Using tangential flow ultrafiltration, total mercury (HgT) and methylmercury (MeHg) concentrations in the colloidal phase (0.4 microm-10 kDa) were determined for 15 freshwaters located in the upper Midwest (Minnesota, Michigan, and Wisconsin) and the Southern United States (Georgia and Florida). Unfiltered concentrations were typical of those reported for freshwater and ranged from 0.9 to 27.1 ...

We show how to implement stick boundary conditions for a spherical colloid in a solvent that is coarse-grained by the method of stochastic rotation dynamics. This allows us to measure colloidal rotational velocity autocorrelation functions by direct computer simulation. We find quantitative agreement with Enskog theory for short times and with hydrodynamic modecoupling theory for longer times. ...

Colloidal inclusions in lab-on-a-chip devices can be used to perform analytic operations in a non-invasive fashion. We demonstrate here a novel approach to realize fast and reversible micro-sieving operations by manipulating and transporting colloidal chains via mobile domain walls in a magnetic structured substrate. We show that this technique allows one to precisely move and sieve non-magneti...

We demonstrate complex nonlinear pattern formation dynamics associated with standing wave vibrations induced along a piezoelectric substrate on which a small drop of colloidal suspension is placed. Interfacial colloidal islands which self-assemble due to surface acceleration and capillarity are subsequently erased once fluid streaming becomes significant at higher powers. Due to a peculiar inst...

A cationic polymer containing tris(4,4′-dialkyl-2,2′-bipyridyl)ruthenium groups linked by aliphatic spacers was studied as a photosensitizer for the catalytic oxidation of water in the presence of colloidal IrO2. The polymer-colloidal IrO2 system photocatalytically reduced persulfate, a sacrificial electron acceptor, and oxidized water to O2 and H+ in solutions that were buffered at pH 6 by Na2...

We use substrates chemically micropatterned with anionic and cationic regions to govern the deposition of charged colloidal particles. The direct observation of the colloidal assembly suggests that this process includes two steps: an initial patterned attachment of colloids to the substrate and an additional ordering of the structure upon drying. The driving forces of the process, i.e. , screen...

An efficient and rapid method for the synthesis of 3,4,5-substituted furan-2 (5H)-ones has been achieved through a three-component reaction of aniline, dialkyl acetylenedicarboxylate, and aromatic aldehydes using nano-colloidal silica-tethered polyhedral oligomeric silsesquioxanes with eight branches of 3-aminopropyltriethoxysilane (nano-colloidal silica @APTPOSS) as a superior catalyst under m...

In this study, colloidal germanium nanocrystals were synthesized by a simple and novel method, and their optical properties were also studied. Polyvinyl alcohol (PVA) as a surface modifier was used to control the optical properties of colloidal Ge nanocrystals. Fourier transform infrared spectroscopy (FTIR) analysis was performed to identify the various functional groups present in the sample. ...