Influence of ZnO on the structural, optical, ligand field and antibacterial characteristics of sodium borosilicate glasses containing minor Cr2O3 additions

Abstract In this work, the structural, optical, ligand field, and antibacterial properties of Cr 2 O 3 , ZnO and Na 2 O borosilicate glasses were studied. A glass system of the compositions 70B 2 O 3 −14.8 SiO 2 -(15-x)Na 2 O-0.2Cr 2 O 3 -xZnO, where x = 0, 3, 5 and 7 mol% was prepared via melt-quenching technique. In this study, X-ray diffraction (XRD) spectra were used to check the amorphous state of the prepared glass specimens. Infrared (IR) spectra were used to study the internal structure of the formed units and groups within the glass matrix. Moreover, the optical absorbance spectra were used to study the optical parameters, such as optical band gap and ligand field parameters. Furthermore, the antibacterial activities of the glass samples were investigated against different antibiofilm activities, for example, Staphylococcus aureus and Escherichia coli. The optical studies showed that E g values increased from 3.06 to 3.62 with further ZnO doping. Furthermore, 10 Dq values increased and B values decreased with the increase in ZnO content. The 10Dq increased values reflect the increased interactions between the Cr 3+ cations and their environments, such as oxygen anions. Further, the decreased values of B refer to the tendency of the bonds of Cr 3+ cations and their environments toward the covalent nature. On the other hand, the results showed that the investigated glasses are promising materials owing to high antibacterial activity on a large scale (food covering, wound curing, and surface coatings), especially the glass sample that contains the highest concentrations of ZnO. Furthermore, it demonstrated antioxidant activity using DPPH and H 2 O 2 free radical scavenging activities.