几种商用保护材料对模拟秦俑陶胎的加固和防盐风化性能研究

目前对古代陶胎的研究多集中在加固材料的筛选及其保护效果评估上,普遍缺乏深入的保护机理的研究,尤其保护材料对陶胎盐风化的影响及其机理研究在国内更是罕见。因此,本实验选用TEOS(正硅酸乙酯)、Paraloid B72和WD10对模拟古代秦俑陶胎进行了加固和防盐风化保护研究。重点观察了不同材料处理后陶胎样品表面盐结晶的形貌,并对其形成机理进行了探讨。最后对Paraloid B72在耐盐实验中出现的保护性破坏现象给予关注。结果显示,TEOS处理后陶胎的抗压强度得到提高,但对陶胎的耐盐性能没有改善;Paraloid B72处理后,陶胎颜色加深,耐盐实验中处理陶胎出现了严重的盐风化。WD10处理后陶胎的耐盐性能显著增强。对盐结晶的微观形貌研究初步揭示,保护材料能够对陶胎表面进行改性,不同的憎水性和渗透性会显著影响盐结晶的微观形貌,进而会带来不同类型的盐风化。本研究结果启示文物保护工作者必须深入了解各种保护材料的优缺点,根据被保护文物的具体实际需求,慎重开发和选择保护材料,以避免保护性破坏现象的出现。

Study of the consolidation and antisalt efflorescence performance of several commercial protective materials on simulated Qin terracotta

At present, most of the research work of ancient pottery protection is related to the selection and evaluation of consolidation materials. Research on the protection mechanism, especially in the field of salt weathering, is very limited. In this paper, TEOS, Paraloid B72 and WD10 were selected to be used for consolidation and mitigation of salt efflorescence on the simulated ancient Qin terracotta samples. The morphologies of salt crystals on surface of untreated and treated terracotta samples were investigated; the related salt crystallization mechanism is discussed in a preliminary way. Water absorption, color change, compressive strength and salt artificial ageing tests were conducted on the simulated terracotta samples after treatment with these materials. The results show that the terracotta samples treated with TEOS gain better compressive strength, but that TEOS had no positive effect on mitigating salt efflorescence; WD10 greatly reduced water absorption and is able to mitigate salt crystallization damage; Paraloid B72 deepened the treated terracotta sample color and enhanced salt efflorescence. It show that surface modifications produce different types of salt efflorescence, which relates to the hydrophobicity and permeability generated from protective material. The harmful effect of Paraloid B72 is also captured attention.