NANOTECHNOLOGY IN CONSTRUCTION
The use of nanotechnology in construction involves the development of new concept and understanding of the hydration of cement particles and the use of nano-size ingredients such as alumina and silica and other nanoparticles. With the help of nanotechnology, concrete is stronger, more durable and more easily placed, steel is made tougher, glass is self cleaning and paints are made more insulating and water repelling.
Two nano-sized particles that stand out in their application to construction materials are titanium dioxide (TiO2) and carbon nanotubes (CNT’s). The former is being used for its ability to break down dirt or pollution and then allow it to be washed off by rain water on everything from concrete to glass and the latter is being used to strengthen and monitor concrete.
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Carbon nanotubes (CNTs) are cylindrical in shape with diameter in nanometers and length can be in several millimeters as shown in Fig. 1. When compared to steel, the Young’s modulus of CNTs is 5 times, strength is 8 times while the densite is 1/6 the times. Along the tube axis the thermal conduction is also very high.Titanium dioxide is widely used as white pigments. It can also oxidize oxygen or organic materials, therefore, it is added to paints, cements, windows, tiles, or other products for sterilizing, deodorizing and anti-fouling properties and when incorporated into outdoor building materials can
substantially reduce concentrations of airborne pollutants. Additionally, as TiO2
is exposed to UV light, it becomes
increasingly hydrophilic (attractive to water), thus it can be
used for anti-fogging coatings or selfcleaning windows.