Self-Cleaning Piezoelectric Membrane for Oil-in-Water Separation.

Ultrasound (US) treatment coupled with membrane filtration has been utilized for membrane fouling control in water treatment; however, large-scale implementation of ultrasonic cleaning equipment appeared to be cost-prohibitive. In this study, a porous lead zirconate titanate (PZT) membrane is presented that enables in situ ultrasound generation by the application of an alternating voltage (AV) to mitigate fouling during oil-in-water (O/W) emulsion separation. We expect that this method is much more cost-effective because it is more direct, avoiding buildup of fouling and the need to take the membrane offline.

Synthesis of ultrathin zeolite Y membranes and their application for separation of carbon dioxide and nitrogen gases.

Synthesis of zeolite Y membranes from submicrometer (>100 nm) and nano seed (<100 nm) crystals on alumina supports was examined and the separation characteristics of these membranes for CO(2) and N(2) were studied. Two secondary growth solutions were examined, one for a rapid growth (hours) and one for a slower growth process (days). Membranes formed from the rapid growth solution resulted in 2-2.

Fast mass transport through carbon nanotube membranes.

The May 19, 2006 issue of Science included a paper by Holt et al. on "Fast Mass Transport Through Sub-2-Nanometer Carbon Nanotubes". The paper was also featured on the cover, showing methane molecules translating inside a carbon nanotube (CNT).

Interaction of water with titania: implications for high-temperature gas sensing.

High-temperature gas sensors based on semiconducting metal oxides show potential for optimization of combustion processes, resulting in efficient energy use and minimization of emissions. Such metal oxides can function as gas sensors because of the reaction of the sensing gas (e.g.

Application of the charge regulation model to transport of ions through hydrophilic membranes: one-dimensional transport model for narrow pores (nanofiltration).

The charge regulation concept is combined with the Navier-Stokes and Nernst-Planck equations to describe the ion retention of nanofiltration membranes consisting of narrow cylindrical pores. The charge regulation approach replaces the assumption of a constant charge or a constant potential at the membrane pore surface, and accounts for the influence of pH, salt concentration, and type of electrolyte on ion retention. In the current model, radial concentration and potential gradients are considered to be negligibly small (valid for narrow enough pores), resulting in a one-dimensional transport description.

Synthesis and purification of oxide nanoparticle dispersions by modified emulsion precipitation.

ZrO2 and Fe2O3 precursor nanoparticles are synthesized, well-dispersed in decane, via a modified emulsion precipitation (MEP) method. This method starts with preparing two thermostable water-in-oil (w/o) emulsions with nonylphenol tetra(ethylene glycol) ether (Arkopal-40) as the main surfactant, didodecyldimethylammonium bromide (DiDAB) as the cosurfactant, decane as the continuous oil phase, and either a metal salt solution or a hexamethylenetetramine (HMTA) precipitation agent solution as the dispersed water phase. After mixing of the two emulsions, individual precursor particles are formed by precipitation in the confinement of the aqueous solution droplets.