The thermal, rheological, and mechanical and dielectric relaxation properties of exfoliated dispersions of montmorillonite clay in a molecular liquid, polychlorobiphenyl (PCB), were studied. The viscosity enhancement at low concentrations of clay (≤5%) exceeded by a factor of 50 the increase obtainable with conventional fillers. However, the effect of the nanoclay on the local dynamics, includi...

Nanofilled polymeric matrices have demonstrated remarkable mechanical, electrical, and thermal properties. In this article we review the processing of carbon nanotube, graphene, and clay montmorillonite platelet as potential nanofillers to form nanocomposites. The various functionalization techniques of modifying the nanofillers to enable interaction with polymers are summarized. The importance...

Solute Fe(II) – montmorillonite interactions are studied in anoxic conditions and at room temperature for reaction times from hour to week. Fe is shown to be sorbed on cation exchange site with the same affinity than Ca. In chloride anionic medium, Fe(II) form ionic pairs – FeCl which is sorbed with almost the same affinity than CaCl and MgCl are. The exchange thermodynamics constants derived f...

Abstraet---Ethylenediamine (EDA) is adsorbed from aqueous solution on Na-, Kand Li-montmorillonite as the monoprotonated cation (EDAH +) through an ion-exchange process. On washing with distilled water the second amine function is protonated--probably through dissocmtion of water near the clay surface--and simultaneously formed alkali hydroxide is removed. In air-dried clay films, prepared from...

The hydrolysis of hemicellulosic oligosaccharides (OS) was investigated using acid-activated clays (prepared from natural Porto Santo montmorillonite clay) as catalysts. Acid activation was performed in HCl solution or with aluminium exchange. The clay catalysts were characterized by XRD, N2 adsorption isotherms, CEC, FTIR, titration of acid sites in water and adsorption of sugars and disacchar...

Three different protocols for the preparation of polymer layered silicate nanocomposites based upon a tri-functional epoxy resin, triglycidyl para-amino phenol (TGAP), have been compared in respect of the cure kinetics, the nanostructure and their mechanical properties. The three preparation procedures involve 2 wt% and 5 wt% of organically modified montmorillonite (MMT), and are: isothermal cu...

This study investigates the feasibility of using ethylene oxide chain adsorption to determine the surface area of an expandable clay, montmorillonite. Experimental results indicate that high molecular weight poly(ethylene oxide) or nonionic surfactant with long ethylene oxide chain should be used to provide reasonable estimations for monolayer capacity. The method has advantages over Brunauer, ...

A model describing the electric double layers in clay-electrolyte systems containing particles with different surface charge densities was developed and used to calculate the film thickness of water present in a clay paste. The average water film thicknesses (-18/~) calculated by considering the clay to contain 9 groups of particles of different charge densities did not differ from those calcul...

To address the high salinity of flow-back water during hydraulic fracturing, we have studied the equilibrium partitioning of NaCl and water between the bulk phase and clay pores. In shale rocks, such a partitioning can occur between fractures with a bulk-like phase and clay pores. We use an advanced Grand Canonical Monte Carlo (GCMC) technique based on fractional exchanges of dissolved ions and...

-A method of clay mineral sample preparation for electron microprobe analysis has been developed in which a film of clay plus 10-12 wt. % colloidal graphite is deposited on a porous ceramic disc using a specially designed suction device. Correction procedures are used to obtain quantitative elemental analyses representing the average chemical composition of the prepared sample. A statistical te...