Self-Generated Electrokinetic Fluid Flows during Pseudomorphic Mineral Replacement Reactions

Abhishek Kar, Michael McEldrew, Robert F. Stout, Benjamin E. Mays, Aditya Khair, Darrell Velegol, Christopher A. Gorski

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

Pseudomorphic mineral replacement reactions involve one mineral phase replacing another, while preserving the original mineral's size and texture. Macroscopically, these transformations are driven by system-wide equilibration through dissolution and precipitation reactions. It is unclear, however, how replacement occurs on the molecular scale and what role dissolved ion transport plays. Here, we develop a new quantitative framework to explain the pseudomorphic replacement of KBr crystal in a saturated KCl solution through a combination of microscopic, spectroscopic, and modeling techniques. Our observations reveal that pseudomorphic mineral replacement (pMRR) is transport-controlled for this system and that convective fluid flows, caused by diffusioosmosis, play a key role in the ion transport process across the reaction-induced pores in the product phase. Our findings have important implications for understanding mineral transformations in natural environments and suggest that replacement could be exploited in commercial and laboratory applications.

Original languageEnglish (US)
Pages (from-to)5233-5240
Number of pages8
JournalLangmuir
Volume32
Issue number21
DOIs
StatePublished - May 31 2016

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All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry

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