When oil is mixed with light alkanes, asphaltenes can precipitate out of oil solutions in a multistep process that involves the formation of nano and colloidal scale particles, the aggregation of asphaltene colloids, and their eventual sedimentation. Amphiphilic dispersants can greatly affect this process. The mechanism of the dispersant action in colloidal asphaltene suspensions in heptane has...

In this work, nano-photocatalysts based on ZnS quantum dots (QD) functionalized by chitosan were developed using “green” colloidal chemical process in aqueous media at room temperature. The ZnS/chitosan nano-photocatalysts were extensively characterized and the results demonstrated that chitosan was an effective capping ligand for the direct production of water-soluble ZnS QDs with average nano...

Glasses formed from nano- and microparticles form a fascinating testing ground to explore and understand the origins of vitrification. For atomic and molecular glasses, a wide range of fragilities have been observed; in colloidal systems, these effects can be emulated by adjusting the particle softness. The colloidal glass transition can range from a superexponential, fragile increase in viscos...

Among all of the plasmonic noble metal nanoparticles the gold nanorod (GNR) retains a special place. Its elongated shape gives it unique anisotropic optical and physico-chemical properties. Owing to possibility to control the end-cap geometry, the GNR is the most tunable shape in the terms of localized surface plasmon resonance (LSPR) spectral range. Moreover, the possibility to synthesize GNRs...

Gels of calcium-silicate-hydrates (C-S-H) are the glue that is largely responsible for the mechanical properties of cement. Despite their practical relevance, their nano-scale structure and mechanics are still mainly unexplored, because of the difficulties in characterizing them in a complex material like cement. We propose a colloidal model to investigate the gel mechanics emerging in the crit...

BACKGROUND Viral hepatitis due to hepatitis B virus and hepatitis C virus are major public health problems all over the world. Traditional detection methods including polymerase chain reaction (PCR)-based assays and enzyme-linked immunosorbent assays (ELISA) are expensive and time-consuming. In our assay, a protein chip assay using Nano-gold Immunological Amplification and Silver Staining (NIAS...

Chemical Mechanical Polishing is a unique process enabling technology that allows chip makers to readily drive lithographic patterning steps to smaller dimensions, an ages old, “retro” technology related to glass polishing and metallographic finishing, thus enabling optical lithography to work. It represents a situation that is a true paradigm shift from the typical way in which technological a...

We report a feedback control method to precisely target the number of colloidal particles in quasi-2D ensembles and their subsequent assembly into crystals in a quadrupole electrode. Our approach relies on tracking the number of particles within a quadrupole electrode, which is used in a real-time feedback control algorithm to dynamically actuate competing electrokinetic transport mechanisms. P...