Teoretski taložni dijagrami kalcijevih fosfata

master's thesis

• Title (english): Theoretical precipitation diagrams of calcium phosphates
• Author: Lorena Šulc
• Mentor: Jelena Macan (mentor)
• Committee member: Jelena Macan (predsjednik povjerenstva)
• Committee member: Marko Rogošić (član povjerenstva)
• Committee member: Maja Dutour Sikirić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2019-09-23, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Kalcijevi fosfati (CaP), teško topljive soli fosfatne kiseline, od posebne su važnosti u raznim interdisiciplinarnim područjima znanosti poput geologije, biologije, kemije i (bio)medicine. Široko su rasprostranjeni u živim organizmima i u prirodi. Istraživanja kalcijevih fosfata danas su usmjerena na bolje razumijevanje procesa normalne i patološke biomineralizacije i razvoj novih materijala poboljšanih svojstava. Iako su taložni dijagrami CaP u uvjetima bliskim fiziološkima eksperimentalno istraženi, nisu izrađeni njihovi teoretski taložni dijagrami. U ovom radu izrađeni su teoretski taložni dijagrami četiri biološki važne faze kalcijevih fosfata (amorfni kalcijev fosfat (ACP), oktakalcijev fosfat (OCP), kalcijev hidrogenfosfat dihidrat (DCPD) i hidroksiapatit (HA)) u sustavima bez aditiva te uz dodatak magnezija, citrata (Cit) ili oba aditiva (t = 25 oC i pH 7,4): CaCl2 – Na2HPO4, CaCl2 – Na2HPO4 – MgCl2 (c = 0,0015 mol dm^–3), CaCl2 – Na2HPO4 – Na3Cit (c = 0,000125 mol dm^–3), CaCl2 – Na2HPO4 – MgCl2 (c = 0,0015 mol dm^–3) – Na3Cit (c = 0,000125 mol dm^–3). Dobiveni rezultati su pokazali da se u svim taložnim sustavima mogu, ovisno o sastavu taloga, razlikovati četiri taložna područja, u skladu s topljivosti pojedine soli. Razlike u obliku teoretske granice taloženja za DCPD u odnosu na ostale istraživane CaP ukazuje na moguću razliku u dominantnim procesima kojima otopljene ionske i druge vrste prelaze u krutu fazu. Razlike u položaju teoretskih granica taloženja u različitim taložnim sustavima za pojedinu fazu kalcijevih fosfata u skladu su s eksperimentalno opaženim utjecajima koje Mg2+ i Cit3- ioni imaju na procese njihovog nastajanja.

Abstract (english)

Calcium phosphates (CaP), the sparingly soluble salts of phosphoric acid, are of particular importance in various interdisciplinary fields of science such as geology, biology, chemistry and (bio) medicine. They are widespread in living organisms and in nature. Calcium phosphate research is today focused on a better understanding of the processes of normal and pathological biomineralization and the development of new materials with improved properties. Although CaP deposition diagrams have been investigated experimentally in conditions close to physiological ones, their theoretical deposition diagrams have not been developed. In this paper, theoretical precipitation diagrams of four biologically important phases of calcium phosphate (amorphous calcium phosphate (ACP), octacalcium phosphate (OCP), calcium hydrogen phosphate dihydrate (DCPD) and hydroxyapatite (HA)) are made in systems without additives and with the addition of magnesium, citrate (Cit) or both additives (t = 25 °C and pH 7.4): CaCl2 – Na2HPO4, CaCl2 – Na2HPO4 – MgCl2 (c = 0.0015 mol dm^–3), CaCl2 – Na2HPO4 – Na3Cit (c = 0.000125 mol dm^–3), CaCl2 – Na2HPO4 – MgCl2 (c = 0.0015 mol dm^–3) – Na3Cit (c = 0.000125 mol dm^–3). The obtained results showed that, in all precipitation systems, depending on the composition of the precipitate, four precipitation areas can be distinguished, in accordance with the solubility of each salt. The differences in the shape of the theoretical precipitation boundary for DCPD with respect to the other CaPs studied indicate a possible difference in the dominant processes by which dissolved ionic and other species enter the solid phase. The differences in the position of theoretical precipitation limits in different deposition systems for each phase of calcium phosphates are consistent with the experimentally observed effects that Mg2+ and Cit3- ions have on the processes of their formation.

• Keywords: kalcijevi fosfati; taložni procesi; taložni dijagrami; amorfni kalcijev fosfat (ACP); oktakalcijev fosfat (OCP); kalcijev hidrogenfosfat dihidrat (DCPD); hidroksiapatit (HA); biomineralizacija
• Keywords (english): calcium phosphates; precipitation processes; precipitation diagrams; amorphous calcium phosphate (ACP); octacalcium phosphate (OCP); calcium hydrogen phosphate dihydrate (DCPD); hydroxyapatite (HA); biomineralization
• Language: croatian
• URN:NBN: urn:nbn:hr:149:608732
• Project: Number: IP-2018-01-1493; Title: Mehanizmi nastajanja kalcijevih fosfata na anorganskim nanomaterijalima. Biomimetski put priprave multifunkcionalnih kompozita za regeneraciju čvrstih tkiva; Acronym: CaPBiomimNanocomp; Leader: Maja Dutour Sikirić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Applied Chemistry - Graduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Applied organic chemistry; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra primijenjene kemije (magistar/magistra primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-02-27 16:58:36