Atomic Force Microscopy Studies of Polymer Crystallization in Thin Film: Understanding the Formation Mechanism and Tuning the Properties

Over the past decade, besides fundamental concepts, single-crystal engineering of functional polymers and its applications have attracted increasing attention. With the advances of multiparametric and multifunctional characterization, atomic force microscopy (AFM) not only can image the surface topography of polymer crystals in nanoscale while simultaneously mapping the physical properties, like the electrical and thermal properties, but also provides a unique way of linking molecular structures, crystallization conditions and post-treatment to properties. Furthermore, the nanoscale control afforded by scanning probe lithography (SPL) has prompted the development of a regulation of the polymer aggregation structures and surface patterns in thin films. To explicitly probe the mechanism of polymer crystallization, single layer lamella and few layer lamellae in thin films as a model system, combined with AFM can provide information on polymer nucleation and growth with high spatial and temporal resolution. On the other hand, to promote a better understanding of the nature of heterogeneities of metastable state within the lamellae, lamellar thickening/melting and self-seeding, the effects of annealing temperature and time on lamellar thickness of metastable folded-chain crystals have been investigated in polymer thin films.