Historical photographs are an important category of cultural heritage and present a wealth of historical information. Unfortunately, these photographs are suffering from brittle curling, folding, and fracturing diseases, the previous strategies can correct mildly curled photographs but are inapplicable to severely brittle and extensively curled photographs. This study developed a new method based on the synergistic effects of the molecular plasticisation, cross-linking, and shaping of glycerol triglycidyl ether (GTE) to toughen, flatten, and restore embrittled and curled historical photographs. First, the effects of GTE treatment on the shrinkage and curl resistance of gelatine-based photographic films were evaluated at the macro and micro levels under accelerated humid-heat ageing conditions. Next, spectrophotometry and MATLAB calculations were used to characterise the colour difference, surface light absorption, and grey value of photographs before and after GTE treatment. Comprehensive evaluation revealed that GTE treatment combined with traditional craft techniques could successfully realise the plasticisation, flattening, restoration, and conservation of severely curled historical photographs. A storage apparatus for keeping the restored historical photographs was also devised. This study focuses on a typical practical case for the restoration, conservation, and durable preservation of curled gelatine-based historical photographs and offers theoretical and technical support for the conservation of these valuable historical artefacts.
The low ionic conductivity of poly(ethylene oxide) (PEO)-based polymer electrolytes at room temperature impedes their practical applications. The addition of a plasticizer into polymer electrolytes could significantly promote ion transport while inevitably decreasing their mechanical strength. Herein, we report a supramolecular plasticizer (SMP) to break the trade-off effect between ionic conductivity and mechanical properties in PEO-based polymer electrolytes. Accordingly, the SMP is constructed by tetraethylene glycol dimethyl ether (G4) and SbF3 through halogen bonds. The SMP-plasticized PEO electrolyte (PEO/SMP) presents a simultaneously enhanced ionic conductivity of 2.4 × 10–4 S cm–1 (25 °C) and a high mechanical strength of 8.1 MPa, compared to those of pristine PEO-based electrolytes. Benefiting from the halogen bonds between G4 and SbF3, the Li–O coordination in PEO/SMP is evidently weakened, and thus rapid Li+ transport is achieved. Furthermore, the PEO/SMP electrolyte possesses a wide electrochemical stability window of 4.5 V and, importantly, derives an inorganic-rich SEI with a low interfacial resistance on a lithium metal surface. By using PEO/SMP, the lithium-metal battery with the LiNi0.5Co0.2Mn0.3O2 cathode exhibits a good rate and long-term cycling performance with a capacity retention of 75.3% (500 cycles). This work offers a rational guideline for the design of polymer electrolytes suitable for high-performance lithium-metal batteries.
危险品化学品经营许可证（带存储）