Analysis of calcium clay organophilization with different quaternary ammonium salt concentrations

Full text: In this work, data obtained by organophilization of a natural calcium bentonite clay was compared to itself, using quaternary ammonium salts (QAS), prepared via dispersion, on concentrations of 70 meq/100g and 80 meq/100g of clay. The organophilic clay preparation through dispersion went by on a 4% proportion in clay weight in distilled water, which was made homogeneous in a mechanical stirrer for 30 minutes over a 1000 rpm rotation. Afterwards, the rotation was increased to 2000 rpm and the quaternary ammonium salt was added, and the mixture was stirred for another 30 minutes. In the end, the latter went through filtration followed by a wash to remove the excess salt, and then the samples were sent to an oven at 80 deg C for 24 hours followed by disaggregation and characterization. The samples in its natural and organophilized forms were characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Foster swell in water and organic solvents (gasoline, diesel, kerosene and xylene). The DRX curves showed an increase on the basal distance for the organophilic samples (26.67 Ǻ and 26.26 Ǻ, respectively) compared to the natural clay (15.66 Ǻ), indicating the possibility of QAS intercalation. From the FTIR, it was possible to identify the appearance of bentonite clay characteristic bands, and on treated samples, of the following bond bands - CH₂ and -CH₃, present on the used quaternary ammonium salt constitution, indicating the occurrence of clay organophilization. On the Foster swell in organic solvents it was possible to observe that the treated clays showed affinity with some organic compounds, such as gasoline and xylene, albeit swelling for the sample prepared with a concentration of 70 meq/100g of clay was slightly bigger. (author)