PR – Page 2 – TechConnect Briefs

Thermal Analysis of Polyimide-Cobalt Ferrite Nanocomposites

Mazuera D., Perales-Perez O., Singh S.P., Suarez O.M., University of Puerto Rico-Mayagüez, PR

Thermal stability and thermomechanical behavior of new polymer-based nanocomposite was investigated to assess the viability of the fabrication process. The nanocomposite film consisted of a polyimide (PI) matrix and nanodispersoids of a recently developed high-coercivity [...]

Removal of Heavy Metals From Aqueous Solutions with Calcium Alginate Beads

Luna-Pineda T., Román-Velázquez F., University Of Puerto Rico at Mayaguez, PR

The present research is focused on the development of a bio-sorbent based on alginate beads. The alginate is a natural polymer extracted from brown seaweed with capability of hosting divalent cations in gel state, which [...]

Studies of Ferrite Based Magnetic Nanoparticle Uptake and Magnetocytolysis Effects on Model Cell Cultures

Rodríguez H.L., Barrera C., Herrera A., Ayala V., Latorre M., Rinaldi C., Torres-Lugo M., University of Puerto Rico, PR

To date, two main avenues by which nanoparticles appear to induce cell death have been proposed, magnetocytolysis and magnetic fluid hyperthermia (MFH). Little is known regarding the mechanisms of cell death and the main factors [...]

Effect of Silica Nanoparticles on Rheological Properties and Gelation Temperature of Biodegradable Polymer Gels

Florián-Algarín V., Acevedo A., University of Puerto Rico-Mayagüez, PR

The discovery of new potent and insoluble drugs has emphasized the need for personalized dosages and novel drug-delivery systems. The use of biodegradable polymers is a good alternative to form films in which a solid [...]

Preparation and Characterization of Polyimide-Cobalt Ferrite Nanocomposite

Mazuera D., Cedeño Y., Perales-Perez O., Singh S.P., University of Puerto Rico-Mayagüez, PR

Synthesized 20 nm cobalt ferrite single crystals, which exhibited a coercivity of 2.9kOe at room-temperature, were dispersed in precursor polyamic acid at different volume fractions and cured at 300oC to develop the polyimide matrix. Polyamic [...]

Composition- and Size-Controlled Synthesis of Mn-Zn Ferrite Nanocrystals for Potential Magnetocaloric Applications

Calderón-Ortiz E., Perales-Perez O., Urcio S., University of Puerto Rico-Mayagüez, PR

The use of ferromagnetic fluid for cooling applications where the fluid can be pumped with no moving mechanical parts, using the magnetocaloric effect, can be a great advantage for many applications where maintenance or power [...]

Synthesis and Characterization of Co-Zn Ferrite Nanocrystals for Magnetocaloric Applications

Urcia-Romero S., Renteria B., Gutiérrez G., University of Puerto Rico, PR

Cobalt ferrite (CoFe2O4) is known for its high coercivity, chemical stability and high sensitivity of its Curie temperature (TC) with Zn-doping. A ferrofluid bearing this type of ferrite nanocrystals could be then considered good candidate [...]

Effect of Rare Earth Doping on Magnetic Properties of Cobalt Ferrite Nanocrystals

Cedeño-Mattei Y., Uwakweh O.N.C., Osorio-Cantillo C., University of Puerto Rico-Mayagüez, PR

Cobalt ferrite (CoFe2O4) is a highly anisotropic magnetic material due to the magnetocrystalline anisotropy contribution from Co2+. The addition of foreign cations of different oxidation states, substituting Co2+ or Fe3+, can lead to an atomic [...]

Synthesis and Characterization of Nanocrystalline Eu3+-doped Gd2O3

Jáuregui-Rosas S., Tomar M., Jia W., Vásquez O., Fachini E., University of Puerto Rico, Mayaguez Campus, PR

Nanocrystalline Gd2-xEuxO3 phosphors by a simple sol-gel method have been synthesized. The effects of the annealing temperature and atomic fraction of Eu3+ ions (x) on the structural and luminescence properties of the mixed oxides have [...]

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 [...]