Water radiolysis in exchanged-montmorillonites: the H2 production mechanisms.

The radiolysis of water confined in montmorillonites is studied as a function of the composition of the montmorillonite, the nature of the exchangeable cation, and the relative humidity by following the H2 production under electron irradiation. It is shown that the main factor influencing this H2 production is the water amount in the interlayer space. The effect of the exchangeable cation is linked to its hydration enthalpy.

Internally structured pickering emulsions stabilized by clay mineral particles.

The present study aims to describe emulsion particles containing a dispersed phase composed of nanostructured lipid mesophases and stabilized by montmorillonite and/or Laponite clay platelets. The size distributions of these emulsion particles were found independent of the clay mineral content and of the initial internal composition that determines the internal structure. The stabilization of the droplets by a shell of smectite layers was found possible even by montmorillonite which has a length of the same order or more than the droplets to stabilize.

Effect of pH on Rheological Properties of Purified Sodium Bentonite Suspensions.

The effect of pH on the rheological behavior of three purified sodium bentonite (HP, GP, and WP) suspensions is studied. Each clay is studied as a function of pH, at a chosen constant concentration. These concentrations correspond to the lower concentrations at which the yield stress can be detected.

Adsorption of a Cationic Surfactant on Na-Montmorillonite: Inspection of Adsorption Layer by X-Ray and Fluorescence Spectroscopies.

The adsorption of the cationic surfactant BDDAC on a hydrophilic smectite (montmorillonite) surface has been investigated, especially in the range of low coverage ratios where surfactant ions are adsorbed through cation-exchange with the counterions of the clay. The surfactant coions (Cl(-)) were found to be adsorbed simultaneously with the cationic part after a complete alkyl ammonium ion-exchange of montmorillonite (CEC). We observe that organoclay particles remain flocculated in aqueous medium in almost all the range of adsorption isotherms up to 1.