惰气熔融-红外吸收法测定铬铝、钼铝中间合金粉中氧

铬铝(铝铬)、钼铝(铝钼)中间合金是重要的钛合金用新型合金剂,准确测定其中的氧含量有利于从源头上指导钛合金的质量控制。称取(100±50)mg样品采用锡囊包裹,设定分析功率为5.0~5.5kW,采用钢铁标准样品校准仪器(分析功率4.0kW),使用石墨套坩埚进行测定,建立了脉冲加热-惰气熔融-红外吸收法测定铬铝、钼铝中间合金粉中氧含量的方法。对样品量、分析功率进行了优化,并重点探讨了锡囊、镍箔、镍篮为助熔剂对氧量测定的影响。结果表明,助熔剂对氧含量的释放有较大的影响;部分程度上,镍箔、镍篮或会抑制或阻碍氧化铝中氧的释放,造成铬铝、钼铝中间合金中氧的释放率和测定结果存在显著偏低及不稳定的质量风险。在选定的实验条件下,方法检出限、定量限分别为0.004%、0.012%,定量范围为0.012%~0.58%。按实验方法分析铬铝、钼铝合金粉状样品,结果的相对标准偏差(RSD,n=6)不大于6%,极差显著小于参考YS/T 1075.7—2015《钒铝、钼铝中间合金化学分析方法第7部分:氧量的测定惰气熔融-红外法》计算的临界差(1.4倍重复性限)。采用加入氧化铝粉的方法合成加标样品,氧化铝中氧的回收率为90%~109%。方法可适用于铬铝、钼铝中间合金粉中氧含量的测定,并有望在以铬、钼为合金元素的钛合金用新型铝基中间合金(如铝钼铬、钼钒铝、钒铝锡铬)中得到推广和应用。

镍基非晶合金/钛硅分子筛复合材料的制备及其电催化性能

以纳米钛硅分子筛(TS-1)晶体作为复合相与镍磷合金在泡沫镍(NF)表面共沉积,制备了镍基非晶合金/钛硅分子筛复合材料(Ni-P-TS-1/NF),并采用原位处理工艺对其催化性能进行优化。催化性能测试结果表明:原位处理过的复合材料具有优异的电催化析氧性能。这是由于纳米钛硅分子筛的共沉积提升了复合材料表面的电子转移速率及电催化活性表面积,原位处理工艺改变了复合材料的表面形貌及电子状态,暴露出更多的催化活性中心,并形成了能为电催化析氧反应提供活性中心的镍的磷化物及氢氧化物,从而有效提升了复合材料的电催化析氧性能。

镍钛合金纤维基体表面纳米多孔复合氧化物的可控生长及其对多环芳烃的选择性固相微萃取

采用水热氧化法制备镍钛合金(Ni Ti)固相微萃取纤维。实验结果表明,在80℃的H2O2溶液中,直接氧化Ni Ti纤维基体可在其表面原位生长纳米多孔氧化镍/氧化钛复合涂层,其中氧化镍含量显著高于氧化钛含量。与高效液相色谱-紫外检测器(HPLC-UV)检测技术联用,考察了所制备Ni Ti纤维对典型芳香族化合物的萃取性能。结果表明,富Ni复合氧化物涂层对多环芳烃(PAHs)表现出良好的萃取选择性。在优化实验条件下,方法的线性范围为0.1~400.0 ng/m L,相关系数大于0.999,PAHs的检出限为0.026~0.056 ng/m L。对于50 ng/m L加标水样,单支Ni Ti纤维日内和日间测量的相对标准偏差(RSDs)分别为4.8%~6.2%和5.4%~6.5%(n=5),使用5支不同批纤维测量的RSDs为6.4%~8.4%。本方法适用于环境水样中PAHs的富集和测定,相对回收率为89.9%~108.5%,RSDs<8.1%。而且,Ni Ti纤维机械强度高,化学稳定性好,制备过程精密可控。

Antibacterial ability and cytocompatibility of Cu-incorporated Ni–Ti–O nanopores on NiTi alloy

Nearly equiatomic nickel–titanium(NiTi) alloy is an ideal implant biomaterial because of its shape memory effect, superelasticity, low elastic modulus as well as other desirable properties.However, it is prone to infection because of its poor antibacterial ability.The present work incorporated Cu into Ni–Ti–O nanopores(NP–Cu) anodically grown on the NiTi alloy to enhance its antibacterial ability, which was realized through electrodeposition.Our results show that incorporation of Cu(0.78 at%–2.37 at%)has little influence on the NP diameter, length and morphology.The release level of Cu ions is in line with loadage which may be responsible for the improved antibacterial ability of the NiTi alloy to combat possible bacterial infection in vivo.Meanwhile, the NP–Cu shows better cytocompatibility and even can promote proliferation of bone marrow mesenchymal stem cells(BMSCs),up-regulate collagen secretion and extracellular matrix mineralization when compared with Cu-free sample.Better antibacterial ability and cytocompatibility of the NP–Cu render them to be promising when serving as NiTi implant coatings.

惰气熔融-红外吸收光谱法测定镍钛形状记忆合金中氧

镍钛形状记忆合金中氧含量直接影响合金的记忆和力学等性能,因此需要严格控制其含量。针对块/粉两种形态样品,采用单因素法,通过对仪器功率、助熔剂种类和称样量等试验条件的优化选择,建立了惰气熔融-红外吸收光谱法测定块/粉状镍钛形状记忆合金中氧含量的分析方法。根据氧含量称取0.06~0.12g样品,以镍箔-镍篮为助熔剂,在5.0~5.5kW功率下进行测定,方法定量限为0.0008%。对实际镍钛形状记忆合金进行分析,结果的相对标准偏差(RSD,n=7)小于4%;加标回收率为96%~104%。

Selective inhibition effects on cancer cells and bacteria of Ni–Ti–O nanoporous layers grown on biomedical NiTi alloy by anodization

Stents made of nearly equiatomic NiTi alloy are used to treat malignant obstruction caused by cancer,but prevention of re-obstruction after surgery is still a challenge because the bare stents possess poor anticancer and antibacterial properties to inhibit cancer/bacteria invasion.The present work aims at endowing the NiTi alloy with anticancer and antibacterial abilities by surface modification.Ni–Ti–O nanoporous layers with different thicknesses were prepared on NiTi by anodization,and biological experiments were conducted to evaluate the effects on gram-positive Staphylococcus aureus,human lung epithelial cancer cells(A549),as well as human endothelial cells(EA.hy926).The nanoporous layer with a thickness of 10.1 lm inhibits growth of cancer cells and kill bacteria but shows little adverse effects on normal cells.Such selectivity is related to the larger amount of Ni ions leached from the sample in the acidic microenvironment of cancer cells in comparison with normal cells.The Ni–Ti–O nanoporous layers are promising as coatings on NiTi stents to prevent re-obstruction after surgery.

镍-磷-钛硅分子筛复合材料的制备与催化性能

以多级孔钛硅分子筛(HTS-1)为复合相、泡沫镍(NF)为基体,采用化学复合镀和原位处理工艺制备了镍-磷-钛硅分子筛(Ni-P-HTS-1/NF-T)复合材料,并对其电催化析氧反应(OER)性能进行研究。结果表明,Ni-P-HTS-1/NF-T复合材料在1 mol/L的KOH电解液中具有较快的OER动力学及电子转移速率,优异的OER性能及长期运行稳定性。HTS-1分子筛的掺杂及原位处理工艺降低了Ni-P-HTS-1/NF-T复合材料的电子转移电阻,增大其电催化活性表面积,此外还改变了复合材料的化学组成,生成了能为电催化析氧反应提供催化活性中心的镍的磷化物和氢氧化物,从而有效提升了Ni-P-HTS-1/NF-T复合材料的OER性能。