Investigation of nanoscale spatial heterogeneity in polymeric materials by using 3D single-molecule tracking techniques

在这个项目中，我们专注于构建具有三维（3D）分辨率的单分子成像设备，用于研究高分子材料在分子水平上的空间异质性。为了实现三维定位，采用了两种方法。第一种是所谓的散光成像方法，在成像系统中插入一个圆柱形透镜，根据z轴位置改变单个分子的荧光图像形状。第二种方法是由于两个激光束的干涉，沿z轴具有周期性强度调制的结构化照明。这些成像设备提供了几十纳米的三维分辨率。利用三维超分辨技术，我们阐明了客体分子在聚合物薄膜中的异常扩散机理。此外，我们还成功地可视化了高分子材料的空间非均质性。

In this project, we have focused on constructing single-molecule imaging apparatuses with three-dimensional (3D) resolution for the investigation of spatial heterogeneity at the molecular level in polymeric materials. To achieve 3D localization, two approaches were employed. The first one is so-called the astigmatism imaging method, in which a cylindrical lens was inserted into the imaging system to modify the shape of the fluorescent image of a single molecule depending on Z-position. The second approach is a structured illumination with a periodic intensity modulation along the Z-axis due to the interference of two laser beams. These imaging apparatuses provided the 3D resolution of several tens of nanometers. By using the 3D super-resolution techniques, we have clarified the mechanism of anomalous diffusion of guest molecules in polymer films. In addition, we have also succeeded in the visualization of spatial heterogeneity in polymeric materials.