Hydrophilic ZnO Nanoparticle-Based Antimicrobial Coatings for Sandstone Heritage Conservation

Abstract

Exploring efficient and sustainable antimicrobial materials is crucially important for built cultural heritage conservation. The synergic combination of hydrophilic ZnO nanoparticles (NPs), calcium phosphate oligomers (CPO), and oxidized sodium alginate (OSA) exhibits distinctive properties, such as the chemical stability of ZnO NPs being enhanced with strong intermolecular interactions. Herein, an OSA/CPO/ZnO NPs composite has been prepared by embedding hydrophilic ZnO NPs and CPO into OSA molecules. The metastable CPO units bond with OSA molecules via electrostatic attraction between the positively charged calcium ions and negatively charged carboxyl groups and then gradually transform into ultrafine hydroxyapatite nanolines. In addition, the OSA/CPO/ZnO NPs composite shows different particle sizes and zeta potentials depending on the concentration of ZnO NPs in the dispersions. In vitro antimicrobial tests show that these composites have significant antimicrobial activity, inhibiting the growth of bacteria Escherichia coli and Micrococcus yunnanensis and fungus Aspergillus sp. F6. The application of the OSA/CPO/ZnO NPs composite as protective coatings on sandstone presents a potent and long-lasting antimicrobial activity and also has no significant effect on the aesthetic appearance, indicating a potential candidate for cultural heritage conservation.

Study on properties of 3D-printed GelMA hydrogel scaffolds with different nHA contents

“…Scaffolds create a unique physical environment that encapsulates cells and tissues. 30,31 As a result, it’s critical to characterize in vitro biodegradation capability. Figure 6 shows all scaffolds degrade steadily for 4 days until completely collapse.…”

Biosynthesis of Metal and Metal Oxide Nanoparticles Using Microbial Cultures: Mechanisms, Antimicrobial Activity and Applications to Cultural Heritage

“…Despite being a small fraction when compared with studies on the previous fields, in recent decades, the application of MNPs to cultural heritage materials due to their properties (cleaning [ 243 , 244 , 245 ], hydrophobicity [ 244 , 246 ], photocatalytic [ 244 , 247 , 248 , 249 ], consolidation [ 250 , 251 , 252 , 253 , 254 ], deacidification [ 243 , 255 , 256 ] and antimicrobial activity [ 257 , 258 , 259 , 260 , 261 , 262 , 263 , 264 , 265 , 266 , 267 , 268 , 269 , 270 , 271 , 272 ]) has also started to elicit interest ( Table 4 ).…”

“…Most of these studies used MNPs that were synthesized either via chemical, physical or a combination of both methods. Four studies [ 260 , 261 , 272 , 274 ] used biosynthesized MPs.…”

Nanosized ZnO/SiO2-Based Amphiphobic Coatings for Stone Heritage Protection

“…22,23 In addition, the antibacterial properties of ZnO are also particularly significant. 24,25 Based on the respective advantages of SiO 2 and ZnO, such nanocomposites have recently been prepared for some industries. A core−shell structure was formed to exhibit excellent UV resistance 26 and bactericidal properties.…”

“…As known to all, as a wide-band gap semiconductor, ZnO is recognized as one of the most significant multifunctional materials due to its unique physical properties, such as optical, electrical, thermal, and ultraviolet shielding . Here, we must emphasize its optical properties, especially on the nanoscale, which is very stable even in intense ultraviolet radiation. , In addition, the antibacterial properties of ZnO are also particularly significant. , Based on the respective advantages of SiO 2 and ZnO, such nanocomposites have recently been prepared for some industries. A core–shell structure was formed to exhibit excellent UV resistance and bactericidal properties .…”