Séminaire LCMCP | Asher Schimdt "From molecular level to macroscopic properties..."

The LCMCP invites you to a seminar presented by

M. Ascher Schimdt Professor (Technion Israel Institute of Technology, Haifa Israel)

Abstract :

In many marine organisms biomineralization–the precipitation and crystallization of calcium-based ionic lattices–demonstrate how nature regulates processes to optimize for diverse functions. Regulation is often achieved by agents within the precipitation medium which alter the solution properties and by incorporation into the solid lattice, control the macroscopic properties of the resulting solids. Using a primarily solid-state NMR techniques, we target the mechanisms of action of such additives at the molecular level. We study intact biominerals as well as biomimetic model systems. I will review identification of structural bioorganic motifs in the calcareous shells of bivalves and cephalopods, refuting the chitin abundance paradigm for bivalves. Following I will address the control mechanisms exercised by inorganic phosphate and water, and acidic amino acids, in regulating lattice stability and how it relates to hardness. I will show actions required from small-MW additives to achieve nucleation inhibition (anti-scaling), and end with a glimpse at diagenesis, discussing the aragonite-to-calcite pump and its inhibition. While we combine multidisciplinary characterization techniques, the ability to expose the critical molecular evidence responsible for the diverse underlying mechanisms is solely amenable to ssNMR techniques.

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