Study of New Glass–Ceramic and Dense Ceramic Containing Biogenic Hydroxyapatite

Abstract

A novel bioactive glass–ceramic was developed using biogenic hydroxyapatite (BHA) synthesized from Rapana venosa (Black Sea) shells and monocalcium phosphate monohydrate [Ca(H2PO4)2·H2O] via solid-state synthesis. The prepared batches were obtained by combining BHA with SiO2, B2O3, and Na2O, melted at 1200 °C and melt-quenched in water to form glass–ceramic materials. Dense biogenic hydroxyapatite-based ceramics were successfully sintered at 1200 °C (2 h hold) using a 25 mass % sintering additive composed of 35 mass % B2O3, 45 mass % SiO2, 10 mass % Al2O3, and 10 mass % Na2O. Structural characterization was carried out using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The resulting materials consisted of a well-defined crystalline hydroxyapatite phase [Ca10(PO4)6(OH)2] alongside an amorphous phase. In samples with increased SiO2 and reduced B2O3 content (composition 3), a finely dispersed Na3Ca6(PO4)5 crystalline phase appeared, with a reduced presence of hydroxyapatite. Bioactivity was assessed in simulated body fluid (SBF) after 10 and 20 days of immersion, confirming the material’s ability to support apatite layer formation. The main structural units SiO4, PO4, and BO3 are interconnected through Si–O–Si, B–O–B, P–O–P, and mixed Si–O–Al linkages, contributing to both structural stability and bioactivity.