The field of active colloids is attracting significant interest to both enable applications and allow investigations of new collective colloidal phenomena. One convenient active colloidal system that has been much studied is spherical Janus particles, where a hemispherical coating of platinum decomposes hydrogen peroxide to produce rapid motion. However, at present producing these active colloi...

This research compared the influence of (1) dissolution of iron oxides and (2) alteration of electrostatic interactions on the mobilization of colloids in a clayand iron oxidecoated sand obtained from an Atlantic Coastal Plain aquifer in which colloids have been found suspended only in anoxic groundwater. The sediment was flushed with solutions of varying ionic strength, pH, and reductant and s...

Recent advances in the synthesis of polymeric colloids have opened the doors to new advanced materials. There is strong interest in using these new techniques to produce particles that mimic and/or interact with biological systems. An important characteristic of biological systems that has not yet been exploited in synthetic polymeric colloids is their wide range of deformability. A canonical e...

PACS. 61.20Gy – Theory and models of liquid structure. PACS. 82.70Dd – Colloids. Abstract. – We show that a general density functional approach for calculating the force between two big particles immersed in a solvent of smaller ones can describe systems that exhibit fluid-fluid phase separation: the theory captures effects of strong adsorption (wetting) and of critical fluctuations in the solv...

In this paper, the results of the synthesis and characterization of higher fullerene-based colloids is presented. The generation of singlet oxygen 1O2 (1Δg) by fullerene water-based colloids (nC60, nC70 and nC84) was investigated. It was found by electron paramagnetic resonance spectroscopy that the generation of singlet oxygen was the highest by the nC84 colloid. The amplitude of the electron ...

Asymmetric flow-field flow fractionation-inductively-coupled plasma-mass spectrometry was used to determine whether colloidal arsenic (As) exists in soil pore water and soil extract samples at two arsenic-contaminated abandoned gold mines (Montague and Goldenville, Nova Scotia). Colloidal arsenic was found in 12 out of the 80 collected samples (=15%), and was primarily associated with iron (Fe)...

In this paper we propose a framework allowing one to compute the effective interactions between two anisotropic macromolecules, thereby generalizing the Derjaguin, Landau, Verwey, and Overbeek theory [E. J. W. Verwey and J. T. G. Overbeek, Theory of the Stability of Lyophobic Colloids (Elsevier, Amsterdam, 1948)] to nonspherical finite size colloids. We show in particular that the effective int...

The deposition behaviors of carboxylate-modified polystyrene latex microspheres (six sizes ranging from 0.1 to 2.0 μm) in packed porous media (soda-lime glass beads) were examined under a variety of environmentally relevant pore fluid velocities (4-8 m-day-1) in the presence of an energy barrier to deposition. Hyperexponential profiles of retained colloids were observed for all microsphere size...

Achieving control over the directionality of active colloids is essential for their use in practical applications such as cargo carriers in microfluidic devices. So far, guidance of spherical Janus colloids was mainly realized using specially engineered magnetic multilayer coatings combined with external magnetic fields. Here we demonstrate that step-like submicrometre topographical features ca...

Well-defi ned, functional colloids provide critical model systems for a variety of fundamental phenomena in materials and soft matter, and enable a broad range of technological applications from optics [ 1 ] to biotechnology. [ 2 ] The ability to fabricate large quantities of colloids with high uniformity and specifi ed shape and function has thus been greatly desired. For example, magnetic col...