CuO doping tuned structural evolution, chemical durability and antibacterial activity of zinc phosphate glasses

This work investigated the impact of small amounts of CuO on the Cu species, structure, chemical durability, and antibacterial activity of zinc phosphate glasses. Glasses with a composition of 42P2O5-30ZnO-20MgO-8Na2O (mol%) doped with 0–2.0 mol% CuO were prepared using the traditional melt-quenching method. Experimental findings indicate that doping 0.1 mol% CuO leads to the dispersion of metallic (Cu0) particles exceeding 100 nm in size within the glass. These large Cu0 particles can cause localized distortions in nearby phosphorus structural units, resulting in depolymerization of the glass network, which subsequently deteriorates the chemical durability of the glass matrix. The depolymerization process facilitates the release of zinc, which can enhance the antibacterial properties of glass against Escherichia coli. Increasing the CuO content from 0.9–2.0 mol% resulted in the formation of mono- and divalent states of Cu (Cu+ and Cu2+), which appeared to enhance cross-linking between the phosphate units and gradually improved the chemical durability.