Morphology, Structure, Thermal Stability, XR-Diffraction, and Infrared Study of Hexadecyltrimethylammonium Bromide–Modified Smectite

Abstract

We characterized the interlayer structure and morphology of modified natural clays. Organoclay-based materials are increasingly used for multiple applications. We modified a purified Na-bentonite using cation exchange with hexadecyltrimethyl ammonium bromide (HDTMA) and characterized it using; UV spectroscopy, X-ray diffraction, photoacoustic FTIR spectroscopy (PA-FTIR), thermogravimetric analysis (TGA) techniques, laser scattering distribution (LSD), atomic force microscopy (AFM) and transmission electron microscopy (TEM). The adsorption of HDTMA on interlayer sites of Na-smectite fraction is nearly total until an adsorption equivalent to 1.85 times the cation exchange capacity (CEC) of the clay. The formation of the HDTMA-smectite changes the properties of the clay from hydrophilic to hydrophobic. The XRD patterns show an increase in the basal spacings. TGA characterization and analysis were shown to be useful to estimate the amount of surfactant within the organoclay. LSD analyses have shown a decrease of the effective particle diameter with increasing sonication times. AFM images showed that these Na-smectite surfaces appeared foliated with irregular aggregate structures at high HDTMA loading. The present study shows that not only the basal spacing but the morphology and the particle size of the organoclay strongly depend on the packing density of surfactant within the smectite interlayer space.

Organoclay-modified electrodes: preparation, characterization and recent electroanalytical applications

“…Without going into too many details about each of these methods, it is clear to mention that they can provide useful information about the organization and aggregation of clay platelets and by a topographic visualization the changes resulting from the modification process. For example, TEM can be used to estimate the edge-surface areas of organoclays or for the characterization of the microstructure and morphology of pure organoclays [97]; in addition, the particle size and particle size distribution can easily be extracted from the AFM data [98,99]. TEM and SEM micrographs are usually exploited to characterize the layer stacking and the surfactant packing density of organoclays of classes that are most prepared in the literature [100][101][102].…”

Interfacial Interaction of Cationic Surfactants and Its Effect on Wettability Alteration of Oil-Wet Carbonate Rock

“…All surfactants and salt were used with no further purification or modification of their properties. Surfactants selected for the present study are commercial surfactants with good thermal stability as reported in the literature. , Deionized water was used for preparation of surfactant solutions throughout the experiment. The surfactants used in this study are tabulated in Table .…”

A thermal, sorptive and spectral study of HDTMA-bentonite loaded with uranyl phosphate

“…In the present study, we investigated thermal degradation of sorption products to elucidate the mechanism of interaction between the surfactant and the bentonite matrix. There is relatively little research concerning thermal analysis of HDTMA-bentonite [10][11][12][13][14][15][16][17]; however, this problem has received sufficient scrutiny in the works concerning the analog of bentonite, montmorillonite [18][19][20][21][22]. The introduction of phosphate ions to a sorption system is a new problem, and there is a dearth of research concerning thermal analysis of HDTMA-P(V)-bentonite and its modifications with U(VI).…”