ABSTRACT
It has been credited to nanoscience a prominent role of providing full understanding of the macroscopic behavior of materials, since this field of science is capable of conducting studies and distinguishing physical and chemical properties or phenomena of the matter in nanoscale. The exploitation of knowledge on such a large magnification of the matter requires the use of improved analytical techniques, which have arisen mainly in recent years. In the context of cementitious materials, Atomic Force Microscopy (AFM) is considered by the literature as one of the main techniques for analysis and studies in the field of nanoscience. However, to work well, the technique demands highly flat samples, which is a problem considering samples of cementitious materials, with a naturally irregular and rough tendency. In addition, the technique does not perform chemical analysis. These difficulties are dealt with in this work, which aims to contribute with a sample preparation for analysis in the atomic force microscope (AFM), as well as to study the association of the analyzes performed in the AFM to those carried out in the scanning electron microscope (SEM), with the same regions being scanned, in order to verify the possibility of chemical identification by means of SEM of the regions analyzed by AFM. For the study, cement pastes with and without silica fume were used, aiming also to obtain the main differences of one and another in the images obtained by AFM. The sample preparation for AFM was considered satisfactory, which allowed the nanoscale identification of the denser and more complex structure of the pastes with silica fume compared to pastes containing only portland cement. The work also contributes to the theoretical description of the AFM technique, producing an important content in terms of literature revision on the principle and application of the technique, besides its potentialities.
Keywords:
nanoscience; atomic force microscopy; pastes; portland cement; silica fume
