Imaging spatio-temporal fluctuations and local susceptibility in disordered polymers

摘要

Spatial and temporal fluctuations of the electric polarization were imaged in polymer thin films near the glass transition using electric force microscopy. Below the glass transition the fluctuations are quasi-static and spatial fluctuations were found to quantitatively agree with predictions for thermal fluctuations. Temporal fluctuations appear near the glass transition. Images of the space-time nanoscale dynamics near the glass transition are produced and analyzed. Local, complex dielectric susceptibility was also studied, and shows that dynamics on the free-surface are faster relative to the bulk.