硅酸盐对Ferrihydrite相转化为α-Fe2O3微粒形貌的调控作用

以Ferrihydrite(又称水合氧化铁hydrous iron oxide)为反应前驱物, Fe(II)为催化剂, 在微量Na₂SiO₃存在下, 控制pH＝6～9范围内合成出了亚微米级纺锤形和准立方形α-Fe₂O₃微粒. 研究了初始pH, Na₂SiO₃浓度, Ferrihydrite老化方式对相转化时间和产物形貌的影响, 利用XRD, SEM等手段对产物进行了表征. 结果表明, Na₂SiO₃对Ferriihydrite催化相转化有一定的抑制作用, 是影响其相转化过程及产物形貌的关键. 在弱碱性条件下, [Si]/[Fe^3＋]为0.01时可直接获得纺锤形(轴比≥2)或准立方形(300～400 nm) α-Fe₂O₃粒子, 并对形成机理进行了初步讨论.     

金刚石/Fe3O4磁性聚集磨料的制备与表征

以表面缺陷较多的金刚石微粉为实验原料,用混合强酸对其表面进行处理使其羟基和羧基化.然后采用化学沉淀法制备出金刚石/Fe3 O4磁性聚集磨料.用XRD、SEM、EDS、IR、Raman、VSM等检测方法对样品的结构、形貌、元素组成和磁性能进行了表征.结果表明,Fe3+与金刚石表面的含氧基团的络合作用,使金刚石微粉表面被Fe3 O4颗粒包裹,形成不规则类球形金刚石/Fe3 O4磁性聚集体.当金刚石加入量占理论生成总固体量的9.4wt;时,磁性聚集磨料展现较高的磁性能.其饱和磁化强度(Ms=60.8 emu/g)与同等工艺制备的纯Fe3O4样品(Ms=66.3 emu/g)接近.     

基于纳米金／壳聚糖掺杂碳纳米管修饰金电极非标记免疫传感器的研究

应用吸附法将羊抗人IgG抗体直接固定于纳米金(GNPs)/壳聚糖(Chit)掺杂碳纳米管(CNTs)修饰的金电极表面,制备了用于人IgG抗原检测的非标记电化学免疫传感器.利用循环伏安法和交流阻抗研究了修饰电极表面的电化学特性,用差分脉冲伏安法研究了测试底液的pH值对免疫传感器性能的影响.实验表明,在含不同浓度人IgG的...     

Industrial diamonds grown in Ni70Mn25Co5--graphite--sulfur system under HPHT

This paper reports that diamond single crystals were synthesized from sulfur-added Ni70Mn25Co5+C system under high pressure and high temperature(HPHT).It was found that additive sulfur had inhibited the nucleation and growth of diamond to some extent.X-ray diffraction of the collected sample indicated that under the synthesis conditions,a new compound MnS had been formed through the reaction of additive sulfur with manganese in the catalyst.The MnS has a fcc structure,and its average crystal size was about 30 nm.By scanning electron microscope,the {111} surface of diamond was found to be flat,while there was usually a large depression on the central region of {100}.Further observation showed that there were many small upside-down pyramidal pits in the expression.The results of x-ray photoelectron spectroscopy shows that MnS can only be detected in the depression in the range of detection precision.It was inferred that MnS had been dissolved in the melted alloy during the growth experiment,and precipitated in the sequent quenching process.     

硅酸盐对Ferrihydrite相转化为α-Fe2O3微粒形貌的调控作用

以Ferrihydrite(又称水合氧化铁hydrous iron oxide)为反应前驱物, Fe(II)为催化剂, 在微量Na₂SiO₃存在下, 控制pH＝6～9范围内合成出了亚微米级纺锤形和准立方形α-Fe₂O₃微粒. 研究了初始pH, Na₂SiO₃浓度, Ferrihydrite老化方式对相转化时间和产物形貌的影响, 利用XRD, SEM等手段对产物进行了表征. 结果表明, Na₂SiO₃对Ferriihydrite催化相转化有一定的抑制作用, 是影响其相转化过程及产物形貌的关键. 在弱碱性条件下, [Si]/[Fe^3＋]为0.01时可直接获得纺锤形(轴比≥2)或准立方形(300～400 nm) α-Fe₂O₃粒子, 并对形成机理进行了初步讨论.     

Synthesis of industrial diamonds using FeNi alloy powder as catalyst

Synthesis of diamond single crystals in Fe80Ni20 C system was carried out in a cubic anvil high-pressure and high-temperature apparatus. This paper reports that the surface morphology and inclusion distribution of the grown diamonds had been observed. It finds that the inclusions in cubic and octahedral diamonds radiated along certain crystal orientation, while the inclusion distribution in cubo-octahedral diamond seemed independent of crystal orientation. By using scanning electron microscope, the surface morphology of the three shapes of diamonds was observed. The results of Mossbauer spectrum indicated that there were iron-inclusions FeaC and Fe-Ni alloy in the diamonds. According to the Fe-C phase diagram, FeaC should have formed during the quenching process. Nickel might have an inhibitory effect on the formation of Fe3C.     

具有MIL-100和MIL-101结构巨孔羧酸钪配位聚合物

用溶剂热方法首次以DMF为溶剂合成了具有MIL-100和MIL-101结构的巨孔均苯三甲酸钪(1)和对苯二甲酸钪(2)配位聚合物,通过将钯金属纳米粒子沉积到均三苯甲酸钪(1)的骨架结构中的方法,获得了后功能化的载有钯纳米粒子的配位聚合物孔材料Pd@1,并对以上材料进行了X-射线粉末衍射、扫描电镜、透射电镜和氮气吸附表征。