Reactions of organic molecules on Montmorillonite clay mineral have been investigated from various aspects. These include catalytic reactions for organic synthesis, chemical evolution, the mechanism of humus-formation, and environmental problems. Catalysis by clay minerals has attracted much interest recently, and many reports including the catalysis by synthetic or modified clays have been pub...

Iron-bearing phyllosilicate minerals help establish the hydrogeological and geochemical conditions of redox transition zones because of their small size, limited hydraulic conductivity, and redox buffering capacity. The bioreduction of soluble U(VI) to sparingly soluble U(IV) can promote the reduction of clay-Fe(III) through valence cycling. The reductive precipitation of U(VI) to uraninite was...

Organically modified clay was used as reinforcement for HDPE using maleated polyethylene (PEMA) as a compatibilizer. The effect of compatibilizer concentration on the orientation of various structural features in the polymer-layered silicate nanocomposite (PLSN) system was studied using two-dimensional (2D) small angle X-ray scattering (SAXS) and 2D wide-angle X-ray scattering (WAXS). The dispe...

The soybean cyst nematode (SCN), Heterodera glycines Ichinohe, is a severe pest of soybean, Glycine max (L.) Merr., in the United States. Nematode reproduction and the seed yield losses caused by this nematode are influenced by soil texture (3,5,6). Todd and Pearson (5) recovered higher numbers of SCN females and cysts from a sandy loam soil than from silty loams. Soybean yield also has been ne...

Particles with nanometer dimensions (nanoparticles) are all around us. The finest particles of sand are blown by the wind over thousands of kilometers. The finest particles of soils are either eroded by the wind in extremely dry conditions or by water under wet conditions and deposited hundreds of kilometers or more from the origin. The air contains nanoparticles of carbon, ice, and oxides and ...

X-ray analyses of the clay minerals from thousands of sediments indicate that any of the major clay minerals can occur in abundance in any of the major depositional environments and there is no consistent coincidence between specific clay minerals and specific depositional environments. It is concluded that the great majority of clay minerals in sedimentary rocks are detrital in origin, strongl...

Adsorption of organic cations on several clay minerals is reviewed with an emphasis on the effect of ionic strength and modeling. The clay exchanged with suitable organic cations forms a basis for ecologically acceptable formulations of herbicides with reduced leaching, ground water contamination and enhanced weed control efficacy. Incomplete neutralization of the clay surface charge by an orga...

" A supplement of 1% to 4% clay or 4% salt mixture caused an increase in body weight and prevented the pathologic changes. " " Findings indicated that the various clays differed significantly in growth-promoting activity (Table 4). The most active material tested was clay sample A (ION-MIN from CEM); whereas, clay sample J, kaolin, and hydrobiotite were virtually devoid of growth-promoting acti...

Focus here is placed on the pharmaceutical and biomedical applications of novel clay-drug hybrid materials categorized by methods of administration. Clay minerals have been used for many years as pharmaceutical and medicinal ingredients for therapeutic purposes. A number of studies have attempted to explore clay-drug hybrid materials for biomedical applications with desired functions, such as s...

Second harmonic generation (SHG) is applied for the first time to study the surfaces of clay particles. An SHG signal was detected from an aqueous suspension of disk-shaped montmorillonite clay particles of 0.5 μm diameter and 0.01 μm thickness. The origin of the SHG signal is the polarization of water molecules by surface charges located in the edge region of the clay particles. On addition of...