Antimicrobial materials in the building industry

Abstract

Microbial deterioration in the building industry poses both economic impacts (maintenance costs and structural damage) and social implications (public health and safety). Affected materials include concrete and stone, wood and metal. The biodeterioration is often controlled using biocide formulations. Nanomaterials (NM) offer a groundbreaking approach to controlling biodeterioration in the building industry. NMs are increasingly utilized in the construction and preservation of stone surfaces due to their self-cleaning, antimicrobial, and hydrophobic properties. These properties are useful for their antifouling capabilities, reducing maintenance and restoration costs, as well as protecting against biofilm formation, preventing surface degradation on modern and historic buildings and for their hydrophobic properties, reducing water infiltration and increasing structural longevity. Titanium dioxide (TiO₂) nanoparticles are photocatalysts, which generate Reactive Oxygen Species (ROS), break down organic contaminants and microbial biofilms. Metal ion release from Ag, ZnO and CuO nanoparticles also disrupts microbial cell functions, enhancing antimicrobial effectiveness, and hybrid nanocoatings combine TiO₂ with Ag or Cu, increasing efficiency and extending antimicrobial effects under visible light. Other nanoparticles, such as zinc, silver, and copper oxides, also exhibit antimicrobial properties and are often mixed with stone consolidants to enhance their effectiveness, enhance durability, and protect against environmental degradation. However, the release of nanoparticles into the environment raises concerns regarding their ecotoxicological impact, particularly on aquatic life. Also, there is no activity against specific microbial groups; NMs exert toxic activity using similar modes of action and thus may negatively impact soil microbial communities and fertility. These particles need to be assessed both for their efficiency and environmental safety. It is the goal of this presentation to provide an overview of the current state of use and applications of antimicrobial NMs in the building industry and discuss the main ecological concerns and regulations of extended use that are essential to optimize safety, durability, and environmental sustainability for real-world applications.