To reduce Ni ion release and improve biocompatibility of NiTi alloy, the cathodic plasma electrolytic deposition (CPED) technique was used to fabricate ceramic coating onto a NiTi alloy surface. The formation of a c...To reduce Ni ion release and improve biocompatibility of NiTi alloy, the cathodic plasma electrolytic deposition (CPED) technique was used to fabricate ceramic coating onto a NiTi alloy surface. The formation of a coating with a rough and micro-textured surface was confirmed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy, re- spectively. An inductively coupled plasma mass spectrometry test showed that the formed coating significantly reduced the release of Ni ions from the NiTi alloy in simulated body fluid. The in- fluence of CPED treated NiTi substrates on the biological behaviors of osteoblasts, including cell adhesion, cell viability, and osteogenic differentiation function (alkaline phosphatase), was inves- tigated in vitro. Immunofluorescence staining of nuclei revealed that the CPED treated NiTi alloy was favorable for cell growth. Osteoblasts on CPED modified NiTi alloy showed greater cell viability than those for the native NiTi substrate after 4 and 7 days cultures. More importantly, osteoblasts cultured onto a modified NiTi sample displayed significantly higher differentiation lev-els of alkaline phosphatase. The results suggested that surface functionalization of NiTi alloy with ceramic coating via the CPED technique was beneficial for cell proliferation and differentiation. The approach presented here is useful for NiTi implants to enhance bone osseointegration and reduce Ni ion release in vitro.展开更多
Electroreduction of Co(Ⅱ)to metallic cohalt in urea melt is irrevsible in one step.The transfer coeffi-cient of electrode reaction of Co(Ⅱ)+2e=Co(O)and the diffusion coefficient of Co(Ⅱ)were determined.The lanthanu...Electroreduction of Co(Ⅱ)to metallic cohalt in urea melt is irrevsible in one step.The transfer coeffi-cient of electrode reaction of Co(Ⅱ)+2e=Co(O)and the diffusion coefficient of Co(Ⅱ)were determined.The lanthanum can be inductively codeposited with cobalt. The contents of lanthanum in cobalt-lanthanum de-posts increase with the shift of electrode potential to the negative direction and the raise of La(Ⅲ)/Co(Ⅱ)mo-lar ratio in the melt. The cyclic voltammetry,open circuit potential-time curve after potentiostatic electrolysisand electron probe analyas were used.展开更多
Dendrite growth of lithium(Li)metal anode severely hinders its practical application,while the situation becomes more serious at low temperatures due to the sluggish kinetics of Liion diffusion.This perspective is int...Dendrite growth of lithium(Li)metal anode severely hinders its practical application,while the situation becomes more serious at low temperatures due to the sluggish kinetics of Liion diffusion.This perspective is intended to clearly understand the energy chemistry of lowtemperature Li metal batteries(LMBs).The lowtemperature chemistries between LMBs and traditional Liion batteries are firstly compared to figure out the features of the lowtemperature LMBs.Li deposition behaviors at low temperatures are then discussed concerning the variation in Liion diffusion behaviors and solid electrolyte interphase(SEI)features.Subsequently,the strategies to enhance the diffusion kinetics of Li ions and suppress dendrite growth including designing electrolytes and electrode/electrolyte interfaces are analyzed.Finally,conclusions and outlooks are drawn to shed lights on the future design of highperformance lowtemperature LMBs.展开更多
基金supported by China Ministry of Science and Technology (973 project No. 2009CB930000)National Natural Science Foundation of China (Nos. 11032012 and 51173216)+3 种基金Fok Ying Tung Education Foundation (121035)Natural Science Foundation of Chongqing Municipal Government (CSTC2011jjjq10004 and CSTC2012gg-yyjs10023)Fundamental Research Funds for the Central Universities (Nos. CDJXS10232211, CDJZR11230005)the sharing fund of Chongqing University's large-scale equipment (Nos. 2011063046,2011063047)
文摘To reduce Ni ion release and improve biocompatibility of NiTi alloy, the cathodic plasma electrolytic deposition (CPED) technique was used to fabricate ceramic coating onto a NiTi alloy surface. The formation of a coating with a rough and micro-textured surface was confirmed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy, re- spectively. An inductively coupled plasma mass spectrometry test showed that the formed coating significantly reduced the release of Ni ions from the NiTi alloy in simulated body fluid. The in- fluence of CPED treated NiTi substrates on the biological behaviors of osteoblasts, including cell adhesion, cell viability, and osteogenic differentiation function (alkaline phosphatase), was inves- tigated in vitro. Immunofluorescence staining of nuclei revealed that the CPED treated NiTi alloy was favorable for cell growth. Osteoblasts on CPED modified NiTi alloy showed greater cell viability than those for the native NiTi substrate after 4 and 7 days cultures. More importantly, osteoblasts cultured onto a modified NiTi sample displayed significantly higher differentiation lev-els of alkaline phosphatase. The results suggested that surface functionalization of NiTi alloy with ceramic coating via the CPED technique was beneficial for cell proliferation and differentiation. The approach presented here is useful for NiTi implants to enhance bone osseointegration and reduce Ni ion release in vitro.
文摘Electroreduction of Co(Ⅱ)to metallic cohalt in urea melt is irrevsible in one step.The transfer coeffi-cient of electrode reaction of Co(Ⅱ)+2e=Co(O)and the diffusion coefficient of Co(Ⅱ)were determined.The lanthanum can be inductively codeposited with cobalt. The contents of lanthanum in cobalt-lanthanum de-posts increase with the shift of electrode potential to the negative direction and the raise of La(Ⅲ)/Co(Ⅱ)mo-lar ratio in the melt. The cyclic voltammetry,open circuit potential-time curve after potentiostatic electrolysisand electron probe analyas were used.
基金supported by National Natural Science Founda-tion of China(22179070,22109083,22108151,22075029,and 22061132002)China Postdoctoral Science Foundation(BX2021135,2021TQ0164)+1 种基金the Seed Fund of Shanxi Research In-stitute for Clean Energy(SXKYJF015)the Tsinghua University Initiative Scientific Research Program,and the“Shuimu Tsinghua Scholar Program of Tsinghua University”.
文摘Dendrite growth of lithium(Li)metal anode severely hinders its practical application,while the situation becomes more serious at low temperatures due to the sluggish kinetics of Liion diffusion.This perspective is intended to clearly understand the energy chemistry of lowtemperature Li metal batteries(LMBs).The lowtemperature chemistries between LMBs and traditional Liion batteries are firstly compared to figure out the features of the lowtemperature LMBs.Li deposition behaviors at low temperatures are then discussed concerning the variation in Liion diffusion behaviors and solid electrolyte interphase(SEI)features.Subsequently,the strategies to enhance the diffusion kinetics of Li ions and suppress dendrite growth including designing electrolytes and electrode/electrolyte interfaces are analyzed.Finally,conclusions and outlooks are drawn to shed lights on the future design of highperformance lowtemperature LMBs.