Fachbereich Material-und Geowissenschaften, Technische Universität Darmstadt , Jovanka Bontschits Strasse 2, D-64287 Darmstadt, Germany.
ACS Appl Mater Interfaces. 2014 Aug 13;6(15):12270-8. doi: 10.1021/am501892z. Epub 2014 Jul 24.
Superparamagnetic Ni nanoparticles with diameters of about 3 nm are formed in situ at room temperature in a polysilazane matrix, forming Ni/polysilazane nanocomposite, in the reaction between a polysilazane and trans-bis(aceto-kO)bis(2-aminoethanol-k(2)N,O)nickel(II). The thermolysis of the Ni/polysilazane nanocomposite at 700 °C in an argon atmosphere results in a microporous superparamagnetic Ni/silicon oxycarbonitride (Ni/SiCNO) ceramic nanocomposite. The growth of Ni nanoparticles in Ni/SiCNO ceramic nanocomposite is totally suppressed even after thermolysis at 700 °C, as confirmed by HRTEM and SQUID characterizations. The analysis of saturation magnetization of Ni nanoparticles in Ni/polysilazane and Ni/SiCNO nanocomposites indicates that the saturation magnetization of Ni nanoparticles is higher than expected values and infers that the surfaces of Ni nanoparticles are not oxidized. The microporous superparamagnetic Ni/SiCNO nanocomposite is shaped as a free-standing monolith and foam. In addition, Ni/SiCNO membranes are fabricated by the dip-coating of a tubular alumina substrate in a dispersion of Ni/polysilazane in THF followed by a thermolysis at 700 °C under an argon atmosphere. The gas separation performance of Ni/SiCNO membranes at 25 and 300 °C is assessed by the single gas permeance (pressure rise technique) using He, H2, CO2, N2, CH4, n-propene, n-propane, n-butene, n-butane, and SF6 as probe molecules. After hydrothermal treatment, the higher increase in the hydrogen permeance compared to the permeance of other gases as a function of temperature indicates that the hydrogen affinity of Ni nanoparticles influences the transport of hydrogen in the Ni/SiCNO membrane and Ni nanoparticles stabilize the structure against hydrothermal corrosion.
在室温下，通过硅氮烷与反式双（乙酰基-O）双（2-氨基乙醇-K（2）N，O）镍（II）的反应，原位形成直径约为 3nm 的超顺磁 Ni 纳米粒子，形成 Ni/硅氮烷纳米复合材料。在氩气气氛中，将 Ni/硅氮烷纳米复合材料在 700°C 下热解，得到微孔超顺磁 Ni/硅氧碳氮化物（Ni/SiCNO）陶瓷纳米复合材料。通过高分辨透射电子显微镜（HRTEM）和超导量子干涉仪（SQUID）的表征证实，即使在 700°C 下热解后，Ni/SiCNO 陶瓷纳米复合材料中 Ni 纳米粒子的生长也完全受到抑制。Ni/硅氮烷和 Ni/SiCNO 纳米复合材料中 Ni 纳米粒子的饱和磁化强度分析表明，Ni 纳米粒子的饱和磁化强度高于预期值，并推断出 Ni 纳米粒子的表面未被氧化。微孔超顺磁 Ni/SiCNO 纳米复合材料呈独立的块状和泡沫状。此外，通过将管状氧化铝基底浸入 Ni/硅氮烷在四氢呋喃中的分散体中进行浸涂，然后在氩气气氛下于 700°C 下热解，制备了 Ni/SiCNO 膜。使用 He、H2、CO2、N2、CH4、n-丙烯、n-丙烷、n-丁烯、n-丁烷和 SF6 作为探针分子，通过单气体透过率（升压技术）评估 Ni/SiCNO 膜在 25 和 300°C 下的气体分离性能。在水热处理后，与其他气体的透过率相比，氢气透过率的增加幅度更大，这表明 Ni 纳米粒子的氢亲和力影响了氢气在 Ni/SiCNO 膜中的传输，并且 Ni 纳米粒子稳定了结构免受水热腐蚀。
