Yang Yipan, Lian Xiaodong, Yang Zhaoxiang, Zhou You, Zhang Xiaogang, Wang Yapei
Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China.
Langmuir. 2021 Oct 5;37(39):11474-11483. doi: 10.1021/acs.langmuir.1c01649. Epub 2021 Sep 23.
Cleaning is a foundational and essential operation of protection and restoration of cultural relics, which is also the key step of follow-up works. To overcome the problems of uncontrollable diffusion of cleaning solvents and poor coverage of the cleaning solvent carriers on rough surfaces, here, we propose a strategy of using a self-shaping microemulsion gel that is prepared via emulsifying oleophilic solvents into the specific shear-thinning hydrogel structures. The gel can adaptively cover rough surfaces during the cleaning process coupled with avoidance of unnecessary diffusion of the cleaning solvents, and the mechanical reinforcement of in situ polymerized double-network gels enables its easy peeling off from the surfaces without leaving determinable residues. As a representative demonstration, Paraloid B72, a widely used material for the repair and reinforcement of cultural relics, is employed as a model discolored coating, which can be effectively removed from the rough surface of simulated cultural relics after treatment with the resulting gels. Convincingly, the strategy of constructing agarose/polyacrylamide hybrid double-network gels with shear-thinning and self-shaping performances for the cleaning of cultural relics not only improves the convenience and accuracy of operation but also exhibits an efficient cleaning effect, which will greatly expand the application of microemulsion gels in the cleaning of rough surfaces of cultural relics.
清洗是文物保护与修复的一项基础性且必不可少的操作，也是后续工作的关键步骤。为克服清洗溶剂扩散难以控制以及清洗溶剂载体在粗糙表面上覆盖性差的问题，在此，我们提出一种使用自成型微乳液凝胶的策略，该凝胶是通过将亲油性溶剂乳化到特定的剪切变稀水凝胶结构中制备而成。这种凝胶在清洗过程中能够自适应地覆盖粗糙表面，同时避免清洗溶剂不必要的扩散，并且原位聚合双网络凝胶的机械增强作用使其能够轻松从表面剥离而不留下可检测的残留物。作为一个典型示例，广泛用于文物修复与加固的材料Paraloid B72被用作模型变色涂层，用所得凝胶处理后，它能从模拟文物的粗糙表面有效去除。令人信服的是，构建具有剪切变稀和自成型性能的琼脂糖/聚丙烯酰胺混合双网络凝胶用于文物清洗的策略不仅提高了操作的便利性和准确性，还展现出高效的清洗效果，这将极大地拓展微乳液凝胶在文物粗糙表面清洗中的应用。
