Plenary lectures: world-class science with social impact.


Plenary lectures: very good attendance.

The scene repeated itself daily while the event lasted: around 8.30 a.m. and 2 p.m., under the strong João Pessoa sun, lines of hundreds of participants entered the convention center and settled at the refrigerated plenary room. There, scientists with outstanding careers, attested by their H indexes of values ranging from 40 and 73, coming from England, France, Germany, Italy, Portugal and United States, shared their knowledge about matters on which they are, without a shadow of a doubt, qualified specialists.

In the event’s final plenary lecture, Robert Chang, professor at the first department of materials science in the world, at Northwestern University, resumed two subjects that had been explained by Professor Arana Varela in the memorial lecture, and which permeated almost every plenary. The first one is the essential role that materials field and, in particular, nanotechnology play in meeting, in a sustainable way, the needs and demands of humanity in healthcare, food, transportation, security and communication. The second subject is the need for collaboration to face this challenge of the 21st century.

In this context Chang, who was president of the American Materials Research Society (MRS) and founded in 1991 the International Union of Materials Research Societies (IUMRS), called upon the young Brazilians [see video below] to be part of a global network released in 2012, which promotes the interaction of young researchers in the field around these global challenges through a biennial conference and virtual platforms.

However, Chang said, the scientific collaboration among physicists, chemists, engineers, mathematicians, biologists and other researchers to develop the necessary technologies is insufficient. It is also necessary, he added, to rely on the collective, global effort from governments, companies, communities, families and individuals to deploy these technologies on peoples’ daily lives. “That requires education”, he said. For the last 20 years, the scientist has conducted the Materials World Modules Programme, which developed interactive educational material about Materials and Nanotechnology for middle and high-school students.

Nanomedicine

Luís Carlos

Portuguese professor Luís Carlos, from the University of Aveiro, brought to XIII SBPMat Meeting many examples about the applications of nanotechnology in the healthcare field that are making a difference, or may make a difference in the short-term.

Being an expert in luminescent materials, which emit light not derived from heat, the scientist showed in his plenary lecture that these materials are already of great use in medical diagnosis. Luminescent organic complexes, for example, are marketed as contrast agents for magnetic resonance imaging, and as markers for fluoroimmunoassays (used in pre- and neonatal screening and detection of proteins, viruses, antibodies, drug residues etc.).

Besides, Luís Carlos said, luminescent nanoparticles (quantum dots and nanocrystals with lanthanide ions) emerge in diagnostic techniques and also in treatments, such as the hyperthermia process. This consists in the exposition of biological tissues, usually cancerous cells, at temperatures above 45°C, causing their deaths, with minimum collateral lesions to surrounding normal tissues. With proper temperature monitoring and control, the technique can soon become popular.

For the last few years, there have been efforts to develop nanothermometers that measure intracellular temperature to service this and other applications, not only regarding Nanomedicine, but also in fields such as Microelectronics, Photonics and Microfluidics. A successful example, presented by Luís Carlos at the plenary, is the development of a nanometric platform composed by nanorods, which work as thermometers, with gold nanoparticles on its surface, which function as heaters. This is a platform that, in contrast to its small size, can bring great benefits to the improvement of the technique of hyperthermia and the study of the processes of heat transfer at the nanoscale.

LEDs and other gallium nitride devices: savings of 25% in the global electricity consumption

Sir Colin Humphreys

When the Nobel Prize in Physics was announced for three Japanese scientists whose works were essential for the development of LED white light bulbs, those who had participated in XIII SBPMat Meeting certainly remembered the plenary lecture by Sir Colin Humphreys from University of Cambridge. The material chosen by the laureates when they decided to face the challenge of creating the blue LED that would allow the white light emitting LED was gallium nitride, which was also the object of Sir Colin’s lecture.

Professor Humphreys is an expert in this material. He created and directs a research center in Cambridge devoted to gallium nitride, and he also founded two spinoff companies to commercially exploit the technology developed by his research group and manufacture LEDs grown on relatively large silicon wafers, of about 15 cm, for low cost lighting. In 2012, the spinoffs were purchased by Plessey, a manufacturer of products based on semiconductor materials with over 50 years in the market. Now these LEDs are produced by Plessey in the United Kingdom.

The gallium nitride LED bulb currently offers one of the longest shelf lives in the market – 100,000 hours of use, equivalent to 69 years without switching the bulb, against 1,000 hours of life of the incandescent light bulb and 10,000 of the fluorescent. These LEDs also provide high energetic efficiency, ranging from 100 to 200 lumens (amount of light emitted in a second) per watt of power consumed.

At the plenary lecture, Sir Colin showed that the widespread use of LEDs in lighting would result in savings of about 15% in the total electricity consumed on the planet, and thus in a substantial decrease in emissions of carbon dioxide. In fact, lighting is one of the few segments where devices with high-energy efficiency are not yet universal.

More energy can be saved, Professor Humphreys said, by replacing silicon by gallium nitride in various electronic devices. In total, Humphreys concluded, up to 25% of all electricity used in the world today could be saved, reason why, added to the other applications of gallium nitride in the healthcare field, it was enough for the British scientist to state that this manmade material is one of the most important in the world.

Organic semiconductors: OLEDs and solar cells in the spotlight

Karl Leo

Just like it happens with LEDs, the OLEDs, which are manufactured with organic materials justifying the “O” in the acronym, directly convert electricity into light and are, therefore, devices with high potential efficiency, which has been improved every year. Having each one particular advantages, LEDs and OLEDs already compete in certain markets, such as the one of displays and, in a more incipient manner in the case of organics, in the lighting market.

Along with organic solar cells, OLEDs were the focus of Karl Leo’s plenary lecture. He is a professor at the German TU Dresden and at the Saudi Arabian KAUST universities, and wrote over 550 papers with 23,000 references and 50 patent families. He is also founder of 8 spinoff companies, such as Heliatek and Novaled, which manufacture organic solar cells and OLEDs, respectively.

Professor Leo showed an important quantity of results achieved by his research groups, regarding the improvement of organic semiconductor devices. Along with his collaborators, Karl Leo has developed an extensive work about doping organic semiconductors in the transport layers of OLEDs and solar cells to increase significantly their electrical conductivity. This work resulted, for example, in obtaining white light-emitting OLEDs with energetic efficiency greater than those of fluorescent tubes.

From the left, A. Salleo, F. So, R. Faria, H. von Seggern and J. Nelson.

Karl Leo was not the only internationally renowned scientist in João Pessoa in the field of organic semiconductors. On Wednesday afternoon, a roundtable organized by Symposium D gathered four of these specialists: Alberto Salleo (Stanford University), Franky So (University of Florida), Heinz von Seggern (TU Darmstadt) and Jenny Nelson (Imperial College London). Moderated by a prominent Brazilian scientist of the field, Roberto Mendonça Faria, professor at the São Carlos Institute of Physics at University of São Paulo and SBPMat president, the session gathered dozens of participants of the meeting, of various ages, that actively participated at the debate.

The discussion was around the challenges of organic electronics, from basic research to mass production (or individual production, as pointed out by a young man of the public drawing attention to the 3D printing techniques). Various subjects of the scientific, industrial and social fields were addressed bythe panelists based on the audience’s questions. “Fortunately, there are challenges for Materials Science. Unfortunately, there are challenges for mass production,” Professor Faria summed up, resuming, somehow, one of the first lines of the round table, in which Professor Jenny Nelson lamented that the scientific community celebrated a lot more the development of a device that works than the understanding of why a particular device did not work.

Alberto Salleo

Alberto Salleo, creator of a group in Stanford that studies the relation between structure and properties on polymeric semiconductors to better understand the charge generation and transport, also delivered a plenary lecture at the event. In the lecture, Salleo cast doubt on the universality of a widespread assumption that links a high degree of crystallinity (or order) in the microstructure of these polymers to a higher charge mobility, or better performance of the devices. The scientist showed that the disorder is good for organic solar cells and cited examples of almost amorphous semiconducting polymers having similar performance to others much ordered.

Professor Salleo presented a model developed by his group to show how the charge transport in organic semiconductors works, since they are materials with heterogeneous microstructures, where disordered and ordered aggregates coexist with each other and with long polymer chains. In order to have high charge mobility, Salleo revealed, the important thing is for the aggregates to connect among themselves, which happens through the polymeric “spaghetti”.

Order, but without periodicity

Jean-Marie Dubois

The quasicrystals are far from the disorder, but also outside the traditional crystalline order. These materials were the general theme of the plenary of French researcher Jean-Marie Dubois, from Institut Jean Lamour, whose experience in this field was recognized by the scientific community through the creation of the “Jean-Marie Dubois International Award”, given every three years to research works related to quasicrystals.

First, Dubois presented an introduction to quasicrystals, materials in which the atoms are grouped into unit cells in patterns which are ordered (which may be determined by algorithms) but not periodic (never repeat themselves). Beautiful scientific and artistic images intermixed in Dubois’ presentation allowed the audience to view this aperiodic order.

The lecturer also paid homage to Dan Shechtman, who discovered quasicrystals in 1982 and, after many fights and resistance in the scientific community, eventually won the Nobel Prize in Chemistry in 2011 and generated a big shift in the vision of ordered condensed matter. Today, quasicrystalline materials are synthesized and used in various products, such as auto parts and pans, to improve their thermal conductivity, adhesion, friction, corrosion resistance etc. It is noteworthy that Dubois is among the pioneers in filing patents targeting applications of quasicrystals.

The quasicrystalline order can be observed in various types of materials. In the lecture at the XIII SBPMat Meeting, Dubois addressed, in particular, metal alloys formed by three elements (A, B and C), in which A – B and B – C form chemical bonds, while B and C repel themselves. Named by Dubois “push-pull alloys”, these materials can form very complex intermetallic compounds, with up to hundreds of atoms per unit cell. Among these, only a few can further increase their complexity to form a quasicrystalline order, which results in unique properties and open up possibilities for new applications.

Computer simulation

Roberto Dovesi

In another plenary lecture of the XIII SBPMat Meeting, supporters of computer simulation as a complement to the experimental work in the investigation of material properties, and those interested in using it, were able to hear from Professor Roberto Dovesi (Università di Torino) that this dual approach is worthwhile.

Dovesi is one of the creators of CRYSTAL, a computational tool that allows the characterization of crystalline solids from the point of view of quantum mechanics, through ab initio calculations. The first version of the program was developed from 1976 onwards and released in 1988, making CRYSTAL the first periodic code distributed publicly to the scientific community. Now in its seventh version, the program allows the study of elastic, piezoelectric, photoelastic and dielectric properties, polarizability and hyperpolarizability tensors, IR and RAMAN spectrum, structure of electronic and phononic bands, among other properties.

The Italian chemist highlighted the affordable price and high working speed of today’s computers that are suitable to run such programs. As an example, he cited a machien recently acquired by his research group for computer simulation, which, costing around 6,500 euros, is able to do long calculations in a few hours with its 64 cores. Supercomputers are not necessary, Dovesi said, and are less robust. As for software, Dovesi remarked that today the field of materials has powerful, robust, easy-to-use programs at affordable prices (a basic license of the latest version of CRYSTAL, for example, costs 600 euros.

SBPMat newsletter. English edition. Year 1, issue 9 – special: XIII SBPMat Meeting.


 

Brazilian Materials Research Society (SBPMat) newsletter

News update from Brazil for the Materials community

 

English edition. Year 1, issue 9. 

Greetings, .

Final arrangements for our meeting in João Pessoa!

– Read the message of the chairs of the event, which this year accepted 2,141 papers and has nearly 2,000 registrations from 28 countries so far. In the message, professors Ieda Garcia and Severino de Lima show the highlights of the program of this year’s meeting! Here.

– After lunch and before the afternoon plenary lectures, you can attend technical lectures of the meeting´s sponsors in João Pessoa: Shimadzu/Tescan will discourse about SEM with ion beam and TOF SIMS detector, and FEI will address DualBeam TEM. Learn more.

– Why is João Pessoa called “the sun door“? Learn more about the city, one of the oldest in Brazil, and its natural and cultural features. And get ready to dive into green waters at 28 °C! Read about João Pessoa.

– What to pack? Track the weather, whose temperatures should be between 20 °C and 30 °C. But pay attention, the meeting organization warns that, at the Convention Center, the air conditioner will make the room fresh … Link to weather in João Pessoa.

– Registration: here.

Program at a glance: here.

Detailed schedule. Search for times and locations of symposia presentations: here.

–  Some options of accommodation, car rental, transfers from the airports of the region, transportation from hotels to convention center, and tours: see on the home page of the site of the event.

– And what about the conference party? This year, it will be held on Wednesday evening at Espaço Caixa Econômica Federal in Cabo Branco. Tickets may be purchased in the information desk as of Monday 1 p.m..

 

Interviews with our plenary speakers

We interviewed Robert Chang, professor of the first department of Materials Science in the world at Northwestern University. Besides having a remarkable career as a researcher (his H index is 56), “Bob” has dedicated the past 20 years guiding the development of the Materials World Modules program, which develops educational, interactive and playful material (for example, card games) on Materials and Nanotechnology for pre-college students and their teachers. In his plenary lecture at the XIII SBPMat Meeting, Professor Chang will try to mobilize citizens of the world to solve global problems together. See our interview with the scientist.

We also spoke with Professor Colin Humphreys, a professor at the University of Cambridge.  Among other honors, the scientist was knighted by the Queen of England for his services to science. Besides being the author of over 600 publications, the professor developed materials for the industry that currently fly in aircraft engines and created low cost LEDs based on gallium nitride, material on which he specialized. In João Pessoa, he will show, among other issues, how gallium nitride could reduce electricity consumption by 25% in the world. See our interview with Colin Humphreys.


We interviewed the German physicist Karl Leo, specialist in organic semiconductors. Beyond being the author of more than 550 papers with more than 23,000 citations and 50 families of patents, the scientist has already participated of the creation of 8 spin-off companies. In his lecture at the XIII SBPMat Meeting, Karl Leo will speak on highly efficient organic devices, as OLEDs and solar cells. See our interview with Karl Leo.

We also spoke with the Portuguese physicist Antonio Luis Ferreira Martins Dias Carlos, of the University of Aveiro, who will perform a lecture in our meeting in João Pessoa on luminescence applied to nanomedicine. In the interview, the professor shared with us his most prominent works in the field of Materials. He also told us about some challenges in the area of luminescence for medical applications, both in medical imaging and intra-cellular temperature mapping, and cited examples of applications of luminescent materials that have already been used in the diagnosis and treatment of various diseases. See our interview with Luis Dias Carlos.


We interviewed the French scientist Jean-Marie Dubois (Institut Jean-Lamour), specialist in quasicrystals (ordered, but aperiodic structures on solid materials) and pioneer in patenting applications for them. He told us a little about his main contributions to the field of Materials and gave a teaser on the theme of his plenary lecture in the XIII SBPMat Meeting: he will talk about quasicrystal structures, found in metallic alloys, polymers, oxides and artificial nanostructures, and their unprecedented properties. In the picture, Jean-Marie Dubois (on the left) and Dan Shechtman, who received a Nobel Prize in 2011 for the quasicrystals, using equal ties, both decorated with the Penrose tiling, an example of aperiodicity.  Read our interview with Jean-Marie Dubois here.

We also interviewed the Italian chemist Roberto Dovesi (Universita’ degli Studi di Torino), one of the creators of CRYSTAL, a computational tool for ab initio quantum calculations used in the study of several solid materials properties. The CRYSTAL code is currently used in over 350 laboratories around the world.  In his plenary lecture in the XIII SBPMat Meeting, Dovesi will attempt to demonstrate that today quantum simulations may be very useful tools to complement experiments. See our interview with Roberto Dovesi.


We have interviewed Professor Alberto Salleo, from Stanford University, who is going to give a plenary lecture on organic electronic devices in the XIII SBPMat Meeting. Young, yet holding a career that stands out internationally, Salleo told us about the work conducted by his group, which has been developing a deeper understanding on the role provided by the defects in charge transport in organic semiconductors. He also shared with us his main papers, published in Nature Materials. Finally, Salleo discussed the next challenges and applications on organic electronics, and anticipated what he is going to address in the plenary lecture, which promises to be very informative while mild enough for a wider audience. Read our interview with Alberto Salleo.

To suggest news, opportunities, events or reading recommendations items for inclusion in our newsletter, write to comunicacao@sbpmat.org.br.
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Interviews with plenary lecturers of the XIII SBPMat Meeting: Luís Carlos (Universidade de Aveiro, Portugal).


Prof. Luís Carlos.

“Luminescence applied to nanomedicine” is the subject of one of the plenary lectures that the Materials research community is going to enjoy in our XIII SBPMat Meeting (João Pessoa, Brazil, September 28th to October the 2nd). The speaker will be the Portuguese physicist Luís António Ferreira Martins Dias Carlos, full professor at the University of Aveiro (Portugal), who got his Ph.D. in physics from the University of Évora (Portugal) in 1995 working on photoluminescence of polymer electrolytes incorporating lanthanide salts.

At the University of Aveiro, Luís Carlos created in 2000 a research group in functional organic-inorganic hybrids. The group has established an international network devoted to these luminescent hybrid materials with more than 30 research groups in Europe, China, Japan, Singapore, Brazil and Australia. Also at Aveiro, Luís Carlos has been, since 2009, the vice-director of the Centre for Research in Ceramics and Composite Materials (CICECO), one of the largest European institutes in the Materials and Nano fields.

He is member of the Lisbon Academy of Sciences (Physics section) since 2011. He was visiting professor of São Paulo State University (UNESP), Brazil, in 1999, 2012 and 2013, and of University of Montpellier 2, France, in 2008. He awarded a ‘Pesquisador Visitante Especial’ grant by the CNPq, Science Without Borders Program, Brazil in 2013.

He has co-authored more than 345 papers in international journals, 8 invited reviews, 5 book chapters, and 2 international patents. He has more than 8.050 citations, having h-index of 47. He has given 40 plenary and invited lectures at conferences. He is associate editor of the Journal of Luminescence.

Read our interview with the plenary speaker.

SBPMat newsletter: – Are there nanomedical applications to luminescent materials already on the market/spread in society? Please, give some high-impact examples. 

Luís Carlos: – Undoubtedly yes, there are luminescent materials with important applications in nanomedicine already on the market. I can highlight two examples:

1. Organic complexes based on lanthanide ions (as, for example, cryptates and β-diketonates) are sold as contrast agents for magnetic resonance imaging  (essentially using Gd³+) and luminescent markers (using Eu3+, Sm3+ and Tb3+) for fluoroimmunoassays. The fluoroimmunoassay is an immunological method for clinical diagnosis that is particularly relevant in prenatal and neonatal screening tests, as well as to detect proteins, viruses, antibodies, tumor biomarkers and medicine residues. In this respect, it is worth mentioning the work conducted by several researchers from the INCT INAMI (Brazilian National Institute of Science and Technology on Nanotechnology for Integrated Markers), implementing a prototype in the hospital environment in order to develop methods to diagnose the American cutaneous leishmaniasis, prostate cancer (PSA) and low density lipoprotein (LDL) by fluoroimmunoassay, using recombinant antigens marked with lanthanide ions complexes (for example, Eu3+, Tb3+ and Nd3+). The international market for contrast agents and luminescent markers based on lanthanide ions is valued in many hundreds of millions of US dollars.

2. Luminescent nanoparticles (“quantum dots”, QDs, and nanocrystals incorporating lanthanide ions) have played a major role in the last years thanks to very important applications for diagnosis by optical imaging and therapy techniques. Recent estimates value the international market for luminescent nanoparticles in the medical field in over 20 million US dollars. A notable example in the treatment of tumors is the local hyperthermia. Local hyperthermia, also referred as local thermotherapy, is a type of treatment in which biological tissues (typically cancer cells)  are exposed to temperatures above 45° C, irreversibly damaging them and causing their death (the collateral damage to the healthy tissues surrounding the tumor is usually minimal). Numerous clinical trials with hyperthermia are being currently performed around the world so we can better comprehend and improve the technique. For example, the use of luminescent or magneto-luminescent particles (with magnetic ions such as Iron or Cobalt), vectored to bind to specific points in the cancer cells, enabling the local heating by the absorption of electromagnetic radiation and magnetic induction, respectively, is a new type of local hyperthermia. Precise temperature control in the irradiated area, limiting the effects of high temperature on the rest of the body, still is one of the key challenges for the popularization of the technique.

SBPMat newsletter: –  Could you briefly describe the main challenges in the field of luminescence applied to nanomedicine?

Luís Carlos: – I can point out two examples: improving the imaging techniques for diagnosis and developing luminescent micro/nanothermometers which allow mapping the intracellular temperatures with a resolution of the order of tenths of a degree.

In regard to imaging applications in nanomedicine, emitting centers in the near-infrared region (for example, lanthanide ions such as Nd3+ and Yb3+, QDs and organic dyes) have great advantages over those in the visible region.  For instance, biological tissues present less autofluorescence in the near-infrared window, which enables a better signal-to-noise discrimination and improves the sensibility to detection. Also, in comparison to the ones in the visible region, near-infrared photons interact less with biological tissues, which reduces the risk of disturbance or damage in the observed biological system. Thus, there is no doubt that the synthesis of new luminescent nanoparticles, emitting efficiently in near-infrared (in some cases producing persistent luminescence, i.e., light emissions that last for minutes, hours or even days, after the excitation is over), will lead us to a revolution in fluorescence microscopy, with the development of in vitro and in vivo imaging techniques in near-infrared (whose radiation penetrates deeper into the biological tissue, when compared to visible light).

The development of luminescent micro/nanothermometers to map the intracellular temperature, particularly in cancer cells, will surely improve our current perception on their pathology and physiology, optimizing early diagnosis and therapeutic processes (as seen above in the case of local hyperthermia).  These non-invasive thermometers are a critical tool for better understanding a set of cellular processes followed by alterations in temperature, such as cell division, gene expression, or changes in the metabolic activity. Finally, the development of luminescent nanothermometers in the near-infrared region,  which are capable of sensing heat and penetrate deeper into the biological tissue, will pave the way for in vivo thermal sensing and imaging (in small animals, in a first stage).

SBPMat newsletter: – Under your viewpoint, which are the main contributions you made to the field of Materials Science and Engineering during your scientific career? Could you please include a selection of 3 or 4 of the most important publications among your work in your answer?

Luís Carlos: – Normally, our latest works tend to seem to be the most important… Regardless, I understand that my main contributions to Materials Science and Engineering are related to the development of i) luminescent organic-inorganic hybrid materials, ii) ratiometric nanothermometers based on the characteristic emission of lanthanide ion pairs (Eu3+/Tb3+ and Er3+/Yb3+) and iii) nanoplatforms combining nanoheaters (metal particles of Gold or Silver) and nanothermometers which allow to increase the local temperature by laser irradiation while simultaneously mapping such temperature increase with precision. The following four papers illustrate these contributions:

Full Colour Phosphors From Eu(III)-Based Organosilicates. L. D. Carlos, Y. Messaddeq, H. F. Brito, R. A. Sá Ferreira, V. de Zea Bermudez, S. J. L. Ribeiro, Adv. Mater. 12, 594–598 (2000)

Nanoscopic Photoluminescence Memory as a Fingerprint of Complexity in Self-Assembled Alkylene/Siloxane Hybrids. L. D. Carlos, V. de Zea Bermudez, V. S. Amaral, S. C. Nunes, N. J. O. Silva, R. A. Sá Ferreira, J. Rocha, C. V. Santilli, D. Ostrovskii, Adv. Mater. 19 341–348 (2007)

A Luminescent Molecular Thermometer for Long-Term Absolute Temperature Measurements at the Nanoscale. C. D. S. Brites, P. P. Lima, N. J. O. Silva, A. Millán, V. S. Amaral, F. Palacio, L. D. Carlos, Adv. Mater. 22, 4499–4504 (2010)

All-In-One Optical Heater-Thermometer Nanoplatform Operative From 300 to 2000 K Based on Er3+ Emission and Blackbody Radiation. M. L. Debasu, D. Ananias, I. Pastoriza-Santos, L. M. Liz-Marzan, J. Rocha, L. D. Carlos, Adv. Mater. 25, 4868–4874 (2013)