Andreja Pondelak (Author), Francesca Rosi (Author), Celeste Maurich (Author), Costanza Miliani (Author), Srečo D. Škapin (Author), Andrijana Sever Škapin (Author)

Abstract

Calcium acetoacetate, Ca(OAcAc)2, was exposed 7, 30 and 365 days to different values of relative humidity (33%, 48%, 75% and 96%) at 40 °C in order to study its transformation to CaCO3. The resulting Ca(OAcAc)2 decomposition and the time dependence of the phase transformations were monitored and critically evaluated by Fourier transform infrared spectroscopy, field emission scanning electron microscopy and X-ray powder diffraction. The impact of relative humidity on CaCO3 polymorph formation was thoroughly assessed. In all of the conditions used and for all ageing periods, the formed crystal structure is found to be vaterite. At the lowest relative humidity (33%), the amorphous CaCO3 remains more or less almost untransformed even after one year of exposure. It is proposed that the reason for the stability of amorphous CaCO3 is due to the limited amount of physisorbed water on the surfaces of the particles, which is considered the driving force for its transformation. However, the carbonation process is faster in the case of the highest humidity (96%). The findings are not only important for better solutions in the field of cultural heritage, but also shed new light on the fundamental mechanism of CaCO3 crystallization.

Keywords

kalcijev acetoacetat;relativna vlažnost;karbonatizacija;amorfni karbonat;vaterit;mehanizem;calcium acetoacetate;relative humidity;carbonation;amorphous carbonate;vaterite;mechanism;

Data

Language: English
Year of publishing:
Typology: 1.01 - Original Scientific Article
Organization: ZAG - Slovenian National Building and Civil Engineering Institute
Publisher: North-Holland
UDC: 54
COBISS: 2500199 Link will open in a new window
ISSN: 0169-4332
Views: 4
Downloads: 4
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: Slovenian
Secondary keywords: kalcijev acetoacetat;relativna vlažnost;karbonatizacija;amorfni karbonat;vaterit;mehanizem;
Chronology: Nov. 2019
DOI: 10.1016/j.apsusc.2019.144768
ID: 21172243