Biomedical subjects

Vilas G Pol

Publications and source records attributed to Vilas G Pol.

6 recordsLinked to original sources

PubMed2005

Controlling the agglomeration of anisotropic Ru nanoparticles by the microwave-polyol process.

A rapid polyol process for the synthesis of ruthenium nanoparticles was developed using microwave irradiation. A colloidal solution of monodispersed anisotropic Ru metal nanoparticles (mean particle size 2-6 nm) with different aspect ratios was obtained first. Particles with different degrees of agglomeration have also been synthesized using monodisperse particles as seeds and PVP (poly-N-vinyl-2-pyrrolidone) as the stabilization reagent. The stabilization mechanisms of different protective reagents were studied by UV-vis spectra. The HRTEM images indicated that dendritic particles formed by controlling agglomeration consisted of single-crystal domains with a random crystalline orientation.

Journal Article↗

PubMed2005

Applied magnetic field rejects the coating of ferromagnetic carbon from the surface of ferromagnetic cobalt: RAPET of CoZr2(acac)2(OiPr)8.

We present the results of the RAPET (reaction under autogenic pressure at elevated temperatures) dissociation of CoZr(2)(acac)(2)(O(i)Pr)(8) at 700 degrees C in a closed Swagelok cell under an applied magnetic field of 10 T. It produces a mixture of carbon-coated and noncoated metastable ZrO(2) nanoparticles, bare metallic Co nanoparticles, and bare carbon. The same reaction in the absence of a magnetic field produces spherical Co and ZrO(2) particles in sizes ranging from 11 to 16 nm and exhibiting, at room temperature, metastable phases: fcc for cobalt and a tetragonal phase for zirconia. The metastable phases of Co and ZrO(2) are manifested because of a carbon shell of approximately 4 nm thickness anchored to their surfaces. The effect of an applied magnetic field to synthesize morphologically different, but structurally the same, products is the key topic of the present paper.

Journal Article↗

PubMed2005

Synthesis of tin nanorods via a sonochemical method combined with a polyol process.

Metallic tin nanorods were synthesized by a sonochemical method employing the polyol process. In the reaction a solution of SnCl2 in ethylene glycol was exposed to high-intense ultrasound irradiation. The phase and elemental compositions, and thermal properties of the as-synthesized samples were characterized by XRD, EDX, SAED, XPS, DSC, TGA, and BET measurements. The morphologies of the products were further characterized with SEM, TEM, and HRTEM. The results show that crystallized metallic tin nanorods in diameters of 50-100 nm and in lengths of up to 3 microm were synthesized. The nanorods are encapsulated in a thin layer containing Ti and carbon compounds. On the basis of the obtained data, a possible mechanism of the formation of tin nanorods was proposed.

Journal Article↗

PubMed2005

Sonochemical deposition of Au nanoparticles on titania and the significant decrease in the melting point of gold.

In this article, sub-micron size particles of titania were coated by a nanosized gold particles with the aid of power ultrasound. We could achieve a uniform coating of gold nanoparticles on a titania surface with a maximum gold loading of 10 wt%. In addition, we report on the experimental evidence for a significant decrease in the melting point of gold nanoparticles (<2 nm) by approximately 850 degrees C from that of the bulk material.

Coated Materials, Biocompatible↗

PubMed2004

Reactions under autogenic pressure at elevated temperature (RAPET) of various alkoxides: formation of metals/metal oxides-carbon core-shell structures.

The RAPET reaction at 700 degrees C, of different alkoxides (Ti, V, and Si) led to three different nanocomposites. Carbon is the element common to all three structures. Carbon was found as the core in the decomposition of TEOS, as the shell in the decomposition of VO(OEt)3 and embedded in, or mixed completely with, TiO2 in the decomposition of Ti(OiPr)4. This novel method using only metallic alkoxide precursor, in the absence of catalyst, leads in a one-step process to core-shell structures.

Carbon↗

PubMed2004

Synthesis of alpha-MoTe2 nanorods via annealing Te-seeded amorphous MoTe2 particles.

Semiconductor alpha-MoTe2 nanorods have been synthesized by annealing Te-seeded particles of an amorphous MoTe2 intermediate. This intermediate is prepared by a solution reaction between Mo(CO)6 and elemental Te in diphenylmethane. The as-synthesized products were characterized by structural, compositional, and morphological techniques of X-ray diffraction, selected area electron diffraction, selected area energy dispersive spectroscopy, energy dispersive X-ray analysis, X-ray photoelectron spectroscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. The results of the annealing process are MoTe2 nanorods with diameters of 50-200 nm and lengths ranging from 0.1 to 3.0 microm. Here, the rodlike structure of MoTe2 is reported for the first time, and added to the list as one kind of new morphology of MoTe2 nanomaterials. A mechanism for the formation of the nanorods is proposed. The sandwich-layered structure of Te-Mo-Te and the similarity in the structure between hexagonal alpha-MoTe2 and hexagonal Te are responsible for the formation of nanorods of MoTe2.

Journal Article↗