SINTESIS DAN KARAKTERISASI HIDROKSIAPATIT [Ca10(PO4)6(OH)2] DARI BATU KAPUR DENGAN METODE SOL-GEL

Limestone was used as a raw material for synthesis and characterization of hydroxyapatite with sol-gel method. Calcination of limestone, was conducted at temperature of 1000oC for 12, 16, and 20 hours to obtain CaO compounds with high crystallinity. The CaO suspension was reacted with H3PO4 as phosphate precursors with stirring time for 1, 2, and 3 hours, then dried at 60??C for 1 day. Sintering of hydroxyapatite synthesis was conducted at temperature of 800 and 900??C for 3 hours. Furthermore, it was characterized using XRD, FTIR, and SEM. Analysis using XRD showed the highest probability of purity of hydroxyapatite obtained at the time of stirring for 2 hours with temperature sintering of 900oC is 73,68421%, with crystallinity equal to 90,867% and average size of crystal diameter equal to 23,35351 nm. Functional groups were identified with FTIR, indicating the presence of OH-, CO32-, and PO43- groups. The morphology of the hydroxyapatite structure was analyzed by SEM, showed clumps of the hydroxyapatite surface and the agglomeration of each particle with a small pore shape