CaltechAUTHORS
  A Caltech Library Service

Bubble nucleation in polymer–CO_2 mixtures

Xu, Xiaofei and Cristancho, Diego E. and Costeux, Stéphane and Wang, Zhen-Gang (2013) Bubble nucleation in polymer–CO_2 mixtures. Soft Matter, 9 (40). pp. 9675-9683. ISSN 1744-683X. http://resolver.caltech.edu/CaltechAUTHORS:20131025-104557519

[img]
Preview
PDF - Published Version
See Usage Policy.

525Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20131025-104557519

Abstract

We combine density-functional theory with the string method to calculate the minimum free energy path of bubble nucleation in two polymer–CO_2 mixture systems, poly(methyl methacrylate) (PMMA)–CO_2 and polystyrene (PS)–CO_2. Nucleation is initiated by saturating the polymer liquid with high pressure CO_2 and subsequently reducing the pressure to ambient condition. Below a critical temperature (Tc), we find that there is a discontinuous drop in the nucleation barrier as a function of increased initial CO_2 pressure (P0), as a result of an underlying metastable transition from a CO_2-rich-vapor phase to a CO_2-rich-liquid phase. The nucleation barrier is generally higher for PS–CO_2 than for PMMA–CO_2 under the same temperature and pressure conditions, and both higher temperature and higher initial pressure are required to lower the nucleation barrier for PS–CO2 to experimentally relevant ranges. Classical nucleation theory completely fails to capture the structural features of the bubble nucleus and severely underestimates the nucleation barrier.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1039/c3sm51477cDOIArticle
http://pubs.rsc.org/en/Content/ArticleLanding/2013/SM/c3sm51477cPublisherArticle
ORCID:
AuthorORCID
Wang, Zhen-Gang0000-0002-3361-6114
Additional Information:© 2013 The Royal Society of Chemistry. Received 26th May 2013; Accepted 3rd August 2013. The Dow Chemical Company is acknowledged for funding and for permission to publish the results. The computing facility on which the calculations were performed is supported by an NSFMRI grant, Award no. CHE-1040558.
Funders:
Funding AgencyGrant Number
Dow Chemical CompanyUNSPECIFIED
NSFCHE-1040558
Record Number:CaltechAUTHORS:20131025-104557519
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20131025-104557519
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:42070
Collection:CaltechAUTHORS
Deposited By: Jason Perez
Deposited On:25 Oct 2013 19:06
Last Modified:05 Oct 2015 19:38

Repository Staff Only: item control page