Wettability of eutectic NaLiCO3 salt on magnesium oxide substrates at 778 K

Research output: Contribution to journalArticle

Colleges, School and Institutes

External organisations

  • Birmingham Centre for Energy Storage (BCES) & School of Chemical Engineering
  • University of Science and Technology Beijing

Abstract

We investigated the wetting behavior of a eutectic carbonate salt of NaLiCO3 on MgO substrates at an elevated temperature of 778 K by measuring contact angle with a sessile drop method. Both sintered and non-sintered MgO were prepared and used as the substrates. The sintered substrates were obtained by sintering compacted MgO powders at 500–1300 °C. For comparison purposes, a single crystal MgO substrate was also used in the work. The different sintering temperatures provided MgO substrates with different structures, allowing their effects on salt penetration and hence wettability and surface energy to be investigated. A scanning electron microscope equipped with energy dispersive spectrometry and an atomic force microscope were used to observe the morphology and structures of the MgO substrates as well as the salt penetration. The results showed a good wettability of the carbonate salt on both the sintered and non-sintered MgO substrates and the wettability depended strongly on the structure of the substrates. The non-sintered MgO substrate has a loose surface particle packing with large pores and crevices, leading to significant salt infiltration, and the corresponding contact angle was measured to be ∼25°. The contact angle of the salt on the sintered MgO substrates increased with an increase in the sintering temperature of the MgO substrate, and the contact angle of the salt on the single crystal substrate was the highest at ∼40°. The effect of the sintering temperature for making the MgO substrate could be linked to the surface energy, and the linkage is validated by the AFM measurements of the adhesion forces of the MgO substrates.

Details

Original languageEnglish
Pages (from-to)148-155
Number of pages8
JournalApplied Surface Science
Volume442
Early online date13 Feb 2018
Publication statusPublished - 1 Jun 2018

Keywords

  • Contact angle, Eutectic carbonate salt, Magnesium oxide, Surface energy, Wettability

ASJC Scopus subject areas