304 stainless steel(SS) used as orthodontic wire during orthodontics faces the risk of microbiologically influenced corrosion(MIC) due to diverse flora environment. Hereinto, Streptococcus mutans(S. mutans)is the most...304 stainless steel(SS) used as orthodontic wire during orthodontics faces the risk of microbiologically influenced corrosion(MIC) due to diverse flora environment. Hereinto, Streptococcus mutans(S. mutans)is the most important cariogenic bacteria. In this work, MIC behavior of a new 304-Cu SS in presence of S. mutans was studied by the observations using scanning electron microscopy(SEM) and confocal laser scanning microscopy(CLSM) including live/dead staining, extracellular polymeric substance(EPS)staining and pitting corrosion, electrochemical test, and X-ray photoelectron spectroscopy(XPS). Above results showed that 304-Cu SS possessed excellent biofilm inhibition ability and presented lower corrosion current density(icorr), larger polarization resistance(Rp) and charge transfer resistance(Rct) in the presence of S. mutans, indicating that 304-Cu SS had a better MIC resistance against S. mutans. It was further affirmed by XPS results that the presence of Cu-oxide in passive film of 304-Cu SS inhibited the formation of biofilm.展开更多
Stainless steel（SS） is not recommended to be used in hospital environments for work surfaces and door furniture due to the lack of antibacterial properties.To this end,a novel SS surface modified layer with both a q...Stainless steel（SS） is not recommended to be used in hospital environments for work surfaces and door furniture due to the lack of antibacterial properties.To this end,a novel SS surface modified layer with both a quick bacterial killing rate and relatively thick has been obtained by plasma surface alloying with Cu.The microstructure,elements distribution and phase identification were analyzed by SEM,GDS,XRD and XPS.A spread plate method was adopted for evaluation of antibacterial property of specimens against Escherichia coli（E.coli） and Staphylococcus aureus（S.aureus）.The experimental results demonstrate that the surface modified layer with the thickness of about 26 μm is uniform and dense.The layer is mainly composed of a mixture of pure Cu,expanded austenite phase and a few Fe3O4 phase.The Cu modified layer exhibits excellent antibacterial effects against E.coli and S.aureus within 1 h.No viable E.coli and S.aureus was found after 3 h（100% killed）.The modified layer is relatively thick,hence it is expected that the Cu modified SS will have a durable antibacterial function展开更多
基金supported financially by the National Natural Science Foundation of China (Nos. 51501199, 51631009 and U1906226)the National Key Research and Development Program of China (No. 2016YFB0300205)。
文摘304 stainless steel(SS) used as orthodontic wire during orthodontics faces the risk of microbiologically influenced corrosion(MIC) due to diverse flora environment. Hereinto, Streptococcus mutans(S. mutans)is the most important cariogenic bacteria. In this work, MIC behavior of a new 304-Cu SS in presence of S. mutans was studied by the observations using scanning electron microscopy(SEM) and confocal laser scanning microscopy(CLSM) including live/dead staining, extracellular polymeric substance(EPS)staining and pitting corrosion, electrochemical test, and X-ray photoelectron spectroscopy(XPS). Above results showed that 304-Cu SS possessed excellent biofilm inhibition ability and presented lower corrosion current density(icorr), larger polarization resistance(Rp) and charge transfer resistance(Rct) in the presence of S. mutans, indicating that 304-Cu SS had a better MIC resistance against S. mutans. It was further affirmed by XPS results that the presence of Cu-oxide in passive film of 304-Cu SS inhibited the formation of biofilm.
基金Sponsored by National Natural Science Foundation of China(51171125)Research Project Supported by Shanxi Scholarship Council of China(2011-038)+1 种基金Science and Technology Key Project of Shanxi Province of China(20110321051)Graduate Innovation Project of Shanxi Province of China(20103024)
文摘Stainless steel（SS） is not recommended to be used in hospital environments for work surfaces and door furniture due to the lack of antibacterial properties.To this end,a novel SS surface modified layer with both a quick bacterial killing rate and relatively thick has been obtained by plasma surface alloying with Cu.The microstructure,elements distribution and phase identification were analyzed by SEM,GDS,XRD and XPS.A spread plate method was adopted for evaluation of antibacterial property of specimens against Escherichia coli（E.coli） and Staphylococcus aureus（S.aureus）.The experimental results demonstrate that the surface modified layer with the thickness of about 26 μm is uniform and dense.The layer is mainly composed of a mixture of pure Cu,expanded austenite phase and a few Fe3O4 phase.The Cu modified layer exhibits excellent antibacterial effects against E.coli and S.aureus within 1 h.No viable E.coli and S.aureus was found after 3 h（100% killed）.The modified layer is relatively thick,hence it is expected that the Cu modified SS will have a durable antibacterial function
