By Nidhi DhullReviewed by Susha Cheriyedath, M.Sc.Jul 29 2024A recent review article published in Case Studies in Chemical and Environmental Engineering explored the use of nanomaterials such as titanium dioxide, carbon nanotubes, nano-silica, nitrocellulose, nano alumina, and nano clays in housing construction.
Study: Nanomaterials in construction industry: An overview of their properties and contributions in building house. Image Credit: kittirat roekburi/Shutterstock.com
Nanotechnology in the Construction Industry
Nanomaterials, with their distinctive physical and chemical properties, hold significant promise for revolutionizing the housing construction industry. By enabling the development of stronger, more durable, efficient, and sustainable structures, nanotechnology offers solutions to challenges such as climate change and global urbanization.
The use of nanomaterials in construction began in the mid-1980s with the advent of carbon-based structures. Since then, their application has become more widespread, driving innovations in the sector. Today, advances in nanotechnology are leading to the creation of increasingly sophisticated, selective, and efficient nanomaterials, broadening the scope of construction capabilities.
This study explored the application of various nanomaterials—titanium dioxide, carbon nanotubes (CNTs), nanosilica, nanocellulose, nanoalumina, and nanoclay—in residential construction. These materials were chosen for their potential to enhance the structural integrity, thermal performance, and overall functionality of building materials used in housing.
Nanomaterials Used in Construction
TiO₂, a prominent photocatalytic nanomaterial, significantly enhances the durability, strength, and efficiency of building composites. Integrating TiO₂ into photocatalytic cementitious composites not only extends the service life of buildings but also helps reduce environmental pollution. TiO₂ offers additional benefits such as economic accessibility, chemical stability, and non-toxicity, enabling innovations like self-cleaning surfaces, antimicrobial properties, and air-purifying structures.
Carbon nanotubes (CNTs), known for their low cost, high conductivity, and large surface area, hold great promise as reinforcements in polymeric materials, metal alloys, and ceramics. Incorporating single-walled and multi-walled CNTs into building materials enhances their mechanical properties, electrical conductivity, and thermal stability.
Nanosilica, with its distinctive nanometric structure, exhibits high crystallinity, biocompatibility, photoluminescence, and thermal resistance. As an additive in cement mixtures, nanosilica improves durability, strength, and thermal management. For instance, the incorporation of nanosilica can increase the compressive strength of ultralightweight foamed concrete by 20-25 %.
Nanocellulose, a sustainable material with numerous hydroxyl functional groups, can be tailored for specific construction applications. Its biocompatibility and biodegradability support environmentally friendly building practices. The controlled arrangement of nanocellulose in polymeric concrete matrices allows for the creation of highly oriented, helical, and gradient structures.
Nanoalumina, or alumina nanoparticles, serves as an effective electrical insulator with high dielectric strength, making it suitable for coatings on construction materials. These coatings protect surfaces from wear and corrosion. Additionally, nanoalumina enhances the bonding of reinforcement layers in cement mortar, reduces porosity, and improves the mortar’s overall functional properties.
Nanoclays, characterized by high thermal stability and hydrophilicity, are ideal for building complex structural components and facilitating rapid on-site construction. When integrated into building envelope components like walls, floors, roofs, and windows, nanoclays contribute to improved energy efficiency. They also enhance the rheological and insulation properties of asphalt mixtures.
Preparing Nanomaterial-Enhanced Construction Admixtures
The choice of synthesis method is critical in producing nanomaterials for construction, as it directly influences their properties and effectiveness.
For nanosilica, common synthesis methods include sol-gel and precipitation techniques, which are favored for achieving a high specific surface area and controlled porosity. These methods enable the precise tuning of nanosilica properties to meet specific construction needs.
Nanocellulose, on the other hand, is typically produced through pulping, hydrolysis, and mechanical disintegration. These processes help tailor the nanocellulose for various applications in construction while maintaining its environmental sustainability.
Nanoalumina is generally synthesized via combustion and hydrothermal processes. These methods enhance the mechanical strength and thermal stability of nanoalumina, but they also present significant environmental impacts due to their complexity.
Nanoclays are prepared using ion exchange and exfoliation techniques, which result in good dispersion within composites. However, these nanoclays can be prone to swelling, which may affect their performance in certain applications.
Incorporating nanomaterials into construction materials like cement involves physicochemical mixing methods such as dispersion. Before mixing, nanomaterials may be treated chemically or mechanically to improve their compatibility with the cement matrix. Surfactants and dispersing agents are often used to enhance this compatibility, but their application must be carefully controlled to prevent degradation of the nanoparticle properties.
Challenges
Integrating nanomaterials into construction processes presents several significant technical, economic, and environmental challenges.
One of the primary technical issues is achieving uniform dispersion of nanoparticles in cementitious matrices. Uneven distribution can lead to agglomeration, which compromises the mechanical properties and overall performance of the material.
Economic barriers include the high costs associated with the production and processing of nanomaterials. These expenses are often exacerbated by the use of toxic solvents and chemicals in traditional synthesis methods. To mitigate this, there is a growing emphasis on developing eco-friendly and cost-effective synthesis routes, such as utilizing agricultural wastes or readily available natural resources.
Environmental concerns also play a crucial role. Traditional production methods can have adverse environmental impacts, so there is a push towards more sustainable practices. Implementing greener synthesis techniques is essential for reducing the environmental footprint of nanomaterials.
Additionally, existing regulations are not fully equipped to address the unique risks associated with nanomaterials. There is a need for updated regulatory frameworks that specifically cater to the safety and efficacy of nanomaterials in construction. These regulations should ensure that safety protocols are in place throughout the lifecycle of structures incorporating nanomaterials, from construction through to operation.
Conclusion and Future Prospects
Overall, each nanomaterial discussed in this review presented specific advantages and challenges. Their benefits in housing construction can be maximized by addressing current challenges and exploring new trends. The authors suggest developing and refining dispersion techniques using advanced surfactants, mechanical agitation, and ultrasonic methods. Ensuring the homogeneous distribution of nanoparticles will enable their efficient application in various structures. Additionally, nanomaterials can help realize smarter, adaptive, and sustainable building environments.
Journal Reference
Macías-Silva, M. A. et al. (2024). Nanomaterials in construction industry: An overview of their properties and contributions in building house. Case Studies in Chemical and Environmental Engineering, 100863–100863. DOI: 10.1016/j.cscee.2024.100863, https://sciencedirect.com/science/article/pii/S2666016424002573
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