Category: News

Interview with Professor Jose Arana Varela, honored with the Bridge Building Award from American Ceramic Society.

Posted on Thursday 27 de February de 2014
Professor Arana Varela (to the left) receiving the award. Photo by American Ceramic Society.

On the last January 27th, in Daytona Beach (Florida, United States), during the 38th edition of International Conference and Exposition on Advanced Ceramics and Composites, the Bridge Building Award of the American Ceramic Society was given to a Brazilian for the first time, Professor José AranaVarela, president of our SBPMat from 2010 to 2011. The honor annually distinguishes people from outside the United States who have notably contributed to the field of engineering ceramics.

Graduated in Physics from University of São Paulo in 1968, Arana Varela also has a Master’s Degree in Physics for the Instituto Tecnológico de Aeronáutica (ITA), becoming a Master in 1975. He took his PhD from 1977 to 1981 at University of Washington (United States), conducting research in the field of ceramic materials.

Currently, Arana Varela is Full Professor at Universidade Estadual Paulista Julio de Mesquita Filho (UNESP) and president-director of the executive board of São Paulo Research Foundation (Fapesp), as well as member of the council for competitivity and innovation at São Paulo Federation of Industries (FIESP). Professor Arana Varela is also full member of the Brazilian Academy of Sciences (ABC), among other associations, and member of the editorial body for the journals Ceramics International, Science of Sintering, Cerâmica and Materials Research. Besides, he coordinates the innovation division at the Multidisciplinary Center for Development of Ceramic Materials.

His scientific papers gather over 6,500 citations. In the last 13 years, he has been the author of more than 500 articles, published in international journals. Up to this moment, he has advised and co-advised assignments for over 30 masters and over 40 doctoral theses.

Throughout his career, he has received more than 20 awards from organizations such as American Ceramic Society, Sociedad Española de Cerámica y Vidrio, CNPq, Associação Brasileira de Metalurgia e Materiais and Associação Brasileira de Cerâmica.

A brief interview with the researcher can be seen below:

SBPMat Bulletin: – Tell us a little bit about your story: which were the opportunities and choices that led you to become a researcher in the field of ceramic materials?

José Arana Varela: – Our choice of being a scientist in mateirals started during the Master’s at ITA, in  1972. During this period (in 1975), I met Professor O. J. Whittemore from the University of Washington, Seattle, during his visit to Universidade Federal de São Carlos for a year. As my master’s research was related to a physico-chemical view of thermal decomposition of talcum, which is a ceramic material, Professor Whittemore became interested in it and made some remarks regarding ceramic processing (his specialty). Thence the invitation for a doctorate in Seattle (from 1977 to 1981).

SBPMat Bulletin: – In your own analysis, which were your main contributions to the science and technology of materials? Specifically, can you comment on your main contributions to the field of engineering ceramics, the focus of Bridge Building Award?

José Arana Varela: — As the main theme of our doctoral theses was related to sintering models, we performed a simple study about variable effects, such as water vapor and heating rate in densification and microstructure of magnesium oxide ceramic. We created a model to take into account the structural rearrangement in sintering process.

Considering the evolution on application of ceramic materials in Microelectronics, due to functionality of these materials, we started the Electroceramic line in the 90’s. The functionality initially chosen was resistivity variation with electrical field (ceramic varistors) due to its application, mostly with lightning rods and electric circuits protectors. After understanding and contributing with varistor’s system based on zinc oxide (ZnO), we proposed to change the system considering another semi-conductor (stannous oxide). In this case, we developed throughout the years a stannous oxide varistor with properties that were much superior to traditional ZnO varistors.

Other contributions are related to development of thin ceramic films with Perovskite structure, with the purpose of optimizing their dielectric, piezoelectric and ferroelectric properties by using chemical deposition. We have advanced in the knowledge of chemical deposition, which we call polymeric precursors methods. One of the applications of these films are related to the manufacture of ferroelectric memories. With this, our students have worked in characterizing thin films with ferroelectric properties in some systems such as barium titanate, lead zirconate titanate, as well as strontium niobate and tantalate. A patent in ferroelectric memories, licensed to Panasonic, was proposed by a group led by Professor Carlos Paz de Araujo, at University of Colorado.

The latest contribution is related to sensors with nanometric structure, in collaboration with a group led by Professor Harry Tuller at MIT. Recent results were very promising and they showed great sensitivity in nanosensors based on stannous monoxide. It is important to point out that we have recently applied for patent regarding this study.

SBPMat Bulletin: – “Bridge building”, building bridges. Can you share with us a retrospective on the main bridges built throughout your career and the ones you would like to build?

José Arana Varela: — Our bridges have been built from the moment we finished our PhD at University of Washington. I continued to collaborate with Professor Whittemore for decade and I started other partnerships with Professor Gary Messing at Penn State University e then Professor Richard Bradt at University of Alabama.

Concurrently, we had joint projects in Europe with Professor João Baptista at Universidade de Aveiro, Portugal and with Doctor José Fernandez from Institute of Ceramics and Glass in Madrid, related to the subject of Electroceramics. We began to collaborate with groups in Bordeaux, France (Professor Marc Onillon), as well as André Perrin at University of Rennes. The collaborations proceeded with groups led by Professor Paolo Nanni at University of Genoa, concurrently with group led by Professor Danilo Suvorov at Josef Stephan Institute, in Slovenia and Professor Harry Tuller at MIT, in Boston.

SBPMat Bulletin: — Would you like to leave a message for our readers who are developing their academic or industry career as materials researchers?

José Arana Varela: — Science of Materials is fundamental to developing new useful technologies that will resolve society’s greatest problems. Great advancement in knowledge of ceramic materials, mostly their application in production of energy, communication, environmental control, etc., has been increasing in the past 20 years, mainly because of increased collaboration among researchers in different parts of the world. Science of Materials stopped being polarized between the United States and Europe (Germany, England and France) and it relies on contributions from other players in Asia and certainly Brazil. Fundamental knowledge of mass and charge transportation mechanisms, as well as structure of materials in nanometric scale, is essential to new developments and advances in technology.

 

New board of SBPMat directors and members of the council: investiture and first meeting.

Posted on Thursday 27 de February de 2014

On February 14th of this year, at 10 o’clock, the Brazilian Society of Materials Research (SPBMat) had an investiture ceremony for the Seventh Board of directors, for a two-year term beginning in January, 2014. Together with the Board of directors, four new full counselors and a deputy counselor were in role, whose term goes until 2018. The ceremony took place at Golden Park Hotel Viracopos, in the city of Campinas, in Sao Paulo. The new Board of directors and the new counselors were elected by vote at the end of 2013.

New Board of directors on the day of the investiture. From left to right, Rodrigo Bianchi, Marco Cremona, André Pasa, Ieda Garcia dos Santos, Julio Sambrano, Maria Aparecida Zaghete and Roberto Faria (president).

First meeting

The first meeting with the new Board of directors, together with the council occurred on the same day, at 2 p.m.

At the meeting, members of the board and council were appointed to take part in SBPMat’s commitee. For the Events Commitee, Professor Marco Cremona, Professor Iêda Maria Garcia dos Santos and Professor José Alberto Giacometti were assigned; for the SBPMat Bulletin Commitee, Professors Fernando Lázaro Freire Junior, André Avelino Pasa and José Antonio Eiras; and for University Chapters Commitee, Professors Rodrigo Fernando Bianchi, Antonio José Felix de Carvalho, Iêda Maria Garcia dos Santos, Maria Aparecida Zaghete and Waldemar Augusto de Almeida Macedo. As responsible for creating the document “Materials Science Impact” together with Institute of Physics, Professors Roberto Mendonça Faria, Marco Cremona and Julio Ricardo Sambrano were chosen. It is important to highlight that other SBPMat associates besides the initial members can be included.

During the meeting, scientific directors were assigned their duties.

See current members of the Board and Council and learn about our directors and their roles.

Research center studies material applied as ozone gas sensor (Text by CDMF and INCTMN)

Posted on Tuesday 18 de February de 2014

Developing multifunctional materials, that is, chemical compounds synthesized in labs, which may be applied in several areas, is a research field increasingly explored in the chemistry departments of universities around the world. The Center for the Development of Functional Materials (CDMF), located at Universidade Estadual Paulista (UNESP), jointly with researchers from Universidade de São Paulo (USP), Universidade Federal de São Carlos (UFSCar) and Instituto de Pesquisas Energéticas e Nucleares (IPEN) have developed an original study using the chemical compound silver tungstate (Ag2WO4) as a resistive sensor to detect small amounts of ozone gas, providing an alternative to environmental solutions.

Luis Fernando Silva, researcher at CDMF, under the supervision of Professor Elson Longo, has investigated the properties of silver tungstate as an ozone gas sensor. Ozone (O3) is an oxidant gas, used in many technological applications, such as the food industry, drinking water treatment, medicine, microelectronics cleaning processes, among others. “Ozone has been successfully used to disinfect effluents, allowing a more efficient drinking water treatment. However, when there are high amounts of this gas in the atmosphere, it becomes harmful, especially to human health, causing serious conditions as headaches, burning and stinging in the eyes, difficulties to breath and lung damages”, he said.

In 2013, researchers from CDMF identified a way to stimulate the growth of nanoparticles of silver in the silver tungstate compound itself. Thereby, the material developed a number of properties that may be used in different sectors, such as health, environment, and technology.

Encouraged by this breakthrough, the researchers studied silver tungstate as a resistive gas sensor. “The preliminary results qualified this compound as a great gas sensor. In one of our trials, we identified that silver tungstate displayed an excellent performance detecting ozone. That was the first time in which this compound was used as a resistive gas sensor”, explained the researcher. The obtained results were published on the journal Nanoscale, a renowned source on the subject.

Silva also explains that following this work, the main goal will be examining the sensibility of silver tungstate when detecting other gases, such as nitrogen dioxide (NO2), ammonia (NH3), ethanol (C2H6O), or even humidity. “These are parameters that enable the potential commercialization of this material”, he stated.

The initiative results from the interaction between CDMF and the INCTMN (National Institute of Science and Technology for Nanotechnology Materials).

Exposition to ozone gas

Ozone is a gas found in the higher layers of the atmosphere, acting as a filter against the solar ultraviolet radiation that comes down to Earth. The gas is not natural where living beings live, presenting a negative impact to health. It is formed by the reactions between gases created by combustions, as in vehicles, for example.

The World Health Organization (WHO) recommends avoiding the exposition to ozone gas above 120 ppb (parts per billion). Based on this date, the constant detection and measurement of the levels of ozone contained in the atmosphere or in certain environments remains indispensable.

SBPMat newsletter – first issue

Posted on Monday 3 de February de 2014

 

Brazilian Materials Research Society (SBPMat) newsletter

News update from Brazil for the Materials community

 

English version – First edition

Greetings, .

SBPMat’s news

XIII SBPMat meeting: symposia.

See the list of the symposia approved for this year’s meeting. Here.

Featured paper with Brazilian participation
Signed by 19 authors, the paper highlighted this month by our newsletter is about nitrogen-doped graphene nanoribbons, synthesized by CVD in one single process. In the article published in Advanced Functional Materials, the scientists show that nitrogen increases the semiconductor behavior and the chemical reactivity of the nanoribbons, expanding the possibilities of application in electronics, in addition to generate a particular morphology in its borders. A part of the work was carried out in the Federal University of the State of Pernambuco (UFPE).  Here.

History of Materials research in Brazil
Six years ago, CAPES (the government agency linked to the Brazilian Ministry of Education in charge of promoting high standards for post-graduate courses in Brazil) included “Materials” in its table of knowledge areas. Know more about this story in the article we have prepared, based on an interview with Professor Lívio Amaral, one of the men behind its creation. Here.

SBPMat’s community people

A former president of SBPMat, José Arana Varela, is the first Brazilian researcher to receive the Bridge Building Award from the American Ceramic Society. Here.

Reading recommendations
Science journalism stories based on papers published in journals with high impact factor.

  • Nanoparticle system that deliver several drugs against cancer into different parts of the cell (based on paper from Advanced Functional Materials). Here.
  • Nanoparticles detect tumors based on the amplification of signals from the microenvironment (based on paper from Nature Materials). Here.
  • Study led by a Brazilian scientist shows metamaterials that perform mathematical operations with electromagnetic waves (based on paper from Science). Here.
  • New technique integrates graphene with other materials, forming a two-dimensional seamless sheet (based on paper from Science). Here.

Books, presentations, multimedia material, etc.

  • Review of book “Nanotechnology for the Energy Challenge“. Here.
  • Review of book “Biopolymer Nanocomposites“. Here.

Innovation: in the market or nearly there.

  • Rubber made of dandelion for tires: multi-disciplinary study carried out by Fraunhofer Institute and the manufacturer Continental. Here.

Anniversaries.

  • 100 years after the discovery of X-ray crystallography, 2014 is the International Year of Crystallography. Here.

Upcoming events in the area.
  • VI Curso do Método Rietveld de Refinamento de Estrutura. Here.
  • 10º Encontro Brasileiro sobre Adsorção. Here.
  • 13th International Conference on Modern Materials and Technologies (CIMTEC 2014). Here.
  • 1st International Conference on Polyol Mediated Synthesis. Here.
  • 13th European Vacuum Conference + 7th European Topical Conference on Hard Coatings + 9th Iberian Vacuum Meeting. Here.
  • 19th International Conference on Ion Beam Modification of Materials. Here.
  • XIII Encontro da SBPMat. Here.
To suggest news, opportunities, events or reading recommendations items for inclusion in our newsletter, write to comunicacao@sbpmat.org.br.
Unsubscribe here.

 

CAPES’s Materials Area Anniversary. Part 1.

Posted on Thursday 30 de January de 2014

At the end of January, 2014, the Brazilian community of Materials research celebrates an anniversary: the Materials Area of CAPES reaches its sixth year of existence. CAPES is the government agency linked to the Brazilian Ministry of Education in charge of promoting high standards for post-graduate courses in Brazil.

In fact, it was on January 30th, 2008, that CAPES’s published a press release announcing the introduction of changes to its table of areas. Such table lists the areas of knowledge and it is used in the evaluations of the post-graduation programs in Brazil. The changes disclosed in such note included the insertion of the Materials Area, which up until then did not exist, and which from then on would be a part of the Multi-disciplinary greater area, which had been recently created.

One day prior to such disclosure, an official letter from CAPES’s Evaluation Office had been sent to all coordinators of post-graduation programs previously identified as possibly being grouped into the new area. The official letter informed that a recent meeting of CAPES’s Superior Board had approved the creation of the new Materials area of evaluation, and also that physicist Lívio Amaral, a professor from the UFRGS (Federal University of the State of Rio Grande do Sul) had been appointed as the pro-tempore coordinator. In addition, the official letter asked the coordinators who deemed it to be in the interest of their programs to become connected to the new area of evaluation, to inform CAPES of their decision.

Background

In September, 2012, professor Amaral had taken part in a meeting at the headquarters of CNPq (Brazilian Council for the Scientific and Technological Development) called by Professor Celso de Melo, who was a director in the council. The theme of the meeting was the Materials Science and Engineering area, and the Advisory Boards of such body. The other participants of the meeting were the professors Glória de Almeida Soares (from COPPE-UFRJ), Elson Longo (from UFSCar) and João Marcos Alcoforado Rebello (from COPPE-UFRJ).

A document signed by the participants of the meeting pointed some problems with the evaluation of research projects in the Materials Area. To sum it up, due to the fact that there was no Advisory Board for the Materials Area at that time, the projects and other requests pertaining to Materials Science or Engineering were often appraised with debatable parameters or sent from area to area until someone was found who could evaluate them, a situation which significantly increased the number of appeals received by the CNPq and the time to reply to the requesting researcher. To solve such issue, the document proposed initially the creation of a committee with representatives from the several areas of knowledge involving Materials and also that the scientific societies with any relation to Materials were to be called to the debate, to find a solution fully backed by the technical and scientific community.

“This matter of the inclusion of a Materials area in the government fostering agencies had been considered since the mid-90s”, Lívio Amaral states. “That occurred within the context of creation of a Brazilian Materials society, having the MRS as a reference, which ended up occurring in the early 00s. At the time, there was a lot of debate in several situations, such as in the Brazilian Meetings on Condensed Matter Physics of the Brazilian Physics Society”, he adds.

In parallel, professor Amaral had been following-up on that matter within CAPES, where he was the coordinator of the Physics and Astronomy Area. According to Amaral, by means of evaluations conducted every three years, it was possible to verify that several post-graduation programs, regardless of the names they had and by which of CAPES’s areas they were encompassed, were awarding master and doctorate degrees with intellectual production in Materials. “Since, in addition to being department coordinator, I also took part in CAPES’s Technical and Scientific Council, I had the opportunity to take that entire matter to debate in such Council”, the professor  comments.

At that time, Jorge Almeida Guimarães, who would become CAPES’s president in 2004, was the coordinator of the Biological Sciences II Area and, like professor Amaral, took part in the Technical and Scientific Council and was a professor in the UFRGS. “We discussed at length the need to create two new areas, the Materials and Biotechnology areas”, Lívio Amaral tells us.

In addition, Amaral recalls that another favorable coincidence then occurred. CAPES’s president at the time was Professor Abílio Afonso Baeta Neves, who had previously been the dean of post-graduation in UFRGS when the program of post-graduation in Materials Science had been submitted to the university, by initiative from professors of the Physics department, Amaral included, and of the Engineering and the Chemistry departments. “In summary, in that scenario, the discussion regarding new areas, inside and outside the Technical and Scientific Council, was very frequent due to such circumstances”, professor Amaral sums it up.

Meeting of CAPES’s Technical and Scientific Council, at the time of professor Abílio Baeta Neves’s presidency. At the table, the third one from the right is the president; the sixth, the one speaking, is professor Jorge Guimarães; the seventh is profesor Lívio Amaral. (Picture provided by Lívio Amaral)

The decision for the creation

According to Amaral, in July, 2007, CAPES held a meeting in Brasília, to consider the possible creation of a new area of knowledge, to be called “Materials”. Representatives from several post-graduation programs were invited, including professor Lívio, who was at the time the coordinator of UFRGS’s program.

The official letter-invitation sent by CAPES’s Evaluation Office contained: “The agency has been granted to such area the importance it deserves, considering the relevance of the creation of new materials for the current science and technology. CAPES’s Superior Council, in addition, has already authorized this Office to create the area at hand. For such decision, the meeting to be held in July 31st shall be decisive, for it will allow us to conclude if such innovative measure is in the interests of the programs – and of the Brazilian science and technologies. The new area would encompass all programs that – currently divided into different areas of knowledge – highlight this theme, which is a priority for the Country and for applied sciences”.

“The meeting was, therefore, conclusive for the creation of the new area and designed the initial milestones for the same”, Amaral states. Thus, on January 25th, 2008, CAPES’s Ordinance No. 09 was published, which ordinance, in its article 3, created two new areas of knowledge, “Materials” and “Biotechnology”, and designated their pro tempore coordinators.

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List of post-graduation programs that adhered to the Materials area (as of March, 2008).

1. Program of Post-Graduation in Materials – UNIVERSIDADE DE CAXIAS DO SUL

2. Program of Post-Graduation in Materials Science – UNIVERSIDADE FEDERAL  DO RIO GRANDE DO SUL

3. Program of Post-Graduation in Materials Engineering and Science – UNIVERSIDADE FEDERAL DO CEARÁ

4. Program of Post-Graduation in Materials Science – UNIVERSIDADE FEDERAL DE PERNANBUCO

5. Program of Post-Graduation in Materials Science and Technology – UNIVERSIDADE ESTADUAL PAULISTA “JÚLIO DE MESQUITA FILHO” – UNESP-BAURÚ

6. Program of Post-Graduation in Materials Engineering – UNIVERSIDADE DE SÃO PAULO – ESCOLA DE ENGENHARIA DE LORENA

7. Program of Post-Graduation in Materials Engineering and Science – UNIVERSIDADE FEDERAL DO RIO GRANDE DO NORTE

8. Program of Post-Graduation in Materials Engineering and Science – UNIVERSIDADE DE SÃO PAULO – SÃO CARLOS

9. Program of Post-Graduation in Materials Science and Technology – UNIVERSIDADE ESTADUAL PAULISTA “JÚLIO DE MESQUITA FILHO” – UNESP- CAMPUS DE ILHA SOLTEIRA

10. Program of Post-Graduation in Materials Engineering and Science – UNIVERSIDADE FEDERAL DE SANTA CATARINA.

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Featured paper: Changing the properties and morphology of graphene nanoribbons with nitrogen.

Posted on Thursday 30 de January de 2014

The scientific paper by members of the Brazilian community in Materials research featured this month is:

Josue Ortiz-Medina,  M. Luisa García-Betancourt,  Xiaoting Jia,  Rafael Martínez-Gordillo,  Miguel A. Pelagio-Flores,  David Swanson,  Ana Laura Elías,  Humberto R. Gutiérrez,  Eduardo Gracia-Espino,  Vincent Meunier, Jonathan Owens,  Bobby G. Sumpter, Eduardo Cruz-Silva,  Fernando J. Rodríguez-Macías,  Florentino López-Urías,  Emilio Muñoz-Sandoval, Mildred S. Dresselhaus,  Humberto Terrones,  Mauricio Terrones. Nitrogen-Doped Graphitic Nanoribbons: Synthesis, Characterization and Transport. Advanced Functional Materials 2013, 23, 3755-3762. DOI 10.1002/adfm.201202947.

Changing the properties and morphology of graphene nanoribbons with nitrogen

Multiple layers of graphene with the shape of ribbons (narrow and long) are called graphitic nanoribbons. These materials have been studied to control their properties by various methods, such as doping, in which are introduced atoms of “foreign” elements in the graphene carbon lattice.

In a study led by scientists at Pennsylvania State University with the participation of researchers from institutions in the United States, Mexico, Spain and Brazil, nitrogen-doped graphitic nanoribbons were manufactured by the chemical vapor deposition (CVD) method and showed new features, linked with the introduction of nitrogen, such as highest semiconductor performance, promising for applications in electronic devices, chemical reactivity and a very particular morphology on its edges.  The research was published in the journal Advanced Functional Materials.

“This article showed by the first time that it is possible to make doping with nitrogen on the same synthesis by CVD of graphite nanoribbons, and that you can control the level of doping during synthesis,” highlights Fernando Rodríguez-Macías, foreign visiting professor at the Brazilian Federal University of Pernambuco (UFPE) and one of the authors of the scientific paper. A Mexican national, Rodríguez-Macías came to UFPE in 2012, during his sabbatical year to work as a foreign visiting professor in the Department of Fundamental Chemistry and in the Graduate Program in Materials Science of the University. “I have prolonged my stay for another year to continue until 2014 doing collaborative studies for the production of carbon nanostructures, of bionanotechnology and toxicity of nanomaterials,” says the professor. “I am also teaching preparation and characterization of materials,” he adds.

The doped nanoribbons

The article’s authors showed that different concentrations of nitrogen generate controlled changes in material behavior. In particular, scientists have proven that the more nitrogen introduced into the structure of graphene, the most predominant the semiconductor behavior of nanoribbons. As an explanation to this phenomenon, the researchers suggested, based on theoretical calculations, that nitrogen atoms of doped nanoribbons act as scattering centers of electrons and decrease the conductive behavior of undoped graphene. “The control of doping level allows you to change the electrical properties of the nanoribbons, which can be useful for applications in transistors and other electronic devices,” says Rodríguez-Macías.

In addition, the paper also shows that the reactivity of nanoribbons can change with the doping level. Pure graphene, explains UFPE’s visiting professor, is very inert and has limited interactions with many chemical substances; on the other hand, nanoribbons doped with nitrogen are more reactive, which makes them useful for applications in sensors and catalysis.

As to the morphology, the article’s authors found that the nitrogen-doped nanoribbons have loops on their edges, uniting different graphene sheets. “This morphology is not presented by undoped graphite nanoribbons,” says Rodríguez-Macías.

This figure, sent by Professor Fernando Rodríguez-Macías, shows the nitrogen-doped graphitic nanoribbons in three scales. The scanning electron microscopy (top left corner) shows how these ribbons are made up of several layers and feature a curved surface with roughness. The transmission electronic microscopy (bottom left corner) shows that the nanoribbon layers are graphene sheets. The high resolution transmission electronic microscopy (right) shows that the layers of graphene on the nanoribbons edges form loops uniting different graphene sheets.

Collaborators

Almost all work of materials synthesis of the paper of Advanced Functional Materials was developed at Pennsylvania State University; the characterization was done in collaboration with other researchers and laboratories, reports UFPE’s visiting professor.

The participation of UFPE in the article happened through the doctoral student Miguel Angel Pelagio-Flores in the analysis and theoretical modeling of doped nanoribbons, and through professor Fernández-Macías himself, who, in addition to having participated in the discussion of results and review of the article from his office at UFPE, was doctoral advisor of the first author of the article, Josué Ortiz-Medina, while professor of a Mexican institution, IPICYT. “Ortiz-Medina did most of the experimental work of the article, besides being an important part of the characterization and theoretical studies of these new nanomaterials, when he was in exchange at Penn State in the laboratory of professor Terrones,” contextualizes the professor.

In total, 19 authors sign the article, among them MIT’s Professor Mildred Dresselhaus, reference in carbon science.

XIII SBPMat Meeting Symposia.

Posted on Thursday 23 de January de 2014

A: Functional hybrid interfaces: from characterization to applications. Main organizer: Welchy Leite

Cavalcanti (IFAM/Germany).

B: Advances in Functional Polymers. Main organizer: Ricardo Vinicius Bof de Oliveira (UFRGS/Brazil).

C: Magnetic Materials. Main organizer: Marcos Flavio de Campos (UFF/Brazil).

D: Organic Electronics and hybrids: materials and devices. Main organizer: Rodrigo F. Bianchi (UFOP/Brazil).

E: Sol-Gel Materials: From Fundamentals to Advanced Applications. Main organizer: Andrea S. de Camargo (USP São Carlos/Brazil).

F: Research Frontiers of Computer Simulations in Materials Science: Developments and Applications. Main organizer: Juarez L. F. Da

Silva (USP São Carlos/Brazil).

G: Anti-fouling Materials and Coatings. Main organizer: Alexander Hiroshi Kasama (PETROBRÁS/Brazil).

H: Luminescent Materials. Main organizer: Hermi F. Brito (USP/Brazil).

I: Beyond Graphene: Low-dimensional systems based on graphene and III-Nitrides. Main organizer: Caio M.C. de Castilho (UFBA/Brazil).

J: IX Brazilian Electroceramics Symposium. Main organizer: Daniel Zanetti (UFABC/Brazil).

K: Structure-Properties Relationship of Advanced Metallic Materials. Main organizer: Leonardo Barbosa Godefroid (UFOP/Brazil).

L: Current Research in Energy Storage Systems. Main organizer: Alexandre Urbano (UEL/Brazil).

M: Nanomaterials for Nanomedicine. Main organizer: Carlos Jacinto da Silva (UFAL/Brazil).

N: Surface Engineering: functional coatings and modified surfaces. Main organizer: Carlos Alejandro Figueroa (UCS/Brazil).

O: Multifunctional materials derived from clay minerals. Main organizer: Maria Gardênnia da Fonseca (UFPB/Brazil).

P: Advanced Carbon Nanostructures and Composites. Main organizer: Ana Flávia Nogueira (UNICAMP/Brazil).

Q: International Symposium on Cementitious Materials. Main organizer: Sandro Torres (UFPB/Brazil).

R: Innovation and Technology Transfer Symposium. Main organizer: Roberto Faria (USP São Carlos/Brazil).

S: Ceramic and metallic materials obtained by wet-chemical methods. Main organizer: Mary Alves (UEPB/Brazil).

Boletim SBPMat – edição 16 – dezembro 2013.

Posted on Friday 10 de January de 2014
Edição nº 16 – Dezembro de 2013
Saudações, .

Felizes festas e ótimo 2014!

São os votos da Sociedade Brasileira de Pesquisa em Materiais (SBPMat) para os leitores do boletim.

Novidades da SBPMat

Eleições na SBPMat: resultados da votação.

O professor Roberto Mendonça Faria será o presidente da nossa sociedade por mais dois anos. Saiba quem são os membros da diretoria e do conselho eleitos. Aqui.

Gente da nossa comunidade

Novos membros titulares da ABC.

O professor Fernando Lázaro Freire Júnior, atual diretor financeiro da SBPMat e ex-presidente da sociedade, é um dos novos membros titulares da Academia Brasileira de Ciências (ABC). Aqui.

Artigo em destaque
Num trabalho de nanoengenharia, um grupo de cientistas, que inclui um doutor brasileiro, conseguiu aumentar dez vezes a eficiência de LEDs fabricados com pontos quânticos. A estratégia foi minimizar o “efeito Auger” que concorre com a emissão de luz nesses materiais. A pesquisa foi reportada na Nature Communications. Aqui.

Dicas de leitura
Divulgação científica de artigos publicados em periódicos de alto fator de impacto.

  • Vídeo da Nature sobre superfície superhidrofóbica texturizada para reduzir ao máximo o tempo de contato com o líquido (divulgação de paper da Nature). Aqui.
  • Nova rota para fabricação de nanorevestimentos poliméricos que tornam superhidrofóbicas as mais variadas superfícies (divulgação de paper da Advanced Functional Materials). Aqui.
  • Nanofolhas de carbono usadas em células a biocombustível para uma melhor transferência de elétrons (divulgação depaper da Advanced Energy Materials). Aqui.

Livros, apresentações, material mutimídia etc.

  • Resenha da professora do MIT Mildred Dresselhaus sobre o livro “Carbon nanotubes and graphene for photonic applications“. Aqui.
  • PPT da palestra plenária sobre OLEDs e iluminação ultraeficiente apresentada pelo professor Andy Monkman (Durham University) no XII Encontro da SBPMat. Aqui.
  • Versão online, gratuita e adaptada a dispositivos móveis das famosas aulas de Física de Richard Feynman, proferidas em 1961 no California Institute of Technology. Aqui.

Aniversários

  • A Materials Reaserch Society (MRS) completou 40 anos. Veja a mensagem de seu presidente sobre passado, presente e futuro da sociedade de pesquisa em Materiais dos Estados Unidos. Aqui.
  • No 25º aniversário da Advanced Materials, seu editor conta um pouco da história, apresenta a evolução de seu fator de impacto, e anuncia algumas novidades. Aqui.

Oportunidades
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  • Vaga para pós-doutorado em materiais multifuncionais com porosidade hierárquica. Aqui.
  • Seleção da Pós-graduação em Física e Química de Materiais da Universidade Federal de São João del Rei (MG). Aqui.
  • Chamada de artigos do Journal of Materials Research para sua “focus issue – Optical Ceramics Science“. Aqui.
  • Chamada de propostas para intercâmbio de pesquisadores entre São Paulo e França. Aqui.
  • Prêmio para jovens inovadores MIT Technology Review aceita indicações na área de nanotecnologia e materiais. Aqui.

Proximos eventos da área
  • 10º Encontro Brasileiro sobre Adsorção. Aqui.
  • 13th International Conference on Modern Materials and Technologies (CIMTEC 2014). Aqui.
  • 19th International Conference on Ion Beam Modification of Materials. Aqui.
  • XIII Encontro da SBPMat. Aqui.
  • Veja a agenda de eventos.
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Artigo em destaque: Pontos quânticos desenvolvidos para LEDs mais eficientes.

Posted on Friday 20 de December de 2013

O artigo científico de membros da comunidade brasileira de pesquisa em Materiais em destaque neste mês é:

Wan Ki Bae, Young-Shin Park, Jaehoon Lim, Donggu Lee, Lazaro A. Padilha, Hunter McDaniel, Istvan Robel, Changhee Lee, Jeffrey M. Pietryga & Victor I. Klimov. Controlling the influence of Auger recombination on the performance of quantum-dot light-emitting diodes. Nature Communications 4, article number 2661, published 25 October 2013. doi:10.1038/ncomms3661.

Texto de divulgação: 

Pontos quânticos desenvolvidos para LEDs mais eficientes

Um trabalho de pesquisa publicado no mês de outubro na Nature Communications, revista científica de conteúdo aberto do grupo Nature, resultou num material que aumenta dezenas de vezes a eficiência de LEDs de pontos quânticos ao diminuir a influência do efeito Auger, um dos principais limitadores da eficiência desses dispositivos que apresentam grande potencial para serem usados em iluminação, entre outras aplicações. O trabalho foi realizado no Grupo de Nanotecnologia e Espectroscopia Avançada do Laboratório Nacional de Los Alamos, localizado no sul dos Estados Unidos, com a participação de um doutor brasileiro, Lázaro Padilha, e com a colaboração de grupos da Coreia.

“O resultado veio depois de mais de um ano de pesquisa sobre como efetivamente minimizar o efeito Auger em pontos quânticos”, relata Padilha, atualmente professor do Instituto de Física da Unicamp, que chegou a Los Alamos em 2010 para fazer um estágio de pós-doutorado. O trabalho que gerou o paper na Nature Communications, além de outros artigos em periódicos de alto fator de impacto como Nano Letters e ACS Nano, começou no final de 2011 e, na sua primeira etapa, visou entender o processo físico para minimizar a influência do chamado “efeito Auger” ou “recombinação Auger” nos pontos quânticos.

Os pontos quânticos, cristais semicondutores de alguns nanometros de tamanho, apresentam propriedades que possibilitam a emissão de luz com brilho intenso e cores puras e podem ser fabricados usando técnicas simples e de baixo custo. Por esses motivos, essas nanopartículas são materiais interessantes para a fabricação de LEDs. Desde a primeira demonstração de LEDs de pontos quânticos, ocorrida em 1994 (Nature 370, 354 – 357, 04 August 1994; doi:10.1038/370354a0), esses dispositivos têm sido objeto de pesquisas visando otimizar sua capacidade de converter eletricidade em luz.

Nos LEDs, a emissão de luz se produz quando, ao se introduzir energia no dispositivo por meio de corrente elétrica, ocorrem recombinações nos átomos do material emissor. Especificamente, elétrons próximos ao núcleo do átomo saem de seu lugar deixando vagas, as quais são preenchidas por elétrons mais distantes, dotados de mais energia. A energia excedente pode sair em forma de fóton, ocorrendo a desejada emissão de luz, ou pode ser transmitida a um terceiro elétron, que será ejetado do átomo. Esta segunda possibilidade constitui o efeito Auger, que pode ser visto como um concorrente da emissão de luz no uso da energia.

Nanoengenharia dos pontos quânticos

Depois de compreender como minimizar a recombinação Auger nos pontos quânticos do ponto de vista físico e constatar que impacta significativamente na eficiência dos LEDs, o grupo de Los Alamos se propôs a desenvolver o material que teria o melhor desempenho frente a esse efeito. “Eu trabalhei nos estudos de espectroscopia para entender os processos físicos que levariam a um melhor desempenho dos materiais como base para LEDs”, diz Lázaro Padilha.

O desenvolvimento do material foi feito a partir de pontos quânticos compostos por um núcleo de seleneto de cádmio (CdSe) e uma casca de sulfeto de cádmio (CdS). Para conseguir a redução da influência do efeito Auger, os cientistas aplicaram duas estratégias de nanoengenharia: a variação da espessura da casca e a introdução de uma camada composta por uma liga de zinco, cádmio e enxofre (ZnCdS) entre o núcleo e a casca.

Após concluir, em Los Alamos, o desenvolvimento do material base, os colaboradores da Coreia do construíram LEDs com uma arquitetura na qual a camada emissora, formada pelos pontos quânticos, ficou inserida entre as camadas de transporte de cargas negativas e positivas, sendo uma inorgânica e a outra orgânica, respectivamente, como mostra a figura a seguir, extraída do artigo da Nature Communications:


“Uma vez encontrado o material que teria o melhor efeito, foram fabricados os LEDs e pudemos confirmar os resultados esperados”, conta Padilha. A confirmação ocorreu através de uma série de medidas espectroscópicas dos pontos quânticos dentro dos dispositivos.

De acordo com Padilha, com os novos materiais desenvolvidos, os cientistas conseguiram obter LEDs de pontos quânticos até 10 vezes mais eficientes, com uma taxa de conversão de energia elétrica em energia luminosa da ordem de 8%.

Diretor e ex-presidente da SBPMat é eleito membro titular da Academia Brasileira de Ciências.

Posted on Thursday 19 de December de 2013
O professor Fernando Lázaro Freire Júnior, eleito membro titular da ABC.

A Assembleia Geral da Academia Brasileira de Ciências (ABC) elegeu, no dia 18 de dezembro, 24 cientistas para integrar seus quadros como membros titulares.

Entre eles figura o diretor financeiro da nossa SBPMat, o professor Fernando Lázaro Freire Júnior (PUC-Rio), eleito na área de Ciências Físicas. O professor Fernando Lázaro foi presidente da SBPMat por dois mandatos consecutivos, de 2006 a 2009. Também foi membro da diretoria fundadora que conduziu a sociedade entre 2001 e 2003 e diretor científico de 2004 a 2005.

A ABC também elegeu, nesta oportunidade, um membro colaborador, seis membros correspondentes e 29 afiliados eleitos para o período 2014 – 2018.

Veja aqui notícia no site da ABC com a lista completa dos membros eleitos neste ano:

http://www.abc.org.br/article.php3?id_article=3080