How do evaporating thin films evolve? Unravelling phase-separation mechanisms during solvent-based fabrication of polymer blends

Wodo, Olga; Ganapathysubramanian, Baskar

How do evaporating thin films evolve? Unravelling phase-separation mechanisms during solvent-based fabrication of polymer blends

Type

Article

Authors

Wodo, Olga
Ganapathysubramanian, Baskar

KAUST Grant Number

CRG-1-2012-THO-015-ISU

Date

2014-10-13

Abstract

© 2014 AIP Publishing LLC. Solvent-based fabrication is a flexible and affordable approach to manufacture polymer thin films. The properties of products made from such films can be tailored by the internal organization (morphology) of the films. However, a precise knowledge of morphology evolution leading to the final film structure remains elusive, thus limiting morphology control to a trial and error approach. In particular, understanding when and where phases are formed, and how they evolve would provide rational guidelines for more rigorous control. Here, we identify four modes of phase formation and subsequent propagation within the thinning film during solvent-based fabrication. We unravel the origin and propagation characteristics of each of these modes. Finally, we construct a mode diagram that maps processing conditions with individual modes. The idea introduced here enables choosing processing conditions to tailor film morphology characteristics and paves the ground for a deeper understanding of morphology control with the ultimate goal of precise, yet affordable, morphology manipulation for a large spectrum of applications.

Citation

Wodo O, Ganapathysubramanian B (2014) How do evaporating thin films evolve? Unravelling phase-separation mechanisms during solvent-based fabrication of polymer blends. Applied Physics Letters 105: 153104. Available: http://dx.doi.org/10.1063/1.4898136.

Acknowledgements

This research was supported in part by the National Science Foundation through XSEDE resources provided by TACC under grant number TG-CTS110007. BG & OW were supported in part by NSF CAREER 1149365, and Global Collaborative Research, King Abdullah University of Science and Technology: CRG-1-2012-THO-015-ISU.