Surface Structure and Morphology of Calcium Carbonate Polymorphs Calcite, Aragonite, and Vaterite:  An Atomistic Approach

Leeuw, NH de; Parker, S. C.

doi:10.1021/jp973210f

Cited by 522 publications

(458 citation statements)

References 57 publications

Supporting

Mentioning

409

Contrasting

Unclassified

Order By: Relevance

“…In this model the oxygen is split into two particles attached to each other by a harmonic spring potential and carrying together the overall charge of the ion. Pavese et al first derived the calcite potential parameters used in this study [30][31] which have since been successfully applied to the accurate representations of calcite surfaces [32][33][34][35][36][37]. These potentials were used to construct flat and stepped surfaces starting from the crystallographic calcite unit-cell using the computer code METADISE [38].…”

Section: Methodsmentioning

confidence: 99%

Growth modification of seeded calcite using carboxylic acids: Atomistic simulations

Aschauer

Spagnoli

Bowen

et al. 2010

Journal of Colloid and Interface Science

Self Cite

View full text Add to dashboard Cite

a b s t r a c tMolecular dynamics simulations were used to investigate possible explanations for experimentally observed differences in the growth modification of calcite particles by two organic additives, polyacrylic acid (PAA) and polyaspartic acid (p-ASP). The more rigid backbone of p-ASP was found to inhibit the formation of stable complexes with counter-ions in solution, resulting in a higher availability of p-ASP compared to PAA for surface adsorption. Furthermore the presence of nitrogen on the p-ASP backbone yields favorable electrostatic interactions with the surface, resulting in negative adsorption energies, in an upright (brush conformation). This leads to a more rapid binding and longer residence times at calcite surfaces compared to PAA, which adsorbed in a flat (pancake) configuration with positive adsorption energies. The PAA adsorption occurring despite this positive energy difference can be attributed to the disruption of the ordered water layer seen in the simulations and hence a significant entropic contribution to the adsorption free energy. These findings help explain the stronger inhibiting effect on calcite growth observed by p-ASP compared to PAA and can be used as guidelines in the design of additives leading to even more marked growth modifying effects.

show abstract

Section: Methodsmentioning

confidence: 99%

Growth modification of seeded calcite using carboxylic acids: Atomistic simulations

Aschauer

Spagnoli

Bowen

et al. 2010

Journal of Colloid and Interface Science

Self Cite

View full text Add to dashboard Cite

show abstract

“…A large amount of theoretical work has been performed on the calcite-water interface [6,7,8]. This modelling has largely been through classical molecular dynamics (MD) simulations, modelling water in its associated form on the calcite {1014} surface, the most stable surface [8,9].…”

Section: Modelsmentioning

confidence: 99%

“…Calcite Structure and Water Interaction 19 polymorph in high pressure environments, although it is possible for aragonite to form at atmospheric pressure in certain conditions, such as hot springs [26]. Vaterite is a metastable form of calcium carbonate, and either changes to form another polymorph, or is stabilised by water adsorption on its surfaces [6]. The differences between the three polymorphs originate from the different arrangement of the CO 3 ions in their crystal structures [13].…”

mentioning

confidence: 99%

Investigation of the Interaction of Water with the Calcite (10.4) Surface Using Ab Initio Simulation

2009

View full text Add to dashboard Cite

Density functional theory calculations were employed to explore the interaction between water and the {1014} surface of calcite. In addition a defective {1014} surface and stepped surfaces in contact with water were investigated. A series of percentage water coverages and water configurations were explored, including dissociated water states. Static relaxations found associated water to be favourable on the {1014} surface, although a metastable dissociated state 1.77eV higher in energy was found.Molecular dynamics (MD) simulations of low water coverage reveal fluctuations in the H-O water bond when the H atom is directed towards a surface CO 3 ion. Desorption of an H 2 O molecule was observed in simulations above 900K. Water was found to be strongly bound to the perfect {1014} surface, with an adsorption energy of -0.91eV. MD simulations of a defective {1014} surface found water to favour dissociation at CO 3 vacancies. However, water at Ca vacancies diffused across the surface to form a bond with the nearest surface Ca ion. Water was also found to favour an associated state at both acute and obtuse steps. On all these imperfect surfaces water was found to adsorb strongly to the surface, with adsorption energies ranging from -0.99eV to -1.60eV.

show abstract

“…This explains the hiding power and strong bond between vaterite surface and GA molecules, whereas the GA formed a multilayer at the surface of the particle by intermolecular hydrogen bonding between adsorbed and free GA molecules [48] [69]. At elevated incubation temperature, the GA contaminated CaCO 3 particles exhibit strong resistance towards aggregation into flocs and are stable to recrystallization process in water [48] [69]. This stabilization effect is achieved when the amount of GA is sufficient to cover the surface of all formed particles and formed the GA shell.…”

Section: Discussionmentioning

confidence: 99%

Formation and Stabilization of Vaterite Calcium Carbonate by Using Natural Polysaccharide

Saraya¹,

Rokbaa²

2017

ANP

View full text Add to dashboard Cite

This paper aimed to study the effects of natural polysaccharide (gum arabic, GA) on the formation of vaterite calcium carbonate and its stability in aqueous solution. Gum arabic is a macromolecule that has a high molecular weight and is amphoteric in character. A 0, 2.5, 5 or 10 ml of GA solution (30%) was added to the calcium chloride solution with various initial concentrations to prepare the vaterite calcium carbonate. The calcium carbonate particles were characterized using FTIR, XRD, SEM, TEM and DSC-TG as well as calculation of phase contents. The results of XRD and FTIR analysis were showing that the presence of GA during the precipitation changes the behavior of calcium carbonate to form vaterite until at lower dose used. In addition, the molar content of vaterite increased at the expense of content of calcite with increasing the GA dose. There are slightly improvements in the vaterite content by increasing the initial concentration. The formed vaterite calcium carbonates composed of aggregates as broccoli-like or spherical shape and with particle size 1.6 -2.5 µm in diameter. TEM images showed that these aggregates composed of the sub spherical unit with diameter 15 -30 nm. The thermal behavior of prepared vaterite was conformed the mineral composition of these phases. The prepared calcium carbonate, which is formed in the presence of different doses of gum, has a stability in the aqueous solutions at different temperatures, as the analyzes indicated that a very small percentage of the vaterite were converted to calcite. The gum arabic prevented or depressed the transformation of vaterite to calcite through capped the surface of particles, i.e. it is more effective in stabilizing the vaterite phase with increasing in initial concentration and time.

show abstract

Surface Structure and Morphology of Calcium Carbonate Polymorphs Calcite, Aragonite, and Vaterite: An Atomistic Approach

Cited by 522 publications

References 57 publications

Growth modification of seeded calcite using carboxylic acids: Atomistic simulations

Growth modification of seeded calcite using carboxylic acids: Atomistic simulations

Investigation of the Interaction of Water with the Calcite (10.4) Surface Using Ab Initio Simulation

Formation and Stabilization of Vaterite Calcium Carbonate by Using Natural Polysaccharide

Contact Info

Product

Resources

About