The theological parameters of a clay suspension can be used to evaluate particle-particle interactions. Although there have been many studies of the rheological behavior of suspensions of reference clays, only few studies were performed with suspensions of mixed clays, and the rheological properties of these suspensions are not yet fully understood. The length-to-width ratio of some soil clays ...

The authors develop an ultrasensitive method for the measurement of the charge carried by a colloidal particle in a nonpolar suspension. The technique uses the phenomenon of the resonance of a particle held in an optical tweezer trap and driven by a sinusoidal electric field. The trapped particle forms a strongly damped harmonic oscillator whose fluctuations are a function of gamma, the ratio o...

We study a colloidal suspension confined between two quasiparallel walls as a model system for glass transitions in confined geometries. The suspension is a mixture of two particle sizes to prevent wall-induced crystallization. We use confocal microscopy to directly observe the motion of colloidal particles. This motion is slower in confinement, thus producing glassy behavior in a sample which ...

Fluids with particles in suspension can be extracted through an orifice until particles bridge across the opening and clog it. We derive and study a mathematical model to predict the volume of fluid that can be extracted before clogging. Numerical simulations and closed-form upper and lower bound solutions show the dependency of the expected extracted volume on the volume fraction of particles ...