Of the many ongoing technology developments, it’s arguable that nanotechnology will have the most immediate, visible, and continuing impact. Nano-this and nano-that have already sprung up in the English vocabulary like mushrooms after rain and marketing-speak has long since incorporated the benefits of NEW: With Nano-whatever. Barely a week goes by without an announcement of some advancement in nanotechnology and the majority of these announcements are couched in their relationship to a practical application. So it should not be surprising even to people with only passing knowledge of nanotechnology that one of the areas about to be changed (if not revolutionized) is the construction industry – in particular the enhancement of construction materials by the incorporation of manufactured nanomaterials (MNMs).
Whether you’re following the development or just interested in the possible impact of nanotechnology, a new report published by the American Chemical Society (ACS) in the journal ACS Nano, titled Nanomaterials in the Construction Industry: A Review of Their Applications and Environmental Health and Safety Considerations is a comprehensive look at the future of nanotechnology in the materials used by the construction industry AND their potential impact on health and the environment. A lengthy abstract is available at the above URL; the full text of the report requires subscription or purchase.
The report was prepared by scientists at Rice University (Texas, USA) and the University of California Los Angeles (USA). Its combination of a review of applications with a realistic approach to potential problems makes this report a standout. While the language is at times technical (the target audience is for people familiar with the field), it’s easy to understand the overall picture:
Nanomaterials will be extensively incorporated in construction materials. Nanomaterials will make them stronger, lighter, more flexible, and endow some materials with unusual or even extraordinary properties. Overall the application of nanomaterials provides a major opportunity for more energy conserving and environmentally friendly materials – as long as that is made a top priority.
Examples of uses for manufactured nanomaterials (MNMs)
[Taken from Table 1 of Nanomaterials in the Construction Industry]
Concrete Mechanical durability, crack prevention
Ceramics Enhanced mechanical and thermal properties
MEMS Real-time structural health monitoring
Solar Cell Effective electron mediation
Silicon Dioxide Nanoparticles
Concrete Reinforcement in mechanical strength
Ceramics Coolant, light transmission, fire resistance
Windows Flame proofing, anti-reflection
Titanium Dioxide Nanoparticles
Cement Rapid hydration, increased degree of hydration, self-cleaning
Windows Superhydrophilicity, anti-fogging, fouling-resistance
Solar Cell Non-utility electricity generation
Iron Oxide Nanoparticles
Concrete Increased compressive strength, abrasion resistance
Steel Weldability, corrosion resistance, formability
Coating/Paints Biocidal activity
On the other hand, nanomaterials either in raw form or in the combination with traditional construction materials will become prevalent world-wide. Insofar as these materials have toxic or environmentally damaging properties – and we already know that some of them do – this new exposure at massive scale will probably create dangerous situations (or worse).
Some MNMs could be considered as potential emerging pollutants because their environmental release is currently not regulated despite growing concerns about the associated risks to public and environmental health. Once in the environment, MNMs may undergo diverse physical, chemical, and biological transformations that change their properties, impact, and fate. Thus, a holistic MNM lifecycle exposure profiling is essential to evaluate potential impacts to human and ecosystem health, as well as to mitigate unnecessary risks.
The report stresses the importance of understanding the health and environmental impact of using nanomaterials in construction from all points in the ‘life cycle’ of the materials:
- Creation and transport of the raw (nano)components
- The manufacturing process
- Distribution and application in the construction industry
- Long-term degradation
- Final demolition and disposal.
Without taking into to account the dangers present at each point along the cycle (and they will vary considerably among the different materials), we will not have a profile accurate enough to provide guidance for regulation, prevention, troubleshooting and emergency procedures.