Tag: ifsc usp

Featured paper: Nanoclays to overcome toxicity.

Posted on Tuesday 29 de January de 2019

[Paper: Reaching Biocompatibility with Nanoclays: Eliminating the Cytotoxicity of Ir(III) Complexes. Malte C. Grüner, Kassio P. S. Zanoni, Camila F. Borgognoni, Cristiane C. Melo, Valtencir Zucolotto, and Andrea S. S. de Camargo. ACS Applied Materials & Interfaces 2018 10 (32), 26830-26834. DOI: 10.1021/acsami.8b10842.]

Nanoclays to overcome toxicity

Working in laboratories of the São Carlos Institute of Physics (IFSC – USP), a scientific team developed a strategy that eliminates the cytotoxicity (ability to destroy cells) of a group of compounds with very interesting photophysical properties for health applications . The study made viable the use of these substances, once toxic, in the study of living organisms and in the diagnosis and treatment of diseases. In addition to eliminating cytotoxicity, the strategy modifies some properties of compounds by adding new functions that can be harnessed for intracellular oxygen sensing and to improve the efficiency of luminescent devices such as OLEDs.

The work was reported in an article recently published in the journal ACS Applied Materials and Interfaces (impact factor 8,097).

It all started in an informal conversation between three postdoctoral fellows linked to IFSC-USP laboratories: Malte C. Grüner and Kassio P. S. Zanoni, both linked to the Laboratory of Functional Materials Spectroscopy (LEMAF), and Camila F. Borgognoni of the Group of Nanomedicine and Nanotoxicology (Gnano). Zanoni had worked with iridium (III) complexes during his doctorate, and wanted to take advantage of some properties of these compounds to use them as photodynamic therapy agents. Such therapy refers to a set of treatments for diseased tissues, such as those affected by cancer, in which an external radiation source is used for the activation at the appropriate time of a compound inserted into the body, which is responsible to destroy the cells that need to be eliminated.

The post-doc Zanoni’s desire, however, came up against the high cytotoxicity of iridium (III) complexes. The postdoc Grüner then had the innovative idea of trying to use laponites (materials he had studied in his doctorate) to inhibit the cytotoxicity of the compounds. From this idea, Grüner and Zanoni carried out the preparation and characterization of the materials in LEMAF, coordinated by Prof. Andrea S. S. de Camargo. At GNano, coordinated by Prof. Valtencir Zucolotto, the post-doc Borgognoni and the student Cristiane Melo were in charge to investigate the interactions of the nanoparticles with the cells.

The authors of the paper. From the left: Kassio Zanoni, Camila Borgognoni, Malte Grüner, Cristiane Melo, Valtencir Zucolotto, and Andrea de Camargo.
The authors of the paper. From the left: Kassio Zanoni, Camila Borgognoni, Malte Grüner, Cristiane Melo, Valtencir Zucolotto, and Andrea de Camargo.

Strategy and applications

Illustration of the adsorption of Ir (III) complexes (blue spheres) on the surface of laponite nanodisks (yellow disks), in solution.
Illustration of the adsorption of Ir (III) complexes (blue spheres) on the surface of laponite nanodisks (yellow disks), in solution.

One of the main properties of iridium (III) complexes is their intense luminescence (emission of light not resulting from heat) in a wide range of colors. This feature may be useful for illuminating cells within living organisms in bioimaging techniques, used for both research and for diagnosis and treatment of diseases.

In turn, laponites, which are synthetic nanoclays fully compatible with living tissues, have often been proposed in the scientific literature as nanoplataforms for transporting drugs and other compounds within living organisms. The laponites are about 25 nm in length and only 1 nm in height.

In the work of the IFSC-USP team, a new material was developed as a result of the adsorption of iridium (III) complex molecules on the surface of laponite nanodiscs.

The researchers found in the laboratory (in vitro) the ability of the new material to be absorbed by cells, its luminescence within cells and its low citotoxicity. For this, they used liver cells and observed their interaction with the new nanomaterial, comparing it with the interaction with the pure iridium (III) complex. The results were highly favorable to iridium (III) laponite nanodiscs, which proved to be harmless to the cells, besides presenting good penetration and high luminescence – characteristics that make them very suitable for application in bioimaging techniques.

Light emission in various colors of the developed nanomaterials (Ir (III) complexes adsorbed on laponite) distributed in xerogels (upper part) and in liver tissue cells (lower part).
Light emission in various colors of the developed nanomaterials (Ir (III) complexes adsorbed on laponite) distributed in xerogels (upper part) and in liver tissue cells (lower part).

“In this work, it was demonstrated for the first time that the adsorption of iridium (III) complexes (in general, highly toxic) on the surface of laponite nanodisks is capable to completely extinguish the cytotoxicity of these compounds “, summarizes the post-doc Kassio Zanoni , who in 2017 was the winner of B-MRS Young Researcher Award. “This makes it highly feasible to use previously toxic compounds in cell media without impairing the integrity of the medium and therefore has the potential to expand the research of new biocompatible materials for use in cell mapping, theranostics and photodynamic therapy”, he adds.

According to the authors, the new nanomaterial could act as a photodynamic therapy drug, since, when irradiated with certain types of radiation, it produces a molecule (the singlet oxygen) that acts in the destruction of cancer cells. In this way, the nanomaterial also becomes promising in the field of theranostics, which proposes the combination, on the same platform, of the diagnosis of diseases by bioimaging with its cure through photodynamic therapies.

In addition, the nanomaterial can be used as a sensor to accurately determine the amount of oxygen distributed inside a cell. “As demonstrated in our work, the emission intensity of this nanomaterial is a variable as a function of the concentration of oxygen”, justifies Zanoni.

Finally, the nanomaterial, in the form of a thin nanometric film, could also be applied to organic light-emitting diodes (OLEDs) – devices that are already used, for example, in cellular screens. “This is because the iridium (III) complex adsorbed on laponite aggregates photophysical, photochemical and electrochemical properties that are strategic for the development of more efficient devices”, explains Zanoni.

This research was carried out with funding from The São Paulo Research Foundation (FAPESP).

B-MRS members named editors of international scientific journals.

Posted on Tuesday 10 de October de 2017
Prof. Novais de Oliveira Jr (left), associate editor of ACS Appl. Mater. Interfaces with editor-in -chief Prof. Schanze at XVI B-MRS Meeting.
Prof. Novais de Oliveira Jr (left), associate editor of ACS Appl. Mater. Interfaces with editor-in -chief Prof. Schanze at XVI B-MRS Meeting.

B-MRS President Osvaldo Novais de Oliveira Junior is the newest associate editor of ACS Applied Materials and Interfaces, an ACS Publications journal with an impact factor of 7,504. The full professor of IFSC – USP (Institute of Physics of São Carlos of the University of São Paulo) assumed this post in early September. At B-MRS, Oliveira Junior has been administrative director and counselor, and has been chairing the society since early 2016.

The Solar Energy journal (impact factor 4,018) also recently incorporated a member of B-MRS among its editors, Carlos Frederico de Oliveira Graeff, full professor and pro-rector of research at Unesp (Universidade Estadual Paulista Júlio de Mesquita Filho). Graeff was named associate editor in the area of Photovoltaics in this periodical of the publisher Elsevier. A member of B-MRS since its beginning, Graeff was scientific director of the society and served on the scientific committee of the B-MRS Newsletter.

Finally, Carlos José Leopoldo Constantino, also a professor at Unesp and a member of the B-MRS community, took over as Associate Editor in the Nanomaterials area of the Journal of Nanoscience and Nanotechnology (Impact Factor 1,483) from American Scientific Publishers.

Prof. Graeff (left) and Constantino, associate editors of international journals.
Prof. Graeff (left) and Constantino, associate editors of international journals.

Featured paper: Analytical contribution to sustainable energy.

Posted on Friday 29 de January de 2016

[Paper: Influence of charge carriers mobility and lifetime on the performance of bulk heterojunction organic solar cells. D.J. Coutinho, G.C. Faria, D.T. Balogh, R.M. Faria. Solar Energy Materials and Solar Cells, Volume 143, Pages 503-509 (December 2015). DOI:10.1016/j.solmat.2015.07.047]

Analytical contribution to sustainable energy 

A scientific study entirely conducted at the São Carlos Institute of Physics from the University of São Paulo (IFSC-USP) has made significant contribution to the assessment of performance of organic solar cells, devices that are able to produce electricity from sunlight – a renewable, clean, safe and practically inexhaustible source of energy. The results of this piece of research were recently published on the journal Solar Energy Materials & Solar Cells, which has an impact factor of 5.337.

Composition of the bulk-heterojunction organic solar cell used in the experiments reported in the paper. In the active layer, the configuration of the electron acceptor (Blue) and donor (Red) materials.

With a structure comparable to a sandwich, the organic solar cell is comprised of layers of nanometric thickness, made of several materials that execute specific functions in the device.

The so-called “active layer”, the one responsible for the main stages of transforming light (flow of photons) into electric current (flow of electrically charged particles), is made of semiconducting organic materials (whose molecules have carbon atoms).  In the electronic band structure of traditional semiconductors, electrons located in the so-called “valence band” jump from their state when they absorb photons, leaving vacant spaces, or holes, and occupying new places in the so-called “conduction band”. In organic semiconductors, the mechanism that produces the electron-hole pairs is similar, with the difference that, instead of a direct transition from one band to the other, there is a molecular exciton (a system containing one negative charge, and one positive charge), which is easily dissociated, producing free charges (electrons and holes).

For the next stage in the conversion of light into electricity to occur, the active layer of the organic solar cells must have many interface regions between two types of materials: the donor and the acceptor of electrons (usually an electronic polymer and a fullerene derivative, respectively).  If the exciton, in its few picoseconds of existence, manages to reach an interface region, the forces keeping the electron and the hole together are broken, so the donation of the electron from the polymer to the fullerene happens.  At this moment, if no traps are on the way to prevent their movement, electrons and holes flow in opposite directions, attracted and collected by electrode elements, producing an electric current that can be used in an external circuit.

In this succession of stages, efficiency losses in the conversion of solar energy into electrical energy may happen due to several factors. One example is the recombination of electrons and holes after the dissociation of the exciton, which prevents these charge carriers to flow freely. Other examples include defects or impurities in active layer materials, which act as traps for the charge carriers, decreasing their mobility.

The paper published on Solar Energy Materials and Solar Cells reports the results of a series of experiments conducted for the purpose of studying, in detail, the mobility and lifetime of charge carriers (electrons and holes), as a function of temperature, in a bulk-heterojunction organic solar cell produced at IFSC. In this kind of device, the electron donor and acceptor materials coexist in a particular configuration (a nanometric film with a dual-phase structure) that increases the interface area between the two, compared to other possible configurations.

The authors also presented in the paper the results of electric current measurements, based on external applied voltage (J-V) under lighting – one of the most relevant experiments in the characterization of solar cells. In fact, this experiment is necessary for assessing the efficiency of a solar cell.

Organic solar cell during electrical characterization under artificial lighting equivalent to sunlight. In the prototype pictured above, on a 5 x 5 cm plate, five devices are connected in series, producing a total of approximately 2V. The individual efficiency of each device studied is around 4%.

In order to adjust and analyze the experimental results, the authors developed a model, based on a set of equations. This model filled a gap in the scientific literature as, up to its release, these analyses were made from approximations, being inaccurate, or using numerical methods, which require hard time-consuming work.

“To this day, there is no formal description of the J-V curve”, says Roberto Mendonça Faria, full professor at IFSC-USP and corresponding author of the paper. “Our research had the merit of developing a J-V analytical expression, which successfully reproduces the characteristics of an organic solar cell in the event the positive and negative carriers have equal mobility”, he points out. With this expression, he adds, it is possible to carry out a more precise assessment of the cells performance, even for cases in which the electrons and holes do not have the exact same mobility.

Left side: Roberto Mendonça Faria corresponding author of the paper). Right side: Douglas José Coutinho (first author).

The paper also features all the analyses the team managed to do from the experimental results and the model, mainly in regard to some factors leading to efficiency loss in the conversion of light into electricity.

This way, the authors of the paper made a contribution to the challenge of producing sustainable energy. “Energy production is crucial for humanity to keep its economic and social development, but it cannot go on with its terrible side effects, polluting the planet and contributing to global warming”, says Faria.

The results reported in the paper comprise the Master’s and Doctoral studies of Douglas José Coutinho, advised by Professor Faria and financed by Brazilian research funding agencies, FAPESP (São Paulo Research Foundation) and CNPq (National Council for Scientific and Technological Development), including through the CNPq National Institute of Science and Technology for Organic Electronics (INEO).

SBPMat´s community people: interview with Osvaldo Novais de Oliveira Junior.

Posted on Friday 29 de January de 2016

On January 29, 2016, in the city of Campinas (São Paulo State, Brazil), Osvaldo Novais de Oliveira Junior took office in the new executive board of the Brazilian Materials Research Society (SBPMat), acting as president. Novais is a professor of the São Carlos Institute of Physics (IFSC) at the University of São Paulo (USP). He has been a researcher in the field of Materials for 35 years, during which time he has published over 460 articles in indexed journals, 7 patents and 16 book chapters, among other publications. In total, the scientific production of professor Osvaldo has received, so far, over 8,500 citations according to Web of Science (index h=46) and 12,100 (h = 53) according to Google Scholar.

Osvaldo Novais de Oliveira Jr. was born on August 13, 1960 in Barretos, a city of the northern part of the State of São Paulo that, at that time, had approximately 60,000 inhabitants. When he was a teenager, he received the nickname of Chu, which accompanies him to this day, being also part of his professional electronic address.

He began his university studies in the Educational Foundation of Barretos. In 1980, while he was attending courses to obtain a teaching degree in Physics, he transferred to IFSC/USP to pursue a Bachelor degree in Physics, and started to work in research projects in the Electrets Group, nowadays referred to as Polymers Group “Bernhard Gross”. Within such group he began his master’s degree in 1983, supervised by professor Guilherme Fontes Leal Ferreira, obtaining in 1984 the title of Master in Applied Physics. In the following year he began to teach courses in the Bachelor Degree in Physics at USP São Carlos and continued developing research activities in the Polymers Group.

In 1986, he moved from São Carlos to the Welsh city of Bangor, United Kingdom, for doctoral degree studies in the University of Wales – nowadays Bangor University. In 1990, he obtained the title of Doctor in Electronic Engineering by defending his doctoral dissertation concerning electrical properties of Langmuir films, supervised by professor David Martin Taylor.

Back to Brazil in 1991, he added to his teaching activities at USP São Carlos, some classes in the graduation courses in Applied Physics. In 1993, he was named associate professor in that university.

In the same year, he conducted his first academic research works in natural language processing, an area that basically deals with problems related to automatic generation and understanding of texts by means of computers. Professor Osvaldo Novais was part of the team that founded the Interinstitutional Center for Computational Linguistics (NILC) and participated in the development of the first software for grammar revision of Brazilian Portuguese, which was named “ReGra”. The grammar checker was part of several versions of Microsoft Word processor as from 1999. From the work in NILC and scientific writing courses, he produced a book, together with more 7 authors, on scientific writing in English (“Writing Scientific Papers in English Successfully: Your Complete Roadmap”).

Osvaldo Novais was a visiting researcher in the University of Massachusetts Lowell (UMass Lowell), in the United States, between 2000 and 2001, and a visiting professor of University of Aveiro (Portugal) in 2006. Also in such year, he received Scopus Award, granted by Elsevier do Brasil and Capes (the Brazilian agency in charge of post-graduate programs), as one of the 16 Brazilian researchers with greatest scientific production, based on the number of publications, citations and supervisions (nowadays, there are 40 completed master theses and doctoral dissertations).

In 2008, he became a full professor of USP.

Nowadays, in addition to his activities as professor and researcher in IFSC-USP, Prof. Osvaldo Novais is a member of the coordination in Physics at FAPESP (the São Paulo research foundation), regional editor for South America of “Display and Imaging” scientific journal and associate editor of “Journal of Nanoscience and Nanotechnology”.

Here you find an interview with the researcher.

SBPMat Newsletter: – Tell us what made you become a researcher and work in the field of Materials.

Osvaldo Novais: – My professional choices almost always occurred without planning or specific motivation. I began the course for obtaining a teaching degree in Sciences in the Educational Foundation of Barretos, since I did not pass the entrance examination for being admitted in the Electronic Engineering graduation course, which I thought was the career I would like to have. After having decided to change area at the end of the first year and to do the entrance examinations for Philosophy and Psychology courses, for financial and personal reasons, I ended up continuing in the Sciences course and chose a teaching degree in Physics in the third year. There was a major transformation when I transferred to the Bachelor degree in Physics in USP São Carlos, and started participating in research projects. There I decided to become a teacher and researcher. My choice for the area of polymers was the result of a suggestion from a friend, who had great admiration for the faculty members of the Electrets Group at that time. Thus, I began doing research activities in such group, nowadays called Polymers Group “Bernhard Gross”, where I have been for 35 years.

Although I have not chosen a career or a research area due to a vocation or conviction, I was very fortunate because I consider the study of materials both fascinating and essential for society. Researchers in materials may amuse themselves with challenges and contribute to make this world a better place. Research training also allowed me to act in different areas, which is an important factor for those passionate for knowledge, as it is my case.

SBPMat Newsletter: – What are, in your own assessment, your main contributions to the field of Materials?

Osvaldo Novais: – I believe my greatest contribution was to have participated in the construction of a network of research in materials, mainly in nanostructured organic films. Such network nowadays comprehends researchers in many regions of Brazil,  and also includes international connections. Concerning specific scientific contributions, I could possibly point out the study of electrical properties of Langmuir films, as well as the use of such films as cell membrane models. It could also be worth to point out sensors (such as electronic languages) and biosensors produced with nanostructured films, noting that the main actors of such contributions have been students and doctoral candidates of my research group.

SBPMat Newsletter: – In parallel to your performance in Materials research, you develop studies concerning natural language processing within NILC, center of which you are founding member. Tell us a little bit about this activity.

Osvaldo Novais: – Out of need, I ended up becoming interested in scientific writing in English, in a work that was, at first, informal and that resulted in projects of software tools for writing aid. Being invited to participate in the team that developed the first grammar checker for Portuguese in the 1990s, NILC was created, which to this date is a reference worldwide for Portuguese language automatic processing. I say that without any embarrassment whatsoever, since all merits for this achievement go to a team of computer scientists and linguists, of several universities of Brazil, who have been conducting research and development of the highest level for years. My participation was merely important in the beginning.

For two decades, my research in natural language processing with NILC was fully disconnected from Physics, but in the last years we have used statistical physics methodologies for text treatment. With the new research paradigm based on intensive use of data (called “Big Data”), now there is the possibility of combining nanotechnology – an area that is predominantly of materials – with natural language processing and artificial intelligence, for example, in the diagnosis systems supported by computer. This is a fascinating topic that allows exercising technological convergence, which will boost research and development in the 21st century.

SBPMat Newsletter: – Briefly tell us what are your plans for SBPMat while president of the society within 2016-2018.

Osvaldo Novais: – I believe that the most relevant plan is to continue the excellent work that the previous executive boards have carried out, which made SBPMat be one of the most powerful scientific societies in Brazil. That includes keeping the excellent level of our annual meetings and strengthening the international insertion that it has achieved. Other goals of the new executive board are: to increase the interaction of materials researchers with the industries installed in Brazil, to encourage the participation of young researchers in the society and to promote scientific and technological popularization programs, emphasizing the key role of research in materials for technological and social development.

SBPMat Newsletter: – We always invite the interviewees of this newsletter section to leave a message for the readers who are beginning their scientific careers. Would you like to say something in particular for the future/ junior scientists?

Osvaldo Novais: – My message is: apply yourself and strive towards obtaining strong scientific training, focusing on languages of knowledge, whatever the natural languages (in our case, Portuguese and English) and languages of mathematical formalisms. Such strong training will allow you to continuously learn, which is essential in an ever-changing society. May you follow your dreams by solving scientific and technological problems, which is one of the most amusing and refreshing activities.

Featured paper: Revealing secrets of the luminescence of a lanthanide ion.

Posted on Thursday 7 de May de 2015

Paper: Mechanisms of optical losses inthe 5D4 and 5D3 levels in Tb3+ doped low silica calcium aluminosilicate glasses. J. F. M. dos Santos, I. A. A. Terra, N. G. C. Astrath, F. B. Guimarães, M. L. Baesso, L. A. O. Nunes and T. Catunda. J. Appl. Phys. 117, 053102 (2015). DOI: 10.1063/1.4906781.

A team of scientists from Brazilian institutions has expanded the comprehension of the mechanisms that restrict the light emission efficiency in materials doped with trivalent terbium ion (Tb³+). This ion, found in the rare earth group, subgroup of lanthanides, displays luminescent emissions from ultraviolet to infrared. Its intense green emission, with approximately 545 nm of wave length, is particularly interesting for technological purposes.

Some years ago, for instance, Japanese researchers produced laser emissions with Tb3+ doped optical fibers. However, their device displayed low efficiency, due to the saturation of its optical gain, even at low excitation levels.

Luminescence process of a Tb³ doped LSCAS sample, excited by a blue laser, emitting green light. The pictures portray the sample in a state of (a) non-excitation and (b) excitation.

Taking up this technological issue, the team of Brazilian scientists has conducted a thorough study on the processes that cause the saturation of the green emission. For that, they used Tb3+ to dope a material which, thanks to its properties, ensures high efficiency to the emission, mainly in infrared: the low silica calcium aluminosilicate glass, also known as LSCAS.

The study involved two research groups that have been collaborating for approximately two decades, the group of spectroscopy of solids from the São Carlos Institute of Physics at the São Paulo University (USP), and the photothermics group from State University of Maringá (UEM). The results were reported in a paper that appeared recently on the Journal of Applied Physics.

Firstly, glass samples with different dopant concentrations were prepared by the UEM group.

Picture of the LSCAS samples. The base sample has a Tb3+ concentration of 0.05%.

At IFSC-USP, the samples were excited using a laser at two different wavelengths, 488 nm (visible) and 325 nm (ultraviolet), and their absorption, emission and excitation spectra were obtained. Analyzing them, the scientists from the group of spectroscopy of solids observed certain particularities in the behavior of some luminescent emissions, such as a strong saturation in a green emission, similar to the one found in the laser presented by the Japanese scientists. In other wavelengths, they noted, for example, a decrease in luminescence occurring at lower excitation levels than expected. Thus, the researchers managed to conclude that the mechanism associated in the literature to the emissions from Tb3+ doped materials, also known as cross relaxation, was not enough to completely explain the behavior of the emissions or even the saturation of the green emissions, and proposed the additional action of other processes.

“Additional loss mechanisms, such as emissions by defects in the matrix, energy upconversion processes, to name a few, have a significant influence in the system we have studied”, explains Tomaz Catunda, professor at USP and corresponding author of the article. “These decay paths, previously ignored by the literature, are very important in the manufacturing of optical devices with Tb3+ doped materials”, he adds.

The study of Tb³+ doped glasses by the Brazilian team started during the Doctoral dissertation of Idelma Terra, defended in 2013 at USP, which aimed to develop materials in order to increase the efficiency of solar cells. Her work was granted the 2014 “Vale-Capes Science and Sustainability Award”. The study of these materials continued in Giselly Bianchi’s Doctoral dissertation, performed at UEM, and in the Master’s thesis of Jéssica Fabiana Mariano dos Santos, defended in 2014 at EESC-USP.

The article published on the Journal of Applied Physics has joined dozens of papers born from the collaboration between the groups of spectroscopy of solids and photothermics, in some cases also involving other scientists from Brazil and abroad, focused on the optical spectroscopy of calcium aluminate glasses doped with rare earth ions and their applications in light-emitting devices.

CAPES award for the best doctoral thesis in Materials: fast synthesis of strontium titanate compounds for gas sensors.

Posted on Thursday 23 de October de 2014

Postdoctoral student at the Institute of Chemistry at the São Paulo State University (UNESP), Luís Fernando da Silva received an award for the best doctoral thesis in the field of materials in 2014 by the Brazilian agency for the support and evaluation of graduate education (CAPES). The research, conducted during his doctoral studies at the University of São Paulo (USP), used a new method to synthesize chemical compounds displaying effective properties as gas sensors.

The thesis is titled Synthesis and characterization of SrTiO3 and SrTi1-xFexO3 compounds by microwave-assisted hydrothermal method, and the work was advised by Professor Valmor Mastelaro (from the São Carlos Institute of Physics – USP). Silva also used infrastructure of the laboratories of the Center for the Development of Functional Materials (CDMF) to perform his study. 

The researcher worked with strontium titanate compounds, both in its pure form or added with iron (SrTiO3 and SrTi1-xFexO3). Silva says that to produce such materials in the laboratory used to require an extensive amount of time, which would delay and complicate the synthesis process of the compound. “In my paper, I proposed the use of the microwave-assisted hydrothermal treatment to obtain this compound. The advantage of this method is the low temperature and the short amount of time.”

In general, the titanate synthesis takes 12 hours, at a temperature of 1200 °C. With the new method proposed by Silva in his doctoral thesis, the whole process takes 10 minutes at a temperature of 140 °C. The researcher explains that, in addition to making the compound synthesis faster, the microwave-assisted hydrothermal method also enables a better control over the titanate properties. “This compound managed to display interesting properties as a sensor for ozone gas and nitrogen dioxide, as well as photoluminescence and photocatalysis”.

Gas sensors are usually used by the industry as a key element for safety in production lines. The device helps to detect gases which are odorless and hazardous to human beings. Thus, the detectors play a major role ensuring safety in installations and preventing accidents.

To read the original thesis by Luis Fernando da Silva, click here.

About the CDMF

CDMF is one of the several Research, Innovation and Dissemination Centers (CEPID) supported by FAPESP. The center also receives funds from CNPq, through the National Institute of Science and Technology for Nanotechnology Materials (INCTMN), integrating a research network between UNESP, the Federal University of São Carlos (UFSCar), USP and the – Nuclear and Energy Research Institute (IPEN).

CAPES Award for Thesis

The CAPES award was created in the year of 2005, with the purpose of granting a distinction to the best doctoral thesis defended and approved in Brazilian courses. Its selection takes into account criteria of originality, innovation and quality, considering that the pre-selection is made by the graduate programs.

The award ceremony will be held in the CAPES office, in Brasília, on December 10th.

[Press release from the CDMF]

Concurso para professor no IFSC-USP na área de Materiais.

Posted on Monday 18 de November de 2013

Encontra-se aberta uma (01) vaga para Professor Doutor no Instituto de Física de São Carlos – USP, para atuar junto ao Grupo Crescimento de Cristais e Materiais Cerâmicos nas seguintes áreas de pesquisa:

a) Materiais Hídridos Inorgânicos Multifuncionais,
b) Crescimento de Cristais por Fusão,
c) Espectroscopia de Raios-X (XAS, XPS) Aplicadas ao Estudo de Materiais Inorgânicos.

Mais informações sobre o concurso bem como o acesso ao edital completo podem ser obtidas no endereço: http://www.ifsc.usp.br/images/stories/concursos/atac-ifsc-40-2013/Edital_40_Abertura_conc_Prof.Dr._FCM.pdf