近期,西安交通大学和玲/潘爱钊课题组针对硅酸盐材质的砂岩基石窟文物风化病害的特征及病害形成机理(砂岩内部胶结质流失)等问题,将膨润土基抗膨胀水凝胶在砂岩基文物中原位形成以弥补流失的胶结质。首先通过组分和条件控制调控了膨润土基水凝胶的原位形成时间和抗膨胀性,进而通过荧光示踪技术研究了膨润土基水凝胶材料在砂岩内部的分布,并深入评估了其在砂岩中的长效保护效果,最终研究了其户外应用。该成果在期刊《ACS Applied Materials & Interfaces》上发表,题为“Insight into a Bentonite-based Hydrogel for the Conservation of Sandstone-based Cultural Heritage: In-situ Formation, Reinforcement Mechanism, and High-Durability Evaluation”的文章(DOI: https://doi.org/10.1021/acsami.2c13122)。 要点1:新型抗膨胀膨润土基水凝胶材料设计、制备与原位保护技术
Figure 1. (a) Chemical structure scheme of B-H hydrogel. (b)Schematic illustration of the bentonite-based hydrogel (B-H) formed in-situ in sandstone. 要点2:新型抗膨胀膨润土基水凝胶材料抗膨胀性
Figure 2. Sandstones (a) after protecting with B-H and (b) traditional hydrogel. 要点3:膨润土基水凝胶材料在砂岩内部的分布:荧光示踪技术
Figure 3. (a) Chemical structure and optical images of the Carbon quantum dots (CQDs) used for fluorescent tracer. Photographs of the appearance (b), cross-sectional surface (b1 and b3) of the sandstones treated by hydrogel-CQDs. Photograph of the appearance (b2) of the fresh sandstones. (c) Morphology and element distribution of Si, C and N elements in the internal grains of the treated sandstone by SEM-mapping. (d) Morphology of the internal grains of the treated sandstone by SEM. (e) Schematic diagram of in-situ formation of hydrogel inside the sandstone. 要点4:膨润土基水凝胶材料对砂岩的长效保护效果
Figure 4. (a) Acid resistance, (b) salt crystallization cycles in moisture and heat, and (c) freeze-thaw cycles of unprotected and B-H-sandstone. (d) Schematization of the protecting mechanism for freeze-thaw resistance and salt resistance for B-H- sandstone. 要点5:膨润土基水凝胶材料户外应用研究
Figure 5. Application of bentonite-based hydrogel on actual sandstone-based cultural heritage at Dafo Si. Sampling areas are indicated with red rectangles. Photographs of the sandstones before (a) and after (b) protecting by bentonite-based hydrogel. 西安交通大学化学学院硕士生史承钰为该论文的第一作者,西安交通大学化学学院和玲教授团队的潘爱钊副教授为该论文通讯作者。该工作得到国家重点研发计划(2019YFC1520500)项目的资助。同时也感谢西安交通大学分析测试共享中心在表征方面的帮助。