Mac Fhionnlaoich Niamh, Qi Runzhang, Guldin Stefan
Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , U.K.
Langmuir. 2019 Dec 17;35(50):16605-16611. doi: 10.1021/acs.langmuir.9b02877. Epub 2019 Dec 5.
2D colloidal assembly is a vital process in the fabrication of nanostructured devices and receives widespread attention in fundamental research. Characterizing the ordering is crucial to develop an understanding of the driving forces behind the assembly and to optimize processing conditions. Image analysis offers a direct evaluation pathway, typically via the radial distribution function or the 2D fast Fourier transform. Both methods have inherent limitations; the former provides no angular dependence, while the latter is challenged when confronted with imperfection on the mean size, spacing, and coverage of the building blocks. Here, we introduce the 2D spatial distribution function (SDF) as an alternative pathway to evaluate colloidal ordering. We benchmark the method in case studies of prominent examples and provide a tool kit for implementation, including an ImageJ plugin and the standalone software CORDERLY. Application and interpretation are straightforward and particularly powerful to analyze and compare colloidal assemblies with limited order.
二维胶体组装是纳米结构器件制造中的一个重要过程，在基础研究中受到广泛关注。表征有序性对于理解组装背后的驱动力以及优化加工条件至关重要。图像分析提供了一条直接的评估途径，通常通过径向分布函数或二维快速傅里叶变换。这两种方法都有其固有的局限性；前者没有角度依赖性，而后者在面对构建块的平均尺寸、间距和覆盖率存在缺陷时会受到挑战。在这里，我们引入二维空间分布函数（SDF）作为评估胶体有序性的另一种途径。我们在突出示例的案例研究中对该方法进行了基准测试，并提供了一个实施工具包，包括一个ImageJ插件和独立软件CORDERLY。应用和解释都很直接，对于分析和比较有序性有限的胶体组装特别有效。
