This study was conducted to investigate the influence of the saturating cation on the adsorption of parathion, methyl parathion, fenitrothion, aminoparathion, and paraoxon by montmorillonite suspensions. In all cases the saturating cation distinctly influenced the Freundlich-type adsorption, with adsorption decreasing in the following sequence: Fe—> Ca— > Na-montmorillonite. Adsorption of parat...

In environmental studies, we need to be able to predict the behaviour of contaminants in more or less complex physico-chemical contexts. The improvement of this prediction partly depends on establishing thermodynamic models that can describe the behaviour of these contaminants and, in particular, the sorption reactions on mineral surfaces. In this way, based on the mass action law, it is possib...

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...

Sodium montmorillonite (Na-MMT) clay was modified with three different unnatural amino acids in order to design intercalated clay structures that may be used for bone biomaterials applications. Prior work on polymer-clay nanocomposites (PCNs) has indicated the effect of the appropriate choice of modifiers on enhancing properties of PCNs. Our X-ray diffraction results indicate an increase in the...

Sodium Montmorillonite (NaMMT) has been modified via cation exchange reaction using three different organic cations. Basal spacings, interlamellar structure and thermal stability of these organo-montmorillonites (OMMT) clays have been characterized using wide angle X-ray diffraction (WAXD) and thermogravimetric analysis (TGA) techniques. Increase in the basal spacing due to organic modification...

The article deals with the preparation, properties and the usage of polymer barrier films. The problem of exfoliation and dispersion of the filler in the polymer matrix and mechanical properties of barrier films is discussed. This problem is connected with the use of nanofiller either in the polymer matrix or on the surface of prepared films. Together the evaluating comparison of used nanofille...

nanoporous sodium montmorillonite clay (na+-mmt) was used as a support for the immobilization of 1-methyl-3-(trimethoxysilylpropyl)-imidazolium hydrogen sulfate (na+-mmt-[pmim]hso4). this catalyst showed excellent catalytic activity for the preparation of 2-amino-3-cyano-5-oxo-5,6,7,8-tetrahydro-4h-benzopyrans via three-component reactions between aldehydes, dimedone and malononitrile. the proc...

-The adsorption of the cationic oxidized safranine S + by a Na +, Ni 2+ and Fe 3§ montmorillonite has been studied with X-ray powder diffraction, u.v, visible and i.r. spectroscopy. In solution S + may be protonated: S +, SH e+ and SH~ + have characteristic spectra in the 500-600nm region where the clay structure does not absorb. In the Na + as well as in the Ni 2+ and Fe 3+ clays, the adsorpti...

The main aim of this paper is to study the cation fixation sites in montmorillonite after heating at different temperatures. Montmorillonite was used adsorb cations (Na+, Cu2+ and Li+) solution, montmorillonite-adsorbed were heated temperatures (unheated, 100 °C, 200 °C 300 °C) for 25 h. Subsequently, basal spacing treated monitored by X-ray diffraction (XRD). exchangeable cationic content dete...

The need to consider CaCl and MgCl complexes in Ca-Mg exchange reactions on montmorillonite was evaluated by examining cation selectivity in various anion backgrounds. The Ca-Mg exchange isotherms on SVVy-1 Wyoming bentonite were determined in 0.0125 M SO4, 0.025, 0.050, and 0.100 M Cl and 0.03 M perchlorate background. Calculated selectivity values for the reaction Ca + MgX^ Mg + CaA" were Kv ...