No. 1688, Gaoke East Road, Pudong new district, Shanghai, China.
No. 1688, Gaoke East Road, Pudong new district, Shanghai, China.
Our results show that crystalline calcium carbonate thin films with defined structures and compositions can be generated by the solid-state transformation of ACC containing magnesium ions and small amounts of organic additives.
The main challenges are as follows: (i) calcite has a soluble mineral surface involved in dissolution and precipitation processes in solutions; (ii) Ca 2+ and CO 3 2− are released by calcite dissolution and Ca 2+ ions combine with PO 4 3− to form calcium phosphate precipitates, while CO 3 2−, as a base, has a strong impact on the ...
Calcite precipitation rates on glass tablets located under three drip sites have been recorded monthly for around one year. Recorded rates range from 0.2 to 4.7 mg d−1. ... The assumption that the drip rates are high enough to neglect the temporal variations of concentration in the water film at the apex can be exactly tested verifying that:
4. Kinetic fractionation and evaporation. When calcite precipitates from a thin film of drip water that is supersaturated with respect to calcite Ca 2+ and carbonate are removed from the solution and irreversibly incorporated into the calcite crystal lattice. During this process the concentration of DIC changes with some time dependent function C(t), which depends on …
It operates on the principle of flowing film concentration, in which the feed slurry acts as a flowing film. Feed slurry is injected near the cone's bottom and is accelerated up the cone wall by the centrifugal field. ... They found that high calcite recovery would be obtained at higher water pressure and lower gravity force levels. The ...
the film becomes thinner, the flushing efficiency of dissolved elements through the film decreases and the element concentration increases toward equilibrium concentration, leading to a slower dissolution rate in the film. The water film thickness on a single crystal of quartz, glass, calcite, and muscovite has been measured ex-
Though very smooth, polycrystalline calcite films are generated with both PAA/PAsp and PAH in the presence of Mg 2+, compositional analysis showed that those formed with the PAH comprised only 2% Mg 2+, whereas addition of PAA supported the formation of films containing up to …
A) The experimental setup used to measure the adsorption and desorption kinetics of hollow nano-calcite film via QCM electrodes. VOCs' concentrations were controlled by adjusting the flow amount passing inside VOC solutions. b) Schematic representation of the nano calcite and VOC molecules on top of the QCM electrode.
The PDDA/(calcite film-A) 2 film was also detached from the substrate by applying stronger or more stimuli during fabrication of the PDDA/(calcite film-A) 2 film to form a free-standing calcite ...
It discussed the effect of deposition temperature to the chemical reaction and composition of the produced nanostructured thin film. Nanostructured calcite thin film deposited at 400 °C has shown ...
Addadi et al. pointed out that the first suggestion of a transient ACC precursor in mollusk biominerals by Hamilton and Towe, who back in 1968 observed hollow "crystals" in the developing nacre of the bivalve, and found that "a possibility exists that the incipient calcification is not in the form of aragonite but rather in some o…
To understand the effects of processes that influence the stable carbon and oxygen isotope ratios of DIC in a small planar water film, two model approaches have been developed in the past, a ...
This work aimed to study the detachment mechanism of organic molecules by scCO 2 from a water invasion calcite surface. The model consisted of four layers: the calcite layer, the organic molecule layer, the water layer and the scCO 2 layer, as shown in Fig. 1.The calcite layer was built by cleaving the calcite (104) surface with a size of 40.97 Å × 39.92 Å × 18.21 Å …
Experimental Methods of Calcite Dissolution 107 by Nernst (1904). It assumes that mass transport by molecular diffusion is essentially across a Nernst layer of thickness B, which has to be defined for each special case. For a first-order heterogeneous reaction at …
Semantic Scholar extracted view of "Biomimetic synthesis of calcite films by a polymer-induced liquid-precursor (PILP) process: 1. Influence and incorporation of magnesium" by Xingguo Cheng et al. ... spherical particles of ACC with diameters less than 100 nm and narrow size distribution are obtained at a concentration of only 3 ppm of PEO-b ...
Dissolution rates of limestone covered by a water film open to a CO 2-containing atmosphere are controlled by the chemical composition of the CaCO 3 –H 2 O–CO 2 solution at the water-mineral interface. This composition is determined by the Ca 2+-concentration at this boundary, conversion of CO 2 into H + and HCO 3-in the solution, and by diffusional mass …
The kinetics of crystallization of calcium carbonate (calcite) at 25°C has been examined by following the changes in calcium and hydrogen ion concentration when stable supersaturated solutions ...
The optimal concentration in DHBC was found to be between 3 and 10 ppm, and ACC nanoparticles of 60–100 nm in diameter could be formed. ... They found that oriented large-area calcite films could be prepared by …
The Mg content is given as a molar percentage relative to the number of Ca 2+ ions in the calcite lattice such that the sum of Ca mol% and Mg mol% in the samples is . The Mg contents of the obtained Mg-calcite products in pure phase increase from 8.7 mol% to 58 mol% while the molar ratios of [CO 3 2−]/[Ca 2+] increase from 0.56 to 2.78 according to the …
We demonstrated the crystallization of calcium carbonate (CaCO 3) on polarized calcite single crystal substrates with three different orientations characterized by the (10.0), (00.1), and (10.4) planes in the presence of polyaspartic acid (PAsp) as an organic additive.The precipitates had a multiple phase structure with thin-film-like and hemispherical forms and …
SFA experiments on polycrystalline calcite films have also shown that an amorphous precipitate can form; the precipitate does not attach to the surfaces and a repulsive force acts between the ...
The elongation at break decreases as consequence of matrix mobility restriction by filler particles. By contrast, the strength at break increases as a result of fewer stress concentration points produced by small calcite particles. Large calcite particles decrease the strength of the PVAC composite because of lack of structural continuity.
A further increase in Mg concentration (Mg/Ca > 0.5) resulted in uniform calcite crystals exhibiting faces with rough texture, slightly oblique to the c-axis of calcite (Fig. 9 c and d). Morphological analyses and computer simulations showed that these new faces formed an angle of 5–14° with respect to the c -axis, which roughly corresponds ...
calcite, and ultimately dolomite according to the magnesium content of the ACC, and mosaics of large single crystals are generated at elevated tempera- ... the ACC films scaled with the concentrations of the Mg2+ ions and PAA in the reaction solution (1). Films produced Table ...
The additives used in this study decreased the crystallinity of CaCO(3) (calcite) film in the order of glucose > aspartic acid > serine in a manner inversely proportional to the concentration of ...
For each dissolved species, initial concentrations were determined using the PHREEQC software 64 at 25 °C, for a water density of 1023.6 kg m −3 and a total alkalinity of 1950 μmol kg −1, so ...
A) Bright‐field TEM image and B) corresponding SAED pattern of a single crystal domain in dolomite film generated from ACC films prepared at [Ca²⁺] = 10 × 10⁻³ m and [Mg²⁺] = 100 × 10 ...
Behavior and characteristics of amorphous calcium carbonate and calcite using CaCO 3 film synthesis. Author links open overlay panel Seung-Woo Lee a, Yong-Jae Kim b, Yun-Hee Lee b ... The supersaturation from Ca rich concentration in the experimental condition could influence a sequential phase transition of CaCO 3 [17]. Consequently, it ...
Lozenge-shaped calcite films consisting of iso-oriented nanoscale crystal grains were achieved in a supersaturated aqueous solution through promotion of oriented nucleation …
A combination of Fourier transform infrared spectroscopy, swelling test, inductively coupled plasma optical emission spectrometer, and energy-dispersive spectroscopy analysis showed that the gelation process of alginate …
