Electrostatically assisted fabrication of silver-dielectric core/shell nanoparticles thin film capacitor with uniform metal nanoparticle distribution and controlled spacing.

An electrostatically-assisted strategy for fabrication of thin film composite capacitors with controllable dielectric constant (k) has been developed. The capacitor is composed of metal-dielectric core/shell nanoparticle (silver/silica, Ag@SiO2) multilayer films, and a backfilling polymer. Compared with the simple metal particle-polymer mixtures where the metal nanoparticles (NP) are randomly dispersed in the polymer matrix, the metal volume fraction in our capacitor was significantly increased, owing to the densely packed NP multilayers formed by the electrostatically assisted assembly process.

Influence of particle/solid surface zeta potential on particle adsorption kinetics.

In this paper we attempt to understand monolayer formation of spherical particles on a solid surface immersed in a suspension and driven by electrostatic interaction force. The study focuses on the theoretical aspects of the particle adsorption and modeling work based on the random sequential adsorption (RSA) approach is done in order to describe the particle adsorption kinetics and the saturation coverage. The theoretical model is then compared with experimental data obtained under conditions similar to those of the modeling work.

Experimental studies on irreversibility of electrostatic adsorption of silica nanoparticles at solid-liquid interface.

Adsorption of colloidal nanoparticles (NPs) at solid-liquid interface is a scientifically interesting and technologically important phenomenon due to its fundamental importance in many industrial, environmental, and biological processes, such as wastewater treatment, printing, coating of surfaces, chromatography, papermaking, or biocompatibility. The process is well understood theoretically by the random sequential adsorption (RSA) model, based on the assumption of irreversible adsorption. Irreversible adsorption is defined as a process in which, once adsorbed, a particle can neither desorb, nor to move laterally on the surface.

Electrostatically driven adsorption of silica nanoparticles on functionalized surfaces.

Adsorption of nanoparticles on solid supports is a scientifically interesting and technologically important phenomenon that has been attracting ever-increasing attention. Formation of particle-based films onto surfaces from stable suspensions is at the center of the development of new devices that utilize the plethora of newly synthesized nanoparticles with exciting properties. In this study we exploit the attractive electrostatic interactions between silica (SiO(2)) nanoparticles and functionalized substrates that display an amine termination in order to devise a simple method for the fabrication of SiO(2) nanoparticle films.

Isolation and biophysical study of fruit cuticles.

The cuticle, a hydrophobic protective layer on the aerial parts of terrestrial plants, functions as a versatile defensive barrier to various biotic and abiotic stresses and also regulates water flow from the external environment. A biopolyester (cutin) and long-chain fatty acids (waxes) form the principal structural framework of the cuticle; the functional integrity of the cuticular layer depends on the outer 'epicuticular' layer as well as the blend consisting of the cutin biopolymer and 'intracuticular' waxes. Herein, we describe a comprehensive protocol to extract waxes exhaustively from commercial tomato (Solanum lycopersicum) fruit cuticles or to remove epicuticular and intracuticular waxes sequentially and selectively from the cuticle composite.

Facile synthesis of silver core - silica shell composite nanoparticles.

Combining metal nanoparticles and dielectrics (e.g. silica) to produce composite materials with high dielectric constant is motivated by application in energy storage.

Effect of molecular binding to a semiconductor on metal/molecule/semiconductor junction behavior.

Diodes made by (indirectly) evaporating Au on a monolayer of molecules that are adsorbed chemically onto GaAs, via either disulfide or dicarboxylate groups, show roughly linear but opposite dependence of their effective barrier height on the dipole moment of the molecules. We explain this by Au-molecule (electrical) interactions not only with the exposed end groups of the molecule but also with its binding groups. We arrive at this conclusion by characterizing the interface by in situ UPS-XPS, ex situ XPS, TOF-SIMS, and Kelvin probe measurements, by scanning microscopy of the surfaces, and by current-voltage measurements of the devices.