The advent of three-dimensional(3D)printed porous Mg alloys is considered a significant milestone in the development of metal-based degradable implants.However,the poor corrosion resistance of additively manufactured ...The advent of three-dimensional(3D)printed porous Mg alloys is considered a significant milestone in the development of metal-based degradable implants.However,the poor corrosion resistance of additively manufactured Mg alloys,along with the occurrences of inflammation and bacterial infections following implantation,pose critical challenges.In this study,two drug-loaded coatings were prepared within a porous Mg alloy using in situ incorporation and post-deposition of layered double hydroxides(LDHs)to enhance corrosion resistance,antibacterial properties,and biological compatibility combined with plasma electrolytic oxidation(PEO).The results revealed that in situ incorporation of LDH capsules effectively reduced the porosity of the PEO layer and improved the long-term corrosion resistance of the coating.The postdeposited LDH layer effectively sealed the PEO layer,demonstrating highly stable corrosion resistance during 7 d electrochemical impedance spectroscopy(EIS)test,with the impedance modulus at 10^(-2) Hz stabilizing at 5×10^(5)Ω·cm^(2).After soaking,the surface morphology of the in situ drug-loaded PEO coating exhibited more cracks and defects,whereas the PEO-LDH coating maintained a relatively dense morphology.Among the tested samples,the PEO-LDH coating showed the best performance in terms of corrosion resistance,cell proliferation and differentiation capabilities,and antibacterial efficacy(>99%).Its strong compatibility with the porous structure of 3D-printed Mg alloy highlights the potential of this coating system for biomedical applications.The design strategy proposed in this study offers valuable insights for future development of drug-loaded coatings for 3D-printed porous materials.展开更多
The preparation of high-strengthα-hemihydrate gypsum(α-HH)from dihydrate gypsum(DH)is a potential way to improve the utilization rate of industrial gypsum.α-HH with a low aspect ratio was prepared by atmospheric sa...The preparation of high-strengthα-hemihydrate gypsum(α-HH)from dihydrate gypsum(DH)is a potential way to improve the utilization rate of industrial gypsum.α-HH with a low aspect ratio was prepared by atmospheric salt solution method,using Mg(NO_(3))_(2)solution as the salt medium.The effects of reaction temperature,reaction time,Mg(NO_(3))_(2)concentration,pH value,and the solid-to-liquid ratio on the purity,yield and aspect ratio of the product were investigated systematically.Under the optimal reaction conditions of 95℃,4 h,40%(mass)Mg(NO_(3))_(2),pH 5,and a solid—liquid ratio of 1:5,the yield and purity of the product could reach 89.67%and 99.85%,respectively.Additionally,the average aspect ratio of this product was 2.02,and the compressive strength reached 58.2 MPa.The regulation mechanism was studied by calculating the adsorption energies of Mg(NO_(3))_(2)on different crystal planes ofα-HH,which indicated that Mg(NO_(3))_(2)exhibited the strongest adsorption on the(111)plane,and this preferential adsorption retarded the axial growth ofα-HH,resulting in a reduced aspect ratio of the crystals.These findings suggest that the Mg(NO_(3))_(2)solution is an effective approach for preparing highstrengthα-HH with controlled morphology.展开更多
Mg alloys have the defects of low stiffness,low strength,and high coefficient of thermal expansion(CTE).The composites strategy and its architecture design are effective approaches to improve the comprehensive perform...Mg alloys have the defects of low stiffness,low strength,and high coefficient of thermal expansion(CTE).The composites strategy and its architecture design are effective approaches to improve the comprehensive performance of materials,but the processing difficulty,especially in ceramics forming,limits the control and innovation of material architecture.Here,combined with 3D printing and squeeze infiltration technology,two precisely controllable architectures of AZ91/Al_(2)O_(3)interpenetrating phase composites(IPC)with ceramic scaffold were prepared.The interface,properties and impact of different architecture on IPC performance were studied by experiments and finite element simulation.The metallurgical bonding of the interface was realized with the formation of MgAl_(2)O_(4)reaction layer.The IPC with 1 mm circular hole scaffold(1C-IPC)exhibited significantly improved elastic modulus of 164 GPa,high compressive strength of 680 MPa,and good CTE of 12.91×10^(-6)K^(−1),which were 3.64 times,1.98 times and 55%of the Mg matrix,respectively.Their elastic modulus,compressive strength,and CTE were superior to the vast majority of Mg alloys and Mg based composites.The reinforcement and matrix were bicontinuous and interpenetrating each other,which played a critical role in ensuring the potent strengthening effect of the Al_(2)O_(3)reinforcement by efficient load transfer.Under the same volume fraction of reinforcements,compared to IPC with 1 mm hexagonal hole scaffold(1H-IPC),the elastic modulus and compressive strength of 1C-IPC increased by 15%and 28%,respectively,which was due to the reduced stress concentration and more uniform stress distribution of 1C-IPC.It shows great potential of architecture design in improving the performance of composites.This study provides architectural design strategy and feasible preparation method for the development of high performance materials.展开更多
(Mg,Fe)SiO_(3) is primarily located in the mantle and has a substantial impact on geophysical and geochemical processes.Here,we employ molecular dynamics simulations to investigate the structural and transport propert...(Mg,Fe)SiO_(3) is primarily located in the mantle and has a substantial impact on geophysical and geochemical processes.Here,we employ molecular dynamics simulations to investigate the structural and transport properties of(Mg,Fe)SiO_(3) with varying iron contents at temperatures up to 5000 K and pressures up to 135 GPa.We thoroughly examine the effects of pressure,temperature,and iron content on the bond lengths,coordination numbers,viscosities,and electrical conductivities of(Mg,Fe)SiO_(3).Our calculations indicate that the increase of pressure leads to the shortening of the O-O and Mg-O bond lengths,while the Si-O bond lengths exhibit the initial increase with pressure up to 40 GPa,after which they are almost unchanged.The coordination numbers of Si transition from four-fold to six-fold and eventually reach eight-fold coordination at 135 GPa.The enhanced pressure causes the decrease of the diffusion coefficients and the increase of the viscosities of(Mg,Fe)SiO_(3).The increased temperatures slightly decrease the coordination numbers and viscosities,as well as obviously increase the diffusion coefficients and electrical conductivities of(Mg,Fe)SiO_(3).Additionally,iron doping facilitates the diffusion of Si and O,reduces the viscosities,and enhances the electrical conductivities of(Mg,Fe)SiO_(3).These findings advance fundamental understanding of the structural and transport properties of(Mg,Fe)SiO_(3) under high temperature and high pressure,which provide novel insights for unraveling the complexities of geological processes within the Earth's mantle.展开更多
Exploiting high-performance electrolyte holds the key for realization practical application of rechargeable magnesium batteries(RMBs).Herein,a new non-nucleophilic mononuclear electrolyte was developed and its electro...Exploiting high-performance electrolyte holds the key for realization practical application of rechargeable magnesium batteries(RMBs).Herein,a new non-nucleophilic mononuclear electrolyte was developed and its electrochemical active species was identified as[Mg(DME)_(3)][GaCl_(4)]_(2) through single-crystal X-ray diffraction analysis.The as-synthesized Mg(GaCl_(4))_(2)-IL-DME electrolyte could achieve a high ionic conductivity(9.85 m S cm^(-1)),good anodic stability(2.9 V vs.Mg/Mg^(2+)),and highly reversible Mg plating/stripping.The remarkable electrochemical performance should be attributed to the in-situ formation of Mg^(2+)-conducting Ga_(5)Mg_(2)alloy layer at the Mg/electrolyte interface during electrochemical cycling,which not only efficiently protects the Mg anode from passivation,but also allows for rapid Mg-ion transport.Significantly,the Mg(GaCl_(4))_(2)-IL-DME electrolyte showed excellent compatibility with both conversion and intercalation cathodes.The Mg/S batteries with Mg(Ga Cl_(4))_(2)-IL-DME electrolyte and KB/S cathode showed a high specific capacity of 839 m Ah g^(-1)after 50 cycles at 0.1 C with the Coulombic efficiency of~100%.Moreover,the assembled Mg|Mo_6 S_8 batteries delivered a reversible discharge capacity of 85 m Ah g^(-1)after 120 cycles at 0.2 C.This work provides a universal electrolyte for the realization of high-performance and practical RMBs,especially Mg/S batteries.展开更多
基金Natural Foundation of Science and Technology Department of Sichuan Province(2024NSFSC0949)Sichuan Science and Technology Program(2023ZYD0115)+1 种基金LiaoNing Revitalization Talents Program(XLYC2403026)Shenyang Young and Middle-aged Science and Technology Innovation Talent Support Program(RC231178).
文摘The advent of three-dimensional(3D)printed porous Mg alloys is considered a significant milestone in the development of metal-based degradable implants.However,the poor corrosion resistance of additively manufactured Mg alloys,along with the occurrences of inflammation and bacterial infections following implantation,pose critical challenges.In this study,two drug-loaded coatings were prepared within a porous Mg alloy using in situ incorporation and post-deposition of layered double hydroxides(LDHs)to enhance corrosion resistance,antibacterial properties,and biological compatibility combined with plasma electrolytic oxidation(PEO).The results revealed that in situ incorporation of LDH capsules effectively reduced the porosity of the PEO layer and improved the long-term corrosion resistance of the coating.The postdeposited LDH layer effectively sealed the PEO layer,demonstrating highly stable corrosion resistance during 7 d electrochemical impedance spectroscopy(EIS)test,with the impedance modulus at 10^(-2) Hz stabilizing at 5×10^(5)Ω·cm^(2).After soaking,the surface morphology of the in situ drug-loaded PEO coating exhibited more cracks and defects,whereas the PEO-LDH coating maintained a relatively dense morphology.Among the tested samples,the PEO-LDH coating showed the best performance in terms of corrosion resistance,cell proliferation and differentiation capabilities,and antibacterial efficacy(>99%).Its strong compatibility with the porous structure of 3D-printed Mg alloy highlights the potential of this coating system for biomedical applications.The design strategy proposed in this study offers valuable insights for future development of drug-loaded coatings for 3D-printed porous materials.
基金financial supported by the Opening Project of Hubei Yihua-Sichuan University Joint Innovation Research Center for new chemical materials(24H1402)Fundamental Research Funds for the Central Universities(SCU2024D009)the National Key Research and Development Program of China(2019YFC1905800)。
文摘The preparation of high-strengthα-hemihydrate gypsum(α-HH)from dihydrate gypsum(DH)is a potential way to improve the utilization rate of industrial gypsum.α-HH with a low aspect ratio was prepared by atmospheric salt solution method,using Mg(NO_(3))_(2)solution as the salt medium.The effects of reaction temperature,reaction time,Mg(NO_(3))_(2)concentration,pH value,and the solid-to-liquid ratio on the purity,yield and aspect ratio of the product were investigated systematically.Under the optimal reaction conditions of 95℃,4 h,40%(mass)Mg(NO_(3))_(2),pH 5,and a solid—liquid ratio of 1:5,the yield and purity of the product could reach 89.67%and 99.85%,respectively.Additionally,the average aspect ratio of this product was 2.02,and the compressive strength reached 58.2 MPa.The regulation mechanism was studied by calculating the adsorption energies of Mg(NO_(3))_(2)on different crystal planes ofα-HH,which indicated that Mg(NO_(3))_(2)exhibited the strongest adsorption on the(111)plane,and this preferential adsorption retarded the axial growth ofα-HH,resulting in a reduced aspect ratio of the crystals.These findings suggest that the Mg(NO_(3))_(2)solution is an effective approach for preparing highstrengthα-HH with controlled morphology.
基金supported by the National Key Research and Development Program of China(No.2022YFB3708400)the National Natural Science Foundation of China(No.52305158)+1 种基金the Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001)the Science Innovation Foundation of Shanghai Academy of Spaceflight Technology(No.USCAST2021-18).
文摘Mg alloys have the defects of low stiffness,low strength,and high coefficient of thermal expansion(CTE).The composites strategy and its architecture design are effective approaches to improve the comprehensive performance of materials,but the processing difficulty,especially in ceramics forming,limits the control and innovation of material architecture.Here,combined with 3D printing and squeeze infiltration technology,two precisely controllable architectures of AZ91/Al_(2)O_(3)interpenetrating phase composites(IPC)with ceramic scaffold were prepared.The interface,properties and impact of different architecture on IPC performance were studied by experiments and finite element simulation.The metallurgical bonding of the interface was realized with the formation of MgAl_(2)O_(4)reaction layer.The IPC with 1 mm circular hole scaffold(1C-IPC)exhibited significantly improved elastic modulus of 164 GPa,high compressive strength of 680 MPa,and good CTE of 12.91×10^(-6)K^(−1),which were 3.64 times,1.98 times and 55%of the Mg matrix,respectively.Their elastic modulus,compressive strength,and CTE were superior to the vast majority of Mg alloys and Mg based composites.The reinforcement and matrix were bicontinuous and interpenetrating each other,which played a critical role in ensuring the potent strengthening effect of the Al_(2)O_(3)reinforcement by efficient load transfer.Under the same volume fraction of reinforcements,compared to IPC with 1 mm hexagonal hole scaffold(1H-IPC),the elastic modulus and compressive strength of 1C-IPC increased by 15%and 28%,respectively,which was due to the reduced stress concentration and more uniform stress distribution of 1C-IPC.It shows great potential of architecture design in improving the performance of composites.This study provides architectural design strategy and feasible preparation method for the development of high performance materials.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12174352 and 12111530103)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(Grant No.G1323523065)。
文摘(Mg,Fe)SiO_(3) is primarily located in the mantle and has a substantial impact on geophysical and geochemical processes.Here,we employ molecular dynamics simulations to investigate the structural and transport properties of(Mg,Fe)SiO_(3) with varying iron contents at temperatures up to 5000 K and pressures up to 135 GPa.We thoroughly examine the effects of pressure,temperature,and iron content on the bond lengths,coordination numbers,viscosities,and electrical conductivities of(Mg,Fe)SiO_(3).Our calculations indicate that the increase of pressure leads to the shortening of the O-O and Mg-O bond lengths,while the Si-O bond lengths exhibit the initial increase with pressure up to 40 GPa,after which they are almost unchanged.The coordination numbers of Si transition from four-fold to six-fold and eventually reach eight-fold coordination at 135 GPa.The enhanced pressure causes the decrease of the diffusion coefficients and the increase of the viscosities of(Mg,Fe)SiO_(3).The increased temperatures slightly decrease the coordination numbers and viscosities,as well as obviously increase the diffusion coefficients and electrical conductivities of(Mg,Fe)SiO_(3).Additionally,iron doping facilitates the diffusion of Si and O,reduces the viscosities,and enhances the electrical conductivities of(Mg,Fe)SiO_(3).These findings advance fundamental understanding of the structural and transport properties of(Mg,Fe)SiO_(3) under high temperature and high pressure,which provide novel insights for unraveling the complexities of geological processes within the Earth's mantle.
基金financially supported by National Natural Science Foundation of China(21773291,52303130,62205231,61904118,22002102)Natural Science Foundation of the Jiangsu Higher Education Institutions of China(19KJA210005)+1 种基金Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX23_1710)Postgraduate Research&Practice Innovation Program of Suzhou University of Science and Technology(CLKYCX23_06)。
文摘Exploiting high-performance electrolyte holds the key for realization practical application of rechargeable magnesium batteries(RMBs).Herein,a new non-nucleophilic mononuclear electrolyte was developed and its electrochemical active species was identified as[Mg(DME)_(3)][GaCl_(4)]_(2) through single-crystal X-ray diffraction analysis.The as-synthesized Mg(GaCl_(4))_(2)-IL-DME electrolyte could achieve a high ionic conductivity(9.85 m S cm^(-1)),good anodic stability(2.9 V vs.Mg/Mg^(2+)),and highly reversible Mg plating/stripping.The remarkable electrochemical performance should be attributed to the in-situ formation of Mg^(2+)-conducting Ga_(5)Mg_(2)alloy layer at the Mg/electrolyte interface during electrochemical cycling,which not only efficiently protects the Mg anode from passivation,but also allows for rapid Mg-ion transport.Significantly,the Mg(GaCl_(4))_(2)-IL-DME electrolyte showed excellent compatibility with both conversion and intercalation cathodes.The Mg/S batteries with Mg(Ga Cl_(4))_(2)-IL-DME electrolyte and KB/S cathode showed a high specific capacity of 839 m Ah g^(-1)after 50 cycles at 0.1 C with the Coulombic efficiency of~100%.Moreover,the assembled Mg|Mo_6 S_8 batteries delivered a reversible discharge capacity of 85 m Ah g^(-1)after 120 cycles at 0.2 C.This work provides a universal electrolyte for the realization of high-performance and practical RMBs,especially Mg/S batteries.
基金Supported by the National Basic Research Program of China (973 Program,2010CB732300)the National Natural Science Foundation of China (20673037,20601008)the National Key Technologies R&D Program of China (2007BAJ03B01)
