Magnesium(Mg)-based composites are expected to be useful for biodegradable bone-implant materials due to their degradability,similar elastic modulus to that of bone,and biofunctionalities.However,their rapid degradati...Magnesium(Mg)-based composites are expected to be useful for biodegradable bone-implant materials due to their degradability,similar elastic modulus to that of bone,and biofunctionalities.However,their rapid degradation,poor biotribology performance,and lack of vascularization and antibacterial activity are not conducive to bone-fixation applications.In this study,an in situ Mg_(2)Ge/Mg-Cu-P composite with a nominal composition of Mg-10Ge-2Cu-0.5P(denoted MGCP)was prepared via phosphorus(P)-modified casting followed by hot extrusion for biodegradable bone-fixation applications.For comparison,an in situ Mg_(2)Ge/Mg-Cu composite(Mg-10Ge-2Cu,denoted MGC)was prepared under the same conditions without P-modification.The hot-extruded(HE)MGCP sample showed significantly improved corrosion resistance with corrosion rates of 2.2 mm/y and 2.51 mm/y as measured by potentiodynamic-polarization and hydrogen-release testing in Dulbecco’s Modified Eagle Medium supplemented with fetal bovine serum(denoted DMEM).The HE MGCP also exhibited notably enhanced mechanical properties and biotribological resistance in DMEM,with an σ_(UTS) of ~304.2 MPa,σ_(TYS) of ~202.5 MPa,elongation of ~12.3%,σ_(UCS) of 769.0 MPa,σ_(CYS) of 208.0 MPa,and Brinell hardness of 105.3 HB,along with smallerσ_(TYS) andσ_(CYS) decreases after 3 d of immersion in Hanks’solution.In comparison to pure titanium and Mg,the HE MGCP demonstrated much greater cytocompatibility,angiogenic capacity,and osteogenic differentiation and mineralization capability.Furthermore,the HE MGCP displayed markedly higher in vitro antibacterial activity,in vivo antibacterial and anti-inflammatory ability,and good biosafety in a rat subcutaneous-implantation model compared to pure titanium and Mg,indicating significant potential for biodegradable bone-fixation applications.展开更多
The effect of deposition temperature on the morphology and optoelectronic performance of Ge/Si QDs grown by magnetron sputtering under low Ge deposition(~4 nm)was investigated by atomic force microscopy,Raman spectros...The effect of deposition temperature on the morphology and optoelectronic performance of Ge/Si QDs grown by magnetron sputtering under low Ge deposition(~4 nm)was investigated by atomic force microscopy,Raman spectroscopy,and photoluminescence(PL)tests.The experimental results indicate that temperatures higher than 750℃effectively increase the crystallization rate and surface smoothness of the Si buffer layer,and temperatures higher than 600℃significantly enhance the migration ability of Ge atoms,thus increasing the probability of Ge atoms meeting and nucleating to form QDs on Si buffer layer,but an excessively high temperature will cause the QDs to undergo an Ostwald ripening process and thus develop into super large islands.In addition,some PL peaks were observed in samples containing small-sized,high-density Ge QDs,the photoelectric properties reflected by these peaks were in good agreement with the corresponding structural characteristics of the grown QDs.Our results demonstrate the viability of preparing high-quality QDs by magnetron sputtering at high deposition rate,and the temperature effect is expected to work in conjunction with other controllable factors to further regulate QD growth,which paves an effective way for the industrial production of QDs that can be used in future devices.展开更多
To solve the volume expansion and poor electrical conductivity of germanium-based anode materials,Ge/rGO/CNTs nanocomposites with three-dimensional network structure are fabricated through the dispersion of polyethyle...To solve the volume expansion and poor electrical conductivity of germanium-based anode materials,Ge/rGO/CNTs nanocomposites with three-dimensional network structure are fabricated through the dispersion of polyethylene-polypropylene glycol(F127)and reduction of hydrogen.An interesting phenomenon is discovered that F127 can break GeO_(2)polycrystalline microparticles into 100 nm nanoparticles by only physical interaction,which promotes the uniform dispersion of GeO_(2)in a carbon network structure composed of graphene(rGO)and carbon nanotubes(CNTs).As evaluated as anode material of Lithium-ion batteries,Ge/rGO/CNTs nanocomposites exhibit excellent lithium storage performance.The initial specific capacity is high to 1549.7 mAh/g at 0.2 A/g,and the reversible capacity still retains972.4 mAh/g after 100 cycles.The improved lithium storage performance is attributed to that Ge nanoparticles can effectively slow down the volume expansion during charge and discharge processes,and threedimensional carbon networks can improve electrical conductivity and accelerate lithium-ion transfer of anode materials.展开更多
基金supported by the Zhejiang Public Welfare Technology Application Research Project of China(No.LTGY24H140002,No.LTGY23H140002,No.LGF22H140008)Wenzhou Medical University Basic Scientific Research Expenses Project(KYYW202331)the financial support for this research by the Australian Research Council(ARC)through the Discovery Project(DP240101131).
文摘Magnesium(Mg)-based composites are expected to be useful for biodegradable bone-implant materials due to their degradability,similar elastic modulus to that of bone,and biofunctionalities.However,their rapid degradation,poor biotribology performance,and lack of vascularization and antibacterial activity are not conducive to bone-fixation applications.In this study,an in situ Mg_(2)Ge/Mg-Cu-P composite with a nominal composition of Mg-10Ge-2Cu-0.5P(denoted MGCP)was prepared via phosphorus(P)-modified casting followed by hot extrusion for biodegradable bone-fixation applications.For comparison,an in situ Mg_(2)Ge/Mg-Cu composite(Mg-10Ge-2Cu,denoted MGC)was prepared under the same conditions without P-modification.The hot-extruded(HE)MGCP sample showed significantly improved corrosion resistance with corrosion rates of 2.2 mm/y and 2.51 mm/y as measured by potentiodynamic-polarization and hydrogen-release testing in Dulbecco’s Modified Eagle Medium supplemented with fetal bovine serum(denoted DMEM).The HE MGCP also exhibited notably enhanced mechanical properties and biotribological resistance in DMEM,with an σ_(UTS) of ~304.2 MPa,σ_(TYS) of ~202.5 MPa,elongation of ~12.3%,σ_(UCS) of 769.0 MPa,σ_(CYS) of 208.0 MPa,and Brinell hardness of 105.3 HB,along with smallerσ_(TYS) andσ_(CYS) decreases after 3 d of immersion in Hanks’solution.In comparison to pure titanium and Mg,the HE MGCP demonstrated much greater cytocompatibility,angiogenic capacity,and osteogenic differentiation and mineralization capability.Furthermore,the HE MGCP displayed markedly higher in vitro antibacterial activity,in vivo antibacterial and anti-inflammatory ability,and good biosafety in a rat subcutaneous-implantation model compared to pure titanium and Mg,indicating significant potential for biodegradable bone-fixation applications.
基金Founded by the National Key Research and Development Program(No.2021YFB3802400)the National Natural Science Foundation of China(No.52161037)the Basic Research Project of Yunnan Province(No.202001AU070112)。
文摘The effect of deposition temperature on the morphology and optoelectronic performance of Ge/Si QDs grown by magnetron sputtering under low Ge deposition(~4 nm)was investigated by atomic force microscopy,Raman spectroscopy,and photoluminescence(PL)tests.The experimental results indicate that temperatures higher than 750℃effectively increase the crystallization rate and surface smoothness of the Si buffer layer,and temperatures higher than 600℃significantly enhance the migration ability of Ge atoms,thus increasing the probability of Ge atoms meeting and nucleating to form QDs on Si buffer layer,but an excessively high temperature will cause the QDs to undergo an Ostwald ripening process and thus develop into super large islands.In addition,some PL peaks were observed in samples containing small-sized,high-density Ge QDs,the photoelectric properties reflected by these peaks were in good agreement with the corresponding structural characteristics of the grown QDs.Our results demonstrate the viability of preparing high-quality QDs by magnetron sputtering at high deposition rate,and the temperature effect is expected to work in conjunction with other controllable factors to further regulate QD growth,which paves an effective way for the industrial production of QDs that can be used in future devices.
基金financially supported by National Natural Science Foundation of China(Nos.22379056,52102100)Industry foresight and common key technology research in Carbon Peak and Carbon Neutrality Special Project from Zhenjiang city(No.CG2023003)Research and Practice Innovation Plan of Postgraduate Training Innovation Project in Jiangsu Province(No.SJCX23_2164)。
文摘To solve the volume expansion and poor electrical conductivity of germanium-based anode materials,Ge/rGO/CNTs nanocomposites with three-dimensional network structure are fabricated through the dispersion of polyethylene-polypropylene glycol(F127)and reduction of hydrogen.An interesting phenomenon is discovered that F127 can break GeO_(2)polycrystalline microparticles into 100 nm nanoparticles by only physical interaction,which promotes the uniform dispersion of GeO_(2)in a carbon network structure composed of graphene(rGO)and carbon nanotubes(CNTs).As evaluated as anode material of Lithium-ion batteries,Ge/rGO/CNTs nanocomposites exhibit excellent lithium storage performance.The initial specific capacity is high to 1549.7 mAh/g at 0.2 A/g,and the reversible capacity still retains972.4 mAh/g after 100 cycles.The improved lithium storage performance is attributed to that Ge nanoparticles can effectively slow down the volume expansion during charge and discharge processes,and threedimensional carbon networks can improve electrical conductivity and accelerate lithium-ion transfer of anode materials.
