Additive Speciation and Phase Behavior Modulating Mineralization

Abstract

Natural and synthetic composite materials as yet elude a complete understanding of their formation from organic and inorganic constituents. Addressing the interactions between organic additives and metastable inorganic precursors during mineral nucleation and growth is a critical challenge. In this study, we elucidate additive-controlled mineralization by a novel approach for the in situ continuous monitoring of a widely applied diffusion-based methodology, assisted by the quantitative assessment of mineral nucleation. The formation of amorphous superstructures is attributed to a complex interplay between additives and mineral species viz. ions, ion-clusters, and amorphous precursors as well as a unique phase behavior of the additive molecules relative to the maturing mineral phase. A pHdependent conditioning of nucleation and demixing of transient liquid-like additive-ion complexes are shown to play critical roles in tuning mineral architecture. Thus, the modulation of mineral precursors and mineralization conditions by additive species determine material composition and morphology.

From Solute, Fluidic and Particulate Precursors to Complex Organizations of Matter

“…With heterogeneous compositions, the solute clusters exhibit relatively distinct properties of stability, structure and solvation. For instance, poly‐dentate ligands such as phytic acid and citric acid associate with ions and ion‐clusters, producing polynuclear complexes ,. With increasing supersaturation levels, these hybrid complexes aggregate into larger assemblies and subsequently nucleate particles.…”

“…(c) Catalytic activity and selectivity of Au 25 nanoclusters in Ullmann heterocoupling reactions influenced by the chemical nature of the protecting ligands . (d) Synthesis of hollow particles via the surface transformation of transient phytic acid‐ion hybrid precursors to mineral shells . Control of material structure and organization by using fluidic precursors are illustrated by (e) the cooling rate dependent domain sizes of mesocrystalline mosaic films of DL‐lysine, (f) self‐assembled monolayer‐directed patterns of CaCO 3 crystals, (g) microporous crystals formed by the infiltration of inverse replica of sea urchin spines with liquid‐like mineral precursors as well as composite particles of (h) core‐shell, (i) microporous sponge and (j) elongated morphologies formed during mineralization in the presence of PILPs based on (h, i) citrate/PEI and (j) caffeine/poly (acrylic acid) (PAA) .…”

On Biomineralization: Enzymes Switch on Mesocrystal Assembly

“…33,34 Given the possibility of protein molecules incorporated in the confined phase, the actual enhancement in mineral hydration contents relative to ACC is possibly greater. The estimated density of gel-like mineral precursors stabilized by small charged molecules is lower, about 1.2 g/cm 3 ; 35 hence, in the present study, the incorporation of protein species within the stabilized mineral core is plausible. In this regard, the confinement of highly hydrated mineral precursors appears to emerge from the localized self-assembly of biomolecules at the interfaces of kinetically stabilized nascent mineral nanodroplets, also reflecting fundamental contributions of confinement-mediated phase stabilization with morphological similarities to vesicles observed in vivo.…”

“…24,49,50 Lastly, the dynamics and ultrastructure of precrystalline entities and stabilizer populations will help further elucidate phase transformation pathways concerning biomineralization. 35,49,51 Further investigations on the synergetic relations between distinct mineral precursors and biomacromolecules under physiological conditions will help resolve nature's blueprint for hierarchical materials, opening avenues for smart additives that control crystallization processes at different length and time scales.…”

Modulating Nucleation by Kosmotropes and Chaotropes: Testing the Waters

“…Therefore, the effects of sugars on mineralization cannot be absolutely associated with either the D or L enantiomeric forms but are also determined by pH-dependent parameters such as the CO 3 2− :HCO 3 − ratio and the additive conformation. Conditions of pH can alter the chemical nature of ion-clusters and the subsequent interactions between additives and mineral precursors [68,71]. Therefore, the selective trends of mineral nucleation are likely due to direct interactions with mineral species and associated hydration rather than perturbations to the bulk water phase.…”