The corrosion of ancient bronze relics and protection measures after excavation are of great importance to the study of historical and cultural heritage. At present, the bionic superhydrophobic surface anticorrosive coating is one of the main anticorrosive measures of bronze cultural relics. It aims to construct a barrier to prevent the contact between corrosive media and bronze to reduce the invasion of corrosive media. However, due to structural defects such as micropores in a single organic coating, corrosive media (O2, Cl-, and H2O) can penetrate the coating to the metal matrix. Nanomaterials such as MXenes and metal-organic frameworks (MOFs) can fill structural defects such as microholes and microcracks of the coating, thereby improving the density of the coating. Therefore, to improve the performance of organic waterborne polyurethane (WPU) coatings with good chemical protection, nanomaterial ZIF-8/Ti3C2T x was introduced based on the organic-inorganic hybrid theory. Finally, the coating was modified by 1H,1H,2H,2H-perfluorodecyltriethoxysilane, and the organic-inorganic composite coating was prepared. Characterizations of the composite coating were performed via Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer-Emmett-Teller method, field-emission scanning electron microscopy/energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Colorimetric measurements and reversibility experiments of the coating were also evidenced. According to the electrochemical impedance spectroscopy assessments, the |Z|0.01 Hz value of the F-WPU@ZIF-8/Ti3C2T x composite coating in a 3.5 wt % NaCl solution, which was higher compared to other composite coatings. Moreover, the i corr value of the F-WPU@ZIF-8/Ti3C2T x (3.344 x 10-6 A cm-2) composite coating is reduced by 2 orders of magnitude compared with F-WPU@ZIF-8 and F-WPU@Ti3C2T x coatings. As a result, this organic-inorganic F-WPU@ZIF-8/Ti3C2Tx composite coating has good anticorrosion properties to bronze without causing an obvious color difference change and has potential application prospects in various metal material fields.
This study assesses cremation conditions in the Roman period using a multi-proxy analysis (FTIR-ATR and carbon and oxygen isotope analysis) on 332 burned bones from five Belgian Gallo-Roman cemeteries. The results suggest similar pyre structure, size, temperature, and body positioning across Gallo-Roman cremations. However, high variability in delta C-13 and delta O-18 values indicates differences in fuel selection and environmental factors. The wide delta C-13 range likely reflects the use of multiple wood types (e.g., Quercus sp./oak, F. sylvatica/beech) and different tree parts (e.g., trunk, branch, stump) in pyre construction. In contrast, delta O-18 variation may relate to quenching methods and/or seasonal and weather conditions during combustion. Differences were also observed in cremation conditions between the Metal Ages and the Gallo-Roman cremations from Belgium, with Roman cremations presenting better oxygen availability during combustion. Finally, the Gallo-Roman cemetery of Fouches is particularly interesting, as it dates to the Early Roman period and presents similarities in ventilation conditions with the cemeteries from the Metal Ages instead of the other Gallo-Roman cemeteries. The evidence from Fouches suggests a gradual transition from the Metal Ages to Roman cremation practices. The dating of Fouches to the Early Roman period could potentially explain that Roman cremation expertise was not immediately widespread but rather transferred gradually to the edges of the Roman Empire.
It is challenging to extend the species of deep eutectic solvent (DES) based gels, particularly in forming non-toxic polymer gels with good mechanical properties. In this study, we propose an eutectogel system for cleaning purposes in the field of culture heritage conservation. Green gels containing ChCl-EGGVL-PVA and ChCl-EG-PVA are produced by combining choline chloride (ChCl), ethylene glycol (EG) and polyvinyl alcohol (PVA) with or without gamma-valerolactone (GVL). The crosslinking of the gels is primarily formed by ChCl-EG and PVA through hydrogen bonding. The additional green solvent GVL is compatible with the gel composition and plays an important role in cleaning. The developed gels exhibit good mechanical properties and fine microstructures, making them easy to handle and suitable for cleaning cultural relics. Therefore, the gels have been tested on a mockup coated with Paraloid B72 (R) to examine their cleaning efficiency. Furthermore, the selected gel has been validated on a Yuan dynasty mural painting for the removal of aged acrylic coating. The results from both the mockup and the real case study demonstrate the effective cleaning efficiency of the ChCl-EG-GVL2 -PVA2 gel and highlight its potential usefulness in the field of cultural heritage conservation. (c) 2024 Elsevier Masson SAS. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Salt weathering significantly degrades building materials, necessitating a thorough understanding of influencing factors. While prior research has focused on relative humidity (RH), temperature effects on salt crystallisation and dissolution remain less explored. This study examines selected single salts and mixtures, using the ECOS/RUSALT thermodynamic model to assess equilibrium behaviour across temperatures from 1 °C to 50 °C and RH values from 15% to 98%. Results show that crystallisation and dissolution RH generally decrease with rising temperature. Single salts exhibit monotonic changes, whereas mixtures behave variably. Calcium-rich mixtures have lower mutual crystallisation and dissolution RH than sulfate-rich ones, with further reductions in magnesium-containing mixtures. Lower temperatures promote the formation of more output salts. Model limitations are acknowledged to explain discrepancies between predictions and real-world observations. These findings enhance understanding of salt behaviour under climatic variations, aiding strategies to mitigate salt damage in building materials.
The current study investigates the use of precious metals, aesthetic taste, manufacturing techniques, and craftworking practices in the pre-imperial Qin period before the unification of China, focusing on an interdisciplinary study of gold ornaments discovered at the Ta'erpo cemetery in Xianyang, dating to the 4th-3rd centuries BCE. Employing multi-spectral analytical methods, including 3D Digital Microscopy (OM) and Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy (SEM-EDS), we conducted non-invasive analyses and technological study of a selection of gold artefacts. The results reveal the mastery of sophisticated techniques, including granulation and filigree, which were rarely seen in central China prior to the 2nd century BCE. These delicate decorative techniques required precision, skill and deep understanding of gold metalworking, which demonstrated a high level of technological competence among Qin craftsmen. The investigated ornaments were crafted from very pure gold with content reaching up to 99.62 wt% gold, a rarity among early Chinese gold artefacts. Examining pre-imperial Qin goldwork within a broader Eurasian context reveals that these innovative artistic styles and decorative techniques were originally intertwined with wider influences from the Hellenistic world and the central Asian steppes. This research enriches the understanding of ancient civilization's interconnectedness and the ability of local goldsmith to adapt and integrate foreign influences into their own artistic traditions.
