Modified clays were used to remove ethyl acetate from aqueous solutions. These clays were regenerated using supercritical CO2. Structural changes in the montmorillonite clay after treatment with quaternary amines were studied. The surface properties of the modified clay changed from highly hydrophilic to highly organophilic. The clay was regenerated by percolation of a stream of CO2 through the...

This paper deals with the synthesis of a biocompatible chitosan ammonium salt N-(2-hydroxy) propyl-3-trimethylammonium chitosan chloride (HTCC) and using it in montmorillonite ion-exchange process. HTCC-modified montmorillonite (Mt) with different chemical ratios was successfully synthesized, and their characteristics have been verified by XRD and FTIR analyses. Produced samples have been evalu...

1 We studied the interaction between the naturally occurring polycation spermine (SPERM) and 2 Na-exchanged SWy-2 Wyoming montmorillonite (Na-SWy-2 Mt) and between spermine3 exchanged montmorillonite (Mt-SPERM) and the herbicide fluometuron. Mt-SPERM with 4 spermine contents ranging between 0 and 1.2 times the cation exchange capacity (CEC) of 5 Na-SWy-2 were studied by XRD, FTIR and TGA analys...

Bernal suggested that clays might have played a significant role in primitive earth through the process of concentration and adsorption of the biologically formed biomonomers and thus protecting them against hydrolytic fission.Adsorption of adenine was studied in presence of montmorillonite clay with or without cations Ca+,Cu+,Mg+.Studies carried out have shown that adsorption of adenine was de...

Under appropriate conditions, both surface areas and cation exchange capacities of clay minerals can be measured by absorption of methylene blue from aqueous solutions. The method has been applied to two kaolinites, one illite, and one montmorillonite, all initially saturated with Na + ions. For Na-montmorillonite, the total area, internal plus external, is measured. For Ca-montmorillonite, ent...

Expansive soils owe their characteristics to the presence of swelling clay minerals. As they get wet, the clay minerals absorb water molecules and expand; conversely, as they dry they shrink, leaving large voids in the soil. Swelling clays can control the behavior of virtually any type of soil if the percentage of clay is more than about 5 percent by weight. Soils with smectite clay minerals, s...

Adsorption of three sulfonamide antimicrobials to clay minerals was investigated as a function of pH, ionic strength, and type of exchangeable cation. Sulfonamide antimicrobial adsorption exhibited pronounced pH dependence consistent with sorbate speciation and clay properties. Sulfonamide antimicrobials did not intercalate into montmorillonite, and surface charge density influenced sorption by...

The detailed mineralogy of the Bullfrog and Tram Members of the Crater Flat Tuff from drill hole USW-G1 has been examined, primarily to characterize fully the amounts and types of clay minerals in the tuffs and the possible effects clay minerals have on rock properties. Results of bulk sample x-ray diffraction analyses agree closely with previous determinations, although slightly higher clay mi...

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 clay montmorillonite is known to catalyze the polymerization of RNA from activated ribonucleotides. Here we report that montmorillonite accelerates the spontaneous conversion of fatty acid micelles into vesicles. Clay particles often become encapsulated in these vesicles, thus providing a pathway for the prebiotic encapsulation of catalytically active surfaces within membrane vesicles. In a...