[1] Al-rich phyllosilicates (kaolinite, montmorillonite) have been found in layers overlying Fe/Mg-smectites on Mars, and it has been suggested that this stratigraphy formed through in situ leaching at the surface, similar to terrestrial weathering profiles. We are investigating the remotely sensed signatures of this type of weathering using ten samples from a vertical section of altered Deccan...

Direct current resistance measurements were made of kaolinite and serpentine powders to follow the changes in resistances during their dehydroxylation processes in air. The resistance of kaolinite remained almost constant during the dehydroxylation, whereas that of serpentine showed a rapid decrease. The formation of distorted lattice sites where the charge carriers are scattered under an elect...

Theoretical analysis and Computer simulations have proven to be cost-effective and powerful tools in scientific studies of materials, particularly at nano-scale where synthesis of nano-structures, interpretation of their observed character and exploration of new structures are not always straight forward. We present here fundamental principles of techniques used today for computational simulati...

This computational study performed using the density functional theory shows that hydrated and non-hydrated tetrahedral and octahedral kaolinite mineral surfaces in the presence of a cation adsorb the nucleic acid bases thymine and uracil well. Differences in the structure and chemistry of specific clay mineral surfaces led to a variety of DNA bases adsorption mechanisms. The energetically most...

Introduction Conclusions References

High-resolution atomic force microscopy is used to map the surface charge on the basal planes of kaolinite nanoparticles in an ambient solution of variable pH and NaCl or CaCl2 concentration. Using DLVO theory with charge regulation, we determine from the measured force-distance curves the surface charge distribution on both the silica-like and the gibbsite-like basal plane of the kaolinite par...