Ecological Silicate Glasses

The investigated ecological glasses with no toxic compounds, such as BaO, PbO, As2O3, As2O5, fluorine, CdS and CdSe in their composition are located in ternary and quaternary oxide systems: ZnO-SiO2-TiO2 and SiO2-R'2O-R''O-R'''O2, where R' is Na or K, R'' is Ca or Mg and R''' is Zr or Ti. The first system contains P2O5, ZnO and TiO2 in order to obtain opal glasses, without fluorine compounds. The second system replaces the barium oxide and lead oxide with potassium, magnesium, zirconium and titanium oxides, for materials like lead free crystals. The raw materials can be replaced by silicate or borosilicate glass waste. The advantages of borosilicate glass waste are: bringing valuable components into recipes (B2O3, CaO, Al2O3), saving raw materials and energy, creating an ecological environment The characteristic temperatures (vitreous transition point, low and high annealing points, softening point) and the thermal expansion coefficient of the glass are presented. The FTIR and Raman spectroscopy provided structural data, such as characteristic vibration maxima for silicon and titanium oxide, and revealed the role of zinc oxide in the vitreous network. The refraction index and UV-VIS transmission are discussed.