Performance Assessment of Graphene Oxide as a Protective Coating for Historical Stone

Area of Science:

• Materials Science
• Conservation Science
• Nanotechnology

Background:

• Stone cultural heritage is vulnerable to environmental degradation.
• Effective protective treatments are needed to preserve stone's appearance and function.
• Graphene oxide (GO) is a potential nanomaterial for protective coatings.

Purpose of the Study:

• To evaluate graphene oxide (GO) as a protective coating for stone.
• To assess the impact of UV weathering on GO-coated stone samples.
• To determine GO's effectiveness in preserving stone properties.

Main Methods:

• Application of low-concentration GO dispersion (0.5 mg/mL) via brushing.
• Simulated weathering using 7-hour UV light exposure.
• Performance testing including water capillary absorption, water vapor permeability, contact angle, and color variation.
• Material characterization using FT-IR, Raman spectroscopy, SEM, and XRD.

Main Results:

• GO coatings reduced water capillary absorption by up to 49% (Euganean trachyte) and 22% (Vicenza stone).
• Water vapor permeability remained largely unaffected.
• UV exposure caused permanent darkening but slightly increased hydrophobicity.
• Photoreduction effects on GO surface layers were observed.

Conclusions:

• Graphene oxide shows potential as a protective coating for stone cultural heritage.
• UV weathering alters GO coating properties, enhancing hydrophobicity.
• Further research is needed to optimize GO coating uniformity and long-term durability.