جستجوی مقالات مرتبط با کلیدواژه "intercalation" در نشریات گروه "شیمی"

4-methylaniline and its Schiff base derivative were intercalated into the Bentonite clay interlayers in a solid state reaction followed by a condensation reaction to produce two organo-clay composites. X-ray diffraction was used to identify the changes in basal spacing of montmorillonite layers which exhibited noticeable alteration before and after the formation of the composites. FT-IR spectra, on the other hand, were utilized for identifying the structural compositions of the prepared materials as well as the formation of the intercalated Schiff base derivative. The surface morphology of the composites was examined by Scanning Electron Microscopy SEM and Atomic Force Microscope AFM, which reflected some differences in the surface of prepared composites as the particle size decreased with the Schiff base formation.

This study explores the incorporation of aqueous methylene blue (MB+) into a specially prepared metal oxide host.  Derived from the chemical exfoliation of KTiNbO5 into nanosheet colloids, the host material was synthesized in water using acid to restack the colloids into aggregates of nanosheets.  The metal oxide host has a large open pore, disordered, and turbostratic layered structure.  When exposed to aqueous solutions of MB+, within minutes the novel host rapidly intercalated MB+ to saturation, to produce an organic-inorganic composite with an MB+ loading of 226 mg/g.  Well-rinsed composites exhibited a deep purple color, indicative of the high internal content of MB+.  The MB+ loading was quantified using EDX and UV-Vis spectrophotometry.  Small-angle x-ray scattering (SAXS) measurements were carried out and analyzed using a unified exponential/power-law (UEP) model to describe the composite’s nanostructure.  SAXS analyses indicated that intercalated material is composed of two phases, each with different layer spacings for the restacked sheets.  Compared to transmission spectra of aqueous MB+, diffuse reflectance UV-Vis absorption spectra of composite revealed changes in the absorbance maxima of the intercalated MB+, indicating that the MB+ molecules were interacting strongly with each other and with the oxide host.  Raman and IR spectra also revealed significant host-guest interactions.  As determined by x-ray diffraction, the measured layer spacing between restacked nanosheets in the composite is consistent with a molecular orientation of MB+ standing on the end but tilted 40.4° away from the plane of the sheets.  Electron microscopy analysis showed that there were no significant morphological changes occurred in the porous host aggregates during the intercalation of MB+.  From an electrostatics evaluation, the new organic-inorganic composite materials were found to contain 40 % of the theoretical maximum of MB+, which resulted in an empirical formula of (MB)0.4H0.6TiNbO5.

In this study, the main objective is the preparation and the characterization of a modified Algerian bentonite based adsorbent by intercalation with hexadecyltrimethylammonium bromide (HDTMA). Natural and modified bentonites were characterized using thermogravimetric analysis (TGA), X-ray diffraction (XRD) and infrared spectroscopy (FTIR). The X-ray results indicate that the geometry of the interlayer space was changed by the intercalation of HDTMA cations and the basal spacing was increased from 1.34 to 1.96 nm. The adsorption efficiency of natural and HDTMA-bentonite was examined for humic acid (HA) removal by batch adsorption experiments under different operating conditions. The maximum monolayer adsorption capacity qm of HA was found to be 54.80 mg/g and 330.34 mg/g for HDTMA-bentonite and natural bentonite respectively. The kinetic study indicated that HA adsorption followed the pseudo-first-order model. Both natural and HDTMA-bentonite showed quite good capabilities in removing HA from aqueous solutions.