Effect of the Polarity of Solvents on Periodic Precipitation: Formation of Hierarchical Revert Liesegang Patterns

J Phys Chem B. 2022 Oct 20;126(41):8322-8330. doi: 10.1021/acs.jpcb.2c05810. Epub 2022 Oct 11.

Abstract

Liesegang pattern (LP) is one example of self-organized periodic precipitation patterns in nonequilibrium systems. Several studies have demonstrated that the LP morphology can track physicochemical environmental conditions (e.g., temperature); however, the polarity effect has not been explored to date. In this study, a copper chromate system is used to reveal the impact of solvent polarity on the evolving LP structure using water/organic solvent mixtures. In the typical case of using water/dimethyl sulfoxide (DMSO) mixtures, two drastic changes in LP morphology with increasing DMSO contents were found: (i) increasing frequency of the original structure and (ii) formation of a hierarchical pattern with the appearance of another, lower-frequency structure. Furthermore, the simulation model operating with a bimodal size distribution, allowing both homogeneous and heterogeneous precipitations showed good agreement with the experimental results. Therefore, this study demonstrated that LP can be tailored by solvent polarity and can be used for designing hierarchical precipitation patterns in a straightforward manner.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromates
  • Copper*
  • Dimethyl Sulfoxide* / chemistry
  • Solvents / chemistry
  • Water / chemistry

Substances

  • Solvents
  • Dimethyl Sulfoxide
  • Copper
  • Chromates
  • Water