The diammonium hydrogenphosphate (DAP, (NH4)2HPO4) reaction with calcite has been extensively investigated. The availability of free calcium ions in the reaction environment has been acknowledged as a crucial factor in the crystallization of calcium phosphates with a high (hydroxyapatite, Ca/P 1.67) or low Ca/P molar ratio (dicalcium phosphate dihydrate, Ca/P 1.00; octacalcium phosphate, Ca/P 1.33). On the contrary, no data are available on the DAP interaction at room temperature with dolomite in terms of reaction mechanism and composition of the reaction products. Here, a multi-analytical approach based on scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectrometry (EDS) and X-ray powder diffraction before and after heating treatments is proposed to explore how the formation of calcium phosphates occur on Mg-enriched substrates and if the presence of magnesium ions during the reaction influences the crystallization process of calcium phosphates. The DAP reaction with polycrystalline dolomite gives rise to the formation of struvite and of poorly crystalline hydroxyapatite. Calcium and magnesium ions mutually interfered in the crystallization of magnesium and calcium phosphates, respectively, whose effects influenced the properties (size, micro-morphology, composition and crystallinity) of the newly-formed phases.

Diammonium Hydrogenphosphate Treatment on Dolostone : the Role of Mg in the Crystallization Process / E. Possenti, C. Conti, G.D. Gatta, M. Realini, C. Colombo. - In: COATINGS. - ISSN 2079-6412. - 9:3(2019 Mar 04), pp. 169.1-169.11. [10.3390/coatings9030169]

Diammonium Hydrogenphosphate Treatment on Dolostone : the Role of Mg in the Crystallization Process

E. Possenti
Primo
Writing – Original Draft Preparation
;
G.D. Gatta
Writing – Review & Editing
;
2019

Abstract

The diammonium hydrogenphosphate (DAP, (NH4)2HPO4) reaction with calcite has been extensively investigated. The availability of free calcium ions in the reaction environment has been acknowledged as a crucial factor in the crystallization of calcium phosphates with a high (hydroxyapatite, Ca/P 1.67) or low Ca/P molar ratio (dicalcium phosphate dihydrate, Ca/P 1.00; octacalcium phosphate, Ca/P 1.33). On the contrary, no data are available on the DAP interaction at room temperature with dolomite in terms of reaction mechanism and composition of the reaction products. Here, a multi-analytical approach based on scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectrometry (EDS) and X-ray powder diffraction before and after heating treatments is proposed to explore how the formation of calcium phosphates occur on Mg-enriched substrates and if the presence of magnesium ions during the reaction influences the crystallization process of calcium phosphates. The DAP reaction with polycrystalline dolomite gives rise to the formation of struvite and of poorly crystalline hydroxyapatite. Calcium and magnesium ions mutually interfered in the crystallization of magnesium and calcium phosphates, respectively, whose effects influenced the properties (size, micro-morphology, composition and crystallinity) of the newly-formed phases.
calcium phosphate; hydroxyapatite; magnesium phosphate; struvite; dolomite; consolidating treatment; cultural heritage; ammonium phosphate
Settore GEO/09 - Georisorse Miner.Appl.Mineral.-Petrogr.per l'amb.e i Beni Cul
4-mar-2019
Article (author)
File in questo prodotto:
File Dimensione Formato  
Coating_2019.pdf

accesso aperto

Tipologia: Publisher's version/PDF
Dimensione 1.91 MB
Formato Adobe PDF
1.91 MB Adobe PDF Visualizza/Apri
2019 Diammonium Hydrogenphosphate Treatment on Dolostone.pdf

accesso aperto

Descrizione: Versione accettata dall'editore per la stampa
Tipologia: Post-print, accepted manuscript ecc. (versione accettata dall'editore)
Dimensione 696.81 kB
Formato Adobe PDF
696.81 kB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/630336
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 14
  • ???jsp.display-item.citation.isi??? 14
social impact