ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Surface phenomena in gel-derived glasses and glass-ceramics materials of the CaO-P₂O₅-SiO₂ system

M. Laczka and K. Cholewa

Glass and Enamels Department, Faculty of Materials Science and Ceramics, University of Mining and Metallurgy, PL 30-059 Krakow

Abstract: Three types of glass-ceramics materials of the CaO-P2O5-SiO2 system were obtained using the sol-gel method and applying calcium nitrate, tetraethyl orthosilicate, and triethyl phosphate as precursors of the respective oxides. The base materials were also modified with the addition of 5 mole % Al2O3, using aluminium tri-sec-butoxide as its precursor. Gels were heated up to the temperature 700 degrees C. It has been found that after heating these materials contain a glassy phase, hydroxyapatite and wollastonite; there were important differences in the phase compositions as well as in the pore structure of these materials.Materials after treatment were put into simulated body fluid. After a different time periods the surface changes of these materials were examined using FTIR, SEM, and EDAX methods. It has been found that the bone-like hydroxyapatite is formed on the surface of gel-derived materials and the time necessary to forming the continual layer of this compound is dependent upon the chemical composition of the base materials. On I;he basis of conducted examinations the attempt of the explanation of the hydroxyapatite formation mechanism was undertaken, The results of our experiments can be interpreted as indicating the bioactivity of obtained gel-derived materials. This means that these materials used as bone implants can be permanently joined to the bone.

Chemical Papers 51 (6A) 348–356 (1997)