Erosion of stone, brick or concrete is a serious problem in most buildings caused by physical degradation of both the interior and the outer layer of the substrate. The problem of erosion of the stone is very essential for facades and elevation of new buildings and historic architecture, whose restoration is always associated with very high costs.
Acid rain and chemical pollution are the main causes of erosion of mineral substance. Erosion of our national heritage, growing cost of the restoration and the exchange led to focusing attention on reducing these problems. In most cases, the use of preservatives and salt fungicides are the main methods in the fight to preserve important architectural objects. Often, however, it appears that the effectiveness of traditionally used preparations is inadequate. As a result, scientists and researchers began to look for entirely new solutions in the fields of nanomaterials and nanotechnology for efficient and long-term protection of buildings. Through this research, they identified two main criteria to be met by preparations to protect buildings from erosion.
First, they must improve the internal structure of brevity to strengthen the delicate structure of the pores, and secondly they must stop transporting moisture rising into the chlorides and acid substances, without limiting the properties of steam-permeable surface - to reduce the effects of salt crystallization.
There isn’t one clear definition of nanotechnology. It is generally accepted that nanotechnology and nanomaterials is everything that falls within the 1 - 100nm (1 nanometer is one millionth of 1 mm). Nano suffix comes from Greek and means dwarf.
Table 1 shows the size of the selected objects at the nano scale. 1 nanometer is one-hundredth-millionth of meter. For comparison, as seen also in the chart, the diameter of a human hair is about 80.000 nanometers and the size of red blood cells is about 7.000 nm. From the evidence it is simple conclusion - the size of nanomaterials is 800 times smaller than a human hair. The whole science - nanotechnology - is responsible for creating, Preparation, testing and application of nanomaterials by controlling the size and shape of objects at the nano scale. At such small sizes, there are new opportunities and new uses for these materials that were not possible in "normal" size.
Nano-scale materials retain all the physicochemical characteristics of materials at the macro level. In addition, however, have quite a lot of new properties, which are related to their size and their properties such as color, conductivity, strength and reactivity vary considerably between nanomaterials and macromaterials.