Effect of ZnO on sol–gel glass properties toward (bio)application

Abstract

In this study, two spherical nanoglasses based on the binary 83SiO2–17CaO (wt.%) (BG) and ternary 75SiO2–8CaO–17ZnO (BG-ZnO) systems were prepared following a sol–gel method. Changes in the structure, morphology and composition of the glasses after immersion in the buffer that simulates physiological conditions (DPBS) were analyzed by various techniques, namely XRD, IR-ATR, EDS analyses, SEM, and TEM imaging. The obtained results were compared to the 45S5 glass tested as a reference biomaterial. The formation of the hydroxyapatite (HA) layer on the BG started from the first hours of incubation in the buffer, while the presence of ZnO inhibited the formation of HA. Instead, the dissolution of BG-ZnO led to the formation of [Na6(ZnPO4)6(H2O)8]. Nevertheless, the intention of increasing the functionality of glasses doped with ZnO was achieved since biocompatible BG-ZnO exhibited antibacterial properties against Staphyloccocus aureus. Moreover, the material demonstrated the synergistic adsorption–photocatalytic degradation effect on common target pollutants such as methylene blue.