Changes on montmorillonite characteristics through modification

• A Na–Mt suspension characteristic during HDTMA modification was investigated.
• Na–Mt suspension has 4 distinct regions: dispersion, coagulation precipitation, coagulation flotation and re-dispersion.
• Adsorption, electrokinetic and rheological behaviors of Na–Mt suspension were investigated.
• O–Mt was characterized by XRD and TGA.
• O–Mt swelling ability in different solvent was explained.

Since montmorillonite (Mt) and organomontmorillonite (O–Mt) are widely used in many different areas from ordinary to high technological applications, there are lots of studies about them in the literature. However, its unique characteristic and different interaction mechanism with additives make those studies continue in order to explain much more detail on it. In this study effect of hexadecyltrimethylammonium bromide (HDTMA) on Mt through modification process has revealed in detail. Adsorption, electrokinetic, rheology and structural aspects of the system were considered in together to explain the interaction mechanism between Na–Mt and HDTMA. Mt suspensions show four different characteristics that are dependent on the HDTMA concentration as dispersion, coagulation-precipitation, coagulation-flotation and re-dispersion. It is found that sedimentation behavior at this regions are in a good agreement with adsorption isotherm, zeta potential, apparent viscosity, X-ray diffraction patterns, swelling index and filtration losses.

Figure: The dispersion state of the bentonite suspension based on the HTDMA concentration.Figure optionsDownload as PowerPoint slide