In Situ Real-Time Atomic Force Microscopy Observation of the Surface Mobility on Each Domain of a Polystyrene‑b‑poly(methyl methacrylate) Film at High Temperatures

The surface chain movements within the microdomains of a polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) and corresponding homopolymer films were observed via in situ real-time atomic force microscopy (AFM) at high temperatures and analyzed quantitatively using particle image velocimetry (PIV). At low temperatures, mobility within the PS microdomains resembled that within the PS homopolymer film, but movements in the PMMA microdomains were notably accelerated compared to the PMMA homopolymer. Conversely, at high temperatures, mobility within both PS and PMMA microdomains was considerably suppressed compared to their respective homopolymer films, likely owing to the fixed linkage of the block chains at the microdomain interface. This combination of real-time AFM observation and PIV analysis is an effective method for quantitatively evaluating surface chain mobility in real space.