Nanotechnology in architectural restoration

The aim of this study is to examine nanotechnology applications for conservation and restoration of Cultural Heritage in 2 different ways; (1) Original stone samples from the 16th Century Ottoman Bayezid Mosque –which have been restored by Mimar Sinan in 1573. (2) the new limestone samples which will be applied on real site applications for the conservation and restoration projects in Istanbul. Traditional techniques used in conservation and restoration of historical/preserved buildings could not be technically adequate to ensure a long-term (or permanant) solution for these destructive factors. The main idea must be to give strength to the building structural composition rather than only filling the gaps or have some make up for the destroyed facades of the cultural heritage. The long-term effects must be chosen and applied on the problem rather than instant/easy solutions with inadequate outcomes. The solution must treat the building as if it would have restored its strength for future destructive factors like climate conditions, the temperature differences between summer and winter, or day and night and other aforementioned factors. According to Venice Charter in the article 10, which is known like the constitution of conservation and restoration, if the traditional treatment techniques are not adequate in order to restore the preserved building, then the new technology must be applied to the building in a correct way if the scientific results shows the new treatment idea is valid and ready to be used. Thus, under the umbrella of Venice Charter, we need to say that we must find some new technologic conservation and restoration treatments to prevent the preserved building from possible destructive effects and also can be able to restore better for the problems associated with their structural configuration. For instance, when you search for a column's structural morphology you are not able to see its internal cracks and morphology/deformations by traditional techniques, but it is possible to see internal structure in details with the help of Scanning Electron Microscopy (SEM) so that a better understanding of conditions in the historical buildings. Thus, long-term and permanent solutions could be developed with help of innovative and unique approaches by nanotechnology. The aim of the study is also to increase the mechanical durability and flexural strength of the architectural heritage buildings by using innovative technologies like nano-technology. I planned to study not only on site applications but also in laboratory investigations. Under the permission of the General Directorate of Pious Foundations, I have studied on Bayezid Mosque from 16th Century. I have taken some samples from 3 different parts of the mosque; column of the dome, wall of the courtyard and the inside wall of the mosque. The differences between these samples were the deterioration factors between them. The samples which were taken from the columns of the dome were under the effect of pressure, the samples from the wall of the courtyard were under the effect of weather conditions, and the samples which are taken from the inside wall of the mosque were under the effect of exfoliation. At first I have taken SEM images of these samples in order to evaluate the deterioration factors inside the structure. Then I formulated some new nanoparticles in laboratory and I managed to penetrate this nanoformulations into the structure of these samples. Then I put these samples into the climate chamber to provide the suitable conditions for carbonation process. I studied with nanolimes and some modified forms of nanolimes with different nanoparticles for my formulations because my samples were from limestone. After this nanotreatment I have taken SEM images again in order to prove the perfect consolidation effect on the cracks and gaps when compared with before treatment condition. I have also taken 3point bending tests in order to prove the flexural strength increased from 2.81 MPa to 11.82 MPa. According to our studies, the solution to deterioration factors of traditional cultural heritage is using some special designed and new formulated nanoparticles in order to be absorbed completely for the building material and can be able to give strength from the inside to the surface. The main parameter is the correspondence between the nanomaterial, which will take role as a consolidant and the building material which acts as a substrate. The interactions between the nano based consolidant and the surfactant has gained durability and high performance to the building material inside. The importance of the nanoparticles comes from their particle size, they can be able to penetrate from the surfactant easily and they can perform reactions with the building material effectively. The clue is to keep them inside the morphology of the building material effectively and then make them a component of the material combination by saturation and assimilation processes for the building material inside. The solution can be examined by the way of consolidation of stone by new designed nano-formulations, as we have studied on, in our laboratories. Penetration depth and the surface adhesive strength performance prove the success of the treatment. Interaction of the materials inside the building material affects the treatment performance effectively. Besides the application technique, the conditions like temperature and relative humidity also indicates the treatment efficiency. Application has been done on limestone samples from the Ottoman Bayezid Mosque dating from the 16th century, as an instance of on site preserved buildings as a Cultural Heritage. As a result of the experimental analysis, it can be said that the efficiency of nano-restoration treatment is more than 4 times in mechanical durability of the building material. It is important to say that it is a good way to preserve the Cultural Heritage from an instant earthquake and its serious damages. The idea behind the experimental analysis is to restore the cultural heritage with its own building material, but in nano-size. So there will never be a problem like inconsistence between the nano-treatment formulations and building material's inside structure. In the initial stage, the EDX analysis are obtained in order to get informed about the components of the samples which are taken from the cultural heritage. So the nano-formulations are planned to produced according to building material inside morphology. The good correspondence between the nano-solutions and substrate is so important for the efficiency of the treatment. In some European Countries, this science called " Medicine of the Stone". This labeling indicates us the importance of the analysis and correspondence between the consolidant and the substrate. The treatment provides long term consolidation effects, so it is not a short term solution. It is also important to say that the nano-treatment have no residues or poisonous chemicals, it is safe and an advanced method in order to gain mechanical durability. The components which are used to produce the nanoformulations are non-toxic, this also allows comfortable working conditions to the workers who will use this kind of restoration techniques for cultural heritage conservation applications on cites in future. As an instance of the well – known consolidation materials: epoxy resins are not safe and not comfortable for working conditions. The solvents in these kind of synthetic based materials are seriously harmful for human health. The workers are under the risk of breathing this poisonous vapour of these epoxy resins. Moreover, in the experimantal analysis part of this master thesis, it is exactly shown that the consolidation efficiency of the epoxy resins are not adequate when compared with nano-formulation treatments. Besides, epoxy resin deteriorates the cultural heritage building material in a nonreversible way. It also not cares about the patina layer of the surface. It is also important to say that preserving the patina layer is an important point for a well-thought conservation and restoration project of any cultural heritage. One more, epoxy resins consolidation effect are also not a long term solution method. It can easily undergo a change as a result of the weather conditions or salt crystallization. All these factors has shown the difference, importance and long term effects of nano-treatment methods. As a result of this nano-treatment, SEM images can be able to prove that the morphology of the building material gains its mechanical resistance and the development of the flexural strength of the material approves, nanoparticles shape the morphology like a trawl by the way penetrate into deep zones easily.