Dendritic surfactants show evidence for frustrated intercalation: A new organoclay morphology

The study investigates the interaction between smectite clay and dendritic surfactants, particularly focusing on the intercalation process. It finds that when larger dendritic surfactants are used, they do not completely intercalate into the clay's gallery due to their size. However, they still form organoclay materials. X-ray powder diffraction (XPD) analysis shows no significant increase in lattice spacing as these surfactants are added, and infrared (IR) spectroscopy and thermal gravimetric analysis (TGA) reveal that interlayer water remains preserved.

In contrast, smaller dendritic surfactants readily enter the clay's gallery, resulting in traditional organoclay materials. These materials can have varying organic compositions, ranging from 5% to 50% by weight, exceeding the cationic exchange capacity (CEC) of the clay. UV spectroscopy and TGA confirm the organic content, while XPD shows increasing lattice spacings with higher organic content. IR spectroscopy and TGA suggest a more hydrophobic interlayer as organic content increases.

Interestingly, a linear isomer of a frustrated surfactant can intercalate into the gallery in certain proportions, yielding different morphologies based on the amount of surfactant added. This highlights the significance of the surfactant's shape, not just its size, in achieving frustrated intercalation in clay.