Tag: bernhard gross

Featured scientist: Yvonne Primerano Mascarenhas.

Posted on Sunday 31 de March de 2019
Yvonne Primerano Mascarenhas
Yvonne Primerano Mascarenhas

During the opening of the XVIII B-MRS Meeting in Balneário Camboriú (SC), on the night of September 22 of this year, Yvonne Primerano Mascarenhas, a retired professor of the University of São Paulo (USP), will give the Memorial Lecture Joaquim da Costa Ribeiro, an honor granted every year by B-MRS to a researcher with outstanding trajectory in Brazil. In the memorial lecture, Prof. Yvonne will talk about the evolution of crystallography (study of the structure of crystalline materials) in Brazil, a story she can personally narrate in the first person.

In fact, Professor Yvonne was the person who introduced and developed, since the early 1960s, the structural and molecular X-ray crystallography, now widely used in research, development and innovation in Brazil. The technique allows to fully know how the atoms and molecules that make up the organized structure of crystalline materials are arranged in space.

Yvonne Primerano was born on July 21, 1931 in Pederneiras, a small town in the State of São Paulo. When she was 10 years old, after living some years in the city of São Paulo, the family moved to the city of Rio de Janeiro because of the father’s work. Rio de Janeiro was the Capital of the country, and besides being safe at that time, it offered the family a warm reception and a wide range of possibilities, mainly in culture and education.

Yvonne’s secondary education was at Colégio Mello e Souza, a renowned private school in Rio. Due to her fondness for literature, in the last cycle of secondary school she opted for the so-called “classical course,” which reinforced the study of philosophy and literature and more superficially approached the natural sciences. However, it was in these chemistry classes taught by a great teacher – Albert Ebert – that Yvonne was captivated by the diversity of molecules created by nature and with the possibility of synthesizing them in the laboratory.

After graduating from secondary school, Yvonne chose to study chemistry, and after working hard for the university entrance exam, in order to fill the gaps of her humanistic education, in 1949 she entered the bachelor’s degree course in Chemistry at the University of Brazil, currently the Federal University of Rio de Janeiro (UFRJ). There, once again, a special teacher intervened in her professional trajectory. It was Elisario Távora, professor of the Crystallography discipline. Professor Távora had just returned from the United States, where he had completed his doctorate from the Massachusetts Institute of Technology (MIT) under the guidance of Professor Martin Julian Buerger – renowned crystallographer, author of innovations in techniques and instruments in the area. Thus, Yvonne, through Távora, had contact with the state of the art in crystallography techniques; mainly techniques based on X-ray diffraction, which led her to perceive the potential of the area. In young Yvonne’s mind, the idea was that studying the structure of molecules by X-ray diffraction might be a good idea.

Yvonne then felt she needed to learn more Physics, and in 1951 she started to study in this area her second degree at the current State University of Rio de Janeiro (UERJ). In 1954, she had two bachelor’s degrees and a solid baggage in Physical Chemistry. That year she married the physicist-chemist Sergio Mascarenhas, with whom she would form a family, and become a standard-bearer couple in the history of materials research in Brazil.

At the University of Brazil, Yvonne met Professor Joaquim da Costa Ribeiro and participated in the scientist’s research work. At that time, Costa Ribeiro – who a few years earlier had discovered the thermo-dielectric effect while studying Brazilian natural materials – was one of the very few researchers, along with Professor Bernhard Gross, who worked in Material Physics in Brazil. In fact, at that time research resources and efforts in the country were concentrated in nuclear and high energy physics.

In 1956, after living in Rio de Janeiro for fifteen years, Yvonne returned to live in the interior of the state of São Paulo. This time, she settled in São Carlos, a city of about 40 thousand inhabitants, with her husband and the couple’s first two children (a little boy and pregnant with a baby girl). The reason for moving to São Carlos was because the couple had been hired as full-time professors at a unit of USP that had been recently created in São Carlos, the School of Engineering of São Carlos (EESC).

If Rio de Janeiro had provided Yvonne the possibility of a solid preparation, São Carlos now offered both members of the Mascarenhas couple a series of benefits: belonging to an important university, teaching and research activities concentrated in one place (in Rio de Janeiro, Sergio worked in four different places) and, no less relevant, two wages enough to support the family. All of this in the practicability of a small city, saving several hours of driving to work every day.  In addition, the couple would be free to develop research in the area that most interested them in that context: the application of Physics and Chemistry to the study and development of materials.

At EESC, a happy coincidence put Professor Yvonne, once again, on the path of structural crystallography. Forgotten in a corner, there was a medical X-ray machine that had been purchased by a French researcher who had spent some time at the institution. The device had not being used and was of no use to the engineering school. Professor Sérgio Mascarenhas then talked to the manufacturer and was able to exchange it for an X-ray diffraction instrument, which was used in the couple’s first experimental work in São Carlos. From these works, it became clear to Professor Yvonne that knowing the structure of materials was essential to know and modify their properties.

Between 1959 and 1960, the Mascarenhas spent 16 months in the city of Pittsburgh (United States) doing research internships with financial support from the Fulbright Commission, which was in Brazil since 1957. Yvonne intended to train in the study of the structure of materials by X-ray diffraction with a group in the Carnegie Institute of Technology. But when she met the group, she was disappointed. It was then that, by chance, she met the Brazilian physicists Ernesto and Amélia Hamburguer, who were at the University of Pittsburgh doing a doctorate and a master’s degree, respectively. The Hamburguers suggested that Professor Yvonne Mascarenhas should try to do an internship in the Crystallography laboratory coordinated by Professor George Jeffrey at the University of Pittsburgh.

After a few weeks attending a Crystallography course taught by Professor Jeffrey, Professor Yvonne Mascarenhas began working in his research group, where, among other projects, she performed the experimental work of her doctoral thesis, which consisted in obtaining the position of the atoms of a material with magnetic properties by means of X-ray diffraction. At that time, applying this technique was a very complex and time-consuming task due to the limitations of the available equipment, including computers. At the end of her internship at the University of Pittsburgh, she had acquired skills and knowledge that qualified her to work with X-ray crystallography.

After returning to Brazil in 1961, Yvonne (who at that time was the only one working with structural crystallography in Brazil) initiated the Crystallography Laboratory of São Carlos (which would become the first structural crystallography laboratory in the country). The implementation of the laboratory infrastructure and the recruitment and training of its multidisciplinary and international team intensified in the 1970s and continued into later years.

In 1963, after processing the experimental results obtained in Pittsburgh, challenging due to the lack of computers at EESC, Yvonne defended her doctoral thesis titled “Determination of crystalline structures by X-ray diffraction: study of Manganous Formate Dihydrate.”

In 1971, Dr. Yvonne P. Mascarenhas obtained the title of Associated Professor at EESC. In 1981, she became a full professor at the Institute of Physics and Chemistry of São Carlos (IFQSC), another USP unit founded in 1971 in the Sao Carlos Campus. When, in 1994, this unit was split into the Institutes of Physics (IFSC) and Chemistry (IQSC), Professor Yvonne P. Mascarenhas remained in IFSC until her compulsory retirement in 2001, when she became collaborating researcher at the institution. Over the ensuing years, Yvonne began to lead projects related to science teaching and diffusion in public elementary and middle level schools.

Throughout her career, Professor Yvonne P. Mascarenhas has accomplished scientific internships as visiting researcher at some of the world’s most renowned institutions: Princeton University and Harvard University (United States), the National Polytechnic Institute of Mexico, and the University of London (United Kingdom).

She has also had several leadership roles, which until today are predominantly performed by men in the Brazilian academic environment. Within USP São Carlos, she has been the department head, the first director of the Institute of Physics of São Carlos (IFSC) and vice-coordinator of the Institute of Advanced Studies – Polo São Carlos, among other positions. In addition, she led the creation of the Brazilian Society of Crystallography (current Brazilian Crystallographic Association), founded in 1971, and was the president of the society.

Here are some of the many tributes and honors she has received: Distinguished Women in Chemistry or Chemical Engineering Awards of the International Union of Pure and Applied Chemistry (2017), the title of emeritus professor of the Brazilian National Council for Scientific and Technological Development, CNPq (2013), the admission to the Brazilian National Order of Scientific Merit in the Grand Cross Class by the Presidency of Brazil (1998) and the Simão Mathias Medal of the Brazilian Chemical Society (1998). In addition, the researcher has been a full member of the Brazilian Academy of Sciences since 2001.

Over the six decades of working in structural crystallography, Yvonne Primerano Mascarenhas has participated in dozens of projects in various areas that need structural information on materials or molecules, interacting closely with materials scientists, engineers, chemists, physicists, biologists, biochemists, physicians and others. During the period, she supervised 40 master’s and doctoral studies, and coauthored more than 180 articles in international scientific journals. The laboratory created by Yvonne (now called Multiuser Laboratory of Structural Crystallography) has directly generated more than 1,000 articles published in scientific journals and has enabled researchers in many Brazilian states and Latin American countries to perform X-ray diffraction.

Sixty years after the first Brazilian works with structural X-ray crystallography, around 200 structural crystallographers work in Brazilian universities, among them, the pioneer Yvonne Primerano Mascarenhas, now at the age of 87, who still actively participates in scientific research.

Here is a brief interview with this leading scientist.

B-MRS Newsletter: Through crystallography, you have revealed information that is essential to many research projects in many areas. Could you tell us which are the most impacting works in the materials area in which you have participated.

Yvonne Primerano Mascarenhas:

  • Crystal-stucture analysis of deamino-oxytocin – conformational flexibility and receptor-binding. WOOD, SP; TICKLE, IJ; TREHARNE, AM; et al. SCIENCE, 232, 4750, 633-636. MAY 2 1986.

In this work, carried out during an internship at the Department of Crystallography of Birkbeck College, University of London, we were able to contribute to the elucidation of oxytocin, an important hormone produced by the pituitary gland, which in the case of women plays an important role in the stages of childbirth and lactation.

  • Characterization of Polyurethane Resins by FTIR, TGA, and XRD. Trovati, Graziella; Ap Sanches, Edgar; Neto, Salvador Claro; et al. JOURNAL OF APPLIED POLYMER SCIENCE, 115, 1, 263-268. JAN 5 2010.

The measurements performed on the diffractograms of the various types of polyurethane allowed the quantitative determination of the crystallinity percentages of the different samples and related them with other spectroscopic results.

  • Structural transition and pair formation in Fe3O2BO3. Mir, M; Guimaraes, RB; Fernandes, JC; et al. PHYSICAL REVIEW LETTERS, 87, 14, 147201. OCT 1 2001.

The structural determination of the material under study by low temperature X-ray diffraction allowed us to characterize a low temperature crystallographic transition that is important to understand the magnetic properties of the studied material.

  • Crystallographic and spectroscopic characterization of a molecular hinge: Conformational changes in bothropstoxin I, a dimeric Lys49 phospholipase A2 homologue. da Silva Giotto, MT; Garratt, RC; Oliva, G; et al. PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS 30, 4, 442-454. MAR 1 1998.

The determination of the molecular structure of this enzyme, which is one of the components of rattlesnake venom, allowed to better understand its biological action.

  • Crystal structure of perdeuterated violuric acid monohydrate – X ray diffraction analysis. Craven, BM; Mascarenhas, Y. ACTA CRYSTALLOGRAPHICA, 17, 4, 407. 1964

This publication was the result from work done at the University of Pittsburgh during my first internship abroad. The substance under study is a barbiturate that crystallizes with a water molecule. The structural determination revealed the presence of a bifurcated hydrogen bond that had already been predicted theoretically but was experimentally observed for the first time in this crystal.

  • Location of cerium and lanthanum cations in CeNaY and LaNaY after calcination. Nery, JG; Mascarenhas, YP; Bonagamba, TJ; et al. ZEOLITES, 18, 1, 44-49. JAN 1997

This is one of a series of works carried out in collaboration with the Petrobras research center (CEMPES) to analyze changes produced in a series of zeolites that are used as catalytic cracking of petroleum. The results obtained allowed to better understand the mechanisms of catalysis and to suggest other modifications aiming at higher yields.

B-MRS Newsletter: At the XVIII B-MRS Meeting you will give the Memorial Lecture “Joaquim da Costa Ribeiro.” At the end of the event, B-MRS will award students the “Bernhard Gross” Award. You have personally met these two pioneers of materials research in Brazil (Costa Ribeiro and Gross). Could you briefly tell us about your relationship with them?

Yvonne Primerano Mascarenhas: To talk about these individuals in a small paragraph is quite insufficient. Costa Ribeiro and Gross were our mentors in our first research and scientific education activities. We interacted with both scientists during our undergraduate years at the then University of Brazil, currently UFRJ. We had a strong research contact with Bernhard Gross, who visited São Carlos periodically until his death, guiding our activities both experimental and theoretical and guiding some young physicists who had joined our laboratory. Costa Ribeiro supported us quite a bit since our arrival in São Carlos, both with letters of recommendation to the director of EESC, as well as yielding a Wulf electrometer that allowed us to immediately start the dielectrics research. He later spent several years outside Brazil as the representative of Brazil at the Atomic Energy Commission in Vienna and died prematurely a few years after his return to Brazil.

B-MRS Newsletter: You have four children who were raised while you were developing an important scientific career, including holding leadership positions. You usually declare that you did not believe your professional life was undermined because you were a woman. Could you tell us how you managed to reconcile family and professional life at a time when there was no maternity leave in Brazil, and women used to be fired when becaming mothers?

Yvonne Primerano Mascarenhas: Living in a small town enables one to have a great family relationship with children, relatives and friends. So I believe that the decision to move from Rio de Janeiro to São Carlos played a very important role in my professional performance. In addition, I have always valued the help I received from the excellent people who supported me in my domestic needs and in the care of my children. I was very lucky to have this invaluable help from several people who were in my life sharing responsibilities in an interpersonal exchange of much love and respect.

B-MRS Newsletter: Please leave a message for our younger readers who are starting a career as scientists or are contemplating this possibility.

It is never too much to remind them that the economic and social situation of our country will only improve when we can improve the cultural and scientific level of our people, as well as establish notions of responsible, ethical and moral conduct that lead to the good use of our potential natural resources (agriculture, mineral reserves and industrial and commercial processes) and the proper use of taxes collected from the population. In order to do so, the commitment of our young people is crucial both in the educational area and in the exercise of citizenship. I am well aware that it is a great demand, but I am sure that with well-focused effort on these goals, they will be able to achieve great results.

 

Featured scientist: Prof. Heinz von Seggern (TU Darmstadt).

Posted on Friday 30 de November de 2018
Prof. Heinz von Seggern.
Prof. Heinz von Seggern.

In the late 1970s, when he was a doctoral student, German scientist Heinz von Seggern came to Brazil for the first time and met some local researchers with whom he still collaborates. His host was Bernhard Gross, another German scientist who settled in Brazil and is considered a pioneer of materials research in the country. This was the beginning of a series of scientific visits of Heinz von Seggern to Brazil, which included the participation in five B-MRS Meetings, the annual events of the Brazilian Materials Research Society. In the last edition of the event, Prof. Heinz von Seggern gave a plenary lecture on ferroelectrets.

Heinz von Seggern graduated in physics from the University of Hannover (Germany) in 1976. He received his PhD degree in electrical engineering from the Technical University of Darmstadt (Germany) in 1979. His thesis advisor was Prof. Gerhard Sessler, one of the inventors of the electret microphone, the most common type of microphone in use today. After that, Heinz von Seggern became a postdoc and then a principal investigator at AT&T Bell Laboratories (USA). From 1985 to 1997 he worked at Siemens research center in Erlangen (Germany), starting as a principal investigator and then being promoted to department head. Since 1997, he is Full Professor at the Technical University of Darmstadt, where he leads the Electronic Materials Group.

Throughout four decades of scientific research, Heinz von Seggern has made important contributions to the field of materials in understanding fundamental phenomena, developing analysis techniques and applications, and inventing devices. He has published over 280 scientific papers in peer-reviewed journals with more than 7.800 citations, and his h-index is 46 (Google Scholar).

See our interview with this scientist.

B-MRS Newsletter: – What motivated you to become a scientist and, particularly, a materials scientist?

Heinz von Seggern: – Already as a high school student my main interest was directed towards natural science. This passion was strongly motivated by one of my teachers who really understood to ignite my love for this field. So it was a natural thing for me to study physics, however, I always kept in touch with mathematics and chemistry. After finishing my diploma in physics at the Technical University of Hannover, I started my PhD work at the Technical University of Darmstadt in the electrical engineering department and two and a half years later I received my doctoral degree in electrical engineering. The following four out of five years I spend at Bell Laboratories in Murray Hill, New Jersey, USA whose fabulous working conditions made my bonds to science even stronger. My path to materials science started with my return to the Corporate Research Laboratories of Siemens AG in Erlangen where I spend 12 years before being appointed as full professor at the Technical University of Darmstadt, Germany. In the time at Siemens my work was focused on more practical aspects of science which I started to be increasingly interested in. The ability to change and adapt material properties to practical demands, which is the basic task of materials science, fascinated me more and more.

B-MRS Newsletter: – In your opinion, what are your main contributions to the materials field? Please, select a couple of discoveries/developments, describe them briefly, describe the context in which they were developed, and share the papers or patents references.  

Heinz von Seggern: – Since I have been working on different subjects it is not so easy to point out my or our major contributions to the materials field. I will concentrate on one discovery or development in each field. Let’s start with my PhD study. My task was to understand the charge transport and electronic trap structure of Teflon FEP thin films to back up the lifetime expectation of electret microphones. I discovered by means of thermally stimulated discharge measurements that Teflon FEP contains two different types of energetically deep electron traps which are located near the surface and in the bulk of the films, respectively. This discovery was made possible by comparing TSD results of corona and electron beam charged samples whereby corona charging leads to filling of traps close to the surface and electron-beam charging allowed for deposition of charge into surface and bulk traps dependent on the utilized electron energy. From this finding a charge transport model was developed depending on the initial location of the electrons after charging. The model is based on trapping and thermally induced release. In case of corona charging the transport is initiated by a thermally induced release of electrons from surface traps and a subsequent capture and release by deeper bulk traps [Ref: H. von Seggern, J. Appl. Phys. 50, 7039 (1979), Heinz von Seggern, J. Appl. Phys. 50, 2817 (1979)]. The morphological reason for the different trap depth of surface and bulk can be seen in the film production process where different cooling rates apply to the surface and the bulk of the films.

After finishing my PhD degree I continued this research at Bell Laboratories investigating the transport of positive charges. In contrast to the electron traps, hole traps are relatively shallow and are distributed through the complete film. Once filled they empty relatively fast already at room temperature. On the other hand the number to energetically deep traps was found to be rather small resulting in a low capture rate. This implies that holes have a high probability to penetrate the film via hopping through shallow traps without being captured by deep traps which implies a rather low charge stability of Teflon FEP for holes. We were able to show that this problem can be circumvented by charging at high temperatures filling only deep traps [H. von Seggern, J. West, J. Appl. Phys. 55, 2754 (1984)]. This charge stabilization for positive charges recently became important with respect to so called piezoelectrets where by symmetry breaking a novel piezoelectric material was generated utilizing only nonpolar components. For these devices the stability of both charge types is essential.

During my time at the Corporate Research Labs of Siemens AG in Erlangen the field of interest changed to x-ray storage phosphors which are currently applied in so called image plates used commercially in x-ray diagnostics. The image plate thereby combines the classically utilized silver halide film and the intensifying screen where latter was applied to convert incoming x-rays to visible photons which are then detected by the photographic silver halide film. The working principle of the image plate is that by x-ray exposure electrons and holes are generated and trapped as F-centers and Vk-centers, respectively. Readout occurs by photostimulation of the electron and radiative recombination with the Vk-center. The released energy is then converted to a rare earth ion which emits light at its characteristic wavelength. Thereby the intensity of the emitted photons is indicative for the locally absorbed x-ray dose. My major contribution to this field was the discovery of the basic working principle of these photostimulable phosphors and the existence of spatially correlated and uncorrelated PSL centers which allowed for a deeper insight into the physics of storage phosphors [H. von Seggern et al., J. Appl. Phys. 64, 1405 (1988)]. Another contribution was the invention of neutron image plates fabricated by mixing an effective neutron absorber to the granular storage phosphor particles [T. Bücherl, H. von Seggern et al., Nucl. Instr. Meth. A333, 502 (1993)]. This technique is still widely used in neutron image detection.

After accepting the position as full professor in Materials Science at the Technische Universität Darmstadt I concentrated my efforts on the field of Organic Electronics which I already started at Siemens some years before. In the first years we focused on the energetic trap distribution of organic semiconductors. We were the first to experimentally prove the existence of a Gaussian trap distribution predicted earlier by Bässler et al. through Monte Carlo simulation. The experimental method used a refined thermally stimulated discharge technique known as fractional discharge, where a stepwise increase in temperature combined with the corresponding thermal release of charge allows one to determine the trap distribution which up to now is the only technique known to directly determine the distribution of traps  [N. von Malm et al., J. Appl. Phys. 89, 5559 (2001); R. Schmechel et al., Phys. Stat. Sol. (a) 201, 1215 (2004)].The largest scientific attention we received, however, for the invention of the organic light emitting transistor (OFET) based on tetracene and a polyfluorene derivative. In such OFETs it was shown to be possible to obtain ambipolar transport by injection of electrons and holes from source and drain, respectively [A. Hepp, H.von Seggern et al., Phys. Rev. Let. 157406, 1 (2003); M. Ahles, H. von Seggern et al., Appl. Phys. Let. 84, 428 (2004)].  It was also shown that the same ambipolar transport can be used to construct colour tunable OFETs [E. J. Feldmeier, H. von Seggern et al., Adv. Mater 22, 3568 (2010)] where the motion of the emissive recombination zone through the transistor channel is used to excite different overlaying organic semiconductors with different emission wavelength.

In the last years at TU Darmstadt I have revisited charge storage in organic polymers known as ferro- or piezoelectrets. The cellular polymer polypropylene has shown by Finnish scientists to exhibit large piezoelectric d33 coefficients after poling by high electric fields with the only disadvantage that the trapped charge turned out to be thermally unstable. Therefore structures changed quickly to Teflon based sandwiches of solid FEP /ePTFE/ solid FEP, where ePTFE is a highly porous PTFE consisting of up to 98% air, and later to completely air filled structures. My contribution to that field is the physics explaining the hysteresis and thereof the deduction of the maximal stable polarization which then allows for the theoretical deduction of the piezoelectric d33 coefficient for plane-parallel structures. This knowledge allows for the optimization of the piezoelectric effect and therewith increases the potential for future applications [S. Zhukov, H. von Seggern et al., J. Appl. Phys. 102, 044109 (2007); S. Zhukov, H. von Seggern et al., Scientific reports 8, 4597 (2018)].

B-MRS Newsletter: – Please make a brief story of your interaction with Brazil and with Prof Bernhard Gross.

Heinz von Seggern: – During my PhD work at TU Darmstadt Prof. Gross was a frequent guest of Prof. G.M. Sessler, my thesis adviser. Before my final PhD defense he invited me to visit the Institute of Physics of the University of Sao Paulo (USP) in Sao Carlos. Here I met all the people with whom I am still in contact and friendship with, namely Roberto M. Faria and Jose A. Giacometti who in the meantime have become established professors at USP. After finishing my PhD study I went to Bell Laboratories, Murray Hill, NJ. where Profs. Gross and Sessler were welcomed guest almost every year. The collaboration was extremely fruitful and resulted in a number of joint publications. In 1984 I then left Bell Labs and started to work at Siemens Corporate Research on different topics for the next 12 years and naturally the collaboration was at rest. But as soon as I became appointed Professor at TU Darmstadt I revitalized my connection to the Institute of Physics of Sao Carlos, whose polymer group is now called Grupo de Polimeros “Prof. Bernhard Gross”. From that year on I visited initially Prof. Giacometti and later Prof. Faria almost yearly for up to two month financed generously by FAPESP through various programs. These stays were always very enjoyable and busy, and quite a few publications have resulted.

B-MRS Newsletter: – How many times did you attend the B-MRS Meetings? Do you remember when was the first time?

Heinz von Seggern: – In total I have attended five Brazilian MRS meetings starting in Natal 2007, Florianopolis 2012, Joan Pessoa 2014, Rio de Janeiro 2015 and again Natal in 2017. My first stay in Natal 2007 I remember especially since I was allowed to present our work in front of a great audience on the recently discovered light emitting organic field effect transistor and, on a more personal note, I also remember the wonderful Caipirinha my wife and me were enjoying every evening during sunset at the ocean side.

B-MRS Newsletter: – You have about 40 years of strong experience as a researcher. Please leave a short message with some advice for the students and junior scientists of our community. 

Heinz von Seggern: – In the context of scientific education Prof. Bernhard Gross once said to me: “For someone who knows nothing, everything is possible.” There is a lot of truth in these few words. We all tend to sometimes talk about things that seem to be obvious to us but in reality they are not. My advice therefore is, especially to young scientists, to always ask yourself whether you understand the physical and/or chemical grounds of your current research. If not I suggest to you to acquire the missing basics, which then allows you to select from “everything is possible” the physical meaningful trials. This will definitely help you to make the right decisions to continue your research in a meaningful way.

Awards for the best contributions presented at the XVII B-MRS Meeting: list of the winners.

Posted on Friday 28 de September de 2018

Bernhard Gross Award for students

(Established by B-MRS in honor of the pioneer of Brazilian Materials Research, it distinguishes the best oral and poster contributions of all symposia)

  • Felipe Leon Nascimento Sousa (UFPE, Brazil). Ecofriendly aqueous electrosynthesis of AgInS2–ZnS quantum dots with high optical efficiency. Symposium
  • Lucas Fabrício Bahia Nogueira (USP Ribeirão Preto, Brazil). Bioactive biopolymeric membranes reinforced with hydroxyapatite for tissue engineering application.
  • João Saccoman (UNESP – Bauru, Brazil). Analysis of the optical emission lines from the plasma during the deposition of  TiO2 for sputtering.
  • Lukas Augusto de Lima Basilio (UFAM, Brazil). Hydrothermal synthesis of sodium titanate nanotubes for application in solid state electrolytes.
  • Filipe Rogerio de Souza Quirino (UFPE, Brazil). The temperature dependence of saturation magnetization for yttrium iron garnet doped with Zn, Ni and Co.

ACS Publications Prizes for students 

(Sponsored by the journals ACS Applied Materials & Interfaces, ACS Applied Energy Materials, ACS Applied Nano Materials, ACS Applied Bio Materials, Nano Letters, ACS Nano, Chemistry of Materials, JACS and ACS Energy Letters).

ACS Publications Best Oral Presentation Prize

  • João Batista Maia Rocha Neto (UNICAMP , Brazil). Chitosan/hyaluronan coatings tailored for tumor cell adhesion: influence of the topography and surface chemistry.
  • Daniel Alves Heinze (UFABC, Brazil). Influence of Nanoparticles on the Electrical and Mechanical Properties of SEBS Block Copolymers.
  • Samarah Vargas Harb (UNESP, Brazil). Self-healing PMMA-CeO2 coatings for anticorrosive protection of carbon steel.

ACS Publications Best Poster Prize

  • Fabrício Benedito Destro (UFSCAR, Brazil). Number of grain in polycrystalline hematite modified with Sn: Its influence on electrical properties.
  • Michele Duarte Tonet (UFSC, Brazil). Gold nanoparticles into a discotic liquid crystalline matrix.
  • Jean Felipe Oliveira da Silva (UFPE, Brazil). Magnetic configurations and switching processes in cobalt ferromagnetic hollow nanospheres.

E-MRS Best Oral Presentation Award

  • Everton Bonturim (Universidade Presbiteriana Mackenzie, Brazil). Low-energy polarization switching in La-doped BiFeO3 thin films.

IUMRS Best Poster Award

Gold Prize

  • Nazir Monteiro dos Santos (INPE, Brazil). DLC film deposition as protective coating of titanium alloy tibe using PIII&D system.

Silver Prize

  • Aline Alves dos Reis Almeida (UFMG, Brazil). Preparation and Characterization of P3HT/TiO2 Nanocomposites.

Bronze Prize

  • Felipe Conceição dos Santos (Universidade Presbiteriana Mackenzie, Brazil). Phase transition on chemically exfoliated MoS2 nanosheets: electrocatalytic properties for energy application.

Challenge “Aerospace Materials and Manufacturing for the Next Century”

Winning solution: Aerospace Structures and Systems Inspired by Nature – lotus leaf.

Winning team members:

  • Ana Paula Wünsh Boitt (UFSC, Brazil)
  • Angélica Belchior Vital (UFRN, Brazil)
  • Lázaro Aleixo dos Santos (UFRGS, Brazil)
  • Priscila da Costa Gonçalves (UFSC, Brazil)
  • Tahir Jankal (PUC-Rio, Brazil)

 

 

SBPMat´s community people: interview with Roberto Mendonça Faria.

Posted on Friday 26 de February de 2016

The interviewee of this edition of the newsletter of the Brazilian Materials Research Society Newsletter (SBPMat) is Professor Roberto Mendonça Faria, who has just handed over the SBPMat Presidency after four years in office (although he promises to remain active in the society).

Roberto Mendonça Faria was born in Adamantina, a small town on the west side of the State of São Paulo (Brazil), on May 1952. At the beginning of his secondary studies, already oriented towards “hard sciences” and stimulated by a great physics teacher, he started to look at science as a potential profession. In 1976, Faria concluded his bachelor’s degree in physics at the São Paulo University (USP).

In the same year, still passionate about physics, in which humanity was taking great steps towards knowledge, Faria began his academic career. He started teaching in undergraduate courses at USP and began his master´s course in physics at the same university. There, supervised by Professor Bernhard Gross, a pioneer in Materials research in Brazil, Faria learnt the pillars of scientific activity and developed a fascination for uncovering mysteries of materials (in this case, the conductivity induced via radiation in a polymer known as Teflon). Right after obtaining the master’s degree, in 1980, Faria began the doctorate course in physics at USP, once again having Professor Gross as supervisor. In 1984, Faria defended his dissertation about dielectric absorption and induced conductivity via radiation in the polymer PVDF.

In 1985, Faria started lecturing in postgraduate courses at USP. Between 1987 and 1989, he stayed in France on a post-doctorate internship at Université Montpellier 2. In 1990, he obtained the Associate Professor title at USP after defending a thesis about phase transitions in ferroelectric copolymers. In 1999, he became Full Professor of the São Carlos Institute of Physics (IFSC) at USP, where he occupied several management positions throughout the years, such as the head of the Department of Physics and Materials Science (1994-1996), the coordination of the postgraduate program in physics (1997-1998) and the IFSC general direction (2002-2006).

Roberto Faria also was the coordinator of two large scale projects at a national level. The first project was the “Multidisciplinary Millennium Institute of Polymeric Materials”, one of 17 projects selected within the program “Institutes of the Millennium” of the Brazilian Ministry of Science, Technology and Innovation (MCT). This institute gathered around 140 researchers from 17 institutions from Brazil’s five regions, and existed between 2002 and 2008. The second project continued one of the research focuses of the first one – the study of electronic polymers and their applications. Starting in 2009, the Brazilian National Institute for Organic Electronics was approved and established in the context of the Brazilian National Institutes of Science and Technology (INCTs) from the MCT.

Going beyond the frontiers of his scientific area, Faria was the coordinator, between 2010 and 2014, of the São Carlos pole of the Institute of Advanced Studies (IEA) at USP, an organization intended for broad and interdisciplinary research and discussion of fundamental issues on science and culture. In addition, in the context of his interest in contributing with the economical development of his country through research, Faria coordinated the making of the book “Science, technology and innovation for a competitive Brazil”, published in 2012.

In the last few years, Faria has been having an active participation in international scientific entities in the Materials area. In 2014, he was one of the general coordinators of the “Spring Meeting of the European Material Research Society – 2014”, which took place in the French city of Lille.  In 2015, he was elected second vice-president of the International Union of Materials Research Societies (IUMRS).

Faria is a member of the Academy of Sciences of the State of São Paulo and the Brazilian Academy of Sciences and belongs to the editorial board of the journal “Materials Science – Poland”. In 40 years of scientific research on polymeric materials, particularly those with electronic activity and their applications in devices, Professor Faria has produced around 180 articles published in indexed journals, having about 2,000 references, and has supervised 47 master´ss and doctorate thesis.

An interview with the researcher follows below.

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

Roberto Mendonça Faria: – Before High School, I imagined I was going to follow my studies in the “hard sciences” area (engineering, physics, chemistry, mathematics, etc.). But I didn’t have any intention to follow a scientific career, even less so to be a scientist. However, in the first year of High School I started to change my mind, stimulated by an excellent physics teacher, Roberto Stark. I graduated in Physics and soon after I was lucky to be supervised by two great masters: Professor Bernhard Gross and Professor Guilherme Fontes Leal Ferreira. As any newly-graduated person in physics at the time, I was passionate about the extraordinary experimental and theoretical advances of the 20th century physics.  However, my first research study was about an apparently modest theme: the interaction of ionizing radiation with thin films of insulating polymers. Under the supervision of Professor Gross, I definitely learnt how to approach a scientific issue and also how to handle the methodological strictness needed to discover the effects and the phenomena arising from the experiments performed. Those first years of research were crucially important to my career. I never again lost the fascination in discovering the properties and the enigmas of the condensed matter, and I’m happy because materials science and engineering is extremely important for the development of Brazil.

SBPMat Newsletter: – In your assessment, which are your main contributions to the field of Materials?

Roberto Mendonça Faria: – There are different ways to measure the contributions made to the advance of scientific and technological knowledge. The most objective and internationally followed view is the bibliometric, conduced by the Journal of Citation Reports (JCR) from Thomson Reuters. This metric has many merits, but it’s too much focused on numbers. Another fact influencing scientific assessments comes from the pragmatism of the present world. Today, it is required that scientific works aim at specific applications. In this context, researches involving more fundamental studies tend to lose the visibility they deserve. That is, many times scientific works of great value have little mentions. An analysis of my production from JCR may lead to the conclusion that my most relevant contributions are connected to applications, but I particularly believe that my greatest contributions are more related to fundamental works in the areas of phase transitions of ferroelectric polymers and electrical transportation mechanisms in electronic polymers.

One of the interesting areas I have been working on in the last few years is the organic solar cells. I believe that, with my research group, we gave a significant contribution to the understanding of phenomena involving the transportation of electrical carriers inside the cell. Since 2013 we published two works where we developed an analytical equation which rules the electrical current curve in function of the voltage of a solar cell when under lighting. This analytical equation works very well in special cases and has explained many of the optoelectronic effects of the devices we built and measured in our laboratories. One of the works was published in the Applied Physics Letters journal in 2013, and the other was published on Solar Energy Materials and Solar Cells in 2015.

On the other hand, I always dedicated myself to assembling research laboratories and forming human resources. I also have been contributing with several post-graduation programs, directly and indirectly, and for more than 20 years I have been dedicating myself to strengthening the area of Organic Electronics in the country, especially in the formation of a research network in this area: the National Institute of Science and Technology of Organic Electronics. Whenever possible, I try to encourage projects in partnership with private enterprises and research institutes that aim towards applied projects. In the public policies area, I believe my greatest participation was coordinating a document from CAPES (the Brazilian agency in charge of post-graduate programs) and SBPC (Brazilian Society for the Advancement of Science), called “Science, technology and innovation for a competitive Brazil”, which has contributed to the creation of the Brazilian Company of Industrial Research and Innovation (EMBRAPII).

SBPMat Newsletter: – You have just finished your tenure as President of SBPMat. Share with our readers an analysis of the results achieved by the boards you have headed during the last four years.

Roberto Mendonça Faria: – SBPMat is a relatively new society, but it has an important mission to fulfill for the development of the country. Brazil has an extraordinary richness offered to it by nature. However, the country does not take advantage of this richness because it places little knowledge over its natural resources. There was a revolution in agriculture after the country decided to put knowledge over this blessing that nature has offered to it. Today, agribusiness is one of the pillars, perhaps the strongest one, of our economy. We have to do the same with the raw matters that abound in our territory. The publication “Science Impact – A special report on materials science in Brazil”, in partnership with the Institute of Physics (IOP), was one of the projects that worked and gratified me very much. This type of initiative helps raising awareness that Brazil has a natural gift to be a leader in several materials-related segments and to generate a lot more richness than it currently does.

Another valuable contribution that the two previous SBPMat administrations gave to materials science and engineering in Brazil was the definite consolidation and internationalization of the annual meeting, which always take place at the end of September.

I must highlight that the creation of the bilingual electronic newsletter was a realization that worked, especially because of the capability it has been produced with.

SBPMat Newsletter: – You just took over, for two years, the second vice-presidency of IUMRS. Talk about your plans, expectations…

Roberto Mendonça Faria: – I’m starting this activity. My plans are, first of all, to increasingly insert the Brazilian Materials Science in the international scenario. At the same time, I intend to use the IUMRS support to stimulate materials research in other Latin American countries. Brazil and Latin America have many problems that come from their still deficient economies. I have conviction that research studies in the materials area are valuable instruments to improve the living conditions of these populations. Today, as a member of the SBPMat council, I want to take this discussion not only in Brazil, but in several Latin American countries with the help from IUMRS.

SBPMat Newsletter: – Leave a message for the readers that are starting their scientific careers.

Roberto Mendonça Faria: – I decided to register here that one of the fulfillments (still in progress) that makes our administration proud was the creation of the University Chapters program. I’m going to ask the council to allow me to work with Professor Rodrigo F. Bianchi within this program. I have no doubts that the more researchers we form, the more Brazil will gain with this.

I believe that the work with young people starting scientific activity is one of the most valuable works for a senior researcher. It is our duty to show young people how important the work of “manufacturing knowledge” is for the country, especially in scientific and technological areas. There isn’t one example of a country that has eradicated poverty without the development of strong education and competitive science and technology. Therefore, the message to young people is: believe in your work and always try to make it in the most competent way possible.

Some information about the scientific work of Professor Gross.

Posted on Thursday 31 de January de 2013

Great part of the scientific activity of Prof. Bernhard Gross which came before his studies on electrets receive very little attention but are priceless. The papers on electrets started to have international prominence and repercussion after the 70’s and continued until early 80’s. I will comment a little about what he produced since the beginning of his career until the 60’s.

While still in Stuttgart, Germany, he published some papers about latitude corrections in detectors used to study cosmic rays in the atmosphere [references 1 and 2]. These articles were published in German. His work was soon generalized by E. J. Williams and published by Nature magazine [3]. Later on, this correction became known as “Gross’s transformation”. In the celebrated book about cosmic rays, published in 1950 [4], chapter 3 is dedicated to “Gross’s transformation”.

His first paper in Brazil was regarding electrical properties of zeolites [5] which, together with the work on delayed effects on dielectric solids [6] and, later on, on static charges on dielectrics [7], marked the beginning of his research in the field of Materials, which would culminate with famed studies about electrets after the 60’s. However, some seminal works on mathematical models applied to visco-elastic systems were very significant. These works were published in the last years of the 40’s [8-11]. As a result of this works, Gross published a book on the subject, which is still used as essential reference for the field of rheology of solids [12].

Circa 1950, Gross performed a series of studies on the effects of radiation on vitreous and polymeric systems [13.14]. With these studies, he discovered an electrical current in dielectric solids, which was related to the Compton Effect, originating celebrated and seminal work [15]. This effect explained the phenomenon occurring in nuclear plants, which had remained unexplained until then. The glass windows used as protection to radiation spontaneously cracked after being used for some time. Gross was invited by the Radiation Research Center in New York and, together with local researchers, he proved that Compton currents were responsible for the degradation of glass [16]. Right after that, Gross invented the Compton dosimeter [17], which he patented in the Unites States, but lost it for the American army after a legal battle.

Still in Brazil, Gross started his first studies about electrets [18, 19]; being the first to manufacture what he called radioelectrets. After retiring from the National Institute of Technology, he was invited to be in charge of the Department of Scientific and Technical Information of the International Agency of Atomic Energy, in Vienna, where he stayed until the end of the 60’s. He published some relevant papers about scientific information [20] and returns as a researcher in the field of electrets in the 70’s.

Professor Roberto Mendonça Faria
Researcher on Group of Polymers “Prof. Bernhard Gross” (USP São Carlos)
Prof. Bernhard Gross’s PhD student, between 1980 and 1984.

 References

[1] For the Pressure Dependence of the Ionization by Cosmic Ray (Zur Druckabhängigkeit der Ionisation durch. Ultrastrahlung), B. Gross, ZEITSCHRIFT FUR PHYSIK Volume: 78 Issue: 3-4 Pages: 271-278 DOI: 10.1007/BF01337596 Published: MAR 1932.
[2] For the absorption of the ultra radiation (Zur Absorption der Ultrastrahlung), ZEITSCHRIFT FUR PHYSIK, B. Gross,  Volume: 83 Issue: 3-4 Pages: 214-221 DOI: 10.1007/BF01331141 Published: MAR 1933.
[3] Spectrum and latitude variation of penetrating radiation, E. J. Williams, Nature, 512 (1933).
[4] Cosmic rays, L. Janossy (1950), Oxford at Clarendon Press.
[5] On the electric conductivity of Zeolite, B. Gross, ZEITSCHRIFT FUR KRISTALLOGRAPHIE Volume: 92 Issue: 3/4 Pages: 284-292 Published: DEC 19.
[6] On after-effects in solid dielectrics, B. Gross, PHYSICAL REVIEW Volume: 57 Issue: 1 Pages: 57-59 DOI: 10.1103/PhysRev.57.57 Published: JAN 1940.
[7] STATIC CHARGES ON DIELECTRICS, B. Gross, BRITISH JOURNAL OF APPLIED PHYSICS Volume: 1 Issue: OCT Pages: 259-267 DOI: 10.1088/0508-3443/1/10/304 Published: 1950.
[8] ON CREEP AND RELAXATION, B. Gross, PHYSICAL REVIEW Volume: 71 Issue: 2 Pages: 144-144 Published: 1947.
[9] ON CREEP AND RELAXATION, B. Gross, JOURNAL OF APPLIED PHYSICS Volume: 18 Issue: 2 Pages: 212-221 DOI: 10.1063/1.1697606 Published: 1947.
[10] ON CREEP AND RELAXATION .2, B. Gross, JOURNAL OF APPLIED PHYSICS Volume: 19 Issue: 3 Pages: 257-264 DOI: 10.1063/1.1715055 Published: 1948.
[11] FRICTIONAL LOSS IN VISCO-ELASTIC SUBSTANCES, B. Gross, JOURNAL OF APPLIED PHYSICS Volume: 21 Issue: 2 Pages: 185-185 DOI: 10.1063/1.1699622 Published: 1950.
[12] Mathematical structure of the theories of Viscoelasticity, B. Gross, Paris, Hermann Press (1953).
[13] IRRADIATION EFFECTS IN BOROSILICATE GLASS, B. Gross, PHYSICAL REVIEW Volume: 107 Issue: 2 Pages: 368-373 DOI: 10.1103/PhysRev.107.368 Published: 1957.
[14] IRRADIATION EFFECTS IN PLEXIGLAS, B. Gross, JOURNAL OF POLYMER SCIENCE Volume: 27 Issue: 115 Pages: 135-143 DOI: 10.1002/pol.1958.1202711511 Published: 1958.
[15] THE COMPTON CURRENT, B. Gross, ZEITSCHRIFT FUR PHYSIK Volume: 155 Issue: 4 Pages: 479-487 DOI: 10.1007/BF01333129 Published: 1959.
[16] BETA-PARTICLE TRANSMISSION CURRENTS IN SOLID DIELECTRICS, B. Gross, A. Bradley & A. P. Pinkerton, JOURNAL OF APPLIED PHYSICS Volume: 31 Issue: 6 Pages: 1035-1037 DOI: 10.1063/1.1735740 Published: 1960.
[17] Compton Dosimeter for measurements of penetrating x-rays and gamma rays, B. Gross, RADIATION RESEARCH Volume: 14 Issue: 2 Pages: 117-& DOI: 10.2307/3570883 Published: 1961.
[18] GAMMA IRRADIATION EFFECTS ON ELECTRETS, B. Gross & R. J. D. Moraes, PHYSICAL REVIEW Volume: 126 Issue: 3 Pages: 930-& DOI: 10.1103/PhysRev.126.930 Published: 1962.
[19] POLARIZATION OF ELECTRET, B. Gross & R. J. D. Moraes, JOURNAL OF CHEMICAL PHYSICS Volume: 37 Issue: 4 Pages: 710-& DOI: 10.1063/1.1733151 Published: 1962.
[20] PRESENT AND FUTURE TRENDS OF SCIENTIFIC INFORMATION, B. Gross, ATOMIC ENERGY REVIEW Volume: 4 Issue: DEC Pages: 85-& Published: 1966.