Pub Date : 2024-12-27DOI: 10.1038/s41529-024-00547-6
Ankit Kumar, Eshan Ganju, Daniel Sinclair, Nikhilesh Chawla
Aluminum aircraft structures experience severe corrosion from exposure to aggressive chloride environments, including cyclic freezing and thawing of residual water during ascent and descent, introducing a cyclic freeze-thaw component to the corrosion process. While corrosion mechanisms in aircraft structures are well studied at constant temperatures, the microstructural and mechanistic behavior under freeze-and-thaw conditions remains unclear. To understand transformations induced by cyclic temperature, we used three-dimensional (3D) x-ray computed tomography (XCT) with scanning electron microscopy (SEM) to study the behavior of AA7075-T651 in a simulated seawater environment undergoing freezing and thawing cycles. Rods immersed in saltwater were thermally cycled above and below freezing, and structural changes were intermittently characterized in 3D. Under freeze-thaw conditions, cracks initiated within corrosion pits through ice expansion, causing progressive crevice growth and spalling along inclusions and grain boundaries with intermediate misorientation angles. Damage mechanisms in freeze-thaw and conventional corrosion environments are compared, with correlations to microstructural evolution.
{"title":"Mechanisms of corrosive freeze-thaw damage in AA7075 using time-resolved x-ray microtomography and correlative electron microscopy","authors":"Ankit Kumar, Eshan Ganju, Daniel Sinclair, Nikhilesh Chawla","doi":"10.1038/s41529-024-00547-6","DOIUrl":"10.1038/s41529-024-00547-6","url":null,"abstract":"Aluminum aircraft structures experience severe corrosion from exposure to aggressive chloride environments, including cyclic freezing and thawing of residual water during ascent and descent, introducing a cyclic freeze-thaw component to the corrosion process. While corrosion mechanisms in aircraft structures are well studied at constant temperatures, the microstructural and mechanistic behavior under freeze-and-thaw conditions remains unclear. To understand transformations induced by cyclic temperature, we used three-dimensional (3D) x-ray computed tomography (XCT) with scanning electron microscopy (SEM) to study the behavior of AA7075-T651 in a simulated seawater environment undergoing freezing and thawing cycles. Rods immersed in saltwater were thermally cycled above and below freezing, and structural changes were intermittently characterized in 3D. Under freeze-thaw conditions, cracks initiated within corrosion pits through ice expansion, causing progressive crevice growth and spalling along inclusions and grain boundaries with intermediate misorientation angles. Damage mechanisms in freeze-thaw and conventional corrosion environments are compared, with correlations to microstructural evolution.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-12"},"PeriodicalIF":6.6,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00547-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142890101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-20DOI: 10.1038/s41529-024-00541-y
R. Silva, C. L. Kugelmeier, C. B. Martins Junior, P. H. F. Oliveira, D. C. C. Magalhães, A. H. Plaine, R. Magnabosco, C. A. D. Rovere
This study investigated the intergranular corrosion mechanism of lean duplex stainless steel 2404 after long-term aging at 700 and 800 °C using electrochemical methods, thermodynamic calculations, and kinetic models. At 700 °C, σ phase growth significantly increases the degree of sensitization (DOS) and decreases the breakdown potential (Eb). At 800 °C, a self-healing process at the ferrite/σ interface helps recover Cr and Mo depleted regions, reducing DOS after 72 h of aging and stabilizing Eb after 24 h at higher electrode potentials. However, the corrosion process is intensified at the σ/austenite interface, compromising intergranular corrosion resistance during prolonged aging. The findings show that complete recovery of corrosion resistance via self-healing is not achieved when high fractions of σ phase are formed. In addition, DICTRA calculations effectively evaluate corrosion resistance degradation from σ phase growth, providing deeper insights into the intergranular corrosion mechanism.
{"title":"Mechanisms of intergranular corrosion and self-healing in high temperature aged lean duplex stainless steel 2404","authors":"R. Silva, C. L. Kugelmeier, C. B. Martins Junior, P. H. F. Oliveira, D. C. C. Magalhães, A. H. Plaine, R. Magnabosco, C. A. D. Rovere","doi":"10.1038/s41529-024-00541-y","DOIUrl":"10.1038/s41529-024-00541-y","url":null,"abstract":"This study investigated the intergranular corrosion mechanism of lean duplex stainless steel 2404 after long-term aging at 700 and 800 °C using electrochemical methods, thermodynamic calculations, and kinetic models. At 700 °C, σ phase growth significantly increases the degree of sensitization (DOS) and decreases the breakdown potential (Eb). At 800 °C, a self-healing process at the ferrite/σ interface helps recover Cr and Mo depleted regions, reducing DOS after 72 h of aging and stabilizing Eb after 24 h at higher electrode potentials. However, the corrosion process is intensified at the σ/austenite interface, compromising intergranular corrosion resistance during prolonged aging. The findings show that complete recovery of corrosion resistance via self-healing is not achieved when high fractions of σ phase are formed. In addition, DICTRA calculations effectively evaluate corrosion resistance degradation from σ phase growth, providing deeper insights into the intergranular corrosion mechanism.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-16"},"PeriodicalIF":6.6,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00541-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142875308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mineral dissolution by bacteria is thought to depend on mineral properties, solution chemistry, and the carbon sources metabolized. To investigate whether mineral particle size could impact the effectiveness of weathering and the molecular mechanisms employed by bacteria, the strain Caballeronia mineralivorans PML1(12) was considered. Through microcosm and kinetic experiments, we quantified changes in biotite dissolution, bacterial growth, siderophore biosynthesis, and acidification. The use of different solution chemistries, carbon sources, and particle sizes (from <20 to 500 µm) allowed us to decipher the relative role of acidification- and chelation-driven mineral weathering by bacteria. Results revealed a faster dissolution for smaller particles (<100 µm) that strongly affected both solution chemistry and bacterial physiology, while larger particles (>100 µm) showed a slower and steady dissolution with minimal impact on bacterial processes. These findings underscore the influence and feedback effects of particle size on the dynamics of dissolution and the mechanisms employed by bacteria.
{"title":"Feedback effect of the size of mineral particles on the molecular mechanisms employed by Caballeronia mineralivorans PML1(12) to weather minerals","authors":"Cintia Blanco Nouche, Carine Cochet, Marie-Pierre Turpault, Stéphane Uroz","doi":"10.1038/s41529-024-00544-9","DOIUrl":"10.1038/s41529-024-00544-9","url":null,"abstract":"Mineral dissolution by bacteria is thought to depend on mineral properties, solution chemistry, and the carbon sources metabolized. To investigate whether mineral particle size could impact the effectiveness of weathering and the molecular mechanisms employed by bacteria, the strain Caballeronia mineralivorans PML1(12) was considered. Through microcosm and kinetic experiments, we quantified changes in biotite dissolution, bacterial growth, siderophore biosynthesis, and acidification. The use of different solution chemistries, carbon sources, and particle sizes (from <20 to 500 µm) allowed us to decipher the relative role of acidification- and chelation-driven mineral weathering by bacteria. Results revealed a faster dissolution for smaller particles (<100 µm) that strongly affected both solution chemistry and bacterial physiology, while larger particles (>100 µm) showed a slower and steady dissolution with minimal impact on bacterial processes. These findings underscore the influence and feedback effects of particle size on the dynamics of dissolution and the mechanisms employed by bacteria.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-11"},"PeriodicalIF":6.6,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00544-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142875314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-19DOI: 10.1038/s41529-024-00545-8
Chamanthi Denisha Jayaweera, David Fernandes del Pozo, Ivaylo Plamenov Hitsov, Maxime Van Haeverbeke, Thomas Diekow, Arne Verliefde, Ingmar Nopens
Optimizing dosages of corrosion inhibitors requires experimental data gathered from time-consuming methods. The current study examines the feasibility of optimizing inhibitor dosages using a model trained for predicting corrosion rates more easily measured using linear polarization resistance in a full-scale cooling water system. A comprehensive study on variable selection showed that linearly correlated variables are necessary to predict corrosion trends. The Sobol sensitivity of inhibitors is trivialized by variables linearly correlated to the corrosion rate. The study highlights the importance of achieving high model prediction accuracy and high Sobol sensitivity of inhibitors to the corrosion rate, for using the model for inhibitor dosage optimization.
{"title":"Assessing the feasibility of using a data-driven corrosion rate model for optimizing dosages of corrosion inhibitors","authors":"Chamanthi Denisha Jayaweera, David Fernandes del Pozo, Ivaylo Plamenov Hitsov, Maxime Van Haeverbeke, Thomas Diekow, Arne Verliefde, Ingmar Nopens","doi":"10.1038/s41529-024-00545-8","DOIUrl":"10.1038/s41529-024-00545-8","url":null,"abstract":"Optimizing dosages of corrosion inhibitors requires experimental data gathered from time-consuming methods. The current study examines the feasibility of optimizing inhibitor dosages using a model trained for predicting corrosion rates more easily measured using linear polarization resistance in a full-scale cooling water system. A comprehensive study on variable selection showed that linearly correlated variables are necessary to predict corrosion trends. The Sobol sensitivity of inhibitors is trivialized by variables linearly correlated to the corrosion rate. The study highlights the importance of achieving high model prediction accuracy and high Sobol sensitivity of inhibitors to the corrosion rate, for using the model for inhibitor dosage optimization.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-12"},"PeriodicalIF":6.6,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00545-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142875312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-18DOI: 10.1038/s41529-024-00538-7
Abraham Rojas Z, Sam Bakhtiari, Chris Aldrich, Victor M. Calo, Mariano Iannuzzi
This study employs a data-driven methodology to assess the susceptibility of Fe-Cr-Ni alloys to stress corrosion cracking (SCC) in chloride-containing environments. Historical data from constant-load SCC testing in boiling magnesium chloride were used to train an XGBoost regression model. This model overcomes limitations related to multicollinearity and insufficient sample sizes seen in previous studies. The XGBoost model captures complex interactions between alloy compositions and stresses, explaining 94.9% (R² = 0.949) of SCC susceptibility of the specimens. Shapley additive explanations (SHAP) were employed to interpret the model, offering new metallurgical insights, such as the critical role of nickel content. The SHAP analysis identified an optimal nickel range between 14.5 and 45 wt%, which markedly enhances SCC resistance. The XGBoost-SHAP framework in this work comprehensively isolates the contributions of chemical constituents and stress, offering a path toward more systematic alloy design—departing from the traditional reliance on trial and error or serendipity.
{"title":"XGBoost model for the quantitative assessment of stress corrosion cracking","authors":"Abraham Rojas Z, Sam Bakhtiari, Chris Aldrich, Victor M. Calo, Mariano Iannuzzi","doi":"10.1038/s41529-024-00538-7","DOIUrl":"10.1038/s41529-024-00538-7","url":null,"abstract":"This study employs a data-driven methodology to assess the susceptibility of Fe-Cr-Ni alloys to stress corrosion cracking (SCC) in chloride-containing environments. Historical data from constant-load SCC testing in boiling magnesium chloride were used to train an XGBoost regression model. This model overcomes limitations related to multicollinearity and insufficient sample sizes seen in previous studies. The XGBoost model captures complex interactions between alloy compositions and stresses, explaining 94.9% (R² = 0.949) of SCC susceptibility of the specimens. Shapley additive explanations (SHAP) were employed to interpret the model, offering new metallurgical insights, such as the critical role of nickel content. The SHAP analysis identified an optimal nickel range between 14.5 and 45 wt%, which markedly enhances SCC resistance. The XGBoost-SHAP framework in this work comprehensively isolates the contributions of chemical constituents and stress, offering a path toward more systematic alloy design—departing from the traditional reliance on trial and error or serendipity.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-19"},"PeriodicalIF":6.6,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00538-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142875311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-06DOI: 10.1038/s41529-024-00542-x
Liam Jones, Maria Salta, Torben Lund Skovhus, Kathryn Thomas, Timothy Illson, Julian Wharton, Jeremy Webb
Continual challenges due to microbial corrosion are faced by the maritime, offshore renewable and energy sectors. Understanding the biofilm and microbiologically influenced corrosion interaction is hindered by the lack of robust and reproducible physical models that reflect operating environments. A novel dual anaerobic biofilm reactor, using a complex microbial consortium sampled from marine littoral sediment, allowed the electrochemical performance of UNS G10180 carbon steel to be studied simultaneously in anaerobic abiotic and biotic artificial seawater. Critically, DNA extraction and 16S rRNA amplicon sequencing demonstrated the principal biofilm activity was due to electroactive bacteria, specifically sulfate-reducing and iron-reducing bacteria.
{"title":"Dual anaerobic reactor model to study biofilm and microbiologically influenced corrosion interactions on carbon steel","authors":"Liam Jones, Maria Salta, Torben Lund Skovhus, Kathryn Thomas, Timothy Illson, Julian Wharton, Jeremy Webb","doi":"10.1038/s41529-024-00542-x","DOIUrl":"10.1038/s41529-024-00542-x","url":null,"abstract":"Continual challenges due to microbial corrosion are faced by the maritime, offshore renewable and energy sectors. Understanding the biofilm and microbiologically influenced corrosion interaction is hindered by the lack of robust and reproducible physical models that reflect operating environments. A novel dual anaerobic biofilm reactor, using a complex microbial consortium sampled from marine littoral sediment, allowed the electrochemical performance of UNS G10180 carbon steel to be studied simultaneously in anaerobic abiotic and biotic artificial seawater. Critically, DNA extraction and 16S rRNA amplicon sequencing demonstrated the principal biofilm activity was due to electroactive bacteria, specifically sulfate-reducing and iron-reducing bacteria.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-14"},"PeriodicalIF":6.6,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00542-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-04DOI: 10.1038/s41529-024-00540-z
Colleen O. Harper, Julie L. Brown, Richard T. Amos
The uniqueness of the Canadian spent nuclear fuel disposal container design requires a detailed understanding of the copper corrosion processes that could occur in deep geological repositories. This review aimed to identify knowledge gaps surrounding impacts of changing conditions and the evolution of corrosion processes as conditions change from moist/cool, through warm/dry, to cool/fully saturated. This review indicates that early, unsaturated corrosion, and compounding influences of previous corrosion are understudied.
{"title":"Corrosion processes affecting copper-coated used fuel containers for the disposal of spent nuclear fuel: critical review of the state-of-knowledge","authors":"Colleen O. Harper, Julie L. Brown, Richard T. Amos","doi":"10.1038/s41529-024-00540-z","DOIUrl":"10.1038/s41529-024-00540-z","url":null,"abstract":"The uniqueness of the Canadian spent nuclear fuel disposal container design requires a detailed understanding of the copper corrosion processes that could occur in deep geological repositories. This review aimed to identify knowledge gaps surrounding impacts of changing conditions and the evolution of corrosion processes as conditions change from moist/cool, through warm/dry, to cool/fully saturated. This review indicates that early, unsaturated corrosion, and compounding influences of previous corrosion are understudied.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-19"},"PeriodicalIF":6.6,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00540-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-30DOI: 10.1038/s41529-024-00521-2
Hyun-Kyu Hwang, Seong-Jong Kim
Marine scrubbers use seawater as washing water and are damaged by sulfur oxides and chlorides during desulfurization. Therefore, surface treatments to enhance corrosion and pitting resistance of scrubber materials must be investigated. This investigation conducts cyclic potentiodynamic polarization experiments to analyze the effects of electropolishing and plasma ion nitiriding of UNS S31603 in washing water. The corrosion current density (0.186 μA cm-2) of electropolishing is significantly lower than mechanical polishing (1.125 μA cm-2), but plasma ion nitriding is higher (18.995 μA cm-2). Electropolishing forms a uniform and dense passivation film, increasing corrosion resistance, whereas plasma ion nitriding reduces corrosion resistance due to CrN formation. All specimens present local corrosion. Electropolishing reduces the maximum damage depth by 110.13 μm and increases pitting potential by 0.32 V compared to mechanical polishing. Plasma ion nitriding reduces maximum damage depth by 46.59 μm due to suppression of local acidification during hydrolysis.
{"title":"Effects of electropolishing and plasma ion nitriding on UNS S31603 corrosion in ship scrubber water","authors":"Hyun-Kyu Hwang, Seong-Jong Kim","doi":"10.1038/s41529-024-00521-2","DOIUrl":"10.1038/s41529-024-00521-2","url":null,"abstract":"Marine scrubbers use seawater as washing water and are damaged by sulfur oxides and chlorides during desulfurization. Therefore, surface treatments to enhance corrosion and pitting resistance of scrubber materials must be investigated. This investigation conducts cyclic potentiodynamic polarization experiments to analyze the effects of electropolishing and plasma ion nitiriding of UNS S31603 in washing water. The corrosion current density (0.186 μA cm-2) of electropolishing is significantly lower than mechanical polishing (1.125 μA cm-2), but plasma ion nitriding is higher (18.995 μA cm-2). Electropolishing forms a uniform and dense passivation film, increasing corrosion resistance, whereas plasma ion nitriding reduces corrosion resistance due to CrN formation. All specimens present local corrosion. Electropolishing reduces the maximum damage depth by 110.13 μm and increases pitting potential by 0.32 V compared to mechanical polishing. Plasma ion nitriding reduces maximum damage depth by 46.59 μm due to suppression of local acidification during hydrolysis.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-12"},"PeriodicalIF":6.6,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00521-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Natural antibacterial agents with antimicrobial properties have a broad potential to prevent bacterial from forming biofilms adhesion in marine environments. ε-Polylysine (E-PL) consist of homomeric polymer with 25–30 lysine residues with stability, nontoxicity, and biodegradability. ε-Polylysine is a natural cationic antibacterial peptide that can resist microbial forming biofilm adhesion. The current study investigated the action of E-PL against Pseudomonas aeruginosa biofilm isolated from a marine environment. Crystal violet staining was used to examine the effects of E-PL on the formation and destruction of mature biofilms. Scanning Electron and fluorescence microscopy revealed that E-PL treatment damaged the biofilm structure and affected the secretion of extracellular polymers. The CCK8 colorimetric assay showed that E-PL also decreased the metabolic activity and motility of biofilm bacteria. QPCR and transcriptome analysis revealed that E-PL affected biofilm formation and transcriptional regulation by downregulating genes involved in flagellar synthesis (flgE, PA4651, pilW), chemotaxis transduction (PA1251, PA4951, PA4788), biofilm biosynthesis (pelC, pelD, pslK, plsM), transcriptional regulation (PA3973, PA3508, PA0268), phenazine biosynthesis (phzM, phzH, phzS), and electron transfer (PA5401, PA5400, PA3492). This study used multiple methods to identify the mechanism of E-PL action against biofilm, informing the design of novel biofilm treatment methods.
{"title":"The effect of antibacterial peptide ε-Polylysine against Pseudomonas aeruginosa biofilm in marine environment","authors":"Siwei Wu, Quantong Jiang, Dongzhu Lu, Xiaofan Zhai, Jizhou Duan, Baorong Hou","doi":"10.1038/s41529-024-00539-6","DOIUrl":"10.1038/s41529-024-00539-6","url":null,"abstract":"Natural antibacterial agents with antimicrobial properties have a broad potential to prevent bacterial from forming biofilms adhesion in marine environments. ε-Polylysine (E-PL) consist of homomeric polymer with 25–30 lysine residues with stability, nontoxicity, and biodegradability. ε-Polylysine is a natural cationic antibacterial peptide that can resist microbial forming biofilm adhesion. The current study investigated the action of E-PL against Pseudomonas aeruginosa biofilm isolated from a marine environment. Crystal violet staining was used to examine the effects of E-PL on the formation and destruction of mature biofilms. Scanning Electron and fluorescence microscopy revealed that E-PL treatment damaged the biofilm structure and affected the secretion of extracellular polymers. The CCK8 colorimetric assay showed that E-PL also decreased the metabolic activity and motility of biofilm bacteria. QPCR and transcriptome analysis revealed that E-PL affected biofilm formation and transcriptional regulation by downregulating genes involved in flagellar synthesis (flgE, PA4651, pilW), chemotaxis transduction (PA1251, PA4951, PA4788), biofilm biosynthesis (pelC, pelD, pslK, plsM), transcriptional regulation (PA3973, PA3508, PA0268), phenazine biosynthesis (phzM, phzH, phzS), and electron transfer (PA5401, PA5400, PA3492). This study used multiple methods to identify the mechanism of E-PL action against biofilm, informing the design of novel biofilm treatment methods.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-11"},"PeriodicalIF":6.6,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00539-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-29DOI: 10.1038/s41529-024-00543-w
Zeyun Zeng, Shangjun Gu, Jie Wang, Fulong Wei, Xiang Xie, Zhiying Li, Hui Yang, Changrong Li
In this study, the surface analysis, cross-section analysis and electrochemical analysis were used to explore the formation mechanism of Nb contents on the passive film of high-strength anti-seismic rebar in simulated concrete pore solution. The passivation experiments confirmed that the addition of Nb promoted the stability and compactness of surface passive film of Nb-containing rebar, and the passivation efficiency of Nb-containing rebar was stronger than that of CS rebar. Firstly, with the decreases of pH, the increases of Nb promoted that the outer layer of the passive film were mainly composed of Fe oxides and Fe oxyhydroxides, the inner layer were mainly composed of Fe oxides and Nb oxides. Secondly, the increases of Nb were beneficial to the formation of Nb oxides, which enhanced the passivation rate of the passive film and inhibited the degradation of Fe oxides, thus enhancing the thickness of surface passive film of Nb-containing rebar.
{"title":"Effect of Nb contents on the passivation behavior of high-strength anti-seismic rebar in concrete environments","authors":"Zeyun Zeng, Shangjun Gu, Jie Wang, Fulong Wei, Xiang Xie, Zhiying Li, Hui Yang, Changrong Li","doi":"10.1038/s41529-024-00543-w","DOIUrl":"10.1038/s41529-024-00543-w","url":null,"abstract":"In this study, the surface analysis, cross-section analysis and electrochemical analysis were used to explore the formation mechanism of Nb contents on the passive film of high-strength anti-seismic rebar in simulated concrete pore solution. The passivation experiments confirmed that the addition of Nb promoted the stability and compactness of surface passive film of Nb-containing rebar, and the passivation efficiency of Nb-containing rebar was stronger than that of CS rebar. Firstly, with the decreases of pH, the increases of Nb promoted that the outer layer of the passive film were mainly composed of Fe oxides and Fe oxyhydroxides, the inner layer were mainly composed of Fe oxides and Nb oxides. Secondly, the increases of Nb were beneficial to the formation of Nb oxides, which enhanced the passivation rate of the passive film and inhibited the degradation of Fe oxides, thus enhancing the thickness of surface passive film of Nb-containing rebar.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-22"},"PeriodicalIF":6.6,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00543-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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