实验室模拟硅酸盐质文物除盐控盐的可视化研究

Research on the visualization of desalination and salt control of simulated silicate cultural relics in the laboratory

针对目前广泛使用的材料吸附除盐和加湿喷雾控盐等方法对含盐硅酸盐质文物可能造成的损伤,采用扫描电子显微镜、电阻仪和高分辨摄影仪等实时在线记录具有显色性质硫酸铜溶液在吸附除盐和水雾控盐加湿干燥过程中文物内部盐带分布的变化。研究结果表明:吸附材料除盐法和表面喷雾控盐法均会加速样品内部盐离子的扩散迁移,在样品中形成双层或多层盐结晶带;所形成的盐结晶带与样品结构特性、盐溶液在样品中的运移和蒸发速率、加湿-干燥频率等因素有关,其中溶液毛细上升高度和样品透气性越好,以及环境温度和盐溶液浓度越高,加湿-干燥频率越快,样品内部的盐带分布变化越明显。材料吸附除盐和水雾控盐等方法加速了盐溶液在样品内部的扩散,促进多层盐带的形成。这些结果对于目前文物保护所采取的除盐控盐技术手段提出了新的挑战。

In view of the potential damage caused by desalination and salt control methods widely used for salt-containing silicate cultural relics,a variety of instruments such as scanning electron microscopes,resistance meters and high resolution cameras were used to record changes of the distribution of salt zones in the interior of saline cultural relics with chromogenic copper sulfate solutions.The results indicate that the migration and diffusion rate of salt ions in the samples could be accelerated by desalination and surface-spray salt control methods,forming two or more layers of salt crystals in the interior of the samples.The formation of salt crystal band was related to the structural characteristics of the porous samples,the transport and evaporation rates of salt solutions and the frequency of humidification and drying cycles.The results also indicate that with the increases of capillary rise height and air permeability of the samples,ambient temperatures and salt concentrations and even humidification and drying frequency,the changes of salt band distribution in the porous samples became more obvious.The results provide scientific evidence and visual data support for the potential damages of porous cultural relics induced by desalination or salt control with the humidification technology.