Rodrigues Alexandra, Sena da Fonseca Bruno, Ferreira Pinto Ana Paula, Piçarra Susana, Montemor Maria de Fátima
Escola Superior de Tecnologia do Barreiro, Instituto Politécnico de Setúbal, R. Américo da Silva Marinho, 2839-001 Lavradio, Portugal.
Centro de Química Estrutural-CQE, Department of Electrochemistry (DEQ), Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal.
Materials (Basel). 2022 Jan 27;15(3):981. doi: 10.3390/ma15030981.
This study aimed at evaluating the effect of hydroxyapatite (HAp) nanosized structures and nanoparticles of hydrophilic silica as modifiers of both acid- and alkaline-catalysed tetraethoxysilane (TEOS)-based products for the consolidation of carbonate stones. Their initial effectiveness and some compatibility aspects were assessed in a porous limestone (sound and artificially aged Ançã stone samples) and two types of treatment (capillary absorption and brushing). The studied products were examined by scanning electron microscopy (SEM) and micro-Raman spectroscopy. Their depth of penetration and strengthening effect were evaluated through drilling resistance. Their action on the substrate was also further assessed by non-destructive methods based on colour variation and Shore-D hardness. Treated stone samples were dissimilarly affected by the tested treatments and exhibited a significant increase in strength with a low risk of over-strengthening. Adequate in-depth penetration patterns, as well as colour compatibility with the substrate were obtained with some of the prepared formulations through two types of treatment, both in sound and aged stone samples. The potential most effective treatments with the lowest colour change were obtained with the acid-catalysed TEOS-based products modified with HAp nanosized structures.
本研究旨在评估羟基磷灰石（HAp）纳米结构和亲水性二氧化硅纳米颗粒作为酸碱催化的基于四乙氧基硅烷（TEOS）的产品的改性剂对碳酸盐岩固结的效果。在多孔石灰石（完好的和人工老化的安桑石样品）以及两种处理方式（毛细管吸收和涂刷）中评估了它们的初始有效性和一些相容性方面。通过扫描电子显微镜（SEM）和显微拉曼光谱对所研究的产品进行了检测。通过钻孔阻力评估了它们的渗透深度和强化效果。还通过基于颜色变化和邵氏D硬度的无损方法进一步评估了它们对基材的作用。经处理的石材样品受到测试处理的影响各不相同，并且强度显著提高，过度强化的风险较低。通过两种处理方式，在完好的和老化的石材样品中，一些制备的配方都获得了足够的深度渗透模式以及与基材的颜色相容性。用HAp纳米结构改性的酸催化基于TEOS的产品获得了颜色变化最小且潜在最有效的处理方法。
