Structure and composition characterization of biocomposites filled with sol-gel bioglasses from the CaO-SiO2-P2O5-Ag2O systems

摘要

Lately silver has become extremely important among alloying additives used to produce glassy materials with specific tailored properties. The aim of the study is to characterize bioactive glasses belonging to the CaO-SiO2-P2O5-Ag2O system by SEM and EDX methods, as well as biocomposites based on natural rubber containing those fillers. The focus is on the influence that silver oxide and the mechanism of its effect have upon the properties of glasses and biocomposites. The results show that silver particles serve as crystallization centers for apatite formation in sol-gel glasses what leads to a serious change in the morphology and size of crystals and consequently in glass microstructure. Particles in the form of plates have been identified. This is an indication of silver-stimulated crystalline structure. A relation between the hydroxylapatite plaque and the concentration of silver particles has been found. The influence of silver oxide is expressed in noticeable changes in the adsorption texture properties of the glasses. In the composites, the aggregation of the filler particles has been observed and their size increases in the presence of silver oxide. The hydroxylapatite formed as a stand-alone phase in the sol-gel glass and acting as a filler has the most important role in tailoring the composite characteristics.