University of Puerto Rico – Page 2

Preparation of Copper-Bearing Nanofluids for Thermal Applications

Velasco A.F., Perales-Perez O.J., Gutiérrez G., University of Puerto Rico, PR

Stable suspension of nanometer solid particles in suitable solvents, so-called nanofluids, has shown enhanced thermal conductivity when compared with the fluid base. This feature enables these suspensions to be considered a promising material for efficient [...]

Low-Temperature Polyol Synthesis of Nanocrystalline Co and CoPt Alloys

Chávarri-Pajares E., Pérez J., Perales-Perez O., Singhal R., Tomar M.S., University of Puerto Rico, PR

The strong size-dependent magnetic properties of transition metal nanocrystals can be used to estimate the scaling limits of magnetic storage, a key component of information technology. High Ku (magnetocrystalline anisotropy constant) materials become then very [...]

The use of Molecular Precursors for the Preparation of Pd/Co-Alloy Nanoparticles

Montano-Serrano R., Moiras C., Raptis R.G., University of Puerto Rico, PR

The preparation of catalysts from molecular precursors is the main objective of our research. The predetermination of metal composition in molecular precursors is an advantage of this method over others (e.g. co-precipitation). The main objective [...]

Zinc Sulfide and Cadmium Sulfide based Nanocrystals and Shells

Balaguera M., Perales-Perez O., Rivera-Montalvo L., Singhal R., Tomar M.S., University of Puerto Rico, PR

The objective of the current research is to synthesize CdS, ZnS nanocrystals through a two phases-method were quantum dots moved from the aqueous phase to the organic one after proper coating of the particles by [...]

Effect of Reaction Temperature on the Structural and Optical Properties of Zno Nanocrystals

Parra-Palomino A., Sotomayor C., Perales-Perez O., Singhal R., Voyles P., Tomar M.S., University of Puerto Rico, PR

The present research addressed the size-controlled synthesis of ZnO nanocrystals at different temperatures. In order to study systematically the dependence of crystal size with synthesis conditions in ethanol, stable suspensions of these nanocrystals were produced [...]

Low-Temperature Synthesis and Characterization of Fe-Doped ZnO Nanocrystals

Parra-Palomino A., Singhal R., Perales-Perez O., Tomar M.S., University of Puerto Rico, PR

We present here our results on synthesis and characterization of bare and Fe-doped ZnO nanocrystals by a modified sol-gel method, which does not require annealing of the samples. Metal acetate solutions in 2-ethylhexanoic acid were [...]

Synthesis and Magnetic Properties of Polyaniline-Based Magnetic Nanocomposites for EMI Applications

Renteria B., Singhal R., Calderon E., Tomar M.S., Banerjee J., University of Puerto Rico, PR

we have synthesized composite of polyaniline (PANI) with manganese-zinc-ferrite (MnXZn1-XFe2O4) nanoparticles. PANI was synthesized by polymerization of aniline in the presence of ammonium peroxydisulfate and HCl. Electrical conductivity of bare PANI pellets averaged 0.8044 (Ω·m)-1. [...]

Affiliations: University of Puerto Rico