The Interplay between Chain Diffusion and Crystallization of Polyethylene Oxide in its Monolayers

Lateral diffusion of single chain of polyethylene oxide (PEO) in its monolayers on silica surfaces related to the crystallization process is studied by single molecule fluorescence microscopy and single molecule tracking techniques. Diffusion of PEO chains is observed in the super- cooled state before crystallization as well as after crystallization in regions outside crystals, at different temperatures. In the post-crystallization monolayers, the diffusion coefficient of PEO chains in regions outside crystals is an order of magnitude lower than that in the super-cooled state before crystallization. The origin is attributed to the change of polymer surface concentration due to the consumption of polymer molecules in the crystal formation. The results clearly demonstrate a strong mutual effect between the crystallization process and the mass transportation for the polymer crystallization under surface confinement.