The incorporation method was employed to produce potassium sodium niobate [KNN] (K_0.5Na_0.5NbO₃) glass ceramics from the KNN-SiO₂ system. This incorporation method combines a simple mixed-oxide technique for producing KNN powder and a conventional melt-quenching technique to form the resulting glass. KNN was calcined at 800° C and subsequently mixed with SiO₂ in the KNN:SiO₂ ratio of 75:25 (mol%). The successfully produced optically transparent glass was then subjected to a heat treatment schedule at temperatures ranging from 525° C -575° C for crystallization. All glass ceramics of more than 40% transmittance crystallized into KNN nanocrystals that were rectangular in shape and dispersed well throughout the glass matrix. The crystal size and crystallinity were found to increase with increasing heat treatment temperature, which in turn plays an important role in controlling the properties of the glass ceramics, including physical, optical, and dielectric properties. The transparency of the glass samples decreased with increasing crystal size. The maximum room temperature dielectric constant (ε _r ) was as high as 474 at 10 kHz with an acceptable low loss (tanδ) around 0.02 at 10 kHz.

This study identifies the technological signature of ancient and alternative “Chu” and “Kriab” gold glass mosaic mirrors from Thailand. Although these mirrors play an important role in Thai decorative heritage, their production routes and interfacial chemistry at the lead-to-glass interface have remained unclear. A survey of 154 sites across Thailand shows mosaic glass was widely distributed and likely produced during the Ayutthaya period (~300 years ago). PXRF, WD-XRF, SEM, and XPS were used to examine the material properties of observed Chu mirrors. Most samples can be classified as a mixed lead-alkaline glass type, with PbO content ranging from 4.28 to 48.17 wt%. Their yellow tone is controlled by iron and manganese redox states. Chemical and physical analyses distinguish between Chu1 and BKK[7], which share a silica source but rely on different flux, pointing to different glass workshops. Additionally, some Chu and Kriab samples exhibit evidence of potential use of recycled materials. Depth profiling showed that there were lead species at the interface, including PbO4, PbO, and Pb0. The ancient samples had higher Pb0 concentration due to reducing kiln conditions. Silanol groups on the glass surface are identified as the key factor promoting the adhesion of lead coating to the glass surface. Variations in raw materials and coating techniques further differentiate ancient Chu mirrors from modern reproductions. This research offers useful information about the technological ingenuity of ancient artisans and supports the conservation and replication of these culturally significant artifacts. The results contribute to preserving Thailand’s rich heritage in decorative glasswork and lay a foundation for future research into material provenance and historical restoration practices.

This study identifies the technological signature of ancient and alternative “Chu” and “Kriab” gold glass mosaic mirrors from Thailand. Although these mirrors play an important role in Thai decorative heritage, their production routes and interfacial chemistry at the lead-to-glass interface have remained unclear. A survey of 154 sites across Thailand shows mosaic glass was widely distributed and likely produced during the Ayutthaya period (~300 years ago). Portable X-Ray Fluorescence (pXRF), Wavelength-Dispersive XRF (WD-XRF), scanning electron microscopy (SEM), and X-ray Photoelectron Spectroscopy (XPS) were used to examine the material properties of observed Chu mirrors. Most samples can be classified as a mixed lead–alkaline glass type, with a PbO content ranging from 4.28 to 48.17 wt%. Their yellow tone is controlled by iron and manganese redox states. Chemical and physical analyses distinguish between Chu from the northern part of Thailand and Kriab from the central part of Thailand, which share a silica source but rely on different fluxes, pointing to different glass workshops. Crucially, XPS depth profiling reveals a well-defined interfacial reaction zone extending to approximately 6 nm in the ancient mirrors, predominantly characterized by disordered, chain-like Pb–O–Pb linkages. These polymeric structures enable a “chemical bridging” mechanism that effectively accommodates interfacial strain arising from thermal expansion mismatch, thereby ensuring exceptional long-term adhesion. Furthermore, the depth-dependent distribution of hydrated lead species and the emergence of photoelectron energy-loss features beyond ~6 nm distinguish the superior metallic integrity of the ancient coatings from the alternative reproductions. This distinct stratification confirms that ancient artisans achieved a sophisticated balance between a chemically bonded interface and a coherent metallic bulk. These findings offer significant insights into the ingenuity of ancient Thai artisans, providing a scientific foundation for the conservation, restoration, and replication of these culturally significant artifacts.

K2O–Al2O3–SiO2 glass–ceramics, despite their structural advantages, typically exhibit limited intrinsic bioactivity due to the stabilizing effect of Al2O3. In this study, a synergistic HCl–CaCl2 surface-activation strategy is proposed to overcome this limitation and to induce controlled hydroxyapatite (HAp) formation. The glass–ceramics, consisting of boromuscovite and boromullite phases within a borosilicate–aluminosilicate network, were systematically surface modified using single-step and sequential chemical treatments. While single-step treatments failed to trigger apatite nucleation even after prolonged immersion in simulated body fluid (SBF), the combined HCl–CaCl2 treatment enabled rapid and selective formation of an apatite-like Ca–P layer. SEM–EDS and XPS analyses confirmed homogeneous Ca–P deposition and the progressive evolution toward calcium-deficient apatite compositions. Mechanistically, the enhanced bioactivity arises from the synergistic interplay between surface hydroxylation (Si–OH formation) and calcium enrichment, which lowers the nucleation barrier and promotes electrostatically driven Ca–P cluster formation. Furthermore, MTT results demonstrate excellent cytocompatibility at low to moderate extract concentrations, governed by controlled ion release from the boron-modified glass network. This work establishes a clear structure–surface–bioactivity relationship and provides a simple yet effective strategy to activate bioinert glass–ceramics for bone-related applications.