This study reports the design and evaluation of functionally graded sol–gel coatings based on TiO₂, ZnO, and SiO₂ nanoparticles for low-emissivity (Low-E) glazing. By engineering the gradient structure and layer sequence, the coatings combine high infrared (IR) reflectivity for thermal insulation with strong ultraviolet (UV) blocking, while maintaining excellent visible light transmittance. X-ray diffraction revealed nanocrystalline anatase TiO₂ (33.7 nm), hexagonal ZnO (82 nm), and amorphous SiO₂, confirming the tailored nanostructures. Optical analysis demonstrated >80% visible transmittance, >60% UV blocking, high IR reflectance, and emissivity as low as ~0.38, indicating significant energy-saving potential. The synergistic performance arises from TiO₂’s UV absorption, ZnO’s IR reflection, and SiO₂’s protective and anti-reflective roles, surpassing conventional single-layer or metallic coatings. These results establish sol–gel-derived TiO₂–ZnO–SiO₂ coatings as a cost-effective, durable, and sustainable alternative for energy-efficient glazing, with promising applications in smart windows and climate-responsive building envelopes.

The incorporation of copper into pyroxene structure was investigated through the melt quenching technique and one-step crystallization procedure. Two series of glasses have been studied, one set with Ca=Mg and another set with Ca>Mg in diopside formula Cux(Ca Mg)2-xSi2O6. The glasses were nucleated by TiO2, Cr2O3, or CaF2 additions as nucleating agents to variably control the phases produced. X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive X-ray spectroscopy (EDX) were used to characterize the obtained samples. The heat treatment studied at 700, 800, 900 and 1000 °C for 2 h produced green and dark green glasses based on Cu-containing diopside. Various crystalline wollastonite, cuprite, tenorite, cristobalite, quartz, and fluorite phases were developed with different ratios combined with diopside formation depending on the heat treatment and nucleating agents used. As the heat treatment increased in temperature, the crystallized fraction increased with the development of nano-aggregates and the observed reticulated textures confirmed a radical change in the euhedral crystals. This emphasizes that the Cu-containing diopside can be created by a facile one step process. These compositions may find some applications in biological and optical fields.

The influence of PbO content on the structural, optical, mechanical, and chemical durability of commercial lead crystal glasses was investigated. Increasing PbO concentration correlated with higher density and refractive index—characteristics that contribute to the optical brilliance of lead crystal—while generally reducing hardness and thermal stability. Chemical durability was assessed by leaching tests in distilled water, a 25% (v/v) ethanol solution, and 4% acetic acid at 75°C for 6 h; released cations (Na, K, Pb, Si) were quantified by electrothermal atomization–atomic absorption spectroscopy (ETA-AAS). The results indicate that corrosion resistance depends on both PbO content and leaching medium; higher PbO (> 24 wt.%) samples tended to show greater Pb release—especially in acetic acid. Within the limited set of commercial samples tested here, compositions near 24 wt.% PbO showed a compromise between optical qualities and chemical durability; however, this observation should not be generalized without further study.