Lasemi Niusha, Pacher Ulrich, Rentenberger Christian, Bomatí-Miguel Oscar, Kautek Wolfgang
Department of Physical Chemistry, University of Vienna, Währinger Strasse 42, A-1090, Vienna, Austria.
Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090, Vienna, Austria.
Chemphyschem. 2017 May 5;18(9):1118-1124. doi: 10.1002/cphc.201601181. Epub 2017 Feb 16.
The nanosecond-pulse laser-assisted generation of Ni/NiO core/shell nanoparticles (NPs) in water and alcoholic fluids can yield colloidal solutions without surfactants. The size distribution can be controlled by the nature of the alcohol, the number of laser pulses and the laser fluence. The incubation of the nickel target ablation in liquid contact shows a dependence on the carbon number of the respective alcohol. The laser-generated NPs consist of crystalline nickel cores with face-centred cubic patterns and stacking fault defects surrounded by nickel oxide shells. The solvent butanol, in contrast to ethanol and isopropanol, yields a narrow, nearly unimodal, size distribution. The majority of NPs have low size distributions, with medians in the range of 10-20 nm. These can be related to a metal ablation plume interacting with a supercritical liquid that decelerates the ejected material in a low-density metal-water mixing region. NPs in the range above 30 nm result in a minority distribution tail that strongly depends on the fluid nature, the pulse number and the fluence. This coarse NP set may be correlated with the rupture of a superheated molten-metal layer into larger entities.
在水和酒精流体中，通过纳秒脉冲激光辅助生成镍/氧化镍核壳纳米颗粒（NPs）可得到无表面活性剂的胶体溶液。尺寸分布可通过醇的性质、激光脉冲数和激光能量密度来控制。镍靶在液体接触中的烧蚀显示出对相应醇类碳原子数的依赖性。激光生成的纳米颗粒由具有面心立方图案和堆垛层错缺陷的结晶镍核组成，周围是氧化镍壳。与乙醇和异丙醇相比，溶剂丁醇产生窄的、近乎单峰的尺寸分布。大多数纳米颗粒具有低尺寸分布，中位数在10 - 20 nm范围内。这些可能与金属烧蚀羽流与超临界液体相互作用有关，该超临界液体在低密度金属 - 水混合区域使喷射出的物质减速。尺寸大于30 nm的纳米颗粒导致少数分布尾部，这强烈依赖于流体性质、脉冲数和能量密度。这种粗大的纳米颗粒组可能与过热熔融金属层破裂成更大的实体有关。
