Real‐Time Observations of Oriented Crystallization of Poly(<i>ε</i>‐caprolactone) Thin Film, Induced by an AFM Tip

Abstract

Abstract Atomic force microscopy (AFM) was used for modifying the surface structures of poly( ε ‐caprolactone) (PCL) thin film. Oriented growth of PCL crystals at a desired area of the film surface was induced by scanning with a strong, normal load. PCL crystals were first grown edge‐on from the induction line and then their orientation changed to flat‐on at a lamellar length. The effects of molecular weight, crystallization temperature, scanning rate, and normal load on the AFM‐tip‐induced crystallization were examined. The growth kinetics of lamellar crystals in the AFM‐tip‐induced crystallization was the same as that in spherulitic crystallization. It was found that the formation of precursors strongly depends on the applied tip load and is facilitated when the applied load is higher than a threshold. magnified image