Life Cycle Considerations For Engineered Nanomaterials: A Case Study For Nano-Enabled Coatings On Drywall

摘要

Engineered nanomaterials are being incorporated at an increasing rate into various elements of the building industry. Nanoparticles have unique properties and offer tailored benefits to the traditional functions of building materials. Nanoparticle composite coatings are opening up new market opportunities in the global coatings arena, offering properties such as anti-microbialism, thermal insulation, dirt and water repellency, hardness, corrosion resistance, flame retardancy, UV stability, anti-graffiti, self-cleaning, moisture absorbing, and gloss retention. Global revenues for nanocoatings in 2011 were estimated to be $1.6 billion.Particles engineered at the nanometer size scale have been demonstrated as replacements for toxic biocides in applications including air purification, thermal insulation, and self-cleaning. The utilization of engineered nanomaterials in the building envelope is expected to develop rapidly; however, the safety of these novel materials to humans and the surrounding environment must be studied in parallel to their incorporation into consumer products. Currently, there is much uncertainty in the risk of using these materials in the building industry. One valuable way to gather information critical to the development of safe nanomaterials is using a product life cycle approach that integrates product development with manufacturing and worker/consumer exposure. This specific research approach investigates a white paint product as a case study. The bulk material (i.e. dry wall) is characterized with the nanoparticle-enabled product (i.e. white paint) in its intact and degraded forms. Simulated wear-and-tear scenarios are performed on the painted wall, and the released aerosolized particles are analyzed for concentration, size, and composition. Lastly, the released particles are collected and exposed to pulmonary tissue for a toxicological evaluation. Results show that differential physicochemical properties and toxicological responses are induced between particle-types that contain engineered nanomaterials versus particle-types without incorporated nanomaterials. The impact of this research will help to enable sustainable opportunities of nanotechnology in the built environment, and provide methodologies for understanding nanomaterial properties in the context of a developed consumer product.