Synthesis and characterization of magnetic-montmorillonite and magnetic-organo-montmorillonite: Surface sites involved on cobalt sorption

Abstract

Montmorillonite magnetic-clay nanoparticles (MtMag) and its exchanged product with hexadecyltrimethylammonium (O100MtMag) were synthetized by alkaline oxidation of ferrous sulfate, characterized by diverse techniques (XRD, Mössbauer spectroscopy, VSM, SEM, Zeta Potential, total specific surface area, TOC) and used as Co 2+ sorbents. The magnetic characteristic of these materials allows them to be used in cases of decontamination of water polluted with dangerous materials, such as radioactive ones, reducing the risk to health due to indirect manipulation by means of external magnetic fields. For comparison, samples without magnetic material (O100Mt) and in absence of clay (Mag) were also synthetized. The synthesis of magnetic materials disclosed the presence of magnetite and goethite nanoparticles, while the saturation magnetization displayed by O100MtMag was higher than that obtained for MtMag, indicating the existence of a higher amount of magnetite particles in the first one. This suggests that O100MtMag could be manipulated easier than MtMag through external magnetic fields. Moreover, the surface electric charge of MtMag sample can be described as a mixture of Magnetite and montmorillonite, with ratios related to the surface of both components. Co 2+ sorption percentages, using an initial Co 2+ concentration of 85 mg/L, resulted similar for the different materials while the Co 2+ sorption was ascribed to interactions with the montmorillonite interlayer and external surface. The current results indicate that O100MtMag is a more appropriate material than MtMag for Co 2+ removal by external magnets.

Use of organo-montmorillonite for the nitrate retention in water: influence of alkyl length of loaded surfactants

“…Despite the screening effect of the tetra-coordinated silicon band, its intensity increase could be correlated with nitrate adsorption (Fig. 3), in agreement with the results found for NO 3 − adsorbed on different materials [13,51].…”

“…The band at 1382 cm −1 was assigned to asymmetric stretching vibration of the nitrate ion [50], which was overlapped with that corresponding to the vibration of tetra-coordinated silicon in the Mt structure [51]. Despite the screening effect of the tetra-coordinated silicon band, its intensity increase could be correlated with nitrate adsorption (Fig.…”

Organo-montmorillonite with biogenic compounds to be applied in antifungal coatings

“…On the other hand, taking into acount that 001 value of dehydrated Mt is 0.97 nm (Barraqué et al, 2018) the interlayer space thicknesses of SeMt simple would be of 0.42 nm which could be indicating a posible bilayer arrangment of lecithin molecules in the Mt interlayer. The analysis of the reflection (001) for the Mt hybrids (S-Mt40A and S-Mt40B) indicated an increase of the basal spacing of 0.50 nm and 0.35 nm, respectively to the same reflection (001) position found for the Mt sample.…”

Investigations of Latvian Illite/Kaolinite Clays Irradiated Under Action of Accelerated Electrons

“…Clays and ceramics have important role as building and construction materials [1]. Various natural clays are considered for treatment of wastewater containing heavy metal [2,3] ions, as well as radioactive elements, such as 137 Cs [4] and 60 Co [5]. There is perspective of clay application for in situ immobilization of metal ions in soil [6].…”