In this work, we demonstrate the controlled synthesis of silica nanoparticles as small as 30 nm (±5 nm) and as large as 250 nm (±30 nm) in minutes using surfactant free, microwave-assisted synthetic techniques. Proper choice of solvent, silicic acid precursor, catalyst, and microwave irradiation time were the variables used to control nanoparticle size and, ultimately, overcome the previously r...

  Introduction: In the present study, we investigated the role of gold-silica shell-core nanoparticle in megavoltage irradiation of MCF7 breast cancer cells.   Materials and Methods: gold-silicon oxide shell-core nanoparticles (NPs) were obtained by conjugation of gold nanoparticle with amine or thiol functionalized silica nanoparticles (AuN@SiO2 and AuS@SiO...

In this study, we report for the first time the use of silica-coated superparamagnetic iron oxide nanoparticles (SPION) as contrast agents in biomedical photoacoustic imaging. Using frequency-domain photoacoustic correlation (the photoacoustic radar), we investigated the effects of nanoparticle size, concentration and biological media (e.g. serum, sheep blood) on the photoacoustic response in t...

A new route was recently proposed to modify some spectroscopic properties of rare-earth ions in silica-based fibers. We had shown the incorporation of erbium ions in amorphous dielectric nanoparticles, grown in fiber preforms. Here we present the achieved stabilization of nanometric erbium-doped dielectric nanoparticles within the core of silica fibers. We present the nanoparticle dimensional c...

Introduction Titania (TiO2) is an outstanding materials because of its superior physical properties but nanostructured titania films synthesized by an evaporationcondensation aerosol process can be used only for limited applications because of their low mechanical strength. In this study, the surface of titania nanoparticles (TiO2) is modified by a heterogeneous capillary condensation process t...

Herein, we describe a strategy for converting catalytically inactive, highly crystalline nanoparticle superlattices embedded in silica into catalytically active, porous structures through superlattice assembly and calcination. First, a body-centered cubic (bcc) superlattice is synthesized through the assembly of two sets of 5 nm gold nanoparticles chemically modified with DNA bearing complement...

BACKGROUND The purpose of this study was to investigate the mechanism of noxious effects of amorphous silica nanoparticles on human endothelial cells. METHODS Nanoparticle uptake was examined by transmission electron microscopy. Electrochemical nanosensors were used to measure the nitric oxide (NO) and peroxynitrite (ONOO(-)) released by a single cell upon nanoparticle stimulation. The downst...

Further understanding of the chemisorption properties towards CO and H2 on silica-supported Ru nanoparticles is crucial in order to rationalize their high activity towards methanation, Fischer Tropsch and Water Gas Shift reactions. Ru nanoparticles having the same chemisorption properties towards CO and H2 were synthesized on different silica-based supports in order to combine various analytica...

The colloidal stability, phase behavior, and solubility of silica nanoparticles (3-10 nm) that are formed in basic solutions of monovalent cations (primarily tetrapropylammonium) are investigated using a combination of chemical equilibria and electrostatic models. The free-energy gain associated with the formation of an electric double layer surrounding the nanoparticle was obtained by solving ...

Zeolites are nanoporous alumino-silicates used in industrial applications such as catalysis and separations. Understanding how zeolites nucleate and grow is of fundamental scientific and technological importance. In the past decade, silica nanoparticles have been found to play an important role in zeolite formation from clear solutions. To explore the properties of such nanoparticles, we have d...