Influence of the ionic and nonionic surfactants mixture in the structure and properties of the modified bentonite clay

A new surface modification in calcium bentonite clay (Bent-Ca) was investigated in this work, from the sequential intercalation of three types of surfactants: cetyltrimethylammonium bromide (CTAB), cationic surfactant, sodium dodecyl sulfate (SDS), anionic surfactant, and lauryl alcohol ethoxylated (ALEO), nonionic surfactant. Three modifications in the Bent-Ca were prepared in aqueous solution obtaining conventionally the OBent-I with CTAB and OBent-II with CTAB + SDS, beyond the new modification OBent-III with CTAB + SDS + ALEO. The synergistic effect of the sequential mixture of surfactants used in the surface modification of Bent-Ca was characterized by X-ray Diffraction (XRD), Fourier Transform by Infrared Radiation (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersion Spectroscopy (EDS), Optical Microscopy (OM), Thermogravimetric Analysis (TG), Contact Angle Test and Swelling Index. The results indicated that OBent-III was the reinforcement material among the analyzed ones that presented the highest values of basal spacing (13 nm), thermal stability (400 degrees C), superficial lipophilicity index (79.76 degrees) and swelling index in polar or apolar medium (6-10 mL/g). Therefore, a reinforcing material suitable for various applications was proposed. (C) 2018 Elsevier B.V. All rights reserved.