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METHOD FOR PROTECTING AN ORNAMENTAL OBJECT OR SURFACE OF ROCKY ORIGIN, EXPOSED TO THE ELEMENTS
WO20193827
The invention relates to a method for protecting an ornamental object or surface of rocky origin, exposed to the elements. The present invention refers in particular to a method for protecting historical and cultural heritage sites. It therefore belongs to the field of materials science, and more specifically to the field of coatings for protection against wear and erosion of objects or surfaces of rocky origin. Most historical buildings and cultural heritage monuments are exposed to the elements and, therefore subject to different environmental conditions that can cause water erosion in their structures. Fighting the wear and tear implies constant economic investments because treatments for the conservation of these monuments must be applied frequently and through elaborated processes that sometimes are not suitable for outdoor applications. Carbonate rocks, present in most of such constructions, are highly prone to weathering. Currently, there is a lack of products that offer long term protection without altering the aesthetics and functionality of said heritage buildings. Researchers from the Department of Applied Chemistry and Physics of the University of León and the Spanish National Research Council (CSIC) have developed a procedure to protect objects and surfaces of rocky origin using a graphene oxide preparation, that has proved to offer the protection needed against weathering and erosion without altering the properties or characteristics of the treated surfaces.
Compared to existing procedures to protect and coat surfaces of rocky origin, present in historical buildings and monuments, this innovation has multiple advantages: - It offers protection against erosion and less surface wear after adverse environmental conditions while maintaining the aesthetic and functional integrity of the treated surfaces, something of special interest in the conservation of historical buildings, monuments, and ornamental objects of rocky origin. - The waterproofing properties of the coating obtained improve the ornamental rock resistance against dissolution processes, reducing the frequency of additional protection maintenance procedures and costs. - It prevents the microbiological contamination of the surfaces treated due to the solution biocidal properties. - It prevents rock surface colonization by plants, fungi and algae. - It’s a simple, durable and less expensive procedure that can be easily performed outdoors.
Problem solved by the invention:
Carbonate rocks, present in most of the architectural monuments, are highly vulnerable to erosion. Protective treatments like coatings, -with different organic and synthetic products such as acrylic or fluorinated polymers- as well as desalters -that use paper pulp or absorbent clays soaked in deionized water to surface clean extremely damaging salts from facades-, have not proved to be effective because of side effects such as undesirable changes in color or the formation of secondary products. Graphene derivatives, like graphene oxide, have been recently considered in the field of protective coatings for their corrosion inhibition properties on metals. Specifically, graphene oxide has been added to commercial paints containing acrylic polymers because it enhances their protective effect. However, the methods currently employed to apply those type of coatings are expensive and complex, making it difficult to use for outdoors applications. Additionally, the use of polymers affects the transparency and lack of shine on applied surfaces, altering their aesthetics and functionality. Therefore, there is a need for developing new procedures for the protection of historical and cultural heritage monuments exposed to the elements.
Technology to solve the problem:
Researchers from the Department of Applied Chemistry and Physics of the University of León and the Spanish National Research Council (CSIC) have developed a procedure to protect objects and surfaces of rocky origin -such as limestone and dolomite- that are exposed to the elements. This procedure comprises the steps to prepare a graphene oxide-based protective coating, specifically a graphene oxide colloidal dispersion, and subsequently, the method of applying it on the object or surface to treat. The afore-mentioned preparation has proved to offer the protection needed against weathering and erosion without altering the properties or characteristics of the treated surfaces, a significant demand in the preservation of Cultural Heritage Monuments and Historical Buildings.