A flower-like SnO_(2)–SnO/porous Ga N(FSS/PGaN) heterojunction was fabricated for the first time via a facile spraying process, and the whole process also involved hydrothermal preparation of FSS and electrochemical ...A flower-like SnO_(2)–SnO/porous Ga N(FSS/PGaN) heterojunction was fabricated for the first time via a facile spraying process, and the whole process also involved hydrothermal preparation of FSS and electrochemical wet etching of GaN,and SnO_(2)–SnO composites with p–n junctions were loaded onto PGaN surface directly applied to H_(2)S sensor. Meanwhile,the excellent transport capability of heterojunction between FSS and PGaN facilitates electron transfer, that is, a response time as short as 65 s and a release time up to 27 s can be achieved merely at 150℃ under 50 ppm H_(2)S concentration, which has laid a reasonable theoretical and experimental foundation for the subsequent PGaN-based heterojunction gas sensor.The lowering working temperature and high sensitivity(23.5 at 200 ppm H2S) are attributed to the structure of PGaN itself and the heterojunction between SnO_(2)–SnO and PGaN. In addition, the as-obtained sensor showed ultra-high test stability.The simple design strategy of FSS/PGaN-based H_(2)S sensor highlights its potential in various applications.展开更多
To clarify the antibacterial behavior at early adhesion,two titania nanotube(TNT)arrays were fabricated on polished commercially pure titanium(Ti),and the interaction mechanisms between TNT arrays and the model bacter...To clarify the antibacterial behavior at early adhesion,two titania nanotube(TNT)arrays were fabricated on polished commercially pure titanium(Ti),and the interaction mechanisms between TNT arrays and the model bacteria(Escherichia coli,E.coli)were investigated.The results show that TNT arrays exhibit a significant early antibacterial effect,which is highly related to the surface free energy and nano-topography.The underlying antibacterial mechanisms include:(1)the anti-initial-attachment effect at the lag phase(0−4 h);(2)the anti-proliferation and physical bactericidal effects at the logarithmic phase(4−12 h);(3)the reduced antimicrobial properties probably due to the overgrowth of bacteria on TNT arrays at the stationary phase(12 h and then).展开更多
Hydroxyapatite（HA） and strontium（Sr） incorporated HA coatings with different Sr contents were prepared on Mg-4 Zn substrates by electrochemical deposition method. Fourier transform infrared（FTIR） spectroscopy, X...Hydroxyapatite（HA） and strontium（Sr） incorporated HA coatings with different Sr contents were prepared on Mg-4 Zn substrates by electrochemical deposition method. Fourier transform infrared（FTIR） spectroscopy, X-ray diffraction（XRD）, scanning electron microscopy（SEM）, energy dispersive spectroscopy（EDS） and electrochemical workstation were applied for the composition, phase constitution, morphology analyses and corrosion tests. The results reveal that the incorporation of Sr in coatings does not lead to dramatical change of functional groups and the crystal structure of the HA phase, but the crystal size and crystallinity decrease with increasing Sr content, which should be attributed to the lattice distortion and different occupancies of Sr and Ca ions. The 10 Sr HA@Mg-4 Zn samples show the lowest corrosion current density and the highest corrosion potential, and also exhibit the lowest amount of hydrogen evolution among all coated samples.展开更多
One of the critical issues in the development of novel metallic biomaterials is the design and fabrication of metallic scaffolds and implants with hierarchical structures mimicking human bones. In this work, selective...One of the critical issues in the development of novel metallic biomaterials is the design and fabrication of metallic scaffolds and implants with hierarchical structures mimicking human bones. In this work, selective laser melting(SLM) and electrochemical anodization were applied to fabricate dense Ti-6 A1-4 V components with macro-micron-nanoscale hierarchical surfaces. Scanning electron microscopy(SEM), 3 D laser scanning microscopy(3 D LSM), contact angle video system, fluorescence microscopy and spectrophotometer were used to investigate the properties of the samples. The results reveal that the SLMed post-anodization(SLM-TNT) exhibits enhanced or at least comparable wettability, protein adsorption and biological response of mesenchymal stem cells(MSCs) in comparison with the three reference configurations, i.e., the polished Ti-6 Al-4 V(PO-Ti64), the SLMed Ti-6 A1-4 V(SLM-Ti64) and the polished Ti-6 A1-4 V post-anodization(PO-TNT). The improved cytocompatibility of the samples after SLM and anodization should be mainly attributed to the nanoscale tubular features,while the macro-micron-scale structures only lead to slight preference for cell attachment.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52171114)the Innovation-oriented Advanced Technology and Industrial Technology Program Project of Hunan Province,China(No.2020SK2017)。
基金supported by the Natural Science Research Start-up Foundation of Recruiting Talents of Nanjing University of Posts and Telecommunications (Grant Nos. XK1060921115 and XK1060921002)Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 62204125)+1 种基金the National Key R&D Program of China (Grant No. 2022YFB3605404)the Natural Science Foundation of Guangdong Province, China (Grant No. 2019A1515010790)。
文摘A flower-like SnO_(2)–SnO/porous Ga N(FSS/PGaN) heterojunction was fabricated for the first time via a facile spraying process, and the whole process also involved hydrothermal preparation of FSS and electrochemical wet etching of GaN,and SnO_(2)–SnO composites with p–n junctions were loaded onto PGaN surface directly applied to H_(2)S sensor. Meanwhile,the excellent transport capability of heterojunction between FSS and PGaN facilitates electron transfer, that is, a response time as short as 65 s and a release time up to 27 s can be achieved merely at 150℃ under 50 ppm H_(2)S concentration, which has laid a reasonable theoretical and experimental foundation for the subsequent PGaN-based heterojunction gas sensor.The lowering working temperature and high sensitivity(23.5 at 200 ppm H2S) are attributed to the structure of PGaN itself and the heterojunction between SnO_(2)–SnO and PGaN. In addition, the as-obtained sensor showed ultra-high test stability.The simple design strategy of FSS/PGaN-based H_(2)S sensor highlights its potential in various applications.
基金The authors are grateful for the financial supports from the National Natural Science Foundation of China(Nos.51604104,52171114,81702709)the Innovation-oriented Advanced Technology and Industrial Technology Program Project of Hunan Province,China(No.2020SK2017)+2 种基金the Central South University Postgraduate Education and Teaching Reform Project,China(No.2020JGB116)the Natural Science Foundation of Hunan Province,China(No.2020JJ4459)the Fundamental Research Funds for the Central Universities of Central South University,China(No.CX20200267).
文摘To clarify the antibacterial behavior at early adhesion,two titania nanotube(TNT)arrays were fabricated on polished commercially pure titanium(Ti),and the interaction mechanisms between TNT arrays and the model bacteria(Escherichia coli,E.coli)were investigated.The results show that TNT arrays exhibit a significant early antibacterial effect,which is highly related to the surface free energy and nano-topography.The underlying antibacterial mechanisms include:(1)the anti-initial-attachment effect at the lag phase(0−4 h);(2)the anti-proliferation and physical bactericidal effects at the logarithmic phase(4−12 h);(3)the reduced antimicrobial properties probably due to the overgrowth of bacteria on TNT arrays at the stationary phase(12 h and then).
基金Project(51604104) supported by the National Natural Science Foundation of ChinaProject(JCYJ20140417113430610) supported by the Development and Reform Commission of Shenzhen Municipality,China
文摘Hydroxyapatite（HA） and strontium（Sr） incorporated HA coatings with different Sr contents were prepared on Mg-4 Zn substrates by electrochemical deposition method. Fourier transform infrared（FTIR） spectroscopy, X-ray diffraction（XRD）, scanning electron microscopy（SEM）, energy dispersive spectroscopy（EDS） and electrochemical workstation were applied for the composition, phase constitution, morphology analyses and corrosion tests. The results reveal that the incorporation of Sr in coatings does not lead to dramatical change of functional groups and the crystal structure of the HA phase, but the crystal size and crystallinity decrease with increasing Sr content, which should be attributed to the lattice distortion and different occupancies of Sr and Ca ions. The 10 Sr HA@Mg-4 Zn samples show the lowest corrosion current density and the highest corrosion potential, and also exhibit the lowest amount of hydrogen evolution among all coated samples.
基金financially supported by the National Natural Science Foundation of China (No. 51604104)Shenzhen Science and Technology Innovation Commission (No. ZDSYS201703031748354)the National Science Foundation of Guangdong Province (No. 2016A030313756)
文摘One of the critical issues in the development of novel metallic biomaterials is the design and fabrication of metallic scaffolds and implants with hierarchical structures mimicking human bones. In this work, selective laser melting(SLM) and electrochemical anodization were applied to fabricate dense Ti-6 A1-4 V components with macro-micron-nanoscale hierarchical surfaces. Scanning electron microscopy(SEM), 3 D laser scanning microscopy(3 D LSM), contact angle video system, fluorescence microscopy and spectrophotometer were used to investigate the properties of the samples. The results reveal that the SLMed post-anodization(SLM-TNT) exhibits enhanced or at least comparable wettability, protein adsorption and biological response of mesenchymal stem cells(MSCs) in comparison with the three reference configurations, i.e., the polished Ti-6 Al-4 V(PO-Ti64), the SLMed Ti-6 A1-4 V(SLM-Ti64) and the polished Ti-6 A1-4 V post-anodization(PO-TNT). The improved cytocompatibility of the samples after SLM and anodization should be mainly attributed to the nanoscale tubular features,while the macro-micron-scale structures only lead to slight preference for cell attachment.
