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

在这个项目中，我们致力于构建三维(3D)分辨率的单分子成像设备，以在分子水平上研究聚合物材料的空间异质性。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法，在成像系统中插入一个柱面透镜，根据Z位置改变单个分子的荧光图像的形状。第二种方法是结构照明，由于两束激光的干涉，沿Z轴具有周期性的强度调制。这些成像设备提供了几十纳米的3D分辨率。利用3D超分辨技术，我们阐明了客体分子在聚合物薄膜中的反常扩散机制。此外，我们还成功地实现了聚合物材料空间异质性的可视化。

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.