Non-isothermal decomposition kinetics of nano-scale CaCO3 as a function of particle size variation

Ray, S and Bhattacharya, TK and Singh, VK and Deb, D and Ghosh, S and Das, S (2021) Non-isothermal decomposition kinetics of nano-scale CaCO3 as a function of particle size variation. In: Ceramics International, 47 (1). pp. 858-864.

PDF CER_INT_47_1_858-864.pdf - Published Version Restricted to Registered users only Download (4MB) | Request a copy

Abstract

We report the synthesis of nanocrystalline calcium carbonate with varying particle sizes by precipitation techniques from an aqueous solution of calcium nitrate and sodium carbonate at controlled pH. The particle size of the carbonate powder was precisely controlled by changing the precursor concentration. The synthesized carbonate powders were characterized by using scanning electron microscopy, X-ray diffraction technique, and transmission electron microscopy. The particle size, along with the crystallite size of as-synthesized carbonate powder, decreases with increasing precursor concentration. The non-isothermal decomposition kinetics of the carbonate powder was also evaluated by using near to the modified Arrhenius equation's exact solution. The experimental results were best fitted at n = 0.5, and the one-dimensional diffusion-controlled transport process mechanism (D1) and one-dimensional phase boundary movement mechanism (R1) was found to be very close fit of the corresponding evaluated g(α) value. The apparent activation energy of the nano calcium carbonate decomposition was found in the range of 120�175 kJ/mol, which is also inherently functioning with the average particle size. The apparent activation energy of decomposition of CaCO3 found to be decreased with decreasing average particle size of nanocrystalline calcium carbonate. © 2020 Elsevier Ltd and Techna Group S.r.l.

Item Type:	Journal Article
Publication:	Ceramics International
Publisher:	Elsevier Ltd
Additional Information:	Copyright to this article belongs to Elsevier Ltd
Keywords:	Activation energy; Calcite; Calcium carbonate; Carbonation; Crystallite size; High resolution transmission electron microscopy; Isotherms; Nanocrystalline powders; Nanocrystals; Particle size analysis; Precipitation (chemical); Scanning electron microscopy; Sodium Carbonate; Sodium compounds, Apparent activation energy; Modified arrhenius equations; Nano calcium carbonate; Non-isothermal decomposition kinetics; Particle size variation; Precipitation techniques; Precursor concentration; X-ray diffraction techniques, Particle size
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	03 Dec 2020 09:31
Last Modified:	03 Dec 2020 09:31
URI:	http://eprints.iisc.ac.in/id/eprint/66794

Actions (login required)

View Item