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Vaterite Growth and Dissolution in Aqueous Solutions. I. Kinetics of Crystal Growth


Kralj, Damir; Brečević, Ljerka; Nielsen, Arne Eric
Vaterite Growth and Dissolution in Aqueous Solutions. I. Kinetics of Crystal Growth // Journal of Crystal Growth, 104 (1990), 4; 793-800 doi:10.1016/0022-0248(90)90104-S (međunarodna recenzija, članak, znanstveni)


Naslov
Vaterite Growth and Dissolution in Aqueous Solutions. I. Kinetics of Crystal Growth

Autori
Kralj, Damir ; Brečević, Ljerka ; Nielsen, Arne Eric

Izvornik
Journal of Crystal Growth (0022-0248) 104 (1990), 4; 793-800

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Calcium carbonate; vaterite; calcite

Sažetak
The kinetics of precipitation of vaterite (CaCO3) from aqueous solution between about 10 and 45°C and at ionic strengths from 15mM to 315mM was determined by recording pH as a function of time and analysing these data by a BASIC computer program, correcting for complexes and using activity coefficients. The particles were spherulites with diameters less than 5 μm, and the growth kinetics parabolic, with the rate constants (dr/dt)/(S-1)2 equal to 0.180, 0.468, 0.560, 1.250 and 1.860 nm/s at 11.4, 21.7, 25.0, 33.8 and 42.5°C, respectively, and 0.560, 0.588, 0.594 and 0.610 nm/s at ionic strengths 15mM, 65mM, 115mM and 315mM, respectively. The change with temperature corresponds to the activation energy, 57.1 kJ/mol. It is shown that the rate constants found are in quantitative agreement with those calculated from the theory of growth of electrolyte crystals from aqueous solution. This means that the rate-determining mechanism is the release of water molecules from the calcium ions as they “jump” into lattice positions.

Izvorni jezik
Engleski

Znanstvena područja
Kemija



POVEZANOST RADA


Ustanove
Institut "Ruđer Bošković", Zagreb

Časopis indeksira:


  • Current Contents Connect (CCC)
  • Web of Science Core Collection (WoSCC)
    • SCI-EXP, SSCI i/ili A&HCI
  • Scopus


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