Porous clay heterostructures (PCH) based on modified montmorillonite were synthesized using different reaction conditions (different hydration degrees, pH values and reaction times). The PCH precursors and PCH were characterized using FTIR Spectroscopy and X-Ray Diffractions (XRD). The XRD results showed that basal distance of porous clay heterostructures was significantly influenced by the mod...

In situ characterization of colloidal particles under hydrous conditions is one of the key requirements for understanding their state of aggregation and impact on the transport of pollutants in aqueous environments. Scanning transmission X-ray microscopy (STXM) is one of the few techniques that can satisfy this need by providing element- and chemical-state-specific 2-D maps at a spatial resolut...

Surfaces of a Wyoming SWy-2 sodium montmorillonite were modified using microwave radiation through intercalation with the cationic surfactants octadecyl-trimethyl ammonium bromide, dimethyldioctadecylammonium bromide, and methyl-tri-octadecyl ammonium bromide by an ion exchange mechanism. Changes in the surfaces and structure were characterized using X-ray diffraction (XRD), thermal analysis (T...

A b s t r a c t S u r f a c e area determinations were made on a montmorillonite with various cations emplaced on the exchangeable sites, utilizing nitrogen and carbon dioxide as adsorbates at 77~ and 195~ respectively, in a dynamic system. From the fraction of a Mississippi montmorillonite less than about 1/x in size, samples were prepared by replacing the original exchangeable cations with Li...

The liquid phase esterification of phenyl acetic acid with p-cresol over different metal cation exchanged montmorillonite nanoclays yields p-cresyl phenyl acetate. Different metal cation exchanged montmorillonite nanoclays (M n+ = Al3+, Zn2+, Mn2+, Fe3+, Cu2+) were prepared and the catalytic activity was studied. The esterification reaction was conducted by varying molar ratio of the reactants,...

A series of montmorillonite-(Ce or Zr) phosphate crosslinked compounds has been synthesized by reaction of a cerium or zirconium cation exchanged montmorillonite (diameter ~2 pm) with phosphoric acid under appropriate conditions of concentration, addition rate and temperature. The materials thus obtained were characterized by chemical and thermal analyses, X-ray diffraction, IR spectroscopy and...

The midinfrared 2000-400 cm-1 (5-25 /an) optical constants (real (n) and imaginary (k) indices of refraction) are presented for: (1) pyrophyllite; (2) kaolinite; (3) serpentine; (4) montmorillonite; (5) saponite; (6) palagonite; and (7) orthopyroxene. Comparison of the values derived here with those previously presented for serpentine, montmorillonite, and palagonite is generally quite good and...