journal of Coatings Technology and Research","volume":"23 5","pages":"2691 - 2701"},"PeriodicalIF":3.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electron beam-induced crosslinking and property enhancement of PVOH–PEG hybrid films for advanced coating applications","authors":"Bhuwanesh Kumar Sharma,&nbsp;Atanu Jha,&nbsp;Amol Thite,&nbsp;Karuppiah Nagaraj","doi":"10.1007/s11998-026-01283-z","DOIUrl":"10.1007/s11998-026-01283-z","url":null,"abstract":"<div><p>Poly(vinyl alcohol) (PVOH)–polyethylene glycol (PEG) hybrid films were prepared by aqueous solution casting and subsequently modified using electron beam (EB) irradiation to evaluate structure–property relationships. PVOH–PEG (80/20) (PV-EG82) demonstrated the most balanced mechanical performance and was chosen for irradiation. Gel fraction analysis indicated efficient EB-induced crosslinking, with the highest network density attained at 30 kGy (1 kGy/pass). Mechanical tests found that modest doses increased tensile strength, modulus, and surface hardness, whereas higher doses (&gt;30 kGy) caused chain scission and property loss. FTIR spectra revealed structural rearrangements and new vibrational bands associated with crosslinking, whereas contact angle and SEM investigations revealed decreased hydrophilicity and a denser surface shape. Thermogravimetric measurement demonstrated the enhanced thermal stability of irradiated films compared to virgin samples. Together, these results reveal that EB irradiation offers a clean and controllable approach to modify the crosslinking, mechanical, thermal, and surface properties of PVOH–PEG hybrids, emphasizing their promise in advanced packaging, coatings, and biomedical applications.</p></div>","PeriodicalId":619,"journal":{"name":"Journal of Coatings Technology and Research","volume":"23 5","pages":"2665 - 2676"},"PeriodicalIF":3.4,"publicationDate":"2026-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Graphene as a high-performance additive: the importance of fine dispersion for corrosion protection in coatings","authors":"Jan Willem van der Koelen,&nbsp;Frank Kother,&nbsp;Michael Dornbusch,&nbsp;Jochen Stefan Gutmann,&nbsp;Eui-young Shin","doi":"10.1007/s11998-025-01263-9","DOIUrl":"10.1007/s11998-025-01263-9","url":null,"abstract":"<div><p>This study demonstrates a practical route to integrate commercially available graphene into corrosion-protective coatings. Emphasis is placed on processing conditions that govern dispersion quality, and a ready-to-use, letdown graphene intermediate is formulated for solvent- and waterborne systems to minimize in-plant dispersion. Processing windows for graphene loading, dispersant level, and dispersion energy are established. Deagglomeration and dispersion stability are quantified by laser diffraction particle size analysis and supported by SEM and Raman spectroscopy. Corrosion performance is evaluated by salt spray testing and electrochemical impedance spectroscopy. Clear processing–structure–performance relationships are identified. Well-dispersed graphene at an optimized dispersant level enhances barrier performance and corrosion resistance, whereas insufficient deagglomeration or nonoptimal dispersant dosage can negate benefits and even diminish protection. Excessive dispersant contents reduce film integrity, effectively offsetting graphene’s advantage. High-surface-area grades can be challenging due to elevated dispersant demand. Overall, achieving a narrow particle size distribution and maintaining dispersion stability are critical for effective use of graphene in coatings.</p></div>","PeriodicalId":619,"journal":{"name":"Journal of Coatings Technology and Research","volume":"23 5","pages":"2413 - 2437"},"PeriodicalIF":3.4,"publicationDate":"2026-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11998-025-01263-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced antibacterial activity of montmorillonite through tetradecyldimethylbenzylammonium chloride intercalation","authors":"Taotao Yu,&nbsp;Feng Yang,&nbsp;Changchun Liu,&nbsp;Shirong Xu,&nbsp;Xi Chen,&nbsp;Hong Sun,&nbsp;Kenji Ogino","doi":"10.1007/s11998-025-01247-9","DOIUrl":"10.1007/s11998-025-01247-9","url":null,"abstract":"<div><p>In this study, tetradecyldimethylbenzylammonium chloride (TDBAC)-modified montmorillonite (TDBAC-MMT) was successfully synthesized via ion exchange, and its structural characteristics and antibacterial activity were systematically investigated. Multiple characterization methods confirmed the effective intercalation of TDBAC into montmorillonite (MMT): X-ray diffraction (XRD) revealed significant structural reconstruction, attributed to the steric hindrance of the benzyl group and hydrophobic interactions of alkyl chains; scanning electron microscopy (SEM) showed reduced agglomeration and a looser, more porous surface morphology in TDBAC-MMT, increasing the effective surface area; Fourier transform infrared spectroscopy (FTIR) identified characteristic peaks at 1468 cm⁻¹ (benzyl C–H bending vibration) and 2927 cm⁻¹ (alkyl C–H stretching vibration), verifying the incorporation of organic components; and thermogravimetric analysis (TGA) reflected the modified thermal stability of the composite. Antibacterial tests demonstrated potent activity for TDBAC-MMT, showing a 16.01 mm inhibition zone and a minimum inhibitory concentration (MIC) of 2 mg/mL against <i>Escherichia coli</i>, a 18.04 mm inhibition zone and a MIC of 0.5 mg/mL against <i>Staphylococcus aureus</i>. When 0.5% TDBAC-MMT was added to latex paint, the antibacterial rate against both <i>E. coli</i> and <i>S. aureus</i> reached 99.9%. Additionally, after 28 days of mold resistance testing, latex paint containing 0.5% TDBAC-MMT maintained a grade of 0 (no mold growth), indicating excellent mold resistance. This study provides a promising approach for the development of high-performance antibacterial and mold-resistant materials.</p></div>","PeriodicalId":619,"journal":{"name":"Journal of Coatings Technology and Research","volume":"23 4","pages":"2111 - 2123"},"PeriodicalIF":3.4,"publicationDate":"2026-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148519506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Self-polishing antifouling paint with cerium oxide nanoparticles: antibacterial, hydrophilicity, and biocide-release performance","authors":"Arini Nikitasari,&nbsp;Heddy Julistiono,&nbsp;Ahmad Royani,&nbsp;Yudi Nugraha Thaha,&nbsp;Albertus Deny Heri Setyawan,&nbsp;Gadang Priyotomo,&nbsp;Johny Wahyuadi Soedarsono,&nbsp;Rini Riastuti","doi":"10.1007/s11998-026-01295-9","DOIUrl":"10.1007/s11998-026-01295-9","url":null,"abstract":"<div><p>Marine biofouling brings operational and economic issues for maritime industries. Self-polishing antifouling (SPA) paint represents a cutting-edge technology, providing withstanding fouling prevention via a controlled surface hydrolysis mechanism that guarantees a consistent release of biocide. However, the environmental impact of toxic antifoulants in the SPA paint has encouraged investigations on novel co-biocides that improve efficacy while minimizing ecological risks. This study presents a novel SPA paint that incorporates cerium oxide (CeO₂) nanoparticles (0.1–0.5% wt.) as a nontoxic co-biocide. The antifouling paint performance was systematically evaluated based on three key factors: antibacterial efficacy, surface hydrophilicity, and kinetics of biocide release. The antibacterial assessment of CeO₂ nanoparticles and the formulation paint against <i>Pseudoalteromonas shioyasakiensis</i>, a typical marine fouling bacterium, exhibited markedly improved antibacterial efficacy compared to the control, as verified by the plate count test. Furthermore, measurements of the water contact angle confirmed slightly increased surface hydrophilicity, an essential characteristic for diminishing initial microbial attachment. The influence of CeO₂ nanoparticles on the biocide-release properties of the SPA paint was investigated using leaching-out tests, electrochemical impedance spectroscopy (EIS), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM-EDX), and optical microscopy (OM). Leaching-out tests revealed a significant increase of total copper release from 4.4 to 5.7 mg/cm² in the CeO₂-modified SPA paints relative to the control samples. EIS confirmed this finding by revealing a lower coating impedance, which correlated to higher porosity and water permeability. SEM-EDX and OM observations confirmed that CeO₂ nanoparticles facilitate a more porous and uniformly erodible matrix. The synergy of SPA paint technology and CeO₂ nanoparticles provides direct antibacterial action while simultaneously promoting a more effective self-polishing and biocide-release mechanism, indicating that this formulation is a promising and environmentally-friendly option for next-generation marine antifouling paints.</p></div>","PeriodicalId":619,"journal":{"name":"Journal of Coatings Technology and Research","volume":"23 5","pages":"2805 - 2820"},"PeriodicalIF":3.4,"publicationDate":"2026-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrospun PCL nanofiber coating on H2O2‐treated AZ61 magnesium alloy: an effective approach for coating adherence improvement and bio-functional orthopedic application","authors":"Silpa Cheriyan,&nbsp;M. Karthega","doi":"10.1007/s11998-026-01287-9","DOIUrl":"10.1007/s11998-026-01287-9","url":null,"abstract":"<div><p>Magnesium (Mg) and its alloys hold great promise for orthopedic application due to their biodegradability and mechanical compatibility with bone. However, their rapid degradation in physiological environments remains a significant barrier to clinical translation. This study presents a hybrid surface modification approach to reduce the degradation rate and improve the biocompatibility of AZ61 alloy. The alloy surface was pre-treated with hydrogen peroxide (H₂O₂), which resulted in a rougher surface and enhanced adhesion with subsequent polymer coatings. A polycaprolactone (PCL) electrospun nanofiber coating was applied to both untreated (AZ61/PCL) and H₂O₂ treated AZ61 alloy (AZ61ST/PCL) surface to assess the impact of surface pre-treatment. Surface morphology and composition of the specimen were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Adhesion and interfacial bonding were evaluated using peel-off test. Electrochemical test, including open circuit potential (OCP), potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS), indicated the stability of PCL coating as well as significantly improved corrosion resistance in H₂O₂-treated and PCL-coated AZ61 surface. Immersion studies in simulated body fluid (SBF) solution and in-vitro cell culture studies using osteoblast cells confirmed enhanced cell adhesion, proliferation, and biocompatibility of the coating. The combined chemical surface treatment followed by nanofiber coating demonstrates significant potential for improving the functional performance and longevity of Mg-based orthopedic implants.</p></div>","PeriodicalId":619,"journal":{"name":"Journal of Coatings Technology and Research","volume":"23 5","pages":"2703 - 2715"},"PeriodicalIF":3.4,"publicationDate":"2026-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}