The polycondensation of tetrahydrofuran with maleic anhydride catalyzed by Maghnite-H+ (Mag-H) was investigated. Maghnite is a montmorillonite sheet silicate clay that is exchanged with protons to produce Maghnite-H [1]. It was found that the polymerization in bulk is initiated by Mag-H in the presence of acetic anhydride at 40 degrees C. The effects of the amounts of Mag-H and acetic anhydride...

-Treating NH4-bentonite with diazomethane results in methylation of adsorbed ammonium with the formation of the tetramethylammonium ion. This ion, which can be completely removed through ion exchange, is distinguished in the IR spectrum by a strong band at 1480 cm -1 due to CH3 group bending vibrations. X-ray diffractograms, CEC, and surface area of the clay are not modified by treatment with d...

A new, simple and straight-forward protocol for direct carboxylation of terminal alkynes has been developed using Cu-montmorillonite K10 clay as a heterogeneous catalyst and CO2 as the C1 carbon feedstock. Also coupling of terminal alkynes with CO2 (1 atm) in the presence of alkyl halides has been achieved under the same reaction conditions, thereby providing access to a variety of functionaliz...

The effect of temperature in the range of 0–150 8C was studied for homoionic montmorillonite clays with Na and Csqq compensating ions in low hydration states. Both static and dynamic information concerning the interlayer ions and water moleculeswas obtained by Monte Carlo and molecular dynamics. Principal structural changes were limited to the water phase, markeddifference was o...

A montmorillonite has been intercalated with Al3+ polycations, using concentrated solutions and clay mineral dispersions. The reaction has been assisted by microwave radiation, yielding new intercalated solids and leading to Al-pillared solids after their calcination at 500 °C. The solids were characterized by elemental chemical analysis, X-ray diffraction, FTIR spectroscopy, thermal analyses, ...

Consistency limits are the basic parameters used as standard inputs for any soil investigation program to evaluate geotechnical properties of fine-grained soils. The primary objective this study is investigate variations in undrained shear strength clays with different plasticity based on fine content, clay mineralogy, and water absorption capacity. To achieve objective, 33 Fall cone tests were...

BACKGROUND The dispersion-aggregation behaviors of suspended colloids in rivers and estuaries are affected by the compositions of suspended materials (i.e., clay minerals vs. organic macromolecules) and salinity. Laboratory experiments were conducted to investigate the dispersion and aggregation mechanisms of suspended particles under simulated river and estuarine conditions. The average hydrod...

Poly(vinyl alcohol) (PVA)-montmorillonite (MMT) clay nanocomposite films up to 10 wt% clay concentration were synthesized by aqueous solution grown technique. The relative complex dielectric function, alternating current electrical conductivity, electric modulus and impedance properties of these organic-inorganic nanocomposites were investigated in the frequency range from 20 Hz to 1 MHz at amb...

The design and tests of slow-release formulations of sulfometuron (SFM), an anionic sulfonylurea herbicide, are described. The formulations are based on incorporation of the herbicide in octadecyltrimethylammonium (ODTMA) micelles, which adsorb on a clay mineral, montmorillonite. An optimization of herbicide/micelle clay ratios yielded high adsorption of SFM (95%), and at a 1% (w/w) water suspe...

The subject of hybrids based on layered inorganic compounds such as clays has been studied for a considerable time, but the area is enjoying a resurgence of interest and activity as a result of the exceptional properties which can be realized from such nanocomposites. Common clays are naturally occurring minerals, and are thus subject to natural variability in their constitution. Many clays are...