Interaction between cationic surfactants and montmorillonites under nonequilibrium condition

Expansion characteristics of organo montmorillonites during the intercalation, aging, drying and rehydration processes: Effect of surfactant/CEC ratio

“…For all the OMt, their basal spacings can reach a relative stable value within 0.5 h, and this is in agreement with the reports about quick adsorption of CTMA on montmorillonite [40]. While in the aging process the OMt always show the decrease of basal spacing values.…”

Nanohybrid materials from amine functionalization of sepiolite: Preparation, characterization and application as electrode modifiers for the electroanalytical detection of heavy metal ions

“…The peaks observed between 1200 and 400 cm -1 are characteristic of silicate backbone: the bands at 1204, 1050 and 806 cm -1 are assigned to Si-O bond stretching vibration of Si-O-Si group [35]. The bands at 647 and 696 cm -1 correspond to Si-O stretching and Mg-OH bond vibration respectively [36].…”

“…At the opposite, the implication of fibrous clay minerals for electroanalytical purposes is scarce, although many works in literature have been devoted to their chemical modification [24][25][26][27][28]. Depending on the nature of the clay mineral, the preparation of organic-inorganic clay-based composite materials, exploited as electrode material proceeds mainly by two processes: (1) the intercalation of organic molecules within layered clay minerals such as kaolinite [29][30][31][32] and montmorillonite [1,[33][34][35][36], and (2) the grafting of functionalized organic molecules onto the surface of clay minerals [6,[37][38][39][40]. This last approach is convenient for all types of clay minerals bearing hydroxyl groups (aluminol or silanol) in their structure since it leads to the irreversible binding of the organic molecule on the clay surface.…”

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

“…These interlayer cations can be easily replaced in aqueous solutions by more voluminous ones, and quaternary alkylammonium cations (also known as surfactants) are the mostly used to that purposes. Within the interlayer region of the hosting clay mineral, the surfactant molecules can adopt a monolayer, a bilayer, a pseudotrimolecular or a paraffin layer depending on their concentration in relation with the cation exchange capacity of the clay mineral [18,19]. It is important to mention that other kinds of organic groups can be used, the final aim being the elaboration of composite materials with both hydrophilic and hydrophobic surfaces as well as a large porosity and surface area that have been proven to be efficient sorbents for organic molecules.…”