Development of Novel Transparent Radiation Shielding Glasses by BaO Doping in Waste Soda Lime Silica (SLS) Glass

In the current study, BaO was doped in Bi2O3-ZnO-B2O3-SLS glass to develop lead-free radiation shielding glasses and to solve the dark brown of bismuth glass. The melt-quenching method was utilized to fabricate (x) BaO (1 − x)[0.3 ZnO 0.2 Bi2O3 0.2 B2O3 0.3 SLS] (where x are 0.01, 0.02, 0.03, 0.04, and 0.05 mol) at 1200 °C. Soda lime silica glass waste (SLS), which is mostly composed of 74.1% SiO2, was used to obtain SiO2. The mass attenuation coefficient (μm) was investigated utilizing X-ray fluorescence (XRF) at 16.61, 17.74, 21.17, and 25.27 keV and narrow beam geometry at 59.54, 662, and 1333 keV. Moreover, the other parameters related to gamma ray shielding properties such as half-value layer (HVL), mean free path (MFP), and effective atomic number (Zeff) were computed depending on μm values. The results indicated that HVL and MFP decreased, whereas μm increased with an increase in BaO concentration. According to these results, it can be concluded that BaO doped in Bi2O3-ZnO-B2O3-SLS glass is a nontoxic, transparent to visible light, and a good shielding material against radiation.

Revealing the scientific root of scratch formation on soda-lime-silica glass surface: Digging deeper into structural modification of glass surface

Scratch formation on glass surfaces is a ubiquitous phenomenon induced by the virtue of plastic deformation, often accompanied by radial, lateral or median cracks with consequent chipping and brittle fracture caused during and after the event of dynamic abrasion instigated by shear stress by another harder material. This paper deals with the fundamental aspect of scratch formation on soda-lime-silica (SLS) glass surfaces. A constructive combination of surface-sensitive characterization tools including field emission scanning electron microscopy (FESEM), laser scanning microscopy (LSM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and instrumented indentation technique (IIT), helped to investigate the structural cause of generation of visible scratches on SLS glass surfaces. The experimental evidences propose that a silicate network possessing a mechanically-weakening structural characteristic in terms of network connectivity confined to the region between 5 nm and 100 nm below the glass surface, is likely to cause a destructive surface scratch eminently visible to naked eyes.

Hunting colours: origin and reuse of glass tesserae from the Wierum terp

Mosaic glass tesserae were imported to Dutch sites during the Early Medieval period, probably to address the demand for coloured glass needed in ornamental bead manufacture. Although challenging, because of the uncertainty of the material’s context, the Wierum Early Medieval collection represents an extraordinary opportunity, being the most significant find of glass tesserae in the Netherlands to date. The combined use of electron microprobe analysis (EMPA) and hand-held X-ray fluorescence spectrometry (HH XRF) allowed us to examine glass tesserae and other vitreous samples from the site. Low levels for magnesium and potassium oxides (<1.5 wt%) and the chemical components linked with the silica source, fluxes, opacifiers and chromophores are compatible with an older Roman soda-lime-silica glass production. Alumina and calcium oxide contents together with the adoption of antimony-based opacifiers are compatible with mosaic tesserae of a first to third century AD Roman tradition. We assume that these tesserae were collected during the spoliation of a lavish building and reused for glass objects produced locally. The hypothesis seems to be confirmed by the presence in the collection of tesserae still embedded in mortar, stone tesserae fragments and a rounded fragment of Egyptian blue.