脆弱性硅酸盐质文物盐害形成与预防物理化学基础研究

The repeat process of salt crystallization and resolved by absorbing water from the surrounding air, can usually damage the ancient culture heritage, such as pottery and frescoes. That makes the salt problem in the ancient heritage is one of the most important research area, which attract a lot of researchers all of the world to devote themselves to finding the solutions. The proposal will focus the salt problem in the ancient pottery and frescoes, with the help of “local heating-in-situ observation” and “micro displacement” methods to study the whole process of salt moving with water，nucleating, crystallization and resolved by absorbing moisture, as well as their repeat process through high throughput experiment method，meanwhile to establish mathematical model for the above process. In order to forecast the appears of salt problem in the ancient heritage in advance, we apply multispectral method to find the best wavelengths for distinguish salt solution from the mixture of clay particles and the separated salt solution in the surface of the ancient ones, and forward to get the concentration of the salt solution in the ancient heritage in high precision firstly, and “infrared imaging with heating-in-situ” and “micro displacement” techniques to determine the changing speed of salt concentration, and finally to draw the contour lines of salt concertation and its changing speed. The higher the salt concentration and its changing speed, the higher risk of the slat problem to the ancient heritage. To make the atomized water to be absorbed, and meanwhile carry the salt into depths of the ancient heritage, and find the best conditions (such as temperature, pressure of the atomized water) to keep the salt solution far away from the stage of saturated solution for the very weak ancient heritage.

盐害被称为壁画的“癌症”，是硅酸盐质文物最普遍、最严重的病害。本项目将以脆弱性陶器及壁画等典型硅酸盐质文物为研究对象；借助“局部加热-原位观察”和“微位移”以及高通量试验等方法，系统研究多种浓度盐溶液在不同组成、不同结构模拟样品内运移、成核、结晶、溶析全过程，获得多环境变量耦合作用下文物的盐害损毁机理，建立盐害发展变化的数学模型；探讨文物本体大噪音背景的剔除以及非连续性小区域盐溶液信号的放大技术，比较、确定和识别盐溶液浓度的最佳波长，原位无损测定文物内盐溶液的浓度。同时，利用“局部加热-红外观察”结合“微位移”法测定局部区域内盐溶液浓度的变化速度，绘制文物盐溶液浓度、变化速度等高线，为盐害的成功预报奠定科学、技术以及装备基础；最后，系统研究水的雾化方式以及雾化水温度、压力与文物吸附雾化水的特性，以及吸附水携带盐分向文物内部的扩散规律，开发极脆弱性文物非接触法控制盐害的新技术。

本项目重点围绕盐害研究中的薄弱环节，聚焦“一带一路”典型脆弱性硅酸盐陶质和壁画文物，在文物“组成-工艺-结构”研究基础上，利用上海光源µ-CT、低场核磁共振技术、以及显色盐追踪等方法，揭示盐害导致文物劣化的机理和损坏机制，确定存在的浅表面、表面以及深层等三类盐害类型以及对文物的危害程度；采用高光谱检测技术研究文物中水盐浓度及浓度的变化速度，获取了盐液在多孔材料中的运移以及结晶的数学模型，为盐害的预报奠定了基础；同时，探索文物内部诱导除盐、控盐等方法，解决目前除盐技术对文物造成的二次损伤，已获准在陕西考古研究院脆弱文物除盐及内蒙等地的化石保护中应用。本项目的实施，大大提升文物保护科技工作者对盐害成因的理解，使得盐害的防治由被动转为主动，为文物延年益寿的保护提供科学依据。