Séminaire LCMCP | Stephan Wolf ’Potent small molecular-weight antiscalants...’

Le LCMCP vous informe

Stephan Wolf
(Institute of Glass and Ceramics Friedrich-Alexander-Universität Erlangen-Nurnberg Germany)

Will present a seminar entitled

"Potent small molecular-weight antiscalants operate by specific
additive-cluster interactions beyond established mechanistic conception"

Abstract: Transient amorphous calcium carbonate (ACC) is a crucial precursor in various mineralizing environments, and insight into its ultrastructure and formation is vital for understanding formation pathways and identifying molecular control mechanisms by additives. As of yet, small additives take an elusive role in biogenic, geologic, and industrial calcification processes as they can feature a disproportionately high impact on ACC formation.

To corroborate the involvement of prenucleation clusters (PNCs). a highly debated solute species that form spontaneously in non-saturated calcium carbonate solutions we took a close look at small-molecular-weight additives that strongly differ in their impact on the formation of calcium carbonate and stabilization of ACC. We find that only those additives can effectively impede precipitation when actively triggering PNC formation. These additives fully immerse into PNCs, over-stoichiometrically enhancing calcium carbonate solubility, and co-precipitate with ACC and retarding ACC crystallization in dry and wet environments. Only additives selectively co-precipitate with ACC when they strongly interact with PNCs; additives that do not strongly interact with PNCs can hardly be traced in the ACC precipitate. This points to specific molecular interactions between PNCs and additives that allow chemical labeling of PNCs and corroborates that ACC forms via PNC aggregation.

In summary, ACC forms via aggregation of PNCs, i.e., complex calcium carbonate ion associates; this formation process is highly sensitive towards additives that molecularly interact with PNCs. Our results reveal antiscaling mechanisms that operate beyond established mechanistic conceptions, motivating a re-assessment of the role of small molecules in biomineralization and geochemistry.

Related Recent Publications Small-Molecular-Weight Additives Modulate Calcification by Interacting with Prenucleation Clusters on the Molecular Level.
P. Duchstein, P.I. Schodder, S. Leupold, T.Q. Dao, S. Kababya, M.R. Cicconi, D. de Ligny, V. Pipich, D. Eike, A. Schmidt*, D. Zahn* and S.E. Wolf* Angewandte Chemie Int. Edition (2022).

The nano-and meso-scale structure of amorphous calcium carbonate.
S.M. Clark*, B. Colas, D.E. Jacob, J.C. Neuefeind, H.W. Wang, K.L. Page, A.K. Soper, P.I. Schodder, P. Duchstein, B. Apeleo Zubiri, T. Yokosawa, V. Pipich, D. Zahn, E. Spiecker, and SE Wolf* Scientific Reports (2022), 12, 6870.

Nanoscale assembly processes revealed in the nacroprismatic transition zone of Pinna nobilis mollusc shells.
R.M. Hovden and S.E. Wolf, M.E. Holtz, F. Marin, D.A. Muller and L.A. Estroff* iNature Communications (2015) 6, 10097.