In-situ atomic force microscopy of polyethylene crystallization. 1. Crystallization from an oriented backbone

Atomic force microscopy has been used to image the crystallization of polye thylene shish kebab crystals in situ, in real time, with nanometer resoluti on. Images of the extended chain backbone and overgrowth and subsequent int erdigitation of lamellae have been obtained. Direct observation of the inte rdigitation process shows that the lamellae sometimes change direction so a s to avoid meeting, providing evidence of the influence of a growing lamell a on its surrounding environment. The growth rates of individual lamellae a s they grow from the backbone have been measured and found to vary both wit h time and from lamella to lamella, in direct contradiction to many theorie s of polymer crystallization. These data, taken from the first AFM experime nts to obtain such high resolution at such a high temperature during a proc ess, provide a significant advance in the capability of AFM to increase our understanding of polymer crystallization.