Details

Autor(en) / Beteiligte

• Lui, Florence H.Y.
• Wang, Yu
• Yao, Yin
• Mobbs, Ralph J.
• Pogson, Ross E.
• Koshy, Pramod
• Lucien, Frank P.
• Zhou, Dewen
• Sorrell, Charles C.

Titel

Quiescent Mineralisation for Free-standing Mineral Microfilms with a Hybrid Structure

Ist Teil von

• Journal of colloid and interface science, 2021-12, Vol.604, p.327-339

Ort / Verlag

Elsevier Inc

Erscheinungsjahr

2021

Quelle

ScienceDirect

Beschreibungen/Notizen

• [Display omitted] The air-solution interface of supersaturated calcium hydrogen carbonate (Ca(HCO3)2) represents the highest saturation state due to evaporation/CO2-degassing, where calcite crystals are expected to nucleate and grow along the interface. Hence, it should be possible to form a free-standing mineral-only calcium carbonate (CaCO3) microfilm at the air-solution interface of Ca(HCO3)2. The air-solution interface of phosphate buffered saline (PBS) could represent a phase boundary to introduce a hybrid microstructure of CaCO3 and carbonate-rich dicalcium hydroxide phosphate (carbonate-rich hydroxylapatite). Supersaturated Ca(HCO3)2 was prepared at high pressure and heated to form CaCO3 microfilms, which were converted to bone-like microfilms at the air-solution interface of PBS by dissolution-recrystallisation. The microfilms were characterised by scanning electron microscopy, 3D confocal microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, laser Raman microspectroscopy, and X-ray photoelectron spectroscopy. An in situ X-ray diffraction (XRD) system that simulates the aforementioned interfacial techniques was developed to elucidate the microfilms formation mechanisms. The CaCO3 and bone-like microfilms were free-standing, contiguous, and crystalline. The bone-like microfilms exhibited a hybrid structure consisting of a surface layer of remnant calcite and a carbonate-rich hydroxylapatite core of plates. The present work shows that the air-solution interface can be used to introduce hybrid microstructures to mineral microfilms.