A X-Ray Photoelectron Spectroscopy Study of HDTMAB Distribution Within Organoclays

X-ray photoelectron spectroscopy (XPS) in combination with X-ray diffraction (XRD) and high-resolution thermogravimetric analysis (HRTG) has been used to investigate the surfactant distribution within the organoclays prepared at different surfactant concentrations. This study demonstrates that the surfactant distribution within the organoclays depends strongly on the surfactant loadings. In the organoclays prepared at relative low surfactant concentrations, the surfactant cations mainly locate in the clay interlayer whereas the surfactants occupy both the clay interlayer space and the interparticle pores in the organoclays prepared at high surfactant concentrations. The former adopts a lateral arrangement for the intercalated surfactants within the interlayer while the latter has a paraffin arrangement. This can well explain the dramatic surface area and pore volume decrease of organoclays compared to those of starting clays. XPS survey scans show that, at low surfactant concentration ( 1.0CEC). High-resolution XPS spectra show that the modification of clay with surfactants has prominent influences on the binding energies of the atoms in both clays and surfactants, and nitrogen is the most sensitive to the surfactant distribution within the resultant organoclays