Caracterização da nanoargila montmorilonita cálcica bruta com adição de silano γ-APTES

Abstract

Clays have been used since the earliest times of mankind and a few decades ago it has become an indispensable raw material in commercial and industrial sectors. Studies conducted and published show that the surface modification of montmorillonite clay provides interaction with inorganic materials, such as epoxy matrix for manufacture of nanocomposites. In this work a brief study was carried out on the superficial modification of the raw calcic montmorillonite clay with the insert of 3-aminopropyltriethoxysilane (γ-APTES). The clay was extracted from natural deposits and subjected to the following processes: separation and selection by decantation with deionized water; washing with sulfuric acid, nitric acid and hydrogen peroxide and drying by lyophilization; finally subjecting part of the lyophilized clay to the silylation process. Five clay samples were used, named as Raw, Lyophilized, S2.5, S5.0 and S10, where the samples with nomenclature in Sx format are the clay samples that were silanized with 2.5, 5.0 and 10. ml of silane. Each sample represents the clay obtained at the end of each of the three processes. For characterization and silylation verification, the samples were submitted to X-ray diffraction (XRD) analysis, Fourier transform infrared spectrometry (FT-IR) and to BET method. A few MEV-FEG images were taken. The XRD showed that there was displacement of the peak in the region of low angles, with a difference of 1.4° degrees in the 2θ angle, showing the clay exfoliation. Through FT-IR, although the difference was very subtle, it was still possible to verify the presence of silane characteristic bonds in clay. The BET method, through gas adsorption technique, it’s showed a reduction in the surface area of the silanized clays nanoparticles, indicating the silane presence on clay surface.