The conservation of stone monuments is a constant concern due to their continuous weathering, in which biofouling plays a relevant role. To enhance the effectiveness of biocidal treatments and to avoid environmental issues related to their possible toxicity, this research aims at formulating and characterizing a coating charged with an eco-friendly biocide and showing hydrophobic properties. For this purpose, zosteric sodium salt—a natural biocide product—has been encapsulated into two silica nanocontainers and dispersed into a tetraethoxysilane-based (TEOS) coating also containing TiO₂ nanoparticles. The coatings were applied on four different types of stone: brick, mortar, travertine, and Carrara marble. The effectiveness of the coating formulations and their compatibility concerning the properties of coated stones were assessed. The results showed that all coatings conferred a hydrophobic character to the substrate, as demonstrated by the increase of the static contact angle and the reduction in the capillary water absorption coefficient. The transmission of water vapor of the natural stones was preserved as well as their natural aspect. Furthermore, the coatings were homogeneously distributed on the surface and crack-free. Therefore, the protective capability of the coatings was successfully demonstrated.

中文翻译：

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用新型环保型包封杀菌剂评估石材保护涂层

石碑的保护是一个持续的问题，因为它们会持续风化，其中生物污垢起着相关的作用。为了提高杀菌处理的有效性并避免与其可能的毒性相关的环境问题，本研究旨在配制和表征一种含有环保杀菌剂并显示疏水特性的涂层。为此，带状疱疹钠盐（一种天然杀菌剂产品）已被封装到两个二氧化硅纳米容器中，并分散到同样含有 TiO ₂的四乙氧基硅烷 (TEOS) 涂层中纳米粒子。涂料应用于四种不同类型的石材：砖、砂浆、石灰华和卡拉拉大理石。评估了涂层配方的有效性及其与涂层宝石特性的相容性。结果表明，所有涂层都赋予基材疏水特性，如静态接触角的增加和毛细管吸水系数的降低所证明的。天然石材的水蒸气传输以及它们的自然面貌得以保留。此外，涂层均匀分布在表面上且无裂纹。因此，成功地证明了涂层的保护能力。