This article discusses potential solutions to overcome current limitations for clinical implementation of Mg implants by forming the biocompatible hybrid PEO-based inhibitor-and polymer-containing coatings for a contr...This article discusses potential solutions to overcome current limitations for clinical implementation of Mg implants by forming the biocompatible hybrid PEO-based inhibitor-and polymer-containing coatings for a controlled corrosion degradation of the bioresorbable material.Multifunctional hybrid coatings were obtained on MA8 magnesium alloy.The porous ceramic-like coating synthesized by plasma electrolytic oxidation served as a base for further modification with bioresorbable polymer(polycaprolactone,PCL)contained halloysite nanotubes(HNTs)with corrosion inhibitor(benzotriazole,BTA).The method for HNT impregnating with BTA and introducing them into the matrix of PCL was proposed.The chemical composition of the protective layers was studied using SEM-EDX,XRD,XPS,and Raman microspectroscopy.Anticorrosion protection level of the coated specimens was determined by means of electrochemical techniques,weight loss,and hydrogen evolution tests.The samples with hybrid layers showed the best corrosion protection during 23 h exposure to Hanks’Balanced Salt Solution(|Z|_(f=0.1 Hz)=1.02 MΩ·cm^(2),I_(C)=11 nA·cm^(-2),R_(p)=2.4 MΩ·cm^(2))and the lowest degradation rate(0.021 mm/year)after 7 day of exposure to HBSS among all the tested samples.The electrochemical activity on microscale of samples with the studied coatings was estimated by localized electrochemical techniques.The degradation mechanism of specimens with hybrid layers was proposed.The prospects of hybrid layer application in regulating the resorption process of Mg alloys were shown.展开更多
The high corrosion rate of magnesium and its alloys in chloride-containing solution significantly reduces the potential of this material for diverse applications.Therefore,the formation of a smart protective coating w...The high corrosion rate of magnesium and its alloys in chloride-containing solution significantly reduces the potential of this material for diverse applications.Therefore,the formation of a smart protective coating was achieved in this work to prevent degradation of the MA8 magnesium alloy.A porous ceramic-like matrix was obtained on the material by plasma electrolytic oxidation(PEO).Further surface functionalization was performed using layered double hydroxides(LDH) served as nanocontainers for the corrosion inhibitor.Several methods of LDH intercalation with benzotriazole(BTA) were proposed.The composition and morphology of the formed coating were studied using SEM-EDX analysis,XRD,XPS,and Raman microspectroscopy.The corrosion behavior of the coated samples was evaluated using electrochemical impedance spectroscopy and potentiodynamic polarization.The corrosion rate was estimated using volumetry and gravimetry methods.The formed composite coating provides the Mg alloy with the lowest corrosion activity(|Z|_(f)=0.1 Hz)=8.48·10^(5) Ω·cm^(2),I_(c)=1.4·10^(-8)A/cm^(2),P_(H)=0.21 mm/year) and improves the protective properties of the PEO-coated sample(|Z|_(f)=0.1 Hz)=8.37·10^(3) Ω·cm^(2),I_(c)=4.1·10^(-7)A/cm^(2),P_(H)=0.31 mm/year).The realization of the self-healing effect of the inhibitor-containing LDH/PEO-coated system was studied using localized electrochemical methods(SVET and SIET) with two artificial defects on the surface.A mechanism involving three stages for the active corrosion protection of the alloy was proposed.These findings contribute to the follow-up work of developing modified LDH/PEO-based structures that promote the Mg alloy with high corrosion resistance,superior electrochemical performance for applications in various fields of industry and medicine.展开更多
The electrochemical behaviour of biodegradable magnesium alloy Mg-0.8Ca was evaluated in a mammalian cell culture medium(MEM)and Na Cl solutions(0.9 wt.%, 0.3 wt.%) using traditional(EIS, PDP, OCP) and local scanning ...The electrochemical behaviour of biodegradable magnesium alloy Mg-0.8Ca was evaluated in a mammalian cell culture medium(MEM)and Na Cl solutions(0.9 wt.%, 0.3 wt.%) using traditional(EIS, PDP, OCP) and local scanning electrochemical(SVET, SIET with p H-selective microelectrode) methods at the micro-and meso-level. Corrosion rates of samples in two different media were determined using weight loss tests. The influence of testing media components, alloy composition and microstructure on the material’s degradation process was determined.The SVET/SIET test parameters were optimized for in vitro investigation of the bioresorbable material surface. The mechanism of the alloy’s bioresorption was suggested. The effect of microsized phases on the corrosion behaviour of the alloy was proved using complementary in situ monitoring and SKPFM measurements. The rapid degradation rate of the alloy is related to the presence of local microgalvanic cells formed by cathodic α-magnesium matrix and anodic Mg_(2)Ca phase. The highest corrosion activity was revealed in the first 12 min of sample exposure to MEM, followed by stabilization of corrosion process due to the material’s passivation. Using SEM-EDX analysis, micro-Raman spectroscopy and XPS analysis the composition of the corrosion products was determined. Degradation in MEM proceeds with a formation of magnesium-and-carbonate substituted hydroxyapatite-containing film on the sample’s surface. The low possibility of application of Mg-0.8Ca alloy without coating protection in implant surgery was highlighted.展开更多
The efficiency of the green inhibitors(sodium salts of fumarate,glycolate and gluconate)in suppressing corrosion of the structural MA8 magnesium alloy(Mg–Mn–Ce)and the biomedical Mg–0.8Ca alloy was studied using th...The efficiency of the green inhibitors(sodium salts of fumarate,glycolate and gluconate)in suppressing corrosion of the structural MA8 magnesium alloy(Mg–Mn–Ce)and the biomedical Mg–0.8Ca alloy was studied using the hydrogen evolution measurements,mass loss test,EIS,PDP,SVET/SIET.The analysis of the morphology,chemical composition,and growth kinetic of corrosion films formed in 0.9 wt%NaCl solution with and without corrosion inhibitors was carried out.The most compact surface film with the smallest thickness was formed in a saline solution with sodium fumarate.The Mg alloy samples exhibited the highest polarization resistance,the lowest localized electrochemical activity,and the lowest corrosion rate in saline with the addition of sodium fumarate and sodium glycolate.The efficiency of the applied inhibitors was up to 81%.The model of the corrosion mechanism based on the sorption of molecules of organic inhibitors is proposed.The results show the high compatibility of the used inhibitors with the calcium-phosphate PEO-matrix,indicating the possibility of forming a self-healing coating by means of these active substances.展开更多
The properties of coatings formed on the MA8 magnesium alloy by the plasma electrolytic oxidation in electrolytes containing mechanical mixture of zirconia and silica nanoparticles in concentrations of 2,4 and 6 g/l h...The properties of coatings formed on the MA8 magnesium alloy by the plasma electrolytic oxidation in electrolytes containing mechanical mixture of zirconia and silica nanoparticles in concentrations of 2,4 and 6 g/l have been investigated.It has been established by SEM,EDS,and XPS that ZrO_(2)/SiO_(2)nanoparticles successfully were incorporated into the coatings.Micro-Raman spectroscopy showed the presence of ZrO_(2)in tetragonal and monoclinic forms in the PEO-coating composition as well as Mg_(2)SiO_(4) in tetrahedral configuration uniformly distributed in the outer part of coatings.Obtained coatings significantly reduce corrosion current density in comparison with bare Mg alloy and base PEOlayer(from 2.4×10^(–7)A/cm^(2) for base PEO layer to 0.7×10^(–7)A/cm^(2) for coatings with nanoparticles).It has been found that the presence of solid nanoparticles in the composition of coating has a positive effect on their hardness(this parameter was increased from 2.1±0.3 GPa to 3.1±0.4 GPa)and wearproof(the wear was reduced from(4.3±0.4)×10^(–5)mm^(3)/(N×m)to(3.5±0.2)×10^(–5)mm^(3)/(N×m)).展开更多
TiO_(2)-B/anatase nanotubes doped by vanadium have been synthesized through a facile one-step hydrothermal reaction.The material shows a mesoporous structure with a specific surface area of 179.1 m^(2)g^(-1).XPS data ...TiO_(2)-B/anatase nanotubes doped by vanadium have been synthesized through a facile one-step hydrothermal reaction.The material shows a mesoporous structure with a specific surface area of 179.1 m^(2)g^(-1).XPS data presume the presence of V^(3+),V^(4+),V^(5+),and Ti^(3+) in doped TiO2-B/anatase.As found by XRD and EIS investigations,the vanadium expands bronze titania crystal structure and enhances the conductivity of material by three orders of magnitude.When tested for lithium storage,the V-modified titania nanotubes show a specific capacity of 133 mA h g^(-1) after 100 charge/discharge cycles at the current density of 3000 mA g^(-1) with a Coulombic efficiency of around 98.9%,resulting in its good cycleability.The material still possesses a reversible capacity of 114 mA h g^(-1) at a very high current load of 6000 mA g^(-1),demonstrating superior rate characteristics for secondary lithium batteries.Furthermore,V-doped Ti O2-B/anatase mesoporous nanotubes show promise performance as anode material for sodium-ion batteries,delivering about 119 mA h g^(-1) and 101 m A h g^(-1) at the current loads of 10 and 1500 m A g^(-1),respectively.展开更多
The present study investigates the physical and chemical characteristics,behavior in vitro and in vivo,and biocompatibility of coatings containing Ta_(2)O_(5),which are obtained by plasma electrolytic oxidation(PEO)on...The present study investigates the physical and chemical characteristics,behavior in vitro and in vivo,and biocompatibility of coatings containing Ta_(2)O_(5),which are obtained by plasma electrolytic oxidation(PEO)on MA8 magnesium alloy.The obtained coatings demonstrate in vivo biocompatibility and in vitro bioactivity.Compared to the base PEO coating,the layers containing Ta_(2)O_(5)facilitate the development of apatite in simulated body fluid,suggesting that the inclusion of nanoparticles improves bioactivity of the coatings.It was found that incorporation of Ta_(2)O_(5)nanoparticles increases roughness and porosity of the formed layers by increasing particle concentration in electrolytes for the PEO process contributing to sufficient soft tissue ingrowth in vivo.Based on in vivo studies,these coatings also provide favorable tissue response and minimal inflammatory reaction in comparison with the bare magnesium alloy due to protection of living tissues from deleterious corrosion events of magnesium implant such as local alkalization and intense hydrogen evolution.The results obtained in the present study concluded biocompatibility,tissue integration of the PEO coatings containing Ta_(2)O_(5)nanoparticles making them a promising protective layer for biodegradable magnesium implants.展开更多
The work provides the results of the one-step formation of boron-containing coatings on an Mg–Mn–Ce alloy by plasma electrolytic oxidation. The results of studies of the composition, structure and morphology of hete...The work provides the results of the one-step formation of boron-containing coatings on an Mg–Mn–Ce alloy by plasma electrolytic oxidation. The results of studies of the composition, structure and morphology of heteroxide coatings are presented. It was established that the boron is contained in the coating mainly in the form of B or B_(2)O_(3). The introduction of B changes the color of coatings, and also helps to increase their porosity. The method of determining the full cross section of the interaction of thermal neutron absorption efficiency by samples material using the installation of neutron-activation analysis based on ^(252)Cf was developed. It was shown that the introduction of boron into the formed coatings allows to increase the macroscopic cross-section of the interaction of samples with thermal neutrons by 3.8 times. This effect opens the potential for the use of synthesized material in the field of nuclear technologies and aerospace industry.展开更多
基金supported by Russian Science Foundation,Russia(project no.24-73-10008,https://rscf.ru/en/project/24-73-10008/)the government assignments from the Ministry of Science and Higher Education of the RF,Russia(project no.FWFN-2024-0001).
文摘This article discusses potential solutions to overcome current limitations for clinical implementation of Mg implants by forming the biocompatible hybrid PEO-based inhibitor-and polymer-containing coatings for a controlled corrosion degradation of the bioresorbable material.Multifunctional hybrid coatings were obtained on MA8 magnesium alloy.The porous ceramic-like coating synthesized by plasma electrolytic oxidation served as a base for further modification with bioresorbable polymer(polycaprolactone,PCL)contained halloysite nanotubes(HNTs)with corrosion inhibitor(benzotriazole,BTA).The method for HNT impregnating with BTA and introducing them into the matrix of PCL was proposed.The chemical composition of the protective layers was studied using SEM-EDX,XRD,XPS,and Raman microspectroscopy.Anticorrosion protection level of the coated specimens was determined by means of electrochemical techniques,weight loss,and hydrogen evolution tests.The samples with hybrid layers showed the best corrosion protection during 23 h exposure to Hanks’Balanced Salt Solution(|Z|_(f=0.1 Hz)=1.02 MΩ·cm^(2),I_(C)=11 nA·cm^(-2),R_(p)=2.4 MΩ·cm^(2))and the lowest degradation rate(0.021 mm/year)after 7 day of exposure to HBSS among all the tested samples.The electrochemical activity on microscale of samples with the studied coatings was estimated by localized electrochemical techniques.The degradation mechanism of specimens with hybrid layers was proposed.The prospects of hybrid layer application in regulating the resorption process of Mg alloys were shown.
基金supported by the Grant of Russian Science Foundation,Russia (project no.21-73-10148,https://rscf.ru/en/project/ 21-73-10148/)supported by the Grant of Russian Science Foundation,Russia (project no.20-13-00130,https://rscf.ru/en/ project/20-13-00130/)。
文摘The high corrosion rate of magnesium and its alloys in chloride-containing solution significantly reduces the potential of this material for diverse applications.Therefore,the formation of a smart protective coating was achieved in this work to prevent degradation of the MA8 magnesium alloy.A porous ceramic-like matrix was obtained on the material by plasma electrolytic oxidation(PEO).Further surface functionalization was performed using layered double hydroxides(LDH) served as nanocontainers for the corrosion inhibitor.Several methods of LDH intercalation with benzotriazole(BTA) were proposed.The composition and morphology of the formed coating were studied using SEM-EDX analysis,XRD,XPS,and Raman microspectroscopy.The corrosion behavior of the coated samples was evaluated using electrochemical impedance spectroscopy and potentiodynamic polarization.The corrosion rate was estimated using volumetry and gravimetry methods.The formed composite coating provides the Mg alloy with the lowest corrosion activity(|Z|_(f)=0.1 Hz)=8.48·10^(5) Ω·cm^(2),I_(c)=1.4·10^(-8)A/cm^(2),P_(H)=0.21 mm/year) and improves the protective properties of the PEO-coated sample(|Z|_(f)=0.1 Hz)=8.37·10^(3) Ω·cm^(2),I_(c)=4.1·10^(-7)A/cm^(2),P_(H)=0.31 mm/year).The realization of the self-healing effect of the inhibitor-containing LDH/PEO-coated system was studied using localized electrochemical methods(SVET and SIET) with two artificial defects on the surface.A mechanism involving three stages for the active corrosion protection of the alloy was proposed.These findings contribute to the follow-up work of developing modified LDH/PEO-based structures that promote the Mg alloy with high corrosion resistance,superior electrochemical performance for applications in various fields of industry and medicine.
基金the Grant of Russian Science Foundation,Russia(project no.20–13–00130,https://rscf.ru/en/project/20–13–00130/)the Grant of Russian Science Foundation,Russia(project no.21–73–10148,https://rscf.ru/en/project/21–73–10148/)the government assignments from the Ministry of Science and Higher Education of the Russian Federation,Russia(project no.0205–2021–0003)。
文摘The electrochemical behaviour of biodegradable magnesium alloy Mg-0.8Ca was evaluated in a mammalian cell culture medium(MEM)and Na Cl solutions(0.9 wt.%, 0.3 wt.%) using traditional(EIS, PDP, OCP) and local scanning electrochemical(SVET, SIET with p H-selective microelectrode) methods at the micro-and meso-level. Corrosion rates of samples in two different media were determined using weight loss tests. The influence of testing media components, alloy composition and microstructure on the material’s degradation process was determined.The SVET/SIET test parameters were optimized for in vitro investigation of the bioresorbable material surface. The mechanism of the alloy’s bioresorption was suggested. The effect of microsized phases on the corrosion behaviour of the alloy was proved using complementary in situ monitoring and SKPFM measurements. The rapid degradation rate of the alloy is related to the presence of local microgalvanic cells formed by cathodic α-magnesium matrix and anodic Mg_(2)Ca phase. The highest corrosion activity was revealed in the first 12 min of sample exposure to MEM, followed by stabilization of corrosion process due to the material’s passivation. Using SEM-EDX analysis, micro-Raman spectroscopy and XPS analysis the composition of the corrosion products was determined. Degradation in MEM proceeds with a formation of magnesium-and-carbonate substituted hydroxyapatite-containing film on the sample’s surface. The low possibility of application of Mg-0.8Ca alloy without coating protection in implant surgery was highlighted.
基金supported by the Grant of Russian Science Foundation,Russia(project no 20–13–00130,https://rscf.ru/en/project/20-13-00130/)supported by the Grant of Russian Science Foundation,Russia(project no 24–73–10008,https://rscf.ru/en/project/24-73-10008/)XRD data were obtained under the government assignments from the Ministry of Science and Higher Education of the Russian Federation,Russia(project no FWFN-2024-0001).
文摘The efficiency of the green inhibitors(sodium salts of fumarate,glycolate and gluconate)in suppressing corrosion of the structural MA8 magnesium alloy(Mg–Mn–Ce)and the biomedical Mg–0.8Ca alloy was studied using the hydrogen evolution measurements,mass loss test,EIS,PDP,SVET/SIET.The analysis of the morphology,chemical composition,and growth kinetic of corrosion films formed in 0.9 wt%NaCl solution with and without corrosion inhibitors was carried out.The most compact surface film with the smallest thickness was formed in a saline solution with sodium fumarate.The Mg alloy samples exhibited the highest polarization resistance,the lowest localized electrochemical activity,and the lowest corrosion rate in saline with the addition of sodium fumarate and sodium glycolate.The efficiency of the applied inhibitors was up to 81%.The model of the corrosion mechanism based on the sorption of molecules of organic inhibitors is proposed.The results show the high compatibility of the used inhibitors with the calcium-phosphate PEO-matrix,indicating the possibility of forming a self-healing coating by means of these active substances.
基金supported within the frames of the Grant of the Russian Science Foundation, project No. 20-73-00280carried out within the framework of the Grant of the Russian Science Foundation, project No. 20-13-00130collected under the government assignments from Ministry of Science and Higher Education of the Russian Federation (project no. 0265-2019-0001)。
文摘The properties of coatings formed on the MA8 magnesium alloy by the plasma electrolytic oxidation in electrolytes containing mechanical mixture of zirconia and silica nanoparticles in concentrations of 2,4 and 6 g/l have been investigated.It has been established by SEM,EDS,and XPS that ZrO_(2)/SiO_(2)nanoparticles successfully were incorporated into the coatings.Micro-Raman spectroscopy showed the presence of ZrO_(2)in tetragonal and monoclinic forms in the PEO-coating composition as well as Mg_(2)SiO_(4) in tetrahedral configuration uniformly distributed in the outer part of coatings.Obtained coatings significantly reduce corrosion current density in comparison with bare Mg alloy and base PEOlayer(from 2.4×10^(–7)A/cm^(2) for base PEO layer to 0.7×10^(–7)A/cm^(2) for coatings with nanoparticles).It has been found that the presence of solid nanoparticles in the composition of coating has a positive effect on their hardness(this parameter was increased from 2.1±0.3 GPa to 3.1±0.4 GPa)and wearproof(the wear was reduced from(4.3±0.4)×10^(–5)mm^(3)/(N×m)to(3.5±0.2)×10^(–5)mm^(3)/(N×m)).
文摘TiO_(2)-B/anatase nanotubes doped by vanadium have been synthesized through a facile one-step hydrothermal reaction.The material shows a mesoporous structure with a specific surface area of 179.1 m^(2)g^(-1).XPS data presume the presence of V^(3+),V^(4+),V^(5+),and Ti^(3+) in doped TiO2-B/anatase.As found by XRD and EIS investigations,the vanadium expands bronze titania crystal structure and enhances the conductivity of material by three orders of magnitude.When tested for lithium storage,the V-modified titania nanotubes show a specific capacity of 133 mA h g^(-1) after 100 charge/discharge cycles at the current density of 3000 mA g^(-1) with a Coulombic efficiency of around 98.9%,resulting in its good cycleability.The material still possesses a reversible capacity of 114 mA h g^(-1) at a very high current load of 6000 mA g^(-1),demonstrating superior rate characteristics for secondary lithium batteries.Furthermore,V-doped Ti O2-B/anatase mesoporous nanotubes show promise performance as anode material for sodium-ion batteries,delivering about 119 mA h g^(-1) and 101 m A h g^(-1) at the current loads of 10 and 1500 m A g^(-1),respectively.
基金The formation of coatings,as well as SEM,EDS,FTIR spectroscopy and mechanical studies was supported by Russian Science Foundation grant No.22-73-10149,https://rscf.ru/project/22-73-10149/The electrochemical studies,in vitro and in vivo studies was supported by the Russian Science Foundation grant No.23-13-00329,https://rscf.ru/project/23-13-00329/。
文摘The present study investigates the physical and chemical characteristics,behavior in vitro and in vivo,and biocompatibility of coatings containing Ta_(2)O_(5),which are obtained by plasma electrolytic oxidation(PEO)on MA8 magnesium alloy.The obtained coatings demonstrate in vivo biocompatibility and in vitro bioactivity.Compared to the base PEO coating,the layers containing Ta_(2)O_(5)facilitate the development of apatite in simulated body fluid,suggesting that the inclusion of nanoparticles improves bioactivity of the coatings.It was found that incorporation of Ta_(2)O_(5)nanoparticles increases roughness and porosity of the formed layers by increasing particle concentration in electrolytes for the PEO process contributing to sufficient soft tissue ingrowth in vivo.Based on in vivo studies,these coatings also provide favorable tissue response and minimal inflammatory reaction in comparison with the bare magnesium alloy due to protection of living tissues from deleterious corrosion events of magnesium implant such as local alkalization and intense hydrogen evolution.The results obtained in the present study concluded biocompatibility,tissue integration of the PEO coatings containing Ta_(2)O_(5)nanoparticles making them a promising protective layer for biodegradable magnesium implants.
基金The formation of coatings,as well as XRD,XPS,and OSP analyzes was supported by Russian Science Foundation Grant No.22-73-10149,https://rscf.ru/project/22-73-10149/The SEM,EDX analyzes and study of absorption of neutron radiation by coatings was supported by the Russian Science Foundation Grant No.23-13-00329,https://rscf.ru/ project/23-13-00329/。
文摘The work provides the results of the one-step formation of boron-containing coatings on an Mg–Mn–Ce alloy by plasma electrolytic oxidation. The results of studies of the composition, structure and morphology of heteroxide coatings are presented. It was established that the boron is contained in the coating mainly in the form of B or B_(2)O_(3). The introduction of B changes the color of coatings, and also helps to increase their porosity. The method of determining the full cross section of the interaction of thermal neutron absorption efficiency by samples material using the installation of neutron-activation analysis based on ^(252)Cf was developed. It was shown that the introduction of boron into the formed coatings allows to increase the macroscopic cross-section of the interaction of samples with thermal neutrons by 3.8 times. This effect opens the potential for the use of synthesized material in the field of nuclear technologies and aerospace industry.
