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

Microfluidic device with a carbonate‐rich hydroxyapatite micro‐coating

“…The use of CaCO 3 -NPs as a precursor for conversion to carbonate-rich hydroxyapatite by immersion in PBS has been reported previously reported and the possible mechanism was described in detail. [18,19] This dissolution-recrystallization process also has been reported by Ratner et al [29] and Mann et al, [38] albeit at high temperatures under hydrothermal conditions. Briefly, hydroxyapatite has lower solubility than CaCO 3 and other calcium phosphates, so hydroxyapatite would precipitate preferentially as CaCO 3 dissolves, and the solution becomes saturated with respect to hydroxyapatite.…”

“…The free-standing microfilm was comprised of rosette clusters of sheets in the size range of ∼15-30 µm, [19] the carbonate-rich hydroxyapatite coating on PEEK was comprised of ∼1 µm rosette clusters of platelets, [18] while the samples of the present study exhibit clusters of randomly oriented rod-like nanoparticles. Kumar et al [27] have noted that the driving force for hydroxyapatite precipitation includes temperature and the supersaturation level of Ca 2+ and PO 3− 4 with respect to hydroxyapatite.…”

“…A suitable low-temperature technique to deposit a carbonate-rich hydroxyapatite microcoating onto exposed areas of a glass slide has been described by Lui et al [18,19] Briefly, CaCO 3 nanoparticles (CaCO 3 -NP) can be deposited on the exposed area of a glass slide by convective self-assembly (CSA) [18] (Figure 1). The precursor CaCO 3 then can be converted to carbonaterich hydroxyapatite by dissolution-recrystallization in a F I G U R E 1 Schematic diagram of the low-temperature deposition method to form a microcoating of carbonate-rich hydroxyapatite and incorporate it within the microchannels of a microfluidic device.…”

“…Device design: The microfluidic device used in the present study was designed by Middleton et al [7] and has multiple interconnected channels phosphate-containing solution. [19] The microcoating then can be aligned/incorporated within a microchannel when the underlying glass is bonded to a polydimethylsiloxane structure with the device layout.…”

Hybrid scanning electrochemical cell microscopy-interference reflection microscopy (SECCM-IRM): tracking phase formation on surfaces in small volumes

“…Dense layers of ACC are also known to form at interfaces at appropriately high supersaturations. 91 At such negative potentials and low pH, the reductive degradation of ITO may also occur. 32 The formation of CaCO 3 crystals is supported by ITO backgroundsubtracted Raman micro-spectroscopy of a dried meniscus deposited at -0.7 V, which reveals spectra with peaks consistent with the presence of CaCO 3 particles (Figure 5c).…”