Reversible, shear-induced gelation of semi-dilute aqueous colloidal dispersions consisting of monodisperse discoid particles (Laponite) and weakly adsorbing polymer (polyethylene oxide) is studied through a combination of small angle neutron scattering and oscillatory shear. When shaken the samples undergo a dramatic transition from a low viscosity fluid to a self-supporting, turbid gel. This c...

The high aspect ratio of layered silicate nanoparticles is very convenient to modify the properties of the polymer, but the hydrophilic nature of silicate surfaces impedes their homogeneous dispersion in the organic polymer phase. The hydrophilic clay minerals are commonly treated with ammonium cations with long alkyl chains to improve the compatibility between the silicate layers and the polym...

The filtration behaviour of some clay–water dispersions was studied. Two Spanish fibrous phyllosilicates (sepiolite from Vicálvaro and palygorskite from Turón) and a commercial bentonite (Bentopharm©, UK) with similar sizes and different morphologies (fibrous and/or laminar) were selected as model clays. Sepiolite from Vicálvaro is an almost pure fibrous sample, Bentopharm© presents a high amou...

-Protein complexes of smectites in soils are difficult to detect if the usual smectite tests show no peculiarities. Andalusian black earths are typical examples. Investigation of the alkylammonium derivatives, however, allows detection of adhered macromolecules which might be protein-like although this cannot be proved cxactly. Investigation of artificial clay-protein complexes reveals differen...

A Permian bentonite deposit at Melo, Uruguay is composed of a calcite-cemented sandstone containing clay pseudomorphs of glass shards (0-0.50 m) overlying a pink massive clay deposit (0.50-2.10 m). The massive bed is composed of two layers containing quartz and smectite or pure smectite respectively. The smectite is remarkably homogeneous throughout the profile: it is a complex mixed layer comp...

light weight wood base sandwich panels have some special properties and their most important properties is high mechanical strength with its light weight. these panels can replace instead of traditional structural systems in iran. the purpose of this paper is investigating the mechanical properties of light weight wood base sandwich panels that have made from sunflower stalk wastes and particle...

Transport properties in shales were investigated using experimental and computersimulation methods. First, an experimental method based on a transient pressuredecay technique was further developed and used instead of classical Darcy core-flood methods. This has allowed measurement of the permeability of tight shale samples on much shorter time scales than by conventional methods. Second, molecu...