丝织品文物老化行为和结构分析及微观可逆性保护

Ancient silk is exquisite artwork as well as connected to our ancestor’s routine and ritual life, and religious ceremony; lies in human civilization and creation as a unique crystal. It used to be the most significant commodity along the Silk Road, which has reflected the past commerce and transportation, propagation and interaction of science and technology, and communication between countries and regions cross Eurasia. It has provided solid and physical evidences that could help to reconstruct our societies with invaluable historical significance. However, precious silk textiles has suffered severe deterioration due to the inappropriate conservation and preservation treatments in museums and sudden environmental change at archaeological excavations, scientific conservation is thus in urgent need. Analyse of ageing behaviours of silk products from different species，regions and time will be carried out microstructurally and thermomechanically. Artificial ageing methods will also be applied to compare with natural aged silks in order to understand different ageing paths and degradation of silk fibroin with the help of structure characterisation, and finally offering the feasibility for the conservation of silks in terms of slowing down the ageing process. Electrospun nanofibre of regenerated silk fibroin will be chemically modified to increase its beta-sheet orientation thus enhance the mechanical strength to achieve the object of developing tunable and novel reversible material for restoration. The exploration of biodegradable silk and their structure-property relations will also further improve our understanding to the structure of this material and reach the real conservation of cultural heritage.

丝织品文物与古中国人民日常宗教礼仪、祭祀息息相关；是精美的艺术品，亦是人类文明的智慧结晶。作为丝绸之路上最重要的贸易产品之一，它反映了欧亚大陆丝路沿线各国家地区的商贸运输、科技传播以及人们的交流；丝织品文物从而为复原古代社会结构提供了珍贵的史料和现实证据。然而脆弱的丝织品在考古现场发掘环境变化和博物馆修复过程中都面临诸多亟待解决的科学问题。本研究将从丝蛋白分子老化行为研究及微观结构分析入手，对比不同种类、地域和时代的蚕丝，通过比较自然老化和人工加速实验老化的差别，探讨不同老化路径下的丝织品降解的机理和提出减缓老化历程的可行性保护方案。采用静电纺技术纳米纺丝和化学修饰使再生丝蛋白溶液成纤具有一定的β-折叠的取向和强度的提升，从而实现丝织品文物的修复材料进行可调控性、可逆性研发。这也将进一步揭示丝蛋白生物降解性和结构力学性能的相互关联, 加深我们对丝蛋白材料的结构理解和实现真正的文物保护。

本研究涉及古代丝织品光谱学结构分析。通过模拟光、热、及微生物等老化因素及方法，对丝织品进行人工加速老化和老化机理的研究。特别注意到埋藏环境中丝织品的降解，微生物是关键因素，因此开展了微生物引起的丝蛋白的降解问题的深入研究，提出丝的降解中环境氧参与的关键问题的讨论。针对脆弱丝织品的保护修复研究，创新性的采用静电纺技术织出修复材料，并对粘合剂进行了筛选，选择天然丝胶作为胶粘剂, 构成古代丝织品-丝胶-丝蛋白膜的三明治保护结构。由于古代丝织品也存在草木染色，本研究亦包括模拟古代草木染的研究及丝-染料相互作用的研究。