Pub Date : 2025-12-21DOI: 10.1016/j.surfcoat.2025.133101
I. Hidalgo-González, E. Matykina, R. Arrabal
Previous studies have demonstrated that conventional anodizing precursors can reduce the energy consumption of plasma electrolytic oxidation (PEO) by facilitating the transition to the soft sparking regime, which produces denser coatings with improved wear performance. Here, we investigate the influence of anodizing precursors electrolytically coloured with Cu, Sn and Ni prior to PEO. Metal species accelerate the transition to soft sparking, with Cu exhibiting the greatest energy savings (~ 54 %) due to deposits in the inner precursor regions promoting dielectric breakdown. Wear resistance of the most energy-efficient system (A(Cu)-PEO) was comparable to Cu-free coatings (PEO, A-PEO), although A-PEO exhibited a lower friction coefficient (~ 0.69) after long sliding distances, linked to a more compact coating from extended soft sparking. Electrochemical impedance spectroscopy (EIS) revealed that Cu led to a weaker barrier layer in A(Cu)-PEO, yet the substrate showed negligible corrosion after 28 days in 3.5 wt% NaCl. Overall, A-PEO and A(Cu)-PEO are viable alternatives to conventional PEO, offering substantial energy savings without compromising performance.
{"title":"Plasma electrolytic oxidation of aluminium using conventional anodizing precursors and electrolytic colouring with Cu, Sn and Ni","authors":"I. Hidalgo-González, E. Matykina, R. Arrabal","doi":"10.1016/j.surfcoat.2025.133101","DOIUrl":"10.1016/j.surfcoat.2025.133101","url":null,"abstract":"<div><div>Previous studies have demonstrated that conventional anodizing precursors can reduce the energy consumption of plasma electrolytic oxidation (PEO) by facilitating the transition to the soft sparking regime, which produces denser coatings with improved wear performance. Here, we investigate the influence of anodizing precursors electrolytically coloured with Cu, Sn and Ni prior to PEO. Metal species accelerate the transition to soft sparking, with Cu exhibiting the greatest energy savings (~ 54 %) due to deposits in the inner precursor regions promoting dielectric breakdown. Wear resistance of the most energy-efficient system (A(Cu)-PEO) was comparable to Cu-free coatings (PEO, A-PEO), although A-PEO exhibited a lower friction coefficient (~ 0.69) after long sliding distances, linked to a more compact coating from extended soft sparking. Electrochemical impedance spectroscopy (EIS) revealed that Cu led to a weaker barrier layer in A(Cu)-PEO, yet the substrate showed negligible corrosion after 28 days in 3.5 wt% NaCl. Overall, A-PEO and A(Cu)-PEO are viable alternatives to conventional PEO, offering substantial energy savings without compromising performance.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"521 ","pages":"Article 133101"},"PeriodicalIF":6.1,"publicationDate":"2025-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-20DOI: 10.1016/j.surfcoat.2025.133100
Benjamin T. Heronimus, Robert Xavier Castillo Castañaza, Timothy S. Fisher
The present work describes a new morphology of cylindrical graphite synthesized in a unique manner by direct solar decomposition of methane and reports the mechanical properties of its manifestation in woven carbon–carbon composites. Whereas traditional carbon–carbon composites are formed via epoxy impregnation, the deposited material in the process presented here conformally follows the existing shape and orientation of individual carbon fibers. Through this process, cylindrical graphite fibers are synthesized that possess superior strength due to their graphitic layers that amalgamate into interlocked pathways between disparate fibers. Strength measurements, taken in tandem with Raman, XRD, and SEM, paint a picture of the shift from cloth to composite behavior via graphitization of the original substrate combined with sheets of graphene coalescing into a unified composite, with a notable improvement in elastic modulus from 0.19 to 2.66 GPa.
{"title":"Strength characterization of solar-synthesized cylindrical graphite carbon–carbon composites","authors":"Benjamin T. Heronimus, Robert Xavier Castillo Castañaza, Timothy S. Fisher","doi":"10.1016/j.surfcoat.2025.133100","DOIUrl":"10.1016/j.surfcoat.2025.133100","url":null,"abstract":"<div><div>The present work describes a new morphology of cylindrical graphite synthesized in a unique manner by direct solar decomposition of methane and reports the mechanical properties of its manifestation in woven carbon–carbon composites. Whereas traditional carbon–carbon composites are formed via epoxy impregnation, the deposited material in the process presented here conformally follows the existing shape and orientation of individual carbon fibers. Through this process, cylindrical graphite fibers are synthesized that possess superior strength due to their graphitic layers that amalgamate into interlocked pathways between disparate fibers. Strength measurements, taken in tandem with Raman, XRD, and SEM, paint a picture of the shift from cloth to composite behavior via graphitization of the original substrate combined with sheets of graphene coalescing into a unified composite, with a notable improvement in elastic modulus from 0.19 to 2.66 GPa.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"521 ","pages":"Article 133100"},"PeriodicalIF":6.1,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, a core-shell structure powder containing Ti3C2Tx (MXene) and multi-walled carbon nanotube (MWCNT) was synthesized, and the corresponding composite coating was deposited onto the substrate by high-velocity oxygen-fuel (HVOF) spraying. The structural integrity of MWCNT was well-preserved. With the incorporation of MWCNT and MXene, porosity increased from 1.31 % to 1.73 % while H/E ratio enhanced. Compared to the pristine coatings, the reinforced coatings demonstrated superior performance in creep displacement and plastic deformation. This coating further exhibits strain rate sensitivity, with a tendency toward increased plastic deformation as the strain rate rises. The creep mechanism is ascribed to the synergistic effects of multiple deformation modes, including MXene stretching, MWCNT bridging, dislocation and grain boundary sliding.
{"title":"Microstructure and mechanical properties of HVOF-sprayed WC-based cermet composite coating reinforced by MWCNT@MXene","authors":"Zihan Zhang , Zheng Wei , Jiyue Qin , Jiangbo Cheng , Sheng Hong","doi":"10.1016/j.surfcoat.2025.133071","DOIUrl":"10.1016/j.surfcoat.2025.133071","url":null,"abstract":"<div><div>In this work, a core-shell structure powder containing Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub> (MXene) and multi-walled carbon nanotube (MWCNT) was synthesized, and the corresponding composite coating was deposited onto the substrate by high-velocity oxygen-fuel (HVOF) spraying. The structural integrity of MWCNT was well-preserved. With the incorporation of MWCNT and MXene, porosity increased from 1.31 % to 1.73 % while H/E ratio enhanced. Compared to the pristine coatings, the reinforced coatings demonstrated superior performance in creep displacement and plastic deformation. This coating further exhibits strain rate sensitivity, with a tendency toward increased plastic deformation as the strain rate rises. The creep mechanism is ascribed to the synergistic effects of multiple deformation modes, including MXene stretching, MWCNT bridging, dislocation and grain boundary sliding.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"521 ","pages":"Article 133071"},"PeriodicalIF":6.1,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-19DOI: 10.1016/j.surfcoat.2025.133093
Nadia Akter, Fardad Azarmi
NiCr alloy has been widely used in various industrial applications due to its excellent corrosion and wear resistance. Nevertheless, for structural and functional reliability, adequate mechanical properties are also essential. In this study, additional elements were also incorporated into the NiCr alloy, and its mechanical properties were thoroughly investigated. The primary objective of this study was to determine the hardness and elastic modulus of a NiCrSiBMoFeCuC coating deposited by High-Velocity Oxygen Fuel (HVOF) spraying. Hardness measurements revealed a slight increase from the interface toward the surface. The experimental methods were employed to measure the elastic modulus of this coating included resonance frequency analysis (RFA), Knoop hardness testing, and nanoindentation. Additionally, several analytical methods, such as Hashin-Hasselman, Mori Tanaka model, and Marshall model were also employed to predict elastic modulus and evaluate their accuracy. The results indicated that Knoop hardness yields values closely aligned with the elastic modulus obtained from resonance frequency analysis. However, the elastic modulus measured via nanoindentation was notably higher than that determined by resonance frequency analysis. Furthermore, it was observed that the elastic modulus calculated by considering porosity closely aligns with the value obtained from RFA, whereas the modulus derived from dislocation density showed strong agreement with the nanoindentation results. Eventually, a numerical simulation tool, Object-Oriented Finite Element (OOF), was used to determine the elastic modulus, providing additional insights into the mechanical behavior of the coating. The highlight of this study is accuracy of porosity content based analytical model in prediction of elastic modulus of NiCr alloy coating with a rich mixture of alloying elements.
{"title":"Multimodal evaluation of mechanical properties in a nickel-based coating with complex composition deposited via high-velocity oxygen fuel (HVOF) technology","authors":"Nadia Akter, Fardad Azarmi","doi":"10.1016/j.surfcoat.2025.133093","DOIUrl":"10.1016/j.surfcoat.2025.133093","url":null,"abstract":"<div><div>NiCr alloy has been widely used in various industrial applications due to its excellent corrosion and wear resistance. Nevertheless, for structural and functional reliability, adequate mechanical properties are also essential. In this study, additional elements were also incorporated into the NiCr alloy, and its mechanical properties were thoroughly investigated. The primary objective of this study was to determine the hardness and elastic modulus of a NiCrSiBMoFeCuC coating deposited by High-Velocity Oxygen Fuel (HVOF) spraying. Hardness measurements revealed a slight increase from the interface toward the surface. The experimental methods were employed to measure the elastic modulus of this coating included resonance frequency analysis (RFA), Knoop hardness testing, and nanoindentation. Additionally, several analytical methods, such as Hashin-Hasselman, Mori Tanaka model, and Marshall model were also employed to predict elastic modulus and evaluate their accuracy. The results indicated that Knoop hardness yields values closely aligned with the elastic modulus obtained from resonance frequency analysis. However, the elastic modulus measured via nanoindentation was notably higher than that determined by resonance frequency analysis. Furthermore, it was observed that the elastic modulus calculated by considering porosity closely aligns with the value obtained from RFA, whereas the modulus derived from dislocation density showed strong agreement with the nanoindentation results. Eventually, a numerical simulation tool, Object-Oriented Finite Element (OOF), was used to determine the elastic modulus, providing additional insights into the mechanical behavior of the coating. The highlight of this study is accuracy of porosity content based analytical model in prediction of elastic modulus of NiCr alloy coating with a rich mixture of alloying elements.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"521 ","pages":"Article 133093"},"PeriodicalIF":6.1,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1016/j.surfcoat.2025.133085
L.C.M. Rodrigues , G.Y. Koga , T. Ferreira , C. Bolfarini , C.S. Kiminami , G.S. Prass , A.S.C.M. d'Oliveira , W.J. Botta
An innovative approach to process protective coatings used gas-atomized Fe68Cr8Mo4Nb4B16 powders, deposited by Plasma Transferred Arc (PTA) process, with four distinct processing conditions, varying feeding rate (6 g/min and 10 g/min), particle size distribution (fine: 53–106 μm, coarse: 106–180 μm, and a mix: 53–180 μm), and current intensity (120 A and 180 A). The coatings exhibited thicknesses of ~2–3 mm, porosity ranging from 0.11 ± 0.05 vol% to 0.32 ± 0.17 vol%, strong metallurgical bonding, and dilution levels between 7% and 19%. Inspite of the challenges associated with processing crack-free boron-rich alloys, sound coatings were processed under the tested conditions. The best-performing coating, produced with 106–180 μm powders, feeding rate of 10 g/min, and current of 120 A, exhibited the lowest specific wear rate (~5.0 × 10−5 mm3·N−1·m−1). The microstructure consisted of α-Fe, M₂B, and M₃B₂ phases, achieving Vickers microhardness values between 309 and 436 HV0.5. The wear mechanisms observed included abrasive, oxidative, and adhesive processes, with hard debris incorporation and oxygen enrichment on worn surfaces. PTA-processed coating showed a high effectiveness for refurbishing worn parts and to enhance steel components operating under severe wear conditions. The innovations focus on the relevance of processing parameters, which are decisive for the coating efficiency and the final properties of the material.
{"title":"Plasma transferred arc deposition of Fe-Cr-Mo-Nb-B coatings: Influence of processing parameters on wear resistance","authors":"L.C.M. Rodrigues , G.Y. Koga , T. Ferreira , C. Bolfarini , C.S. Kiminami , G.S. Prass , A.S.C.M. d'Oliveira , W.J. Botta","doi":"10.1016/j.surfcoat.2025.133085","DOIUrl":"10.1016/j.surfcoat.2025.133085","url":null,"abstract":"<div><div>An innovative approach to process protective coatings used gas-atomized Fe<sub>68</sub>Cr<sub>8</sub>Mo<sub>4</sub>Nb<sub>4</sub>B<sub>16</sub> powders, deposited by Plasma Transferred Arc (PTA) process, with four distinct processing conditions, varying feeding rate (6 g/min and 10 g/min), particle size distribution (fine: 53–106 μm, coarse: 106–180 μm, and a mix: 53–180 μm), and current intensity (120 A and 180 A). The coatings exhibited thicknesses of ~2–3 mm, porosity ranging from 0.11 ± 0.05 vol% to 0.32 ± 0.17 vol%, strong metallurgical bonding, and dilution levels between 7% and 19%. Inspite of the challenges associated with processing crack-free boron-rich alloys, sound coatings were processed under the tested conditions. The best-performing coating, produced with 106–180 μm powders, feeding rate of 10 g/min, and current of 120 A, exhibited the lowest specific wear rate (~5.0 × 10<sup>−5</sup> mm<sup>3</sup>·N<sup>−1</sup>·m<sup>−1</sup>). The microstructure consisted of α-Fe, M₂B, and M₃B₂ phases, achieving Vickers microhardness values between 309 and 436 HV<sub>0.5</sub>. The wear mechanisms observed included abrasive, oxidative, and adhesive processes, with hard debris incorporation and oxygen enrichment on worn surfaces. PTA-processed coating showed a high effectiveness for refurbishing worn parts and to enhance steel components operating under severe wear conditions. The innovations focus on the relevance of processing parameters, which are decisive for the coating efficiency and the final properties of the material.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"521 ","pages":"Article 133085"},"PeriodicalIF":6.1,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1016/j.surfcoat.2025.133098
Zifeng Li , Zikun Tang , Yonghua Duan , Zhiqi Feng , Lishi Ma , Shanju Zheng , Mingjun Peng , Mengnie Li
This study investigates the use of rare-earth-oxide-assisted boriding (RE-B) to enhance the surface properties of Ti6Al4V alloy. The microstructure and phase composition of the treated layer were characterized using scanning electron microscope (SEM) and X-ray diffractometer (XRD). Dry sliding wear tests show that the RE-B-treated Ti6Al4V exhibits significantly improved wear resistance compared to the untreated substrate. The modified surface, consisting primarily of TiB2 and TiB whiskers, offers strong resistance to abrasive wear, with minor adhesive wear observed. Wear mechanisms were analyzed through microscopic observations. This work highlights rare-earth boriding as a promising method for improving the tribological performance of titanium alloys under harsh conditions.
{"title":"Microstructure and wear properties of boride layer on Ti6Al4V alloy by boriding with rare-earth oxides","authors":"Zifeng Li , Zikun Tang , Yonghua Duan , Zhiqi Feng , Lishi Ma , Shanju Zheng , Mingjun Peng , Mengnie Li","doi":"10.1016/j.surfcoat.2025.133098","DOIUrl":"10.1016/j.surfcoat.2025.133098","url":null,"abstract":"<div><div>This study investigates the use of rare-earth-oxide-assisted boriding (RE-B) to enhance the surface properties of Ti6Al4V alloy. The microstructure and phase composition of the treated layer were characterized using scanning electron microscope (SEM) and X-ray diffractometer (XRD). Dry sliding wear tests show that the RE-B-treated Ti6Al4V exhibits significantly improved wear resistance compared to the untreated substrate. The modified surface, consisting primarily of TiB<sub>2</sub> and TiB whiskers, offers strong resistance to abrasive wear, with minor adhesive wear observed. Wear mechanisms were analyzed through microscopic observations. This work highlights rare-earth boriding as a promising method for improving the tribological performance of titanium alloys under harsh conditions.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"521 ","pages":"Article 133098"},"PeriodicalIF":6.1,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1016/j.surfcoat.2025.133097
Tapas Bera , Indranil Manna , Jyotsna Dutta Majumdar
Ti-13Nb-13Zr is a popular material for bioimplant applications; however, its lifetime as a bioimplant is limited because of its degradation due to wear and tribocorrosion. This study aims at modifying the microstructure of Ti-13Nb-13Zr by laser surface melting (LSM) using a 6 kW fibre-coupled diode laser with the objective to improve the mechanical (microhardness, wear) and mechanochemical (tribo-corrosion) properties. LSM was performed with varied power (700–1100 W) and scan speed (3–9 mm/s) in an argon shroud. The melt zone exhibited a refined α/α′ phase in β matrix, enhancing the microhardness of the surface from 250 VHN (as-received) to 315–477 VHN. A detailed nanomechanical property evaluation shows an increase in nanohardness of the surface (3.92–6.36 GPa) as compared to the as-received alloy (3.6 GPa). Both the H/Er and H3/Er2 ratios were significantly higher on the LSM surface as compared to the base metal, indicating improved elastic strain resistance and resistance to plastic deformation, respectively. Wear resistance of the LSM Ti-13Nb-13Zr surface was improved by 2 times, while tribo-corrosion kinetics were reduced by 1.6 times as compared to the as-received alloy. Finally, the mechanism of wear and tribo-corrosion degradation was evaluated through a detailed microstructural observation of the post-wear/post-tribocorrosion surface. The optimum process parameters were derived through a detailed structure-property process parameters correlation.
{"title":"Laser-assisted microstructural engineering of near-beta titanium alloy (Ti-13Nb-13Zr) surface using fibre-coupled diode laser and its effect on wear and tribo-corrosion performance","authors":"Tapas Bera , Indranil Manna , Jyotsna Dutta Majumdar","doi":"10.1016/j.surfcoat.2025.133097","DOIUrl":"10.1016/j.surfcoat.2025.133097","url":null,"abstract":"<div><div>Ti-13Nb-13Zr is a popular material for bioimplant applications; however, its lifetime as a bioimplant is limited because of its degradation due to wear and tribocorrosion. This study aims at modifying the microstructure of Ti-13Nb-13Zr by laser surface melting (LSM) using a 6 kW fibre-coupled diode laser with the objective to improve the mechanical (microhardness, wear) and mechanochemical (tribo-corrosion) properties. LSM was performed with varied power (700–1100 W) and scan speed (3–9 mm/s) in an argon shroud. The melt zone exhibited a refined α/α′ phase in β matrix, enhancing the microhardness of the surface from 250 VHN (as-received) to 315–477 VHN. A detailed nanomechanical property evaluation shows an increase in nanohardness of the surface (3.92–6.36 GPa) as compared to the as-received alloy (3.6 GPa). Both the H/E<sub>r</sub> and H<sup>3</sup>/E<sub>r</sub><sup>2</sup> ratios were significantly higher on the LSM surface as compared to the base metal, indicating improved elastic strain resistance and resistance to plastic deformation, respectively. Wear resistance of the LSM Ti-13Nb-13Zr surface was improved by 2 times, while tribo-corrosion kinetics were reduced by 1.6 times as compared to the as-received alloy. Finally, the mechanism of wear and tribo-corrosion degradation was evaluated through a detailed microstructural observation of the post-wear/post-tribocorrosion surface. The optimum process parameters were derived through a detailed structure-property process parameters correlation.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"521 ","pages":"Article 133097"},"PeriodicalIF":6.1,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1016/j.surfcoat.2025.133094
Sajida Maryam , Ihtisham Ul Haq , Karolina Wilk , Abdullah , Sara Shakibania , Divine Yufetar Shyntum , Sebastian Student , Janusz Szewczenko , Katarzyna Krukiewicz
Although urinary catheters are an essential part of hospital care, they are responsible for 75 % of hospital-acquired urinary tract infections. For that reason, there is a critical need for the development of long-term medical catheters exhibiting antibacterial properties, stability, and biocompatibility. Antimicrobial peptides, such as poly-l-lysine (PLL), have recently gained attention as promising agents for modifying biomedical devices due to their excellent biocompatibility and minimal toxicity. This study investigates the use of poly(vinyl alcohol) and poly-l-lysine (PVA/PLL) blend films as antimicrobial coatings for urinary catheters to enhance infection prevention, with PVA (0.5 %) and PLL (0.1 %) volume ratios between 400:1 and 100:1. An advanced ultrasonic coating technique (nozzle speed of 5 mm/s, flow rate of 0.25 ml/min, and nozzle rotational speed of 90 rpm) was employed to create durable, uniform films on both flat and tubular surface of catheters. The resulting PVA/PLL coatings were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy, while their biocompatibility was assessed in vitro with human dermal fibroblasts. Microbiological tests indicated antimicrobial activity of PVA/PLL against Escherichia coli (2.5-fold decrease in surface coverage), Staphylococcus epidermidis (98.8 ± 0.5 % inhibition) and Candida albicans (2.5-fold reduction in cell viability). Additionally, computational studies examined the antimicrobial mechanism of PLL on bacterial membranes. Consequently, the optimized PVA/PLL-coated catheters demonstrated biocompatibility together with strong antimicrobial activity against pathogens associated with catheter-associated urinary tract infections.
{"title":"Antimicrobial efficacy of ultrasonically deposited poly(vinyl alcohol)/poly(l-lysine)-based coatings for urinary catheters","authors":"Sajida Maryam , Ihtisham Ul Haq , Karolina Wilk , Abdullah , Sara Shakibania , Divine Yufetar Shyntum , Sebastian Student , Janusz Szewczenko , Katarzyna Krukiewicz","doi":"10.1016/j.surfcoat.2025.133094","DOIUrl":"10.1016/j.surfcoat.2025.133094","url":null,"abstract":"<div><div>Although urinary catheters are an essential part of hospital care, they are responsible for 75 % of hospital-acquired urinary tract infections. For that reason, there is a critical need for the development of long-term medical catheters exhibiting antibacterial properties, stability, and biocompatibility. Antimicrobial peptides, such as poly-<span>l</span>-lysine (PLL), have recently gained attention as promising agents for modifying biomedical devices due to their excellent biocompatibility and minimal toxicity. This study investigates the use of poly(vinyl alcohol) and poly-<span>l</span>-lysine (PVA/PLL) blend films as antimicrobial coatings for urinary catheters to enhance infection prevention, with PVA (0.5 %) and PLL (0.1 %) volume ratios between 400:1 and 100:1. An advanced ultrasonic coating technique (nozzle speed of 5 mm/s, flow rate of 0.25 ml/min, and nozzle rotational speed of 90 rpm) was employed to create durable, uniform films on both flat and tubular surface of catheters. The resulting PVA/PLL coatings were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy, while their biocompatibility was assessed <em>in vitro</em> with human dermal fibroblasts. Microbiological tests indicated antimicrobial activity of PVA/PLL against <em>Escherichia coli</em> (2.5-fold decrease in surface coverage), <em>Staphylococcus epidermidis</em> (98.8 ± 0.5 % inhibition) and <em>Candida albicans</em> (2.5-fold reduction in cell viability). Additionally, computational studies examined the antimicrobial mechanism of PLL on bacterial membranes. Consequently, the optimized PVA/PLL-coated catheters demonstrated biocompatibility together with strong antimicrobial activity against pathogens associated with catheter-associated urinary tract infections.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"521 ","pages":"Article 133094"},"PeriodicalIF":6.1,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1016/j.surfcoat.2025.133095
Yongchao Fang , Kaixuan Zhou , Zhang Li , Senyuan Wang , Chenbing Xiao , Xiuxin Du , Changliang Wang , Xiufang Cui , Guo Jin , Haoliang Tian
To investigate the impact of oxidation behavior on tribological properties of NiCrFe/Al/BN abradable seal coatings (ASCs), NiCrFe/Al/BN ASCs were prepared by thermal spraying. The oxidation behaviors at 650 °C for 192 h and the tribological properties of oxidized coating were discussed. The effect of oxidation on the tribological properties of the coating was that oxidation promoted the formation of hard oxides on the surface of the coating, aggravated the damage to the wear ball, and thus reduced the tribological properties of the coating. Specifically, the formation of θ-Al2O3 and Cr2O3 oxidation products the friction increased coefficient and grinding ball weight loss of oxidized coatings. In the initial 72 h, needle-like θ-Al2O3 and small block-like Cr2O3 formed on the surface of coatings. Over the subsequent 120 h, only Cr2O3 continued to grow, attributed to the depletion of aluminums on the surface. Eventually, the large block-like hard spinel Cr2O3 and needle-like θ-Al2O3 covered coatings, resulting in an increase in the friction coefficient of the oxidized coatings, as well as intensified weight loss on the grinding ball. Additionally, the inner oxidation was concentrated in the pores. The oxidation growth of alumina inside the coating will fill the pores inside the coating, thereby increasing the hardness of the coating. In summary, long-term oxidation would cause the NiCrFe/Al/BN ASCs to harden and intensify wear on the grinding ball, indicating that high-temperature oxidation weakened the abradability of the NiCrFe/Al/BN ASCs. Future research on novel NiCr-based ASCs should prioritize enhancing oxidation resistance as a key focus.
{"title":"Effect of oxidation behavior on tribological properties of NiCrFe/Al/BN abradable seal coatings","authors":"Yongchao Fang , Kaixuan Zhou , Zhang Li , Senyuan Wang , Chenbing Xiao , Xiuxin Du , Changliang Wang , Xiufang Cui , Guo Jin , Haoliang Tian","doi":"10.1016/j.surfcoat.2025.133095","DOIUrl":"10.1016/j.surfcoat.2025.133095","url":null,"abstract":"<div><div>To investigate the impact of oxidation behavior on tribological properties of NiCrFe/Al/BN abradable seal coatings (ASCs), NiCrFe/Al/BN ASCs were prepared by thermal spraying. The oxidation behaviors at 650 °C for 192 h and the tribological properties of oxidized coating were discussed. The effect of oxidation on the tribological properties of the coating was that oxidation promoted the formation of hard oxides on the surface of the coating, aggravated the damage to the wear ball, and thus reduced the tribological properties of the coating. Specifically, the formation of <em>θ</em>-Al<sub>2</sub>O<sub>3</sub> and Cr<sub>2</sub>O<sub>3</sub> oxidation products the friction increased coefficient and grinding ball weight loss of oxidized coatings. In the initial 72 h, needle-like <em>θ</em>-Al<sub>2</sub>O<sub>3</sub> and small block-like Cr<sub>2</sub>O<sub>3</sub> formed on the surface of coatings. Over the subsequent 120 h, only Cr<sub>2</sub>O<sub>3</sub> continued to grow, attributed to the depletion of aluminums on the surface. Eventually, the large block-like hard spinel Cr<sub>2</sub>O<sub>3</sub> and needle-like <em>θ</em>-Al<sub>2</sub>O<sub>3</sub> covered coatings, resulting in an increase in the friction coefficient of the oxidized coatings, as well as intensified weight loss on the grinding ball. Additionally, the inner oxidation was concentrated in the pores. The oxidation growth of alumina inside the coating will fill the pores inside the coating, thereby increasing the hardness of the coating. In summary, long-term oxidation would cause the NiCrFe/Al/BN ASCs to harden and intensify wear on the grinding ball, indicating that high-temperature oxidation weakened the abradability of the NiCrFe/Al/BN ASCs. Future research on novel NiCr-based ASCs should prioritize enhancing oxidation resistance as a key focus.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"521 ","pages":"Article 133095"},"PeriodicalIF":6.1,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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