Structural and morphological characterization of hydrozincite and its interaction with organic molecules

The morphological diversity and complexity of naturally occurring forms and patterns have been a motivation for humans to copy and adopt ideas from Nature to achieve functional, aesthetic and social value. Common biogenic materials, such as biominerals, constructed with mineral phases and an organic matrix exhibit delicate structure with unusual optimal chemical-physical, morphological and mechanical properties, and have inspired ideas for the design and synthesis of biomimetic functional materials. The organic templates play an important role in directing assembly of the mineral/organic composites, and in controlling the nucleation and subsequent crystallization. Consequently, knowledge about the molecular interactions at mineral/organic interfaces is essential for understanding the principles of the organic-matrix-mediated biomineralization process. The microscopic properties of biomineral hydrozincite [Zn₅(CO₃)₂(OH)₆] from Naracauli Creek (SW Sardinia) were investigated by using X-ray Diffraction (XRD), Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (NMR), Scanning Electron Microscopy (SEM), and High-Resolution Transmission Electron Microscopy (HR-TEM) and the organic matrix present has been extracted and characterized by using Fourier Transform Infrared (FT-IR). In the context of molecular interactions at mineral/organic interfaces we describe an experimental study of the interaction of Bis(2-ethylhexil)phthalate (DEHP) with hydrozincite. This interaction, under controlled laboratory experiments, was investigated by using Fourier Transform Infrared (FT-IR) and Nuclear Magnetic Resonance Spectroscopy (NMR).