Calorimetric Study of Crystallization of Polymer Films Formed from Quasi-Vapor Phase Deposition*

Owing to the long-chain nature, crystallization and the resulting properties of polymers are dependent on their processing routes. A novel film fabrication method, termed Matrix Assisted Pulsed Laser Evaporation (MAPLE), is employed to investigate the crystallization behavior and thermal properties of model semi-crystalline polymers: poly(ethylene oxide) (PEO) and polyethylene (PE). This enabling technique holds an intrinsic uniqueness in that it features ultra-slow deposition rate, thereby allowing the manipulation of film structure as well as the crystallization of molecules atop a temperature controlled substrate. In this work, the effect of substrate temperature on crystallization of thin PEO/PE films are probed with the aid of fast scanning calorimetry (FSC). Compared with solution casted films, variances sourced from the new approach help to understand the crystallization of PEO/PE films produced by MAPLE deposition. We expect that this ability to tune the crystallization kinetics during polymeric film growth will be enlightening to engineer thin film polymeric-based devices in ways that are difficult by other means.