论文标题
单个分形骨料的多角度全息表征
Multi-angle holographic characterization of individual fractal aggregates
论文作者
论文摘要
全息粒子表征使用全息显微镜数据的定量分析来精确，快速地测量其天然培养基中个体胶体球的直径和折射率。当将该技术应用于非均匀或非球形颗粒时，测得的直径和折射率代表了封闭每个粒子的有效球的特性。有效的球分析已成功应用于分形骨料的种群，为整个人群提供了总体分形维度。在这里，我们证明全息表征还可以通过探测其有效直径和折射率在经历旋转扩散时如何变化来测量单个分形簇的分形维。该过程从多个角度探测簇的结构，因此构成了断层扫描的形式。在这里，我们通过对在各种条件下生长的二氧化硅纳米颗粒聚集体进行的实验研究来证明和验证对非球颗粒全息图的有效解释。
Holographic particle characterization uses quantitative analysis of holographic microscopy data to precisely and rapidly measure the diameter and refractive index of individual colloidal spheres in their native media. When this technique is applied to inhomogeneous or aspherical particles, the measured diameter and refractive index represent properties of an effective sphere enclosing each particle. Effective-sphere analysis has been applied successfully to populations of fractal aggregates, yielding an overall fractal dimension for the population as a whole. Here, we demonstrate that holographic characterization also can measure the fractal dimensions of an individual fractal cluster by probing how its effective diameter and refractive index change as it undergoes rotational diffusion. This procedure probes the structure of a cluster from multiple angles and thus constitutes a form of tomography. Here we demonstrate and validate this effective-sphere interpretation of aspherical particles' holograms through experimental studies on aggregates of silica nanoparticles grown under a range of conditions.
