无损鉴别古纸涂层及涂料的新方法

New Approach for Non-destructive Investigation of the Coated Ancient Chinese Papers

关键词:  手工纸  扫描CT  涂布  拉曼光谱  铅白

Key Words:handmade Chinese papers  micro-CT  coating  Raman spectroscopy  lead white

摘要:在古纸以往的研究中，对古纸中涂层和涂料的判断主要依赖显微镜观察和表面元素分析，在解释现象和解读数据方面存在一定的主观性。本研究首次将计算机显微断层扫描技术（Micro-Computed Tomography，简称扫描CT）和拉曼光谱联合应用于清代和近现代手工纸涂层和涂料鉴别。结果表明，扫描CT能准确判断涂层的有无并区分单面涂布和双面涂布，拉曼光谱可以鉴别涂层中的涂料（以及其他物质）。两种方法完全无损，对涂层和涂料的鉴别结果清楚，判断标准明确，其联合使用可为研究涂布纸的制作工艺开拓新思路。

Abstract:Previous studies on characterizing ancient Chinese coated papers rely mainly on microscopic observations and/or elemental analysis of the paper’s surface, which are often subjective in interpreting the observations and analytical results. Exploration of new methodologies that produce more reliable results with clearer judging criteria is needed. The present research applied jointly Micro-Computed Tomography (micro-CT) and Raman spectroscopy to the samples of both ancient and modern handmade Chinese papers for the first time. As suggested by the results, micro-CT could distinguish between coated and uncoated papers as well as between single-side and double-side coated papers. Raman spectroscopy could characterize or identify the coating pigment (as well as other substances) in the coating layer. The new methodology established here was completely non-destructive and could produce scientifically conclusive results regarding the coating layer and coating pigment, which offered new insights into the manufacture of ancient Chinese coated papers.