Additive Speciation and Phase Behavior Modulating Mineralization

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 pH-dependent 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.