Surface Passivation by Embedment of Polyphosphate Inhibits the Aragonite-to-Calcite Thermodynamic Pump

Boyang Gao; Kristin M Poduska; Shifi Kababya; Asher Schmidt

doi:10.1021/jacs.3c09027

Surface Passivation by Embedment of Polyphosphate Inhibits the Aragonite-to-Calcite Thermodynamic Pump

J Am Chem Soc. 2023 Dec 6;145(48):25938-25941. doi: 10.1021/jacs.3c09027. Epub 2023 Nov 20.

Authors

Boyang Gao¹, Kristin M Poduska¹, Shifi Kababya², Asher Schmidt²

Affiliations

¹ Departments of Chemistry/Physics & Physical Oceanography, Memorial University of Newfoundland & Labrador, St. John's, NL A1B 3X7, Canada.
² Schulich Faculty of Chemistry and The Russell Berrie Nanotechnology Institute, Technion - Israel Institute of Technology, Haifa 32000, Israel.

PMID: 37984423
DOI: 10.1021/jacs.3c09027

Abstract

We monitored the conversion of aragonite to calcite in water by comparing single and mixed polymorph suspensions. We demonstrate that the enhanced aragonite-to-calcite conversion in mixed polymorph suspensions is dramatically inhibited by adding polyphosphate (sodium hexametaphosphate). ¹³C and ³¹P solid-state magic angle spinning (MAS) NMR and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra allow us to follow quantitatively these effects as imparted by the dissolution-recrystallization processes. 31P{13C} and ¹³C{³¹P} rotational echo double resonance (REDOR)NMR experiments reveal coprecipitated phosphate that is embedded only within the surfaces of both polymorphs during the initial dissolution and recrystallization processes, causing passivation that arrests phase conversion.