Structure and Properties of Calcium Pyruvate in Aqueous Solutions

Abstract

Calcium Pyruvate / Network Structure / Rheology / Light Scattering / FractalsThe dynamic behaviour of calcium pyruvate, Ca(pyr)2, were studied by light scattering and rheology measurements at dilute and semi-dilute concentrations in aqueous solutions at 20°C. The formation of a stabilized film of Ca(pyr)2 were studied and the rheological properties of the films have been measured above the overlap weight concentration, * ϭ 0.9% (w/w), where viscoelastic properties were found to develop. SCEM and BrewsterAngle-Microscopy images indicate that the aggregates of Ca(pyr)2 are elongated in shape with an average length scale of 20 µm. However these particles are in close contact and form fractal clusters with df ϭ 1.75. The determined radii of gyration and the rheology measurements are consistent with a network of cross-linked aggregates with elastic properties even under biochemical relevant concentrations (5Ϫ10 mM). Considering the low overlap weight fraction *, and the radius of gyration (Rg ϭ 21.0 nm) of the individual clusters for Ͻ *, the observed large clusters of 20Ϫ30 µm of Ca(pyr)2 in solution for Ͼ * seem to be rather elongated than spherical.

Nucleation of Calcium Carbonate as Polymorphic Crystals in the Presence of Lipid A-Diphosphate

“…Crystal formation and growth in the presence of biologically active organic molecules are of prime importance in the understanding of nanometric and mesoscopic structures. This is particularly true in the case of microbial-induced metal corrosion and in the fabrication of biochemical materials, as well as for Biofilm (exopolymers), which includes Ca 2+ -dependent biodegradation . Recent evidence discloses the importance of calcium carbonate and hydroxyapatite in the formation of nanobacteria in a number of medical conditions.…”