Nanoindentation and dilatometric testing of synthetically prepared CaC03

Kód výsledku v IS VaVaI

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Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Nanoindentation and dilatometric testing of synthetically prepared CaC03

Popis výsledku v původním jazyce

Calcium carbonate (CaC03) is one of the most abundant mineral on the Earth crust which is largely present in limestone rocks, marine reefs and shells. CaC03 can occur in several forms: three anhydrous crystalline polymorphs (calcite, aragonite and vaterite), two hydrated crystal forms (CaC03 .6H20 (ikaite) and CaC03 .H20) and an amorphous phase. CaC03 has importance in the biomineralization processes and it is widespread used in several industrial sectors. All three anhydrous crystalline polymorphs have been detected in several lime-based building materials e.g. in historic mortars [1] or after the consolidation interventions using so-called nanolimes. Nanolimes are suspensions of nanosized Ca(OH)2 particles in alcohols and their carbonation reaction can lead to the formation of the metastable CaC03 polymorphs (vaterite, aragonite) and calcite [2]. Up to date, in the literature, there is lack of the information about the mechanical properties of these phases. In the past, the mechanical tests were performed on samples of the different origins, like biological or natural, and under different measurements conditions not allowing their direct comparison. For the first t ime, t his contribution will present the direct comparison of the hardness, elasticity modulus (Er) and thermal expansions of vaterite, aragonite and calcite. The anhydrous crystalline CaC03 polymorphs were synthetically prepared without the use of additives. [3] The nanoindentation and dilatometric tests have been performed on specimens prepared from powders and measured under the same conditions. Our preliminary results showed that the value of the Er is lowest for aragonite and the highest Er was detected for vaterite.

Název v anglickém jazyce

Nanoindentation and dilatometric testing of synthetically prepared CaC03

Popis výsledku anglicky

Calcium carbonate (CaC03) is one of the most abundant mineral on the Earth crust which is largely present in limestone rocks, marine reefs and shells. CaC03 can occur in several forms: three anhydrous crystalline polymorphs (calcite, aragonite and vaterite), two hydrated crystal forms (CaC03 .6H20 (ikaite) and CaC03 .H20) and an amorphous phase. CaC03 has importance in the biomineralization processes and it is widespread used in several industrial sectors. All three anhydrous crystalline polymorphs have been detected in several lime-based building materials e.g. in historic mortars [1] or after the consolidation interventions using so-called nanolimes. Nanolimes are suspensions of nanosized Ca(OH)2 particles in alcohols and their carbonation reaction can lead to the formation of the metastable CaC03 polymorphs (vaterite, aragonite) and calcite [2]. Up to date, in the literature, there is lack of the information about the mechanical properties of these phases. In the past, the mechanical tests were performed on samples of the different origins, like biological or natural, and under different measurements conditions not allowing their direct comparison. For the first t ime, t his contribution will present the direct comparison of the hardness, elasticity modulus (Er) and thermal expansions of vaterite, aragonite and calcite. The anhydrous crystalline CaC03 polymorphs were synthetically prepared without the use of additives. [3] The nanoindentation and dilatometric tests have been performed on specimens prepared from powders and measured under the same conditions. Our preliminary results showed that the value of the Er is lowest for aragonite and the highest Er was detected for vaterite.

Druh

O - Ostatní výsledky

CEP obor

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OECD FORD obor

10402 - Inorganic and nuclear chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů