INTECINCONICETUBAFacultad de Ingenieria

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Materials Engineering | Electronic Ceramic Materials Physiochemical

Chemical Synthesis of Magnetic Materials

Faculty of Engineering. Department of Chemistry. UBA
Paseo Colón 850. (C1063ACV ) Ciudad Autónoma de Buenos Aires.
Phone: + 54 11 4343 0891 internal: 116

Research Field

Magnetic Materials and Nanotechnology.

RESEARCH:
Mixed oxide nanoparticles based on iron. Soft magnetic materials (ferrite spinels) and hard (hex). Composite materials: ferrites and polymers. Remediation of effluents (oil) by advanced oxidation methods.
Selection of new methods of preparation, characterization, structure, transport properties, magnetic properties, dielectric behavior of the material in the microwave region. Application to devices: resonators, absorbers, movies.
Ferrofluid, applications in biomedicine.

Members

Direction:

Jacobo, Silvia. PhD. Profesora Titular.

sjacobo@fi.uba.ar

__

Aphesteguy, Juan C. Engineer. Jefe de Trabajos Prácticos.

caphestegu@fi.uba.ar

De La Horra, Enrique. Engineer. Jefe de Trabajos Prácticos.

edelahorra99@hotmail.com

Ruiz, María Sol. Engineer. Ayudante Primera.

mruiz@fi.uba.ar

Russo, Analía. Engineer. Ayudante Primera.

analia_russo@yahoo.com.ar

Herme, Carlos. M.S. FIUBA.

lobocorregidor@yahoo.com.ar

Bessone, Matías. Tesista de grado.

Fossati, Ana. Tesista de grado.

Toriggia, Leonardo. Tesista de grado.

Work Description

This group is dedicated to the study and preparation of magnetic nanoparticles for various applications. Includes ceramic spinel structure, hexagonal ferrites and perovskites.

We can divide the topics to be addressed in four general areas:
a) spinels and hexagonal ferrites for electronic application
b) magnetic nanoparticles in conducting polymer matrices
c) aqueous and organic Ferrofluids biomedical and technological applications
d) magnetic nanoparticles for environmental bioremediation

a) spinels and hexagonal ferrites for electronic application

Ceramic materials, including ferrites, have various applications in the electronics industry. Are widely used as memory devices, magnetic particle recording tape and transformer cores due to the combination of low magnetization and high electrical conductivity, which reduces energy losses by eddy currents.
We are currently working on the preparation and study of new ferrite-ferroelectric materials either in bulk and in thick films. This research will be developed in the framework of the PhD in engineering from Mr. Maria Sol Ruiz (not yet submitted).

The properties of these materials under the plan modelizaránen Master Thesis (for Lic.Silvina Boggi) under the direction of Fano and Dr.Adrián Dr.Gustavo Razzitte

ii) The hexagonal ferrites have multiple commercial applications: magnetic recording, permanent magnets, microwave devices, applications, ferrofluids, and more. Hard magnetic materials are of general formula xSrO • yFe2O3 • zMeO, where Me is a divalent metal, which is structurally related to the magnetoplumbita. Are also characterized by its large magnetocrystalline anisotropy. This property gives rise to an easy magnetization direction (the c axis of the prism), which makes ferrites suitable for a large number of technological applications. In previous work we reported results obtained from the preparation of strontium ferrite partially substituted with Nd (III) and Co (II). We obtained improvements in the magnetic properties [27] (James et al., 2010) and measured the highest coercive field value for the composition sr0, 70Nd0, 30Fe11, 70Co0, 30O19, which turned out to be 4615 Oe (58.00 A / m). The value of Hc is 47% higher than that measured in the unsubstituted material, SrFe12O19. These works are the subject of the doctoral thesis of Mr. Carlos Herme.

b) magnetic nanoparticles in conducting polymer matrices

Today there are more than one hundred polymers capable of conducting electrical current, among the most studied are the polyaniline (PANI) and polypyrrole (PPy), polyurethane (PU), polyacetylene.
Some years ago, we began to assess the properties of composite materials. A composite material "electric-magnetic" original requires high electrical conductivity, high coercive force, good properties of absorption and reflection in a wide frequency range in which it may employ and good processability. Therefore most useful for potential applications in electrochemical devices such as sensors, microwave absorbers, etc..
This is the subject of PhD thesis of Mr. Juan Aphesteguy. Will explore the properties of a new polymer based on 3-amino-1 ,2,4-triazole (ATA) in the context of the development of the doctoral thesis of Mr. Enrique De la Horrocks.

c) aqueous and organic Ferrofluids biomedical and technological applications

The application of magnetic materials in biotechnology has been nearly four decades of study especially on issues related to hyperthermia and biological tissues. However, still not fully delineated application routines. Magnetic media have been used by ceramic microcapsules or suspensions of nanoparticles.Magnetic nanoparticles play in these cases as support for selective chemical reactivity of materials that form a stable coating on its surface. This produces a highly reactive material of relatively low volume and large surface reaction. On the other hand, the use of magnetic nanoparticles is crucial, since having large magnetic moments can be carried and driven by external magnetic fields.Specifically in the field of medicine has started a research in the treatment of tumor diseases by methods based on coated particles. The principle of this technique is to drive the medications that you are coating the magnetic particles so that only move in the area affected by the tumor. This is achieved by locating a magnetic field onto the tumor at the time of the application of the medication, keeping in the affected area until it has completed its healing.Among the magnetic oxides there is strong preference for the magnetite (Fe3O4) and maghemite (γ-Fe2O3), easy to synthesize and proven biocompatibility. However, it is little explored the issue of replacing the biocompatible magnetite with other ions in order to modify its properties. Currently preparing various biocompatible ferrofluids. Preliminary studies gave rise to several publications in our group.

d) magnetic nanoparticles for environmental bioremediation

The decontamination of soil and groundwater requires, with current technology, and in that sense, are being developed techniques oxidation "in situ" using different oxidizing agents. Of all the substances used in the practical application of this technology, the most promising is hydrogen peroxide, along with an iron catalyst, make the Fenton reagent. The basis of this methodology is the formation, in acid, hydroxyl radicals react with a variety of compounds,
including organic pollutants which degrade obtained as final products of oxidation mainly CO2 and H2O2. Decontamination by Fenton reagent sewage or industrial effluents is well developed and commonly used. It is important to note that the temperature does not exceed 50 º C and that decomposes hydrogen peroxide.The study of this advanced oxidation process is adaptable to the composition of each batch of waste to degrade, at present are making efforts to find a design that meets the needs of different effluents (intensification).
In order to expand the scope related to this methodology began using solid-phase catalysts particularly metallic Fe nanoparticles.However, to our knowledge no results have been reported with other solids. For this reason, we propose the inclusion of magnetite as a possible catalyst. These nanoparticles are prepared in our laboratory. The tests are carried out by Ing Analía Russo.