Sinteza, karakterizacija i primena monetitskih i Sr-fosfatnih materijala

Abstract

U ovoj doktorskoj disertaciji ispitane su mogućnosti dobijanja monetita (CaHPO4) i nanosferičnog karbonatno stroncijskog hidroksiapatita [Sr10(PO4)6(OH)(2-2x)(CO3)x ] bržim, jednostavnijim i ekonomski isplativijim postupcima sinteze od dosada korišćenih. Sinteza monetita (CaHPO4) urađena je korišćenjem tehnike mlevenja brušita (CaHPO4∙2H2O) u vibracionom mlinu pri čemu dolazi do njegove fazne transformacije. Ispitivan je uticaj dužine mlevenja na fazni sastav i mikrostrukturne parametre tretiranog materijala. Prikazan je i mehanizam fazne transformacije brušit - monetit pri kratkom vremenu mlevenja (ukupno 12,5 min.). Uočeno je da se monetit formira nakon 5,0 minuta mlevenja u vibracionom mlinu faznim prelazom brušit-monetit. Primenom metode rendgenske difrakcije na polikristalnim materijalima izučavan je fazni sastav i mikrostrukturni parametri sintetisanih i mlevenih kalcijum fosfatnih (CaP) materijala. Ramanska spektroskopija, kao komplementarna metoda rendgenskoj difrakcionoj analizi, upotrebljena je za ispitivanje početnog brušitnog materijala. Infracrvena spektroskopija sa Furijeovom transformacijom iskorišćena je za ispitivanje i praćenje toka promena faznog sastava tokom mlevenja. Adsorpciono-desorpciona metoda (BET) korišćena je za određivanje poroznosti materijala mlevenog 5,0 min, dok su morfološke karakteristike materijala i semikvantitativni sastav ispitane korišćenjem metodom skenirajuće elektronske mikroskopije sa energijsko disperzivnom analizom (SEM-EDS). Mezoporozni monetitski material dobijen je nakon 5,0 minuta mlevenja u vibracionom mlinu. Ovako dobijen material korišćen je za adsorpciju fosfatnog pesticida-malationa iz vodenog rastvora. Rezultati adsorpcije pokazali su da se malation može uspešno odstraniti iz vodenog rastvora korišćenjem monetita kao adsorbenta...

In this doctoral dissertation the main goal was to examine the possibilities for obtaining monetite (CaHPO4) and nanospheric strontium carbonate hydroxyapatite [Sr10(PO4)6(OH)(2-2x)(CO3)x ] materials by using faster, easier and cost-effective methods for synthesis. Monetite (CaHPO4) material was obtained by milling previously synthesized brushite (CaHPO4∙2H2O), in a vibratory mill resulting in its phase transformation occures. The effect of the different time periods of milling treatment on the phase composition and microstructural parameters of the treated material was also examined. The mechanism of phase transformation brushite-monetite during short time milling (12.5 minutes in total) was also shown. It was found that after 5.0 minutes of milling monetite phase starts to form, after brushite-monetite phase transition. The X-Ray powder diffraction (XRPD) method was used to investigate microstructural and phase properties of synthesized and milled calcium phosphate (CaP) samples. Raman spectroscopy, as a complementary method to XRPD analysis was used to confirm the purity of synthesized initial brushite material. Fourier transformation infra red spectroscopy (FTIR) was used for investigation and monitoring of the phase composition changes during milling treatment. The adsorption-desorption method (BET) was used to determine the porosity of the material milled for 5,0 min., whereas the morphological characteristics and semiquantitative analysis of obtained materials was observed using the method of scanning electron microscopy with energy dispersive analysis (SEM-EDS). Monetite material with mesoporous properties was obtained after 5,0 minutes of milling in a vibratory mill. This material was further applied as adsorbent for adsorption of phosphate-pesticides i.e. malathion from aqueous solution...