Halloysite Nanotubes Loaded with Calcium Hydroxide: Alkaline Fillers for the Deacidification of Waterlogged Archeological Woods
Halloysite Nanotubes Loaded with Calcium Hydroxide: Alkaline Fillers for the Deacidification of Waterlogged Archeological Woods
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DOI：
10.1021/acsami.8b09416
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发表时间：
2018-08-15
影响因子：
9.5
通讯作者：
Lazzara, Giuseppe
中科院分区：
文献类型：
--
作者：
Cavallaro, Giuseppe;Milioto, Stefana;Lazzara, Giuseppe
设计了一种新的绿色方案，用于通过聚乙二醇（PEG）1500和含有氢氧化钙的埃洛石纳米管的水分散体来脱酸固化浸水的考古木材。首先，我们制备了功能化的埃洛石纳米管，在其内腔中填充Ca（OH）（2）。Ca（OH）（2）从埃洛石内腔的受控和持续释放延长了其中和作用，使木材样品的长期脱酸得以发展。粘土/聚合物纳米复合材料的初步热机械特性使我们能够确定实验条件，以最大限度地提高木材样品的固结效率。埃洛石-Ca（OH）（2）/PEG复合材料在木材孔隙内的渗透赋予了基于固结剂混合物的粘土/聚合物组合物的考古木材的坚固性。与用纯PEG 1500处理的考古木材相比，在固结剂中加入改性纳米管在弯曲强度和刚度方面的机械性能方面引起了显着的改善。pH值测定表明，埃洛石-Ca（OH）（2）是有效的碱性填料。因此，改性的纳米管为暴露于酸性气氛下的人工老化的木材中存在的木质素提供了长期保护。所获得的知识表明，可以通过PEG聚合物和碱性管状纳米结构的组合来实现用于木制艺术品的长期保存的简单且绿色的方案，所述碱性管状纳米结构通过将Ca（OH）（2）限制在埃洛石腔体内而获得。
A novel green protocol for the deacidifying consolidation of waterlogged archaeological woods through aqueous dispersions of polyethylene glycol (PEG) 1500 and halloysite nanotubes containing calcium hydroxide has been designed. First, we prepared functionalized halloysite nanotubes filled with Ca(OH)(2) in their lumen. The controlled and sustained release of Ca(OH)(2) from the halloysite lumen extended its neutralization action over time, allowing the development of a long-term deacidification of the wood samples. A preliminary thermomechanical characterization of clay/polymer nanocomposites allows us to determine the experimental conditions to maximize the consolidation efficiency of the wood samples. The penetration of the halloysite-Ca(OH)(2)/PEG composite within the wooden pores conferred the robustness of the archaeological woods based on the clay/polymer composition of the consolidant mixture. Compared to the archeological woods treated with pure PEG 1500, the addition of modified nanotubes in the consolidant induced a remarkable improvement in the mechanical performance in terms of flexural strength and rigidity. The pH measurements of the treated woods showed that the halloysite-Ca(OH)(2) are effective alkaline fillers. Accordingly, the modified nanotubes provided a long-term protection for lignin present in the woods that are exposed to artificial aging under acidic atmosphere. The attained knowledge shows that an easy and green protocol for the long-term preservation of wooden artworks can be achieved by the combination of PEG polymers and alkaline tubular nanostructures obtained through the confinement of Ca(OH)(2) within the halloysite cavity.