Abstract
Polymer blend films exhibit unique properties and have applications in various fields. However, understanding their nanoscale structures and polymer component distributions remains a challenge. To address this limitation, we have developed a super-resolution fluorescence microscopy-based technique called oxygen-excluded nanoimaging. By using point accumulation for imaging in nanoscale topography with sulfonate-based dye molecules, we achieved nanoscale imaging of polymer blend films while specifically labeling non-oxygen domains and excluding oxygen-containing domains. This selectivity is attributed to the electrostatic repulsion between the negatively charged sulfonate groups in the dye molecules and the oxygen atoms in the polymer side chains. We demonstrate the applicability of oxygen-excluded nanoimaging to various polymer blend films, enabling domain identification and visualization of nanoscale structures. Our oxygen-excluded nanoimaging technique provides unique insights into the complex phase separation behavior of polymer blends at the nanoscale, opening possibilities for the nanoscale characterization of a wide range of materials beyond polymer blends.