Investigation of PEG4000/Natural clay-based hybrids: Elaboration, characterization and theory

Abstract

In this work, we first examine in depth the chemical composition, the structure and the mineralogy of a local clay mineral as well as its peculiar physicochemical properties. Second, we elaborate new hybrid material models based on natural clay with a polymeric supporting matrix. To this end, the standard procedures combined with analyses by Transmission Electron Microscopy (TEM), X-ray Fluorescence (XRF), X-ray Diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR), are used to analyze both the raw material and the elaborated hybrids. It is found that the clay sample contains essentially kaolinite, illite, chlorite and some typically associated minerals such as calcite and quartz. The study reveals that the clay mineral has a low capacity to adsorb water; thereby, a low porosity is expected. On the other hand, FTIR-analysis shows the presence of new interactions between the polymer-chains and the clay-layers surfaces, which favor its adsorption and contribute to form an intercalated structure. Chromatic features of the considered clay-polymer-samples are also investigated experimentally. Finally, using a scaling theory of adsorption, we explain the inter-plate separation profile as the polymer concentration increases, and it is found that the theoretical predictions agree well with the experimental results.