Fan J-G, Fu J-X, Collins A, Zhao Y-P
Nanoscale Science and Engineering Center, Department of Physics and Astronomy, The University of Georgia, Athens, GA 30602, USA.
Nanotechnology. 2008 Jan 30;19(4):045713. doi: 10.1088/0957-4484/19/04/045713. Epub 2008 Jan 4.
The bundling of densely packed free-standing nanorods/nanotubes in a liquid environment, or the 'nanocarpet effect', has a direct impact on the stability of nanostructures used for chemical and biological sensors. Using glancing angle deposition, we prepared four different structures: vertically aligned, tilted, zigzag, and square spring Si nanorod arrays, and compared their stabilities after water treatment. We found that although the tilted nanorods were bent in the nanorod tilting direction, they did not form nanorod bundles, and this structure was the most stable one. The larger the tilting angle, i.e., the more inclined the nanorod was to the surface, the more stable the structure. We also found that the quasi-vertical nanorod structures, the zigzag and square spring structures, showed improved stabilities compared to vertically aligned nanorods. Furthermore, by properly depositing a capping layer on top of the vertically aligned nanorods, the structure became mechanically very stable while the high porosity nature of the nanorod array was maintained. This work is helpful for designing stable nanostructures used in a liquid environment.
在液体环境中紧密排列的独立纳米棒/纳米管的聚集，即“纳米地毯效应”，对用于化学和生物传感器的纳米结构的稳定性有直接影响。利用掠角沉积，我们制备了四种不同的结构：垂直排列、倾斜、之字形和方形弹簧状硅纳米棒阵列，并比较了它们在水处理后的稳定性。我们发现，尽管倾斜的纳米棒在纳米棒倾斜方向上发生了弯曲，但它们并未形成纳米棒束，且这种结构是最稳定的。倾斜角越大，即纳米棒相对于表面的倾斜程度越大，结构越稳定。我们还发现，准垂直纳米棒结构、之字形和方形弹簧状结构与垂直排列的纳米棒相比，稳定性有所提高。此外，通过在垂直排列的纳米棒顶部适当沉积一层覆盖层，结构在机械上变得非常稳定，同时纳米棒阵列的高孔隙率特性得以保持。这项工作有助于设计在液体环境中使用的稳定纳米结构。
