In this study, two essential oils (EOs) with preventive proved biocidal efficacy, namely oregano and eugenol, are encapsulated in silica nanocontainer, then dispersed in multifunctional, hybrid and nanocomposite coating. The aim of this work is to reduce toxicity of restoration materials, to avoid the chemicals dispersion in the environment and to extent stone protection treatments, preventing biofouling. Composite silica nanocapsules, containing separately the two EOs, are prepared via one-step synthesis, based on oil-in-water miniemulsion polymerisation processes, and fully characterised by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N-2 physisorption (BET/BJH). Micro-Raman spectroscopy (RS) and thermal analysis (TG/DSC). In a second step, nanocomposite coatings, based on a flexible tetraethyl orthosilicate (TEOS) matrix, are synthesised dispersing TiO2 nanoparticles and the two silica nanocapsules incorporating EOs. The coatings were applied on three different lithotypes samples of historical importance: brick, piperine and mortar. The effectiveness and compatibility of the coating formulation with the different stone substrates were assessed through a multi-analytical standard protocol. The silica nanocapsules, show monodispersed spherical shape with size similar to 110 nm, a core-shell structure, a BET surface area of 600-700 m(2)/g and high loading capacity. The results on coatings characterisation show a crack-free and transparent structure. Moreover, the tests on applied coatings reveal the high hydrophobicity of the treated stone samples (static contact angle in the range similar to 130-140 degrees and reduction of liquid water capillary absorption 97-99 %) and unaltered permeability to water vapour (density of water vapour flow rate in the range 150-200 g/m(2)center dot d), demonstrating the suitability of the nanocomposite hybrid coatings for the application in stone protection against biodeterioration.
Privitera, A., Tuti, S., Pasqual Laverdura, U., Duranti, L., Di Bartolomeo, E., Taddei, A.R., et al. (2024). One-step nanoencapsulation of essential oils and their application in hybrid coatings: A sustainable long-lasting treatment of stone materials against biodeterioration. PROGRESS IN ORGANIC COATINGS, 196 [10.1016/j.porgcoat.2024.108759].
One-step nanoencapsulation of essential oils and their application in hybrid coatings: A sustainable long-lasting treatment of stone materials against biodeterioration
Privitera, Antonella;Tuti, Simonetta;Pasqual Laverdura, Umberto;Sodo, Armida
2024-01-01
Abstract
In this study, two essential oils (EOs) with preventive proved biocidal efficacy, namely oregano and eugenol, are encapsulated in silica nanocontainer, then dispersed in multifunctional, hybrid and nanocomposite coating. The aim of this work is to reduce toxicity of restoration materials, to avoid the chemicals dispersion in the environment and to extent stone protection treatments, preventing biofouling. Composite silica nanocapsules, containing separately the two EOs, are prepared via one-step synthesis, based on oil-in-water miniemulsion polymerisation processes, and fully characterised by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N-2 physisorption (BET/BJH). Micro-Raman spectroscopy (RS) and thermal analysis (TG/DSC). In a second step, nanocomposite coatings, based on a flexible tetraethyl orthosilicate (TEOS) matrix, are synthesised dispersing TiO2 nanoparticles and the two silica nanocapsules incorporating EOs. The coatings were applied on three different lithotypes samples of historical importance: brick, piperine and mortar. The effectiveness and compatibility of the coating formulation with the different stone substrates were assessed through a multi-analytical standard protocol. The silica nanocapsules, show monodispersed spherical shape with size similar to 110 nm, a core-shell structure, a BET surface area of 600-700 m(2)/g and high loading capacity. The results on coatings characterisation show a crack-free and transparent structure. Moreover, the tests on applied coatings reveal the high hydrophobicity of the treated stone samples (static contact angle in the range similar to 130-140 degrees and reduction of liquid water capillary absorption 97-99 %) and unaltered permeability to water vapour (density of water vapour flow rate in the range 150-200 g/m(2)center dot d), demonstrating the suitability of the nanocomposite hybrid coatings for the application in stone protection against biodeterioration.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
