Abstract
Preparation of thin films by dissolving polymers in a common solvent followed by evaporation of the solvent has become a routine processing procedure. However, modeling of thin film formation in an evaporating solvent has been challenging due to a need to simulate processes at multiple length and time scales. In this work, we present a methodology based on the principles of linear non-equilibrium thermodynamics, which allows systematic study of various effects such as the changes in the solvent properties due to phase transformation from liquid to vapor and polymer thermodynamics resulting from such solvent transformations. The methodology allows for the derivation of evaporative flux and boundary conditions near each surface for simulations of systems close to the equilibrium. We apply it to study thin film microstructural evolution in phase segregating polymer blends dissolved in a common volatile solvent and deposited on a planar substrate. Effects of the evaporation rates, interactions of the polymers with the underlying substrate and concentration dependent mobilities on the kinetics of thin film formation are studied.
| Original language | English |
|---|---|
| Pages (from-to) | 1833-1846 |
| Number of pages | 14 |
| Journal | Soft Matter |
| Volume | 14 |
| Issue number | 10 |
| DOIs | |
| State | Published - 2018 |
Funding
This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists, Office of Science Graduate Student Research (SCGSR) program. The SCGSR program is administered by the Oak Ridge Institute for Science and Education for the DOE under contract number DE-AC05-06OR23100. This research was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. RK acknowledges support from the Laboratory Directed Research and Development program at ORNL. SW was supported by a grant from the National Science Foundation (NSF-DMS 1418692 and NSF-DMS 1719854). JL acknowledges support from National Science Foundation Grant NSF DMS-1719960, and P50GM76516 for the Center of Excellence in Systems Biology at the University of California, Irvine. † This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE6AC0500OR22725 with the U.S. Department of Energy. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation hereon. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-publicaccess-plan). ‡ Electronic supplementary information (ESI) available. See DOI: 10.1039/c7sm02560b