Synthetic LAPONITE®-clay particles with platelet-like shape display strong aging when dispersed in aqueous solutions, preventing the latter from reaching their natural liquid-crystalline equilibrium state. Here we introduce a facile method that successfully prevents this aging behaviour and enables accessing the systems' liquid-crystal and crystalline phases. We graft the comb-like polymer PLL-...

tashtab mountain is located 25 km from the city of khur in northeastern isfahan province. several bentonite mines formed in this area as a result of the eocene volcanic alteration. these mines are classified as the khur bentonite horizon. studies on trace elements in parent rock and clays show that the studied bentonites formed from andesite-basaltic parent rocks. the xrd analysis shows that st...

A major technological barrier to achieving superior properties of nano-structured composite materials is the difficulty of dispersing fillers uniformly in a host matrix. The existing nanocomposite manufacturing processes achieve property improvements through chemical modifications of filler structures and utilization of chemical interactions between the chemically modified fillers and matrix po...

The Opalinus Clay is a claystone considered as potential host rock for deep geological disposal of radioactive wastes in Switzerland and Gemany. During the operational phase repository, an increase underground water pH , from 7.5 to value high 13.5 expected, due release alkaline plumes concrete degradation, resulting possible changes mineralogy rock. While clay mineral dissolution known occur a...

in this study the environmental problems has been studied in south east of tehran (bibi shahrbanou mount). 31 sediment samples were taken from 10-15 cm extremity of streams and were analyzed by icp. toxic elements studied include: ag, as, cd, cr, cu, ni, pb, sb and zn. the samples were also investigated for mineralogy using xrd. the clay mineral assemblage encountered in the analyzed samples is...

Dependence of mechanical properties of geomaterials on the variable chemical environment or advancement of chemical or mineralogical reactions is known to be a crucial factor in many cases of mechanical stability of geo-masses. Processes of mineral dissolution usually results in material weakening while precipitation of minerals such as of silica in aging or calcite in clay fractures may lead t...

The calcite saturation status of soil-water systems in semiarid regions was reexantined taking into consideration organic ligand alkalinity and Ca-organic complexation. These factors have been forwarded as the reason for earlier reports of calcite Supersaturation in soilwater systems. We examined groundwaters beneath irrigated lands, soil-water suspensions in the laboratory using four soils and...

Uplift of the Tibetan Plateau since the Late Miocene has greatly affected the nature of sediments deposited in the Qaidam Basin. However, due to the scarcity of continuously dated sediment records, we know little about how minerals responded to this uplift. In order to understand this response, we here present results from the high-resolution mineral profile from a borehole (7.3-1.6 Ma) in the ...