It is with deep regret that B-MRS informs the death of its founding member Aldo Felix Craievich, senior professor at USP, which occurred in the early hours of today, April 24, 2023, at the age of 84.

Craievich was a pioneer in glass research in Brazil and one of the protagonists in the history of the National Synchrotron Light Laboratory (LNLS). In addition, he dedicated himself to training users of synchrotron light, mainly in Latin America.

In 2016, B-MRS distinguished him with the Memorial Lecture “Joaquim da Costa Ribeiro” in recognition of his trajectory.

The Executive Board of B-MRS deeply regrets the departure of this Argentine scientist, who had lived in Brazil since 1973, and would like to remember him as a member who made great contributions to our community.

A team of researchers from CeRTEV (one of the largest academic centers for glass research in the world, located in São Carlos, SP, Brazil) has carried out the first experimental observation of the changes that occur in the structure of a glass during relaxation and nucleation, two processes that occur at the nanometer scale in all glasses and that impact their properties.

It is worth remembering that glasses are amorphous materials: their atoms do not appear in an organized and periodic arrangement. Furthermore, they are out of thermodynamic equilibrium and therefore tend to seek stability. In that search, the structure of the glasses undergoes rearrangements, which tend to either make it more fluid (relaxation), or to form the first crystals (nucleation) to, finally, crystallize.

In addition to occurring spontaneously (at the end of almost infinite human times at room temperature), the relaxation and crystallization of glasses can be greatly accelerated by heating the material, which is the method used to produce glass-ceramics. Much more resistant to impacts than common glasses, glass-ceramics have crystalline regions dispersed in the amorphous matrix. Due to their unique properties, they are used in applications such as bulletproof windows and dental restorations.

Understanding the structural changes of glasses during relaxation and nucleation is an old scientific problem, whose resolution was limited by the absence of adequate instrumentation. Therefore, in order to carry out this study, the CeRTEV researchers needed to develop a method. The challenge was finally overcome using experiments based on the nuclear magnetic resonance (NMR) technique combined with computer simulations.

“Our research and the resulting technique offer a valuable tool for monitoring and understanding the relaxation process in many glasses, as well as the early stages of crystal nucleation that occur during heat treatments,” says Henrik Bradtmüller, corresponding author of the article that reports this research in Acta Materialia. “These findings are crucial for the design and production control of technologically advanced glass-ceramics with high performance ”, adds the young German scientist, who has been working as a postdoctoral fellow at UFSCar, with a scholarship of the São Paulo Research Foundation (FAPESP), since 2020.

The discovery

The joint work of highly specialized scientists was one of the keys to achieving success in this research. In fact, the work team added the broad experience of two senior researchers: Professor Edgar Dutra Zanotto (UFSCar) in the area of nucleation and crystallization in glasses, and Professor Hellmut Eckert (IFSC-USP) in the development and refinement of the new NMR technique. Also fundamental were the contributions of postdoctoral fellow Anuraag Gaddam (IFSC-USP), also a FAPESP fellow, who carried out the computational simulations, and Henrik Bradtmüller, who developed and applied the NMR strategies that made the observations possible.

“Through the use of molecular dynamics simulations, we were able to predict the structural changes that occur during glass relaxation,” says Bradtmüller. “In the present contribution we could observe these changes for the first time through sensitive NMR experiments”, he adds. The NMR technique makes it possible to analyze, on the atomic scale, the structure of solid materials, including amorphous structures.

To carry out the experiments, the team chose lithium disilicate (Li2Si2O5), a glass-ceramic widely used, mainly in dental prostheses. The researchers heated it over periods that varied between 15 minutes and 60 days, at 435 °C, a temperature lower than that of the glass transition of this material, in which the atoms gain mobility and the glass begins to become more fluid, without, however, melting.

The samples taken at different times of heating were analyzed using the developed NMR experiments. The results showed, for the first time, what happens to the structure of lithium disilicate during relaxation and nucleation. “The distribution of the network building blocks of this glass (-Si-O-Si-) stays mostly unchanged”, reports Professor Zanotto, who is director of CeRTEV. “In contrast, the network modifier cations (Li+), which are very mobile within the material at annealing temperatures, continously approach a structural configuration that resembles the crystalline state.” Given enough heating time, explains the professor, the first crystal nuclei appear, followed by many others, until the entire material is crystallized.

From now on, the authors of the work hope that the new methodology will be used to study many other vitreous materials and that this detailed understanding of fundamental phenomena will allow adjusting the properties of glass-ceramics to improve their performance and expand their range of applications.

This research was funded by FAPESP.

Paper reference: Structural rearrangements during sub-Tg relaxation and nucleation in lithium disilicate glass revealed by a solid-state NMR and MD strategy. Henrik Bradtmüller, Anuraag Gaddam, Hellmut Eckert, Edgar D. Zanotto. Acta Materialia. Volume 240, November 2022, 118318. https://doi.org/10.1016/j.actamat.2022.118318

Author contact: Edgar Dutra Zanotto – dedz@ufscar.br

Representatives of the Brazilian Materials Research Society (B-MRS) and IEEE Magnetics Society met on March 1st to formalize an agreement between the two scientific societies. At the meeting, which was held online, a memorandum of understanding was signed with the aim of promoting the exchange and dissemination of technical information and encouraging the cooperation among the members of the societies. In this way, B-MRS became a sister society of IEEE Magnetics Society.

“We are constantly looking for international partnerships in order to expand opportunities for our materials community”, says Mônica Cotta (UNICAMP), B-MRS President. “The agreement with IEEE Magnetics Society confirms the excellent work carried out by researchers in magnetism and related areas in Brazil, who should benefit from increased cooperation with our new sister society,” she adds.

“Brazil is a global player in magnetic materials, being a producer of special magnetic materials and owner of large reserves of important raw materials, such as iron, silicon, niobium and rare earths”, contextualizes Rubem Sommer (CBPF), B-MRS Scientific Director.

According to him, the recently signed agreement is a natural evolution of the collaborations that have been taking place through events organized by members of both societies, such as the symposia held within the B-MRS annual meetings, among other actions.

“The evolution of these activities resulted in the ongoing partnership between B-MRS and the IEEE Magnetics Society to hold the INTERMAG 2024 conference in Rio de Janeiro from May 5 to 10, 2024”, announces Sommer.

Print of the online meeting with all the participants: Prof. Min-fu Hsie (IEEE MS International Relations Coordinator), Veronica Savignano (B-MRS Communications Manager), Prof. Angela B. Klautau (B-MRS Scientific Director), Prof. Monica Cotta (B-MRS President), Prof. Rubem Sommer (B-MRS Scientific Director), Prof. Atsufumi Hiroata (IEEE MS President), Prof. Masahiro Yamaguchi (IEEE MS Past President), and Prof. Ivan H. Bechtold (B-MRS Director of Administration and Finance).

Imagine the following situation. You buy a food packaged with a polymeric film that has the property of keeping insects away. After consuming the food, you place the film in water and it starts to dissolve. Sixteen minutes later, you have a new product: a repellent liquid, ready to be sprayed on your plants.

And now, the reverse process. You pour the liquid into molds and wait a few days. As if by magic, the films spontaneously re-form. You can then use them again as repellent packs.

A material like this was recently developed in Brazil by a scientific team from Unicamp, in collaboration with Embrapa, within Izabella Wyne Inacio Alves Caetano’s master’s in Chemical Engineering, carried out with the guidance of Professor Liliane Maria Ferrareso Lona (Unicamp).

This video shows the polymeric film developed by the Unicamp team breaking up in water and forming a colloidal dispersion.

One of the secrets of the new film is its compartmentalized structure. Indeed, under the light of an electron microscope, it is possible to observe that the film contains partitions: spherical polymeric particles of about 500 nanometers, which carry a substance – in this case, neem oil, known for its insecticidal and repellent properties.

The particles help preserve the oil from the degradation that light would cause. At the same time, they allow its release in controlled doses, avoiding waste. When the film dissolves, the tiny particles become dispersed in the water, but they retain their functionality.

This scientific contiribution of the Brazilian team shows the possibility of developing products that the consumer can dismantle using only water, use in another context and rebuild without losing their main properties. Furthermore, the possibility of transforming a liquid into a film (smaller in size and weight) can be used to facilitate the transport and storage of the product and reduce the costs involved.

On the left, the photograph and microscopy image show the compartmentalized film (dry condition). On the right, the film deconstructed in water can be seen, forming a colloidal dispersion containing nanoparticles (aqueous condition).

The work was published earlier this year in the journal Advanced Sustainable Systems. Furthermore, with the help of Unicamp’s Innovation Agency (Inova), the authors filed a patent application on the nanocompartmentalized films in last December.

“The main contribution of this work is the preparation of nanocompartmentalized films with the possibility of upcycling (that is, reuse). Thus, the traditional “linear economy” (discard after use) is directed towards the “circular economy”, prioritizing the sustainability of the process”, says postdoc Filipe Vargas Ferreira, who participated in the work and signs the scientific article as corresponding author with Professor Liliane Lona.

UN and European Union documents suggest that, by 2030, polymeric films used in packaging are manufactured in such a way that they can be recycled or reused. In this context, say the authors of the paper, the upcycling proposal presented in the work constitutes an opportunity to add value to the product, since it increases the functionality of the material and it is in accordance with the new global requirements.

At the beginning, the idea of this work was to prepare a liquid containing nanoparticles (a colloidal dispersion) carrying natural compounds with potential use in pest control in agriculture. To synthesize the nanoparticles, the team chose a commercial polymer blend called ecovio®, which stands out for being compostable, that is, for turning into fertilizer when it is finally discarded. “In the scientific literature, a blend had never been used in an encapsulation process of this type, because it is very difficult to work with more than one polymer in these situations”, reports Professor Liliane. The challenge was overcome by master’s student Izabella after a year of working with her advisor.

Subsequently, new possibilities to reuse the dispersion opened up when the master’s student found that the liquid formed flexible films when left on the laboratory bench for a few days. “When we analyzed these films under a scanning microscope (SEM) we realized that, during drying, the nanoparticles had self-organized, forming compartments in them”, says Izabella, who defended her master’s thesis on this work last year. “Satisfaction was even greater when we verified that the diameter of the particles was maintained when the film returned to the colloidal dispersion form when we added water”, reports Professor Liliane.

The study was funded mainly by the Brazilian agencies FAPESP and CNPq.

The authors of the scientific article. From left: Izabella W. I. A. Caetano, Filipe V. Ferreira, Danilo M. dos Santos, Ivanei F. Pinheiro and Liliane M. F. Lona

Paper reference: Water-Dependent Upcycling of Eco-Friendly Multifunctional Nanocompartmentalized Films. Izabella W. I. A. Caetano, Filipe V. Ferreira, Danilo M. dos Santos, Ivanei F. Pinheiro, and Liliane M. F. Lona. Adv. Sustainable Syst. 2023, 2200430. https://doi.org/10.1002/adsu.202200430

Corresponding authors contact: lona@unicamp.br, f102309@dac.unicamp.br.

The passion for science spoke louder when, in 1981, Monica Alonso Cotta chose physics for her undergraduate degree at Unicamp without directly knowing women who worked in the area.

Later, in her master’s and doctoral studies, also at Unicamp, she opted for applied physics topics because she wanted her work to have the greatest possible impact on people’s quality of life. This choice, which earned her criticism from physicists who considered applied science to be inferior to fundamental, put the young scientist on the path of interdisciplinary research.

The path was consolidated in the post-doctorate, held at the Department of Materials Science at AT&T Bell Laboratories, where Monica worked alongside physicists, chemists and engineers in the challenge of developing wireless technology.

Today, at almost 60 years of age, Monica Cotta is part of a small group of women who have reached the top of their careers and hold management positions in academia. Since 2020, she has been President of the Brazilian Materials Research Society (B-MRS), a multi and interdisciplinary entity in essence. Since 2021, she has been the Director of the Gleb Wataghin Institute of Physics (Unicamp), her alma mater, which is one of the main research, teaching and extension centers in Physics in Brazil. In both institutions, Monica holds a historic place: that of the first woman to occupy the highest position. In addition, she is a professor at Unicamp, executive editor of  ACS Applied Nano Materials and productivity fellow at the National Council for Scientific and Technological Development, where she coordinates the Advisory Committee in Physics and Astronomy.

Those who work with Monica Cotta know that, in her daily work, the quest to improve people’s lives through science and the concern for ensuring gender equity in the scientific environment are always present.

In the month in which the International Day of Women and Girls in Science is celebrated, we invited Professor Monica to talk a little about being a woman and a scientist. Check it out!

B-MRS Newsletter: What was it like for you to be a girl and later a woman in science? Share with us some memories about the particularities and difficulties of being a woman and a scientist.

Monica Cotta: I usually tell students that I am already very old, and, happily, much of what I lived is no longer so present today. I remember being a ‘nerd’ girl, even though that term didn’t exist back then. I liked science fiction and the technology I could reach (I thought the supermarket cash register was great, because personal computers only appeared when I entered university), I idolized Jacques Costeau (I wanted to do oceanography, but it was very difficult in Brazil)… For all that, I remember not fitting into any female stereotypes of that time, and that had a big emotional impact on me. But my parents always supported me in my studies. I’m from Campinas, and to get as close to technology as possible in my situation, I attended a technical college in data processing and then enrolled at Unicamp in physics and computing. I ended up opting for physics, because science has always been my passion. But I liked applied physics, because I always wanted to do science that could become a tool for social well-being… This made my journey very ‘bumpy’, with a master’s degree in biomedical physics and a PhD in materials science. If this made me a ‘non-physicist’ for many of my colleagues, it also gave me a lot of experience with interdisciplinary work and how to ‘talk’ with different areas. Deep down, what was a ‘disadvantage’ became a great asset, because throughout my career I had the chance to interact and learn with scientists from many different areas. This was fundamental when, in the last decade, I decided to go back to the origins and work at the interface with biology, using knowledge in materials. But overall, I still feel like I live two lives, as part of my family to this day doesn’t have much of an idea of what I really do. I was never able to convey my passion for science to my parents and sister. The scientist husband turned out to be the best option, as he understood when I wanted to stay in the lab on Friday nights, or weekends. My two sons understand that they have a ‘workaholic’ mother because she loves what she does… And my daughter is following a similar path, as she is doing a PhD in neurosciences.

B-MRS Newsletter: In your perception, what has changed for girls and women researchers since the time you were a student and what still needs to change?

Monica Cotta: Fortunately, a lot has changed, in general… starting with the type of environment we live in, provided by technology. Today, young people can learn science with (good) YouTube channels or online courses. And the role of women has been expanded in recent decades, at least for part of our society. Today, a girl wanting to do physics can even generate strangeness, but not the incredulity and discomfort that I faced in my days.

But we know that part of our society still doesn’t think so. Unfortunately, there is still a lot of sexism and misogyny, confirmed by the tragic statistics of sexual violence and femicides. And women still face daily barriers in the fight for equity, including in their professional lives. Therefore, we need to continue fighting for education and equal social conditions, for everyone.

B-MRS Newsletter: According to your experience, which measures can be effective to combat gender inequality in universities, research groups, scientific events?

Monica Cotta: First, we need to talk about inequalities and raise awareness about microaggressions, unconscious bias, etc. so that we are alert and prepared to combat these situations on a daily basis, and prevent them from gradually destroying girls’ self-esteem. Another measure is to always be concerned with maintaining the representation of women in all spaces, whether as plenary speakers in scientific events or in management positions. In addition, equity criteria need to be incorporated into funding notices and productivity assessments, as we know how motherhood impacts women’s careers, who are also generally ‘caregivers’ in case of illness or elderly people in the family. On the other hand, these struggles must belong to the whole community, and not just to women. Men can and should be our allies.

B-MRS Newsletter: Why is it important to have girls and women in science?

Monica Cotta: Talent does not choose gender, and in general it makes no sense for science to go on without the talents of half of humanity!! However, good science needs new ideas, and ideas also come from our personal experiences, not just from knowledge acquired at school or university. I am always reminded of an example given by Beverly Hartline, an American professor who promotes gender issues in science and physics in particular. She uses the example of bathrooms in shopping malls. In general, they are similar in layout, but the wearing time is quite different for men and women. Consequently, there is always a huge queue in the women’s restrooms, which is not the case in the men’s restrooms. So whoever designed these bathrooms – probably a man – didn’t think about this detail… Today we have the family bathroom, which helps a lot mothers with sons and fathers with daughters who are walking around there. I remember hearing complaints from women because I would walk my 4-5 year old son into the girls’ bathroom because he was always tall and they thought he was ‘too old’ to go in with me. That was something uncomfortable and simple to solve, but that took decades to be considered…. That is why the diversity of views, arising from each one’s experiences – and gender is just one of the components in our ‘personal luggage’ – are essential for quality and disruptive science, which also helps to find solutions for the most complex problems of our society.

B-MRS Newsletter: What has the scientific career brought you of good, difficult, new, unexpected in your life story so far?

Monica Cotta: It brought many good things, such as contact with students, which for me is fundamental. Nothing gives more pleasure than seeing the personal growth and professional maturity that scientific research can provide, even outside academia. I always say that the scientific method is useful for everything, even for analyzing situations in people’s lives. But I´ll highlight what struck me the most. Unfortunately, in my family, we had several complicated health problems, and one way to control my anxiety in these situations was to study everything I could about the subject, which even helped me to find solutions in those moments. And for this, interdisciplinary training was again my salvation! A doctor once asked for my sources to pass on to his students, as he said my questions were too difficult to answer.

B-MRS Newsletter: Leave a few words for the researchers in our community, especially the younger ones, who are experiencing difficulties related to gender inequality.

Monica Cotta: We have to be realistic and remember that difficulties will always exist, and gender among them. But together we are stronger. Always look for allies among your colleagues, identify who has the same values and willingness to face these barriers. The same goes for institutions – like here at Unicamp, where we have the Executive Board of Human Rights and within it, the gender and sexuality commission (of which I am a part because I believe in that!). Use all the supports you can, as well as support your colleagues, because everything is always more difficult when we are alone.

A team of scientists from Brazilian institutions has increased by about 30 times the capacity of a semiconductor material to produce hydrogen by means of water photolysis, a process that consists of dividing the water molecule using light as the only source of energy. The advance contributes to the development of efficient ways to generate green hydrogen, which is the fuel produced using renewable and clean energy.

For photolysis to take place, it is necessary to have photocatalysts suspended in water. A photocatalyst is a semiconductor capable of absorbing light and, from there, generating the charges (electrons and holes) that are necessary to dissociate water molecules (H2O) into hydrogen (H2) and oxygen (O2) though oxidation and reduction reactions. Furthermore, the material must be stable in an aqueous environment.

“Strontium titanate (SrTiO3) is one of the main semiconductor materials applied to photolysis for the production of green hydrogen, as it meets the physicochemical requirements for oxidizing and reducing the water molecule,” says Professor Renato Vitalino Gonçalves (IFSC-USP) , corresponding author of the article that reports this research in ACS Applied Energy Materials. “However, this material has some intrinsic characteristics that limit its photocatalytic potential, such as, for example, its wide bandgap of ~3.2 eV, which restricts its optical absorption to the UV region, which corresponds to only 4% of the solar spectrum”, completes the scientist. Another limitation of this material, common to all semiconductors, is the rapid recombination of electrons and holes, which prevents these charges from flowing freely and promoting oxidation and reduction reactions.

Thus, the Brazilian team, led by Professor Gonçalves, decided to modify strontium titanate to increase its efficiency in photolysis. Initially, the researchers doped the semiconductor with the transition metal molybdenum (Mo) and obtained disaggregated cubic particles with well-defined faces. The unconventional dopant was responsible for making the material capable of absorbing light in the visible region, which represents around 43% of the solar spectrum.

In a second moment, the authors of the work deposited nickel nanoparticles of around 2 nm on the surface of the particles. The result was a junction of two types of semiconductors: Mo:SrTiO3, n-type, and NiO@Ni(OH)2, p-type. “In this new configuration, the photogenerated holes are directed to the NiO@Ni(OH)2 structure, while the electrons migrate to the Mo:SrTiO3 surface, resulting in better charge separation and, consequently, a reduction in the recombination rate of electrons and holes”, explains Gonçalves.

The photocatalysts were placed in suspension in an aqueous solution with 20% methanol as a sacrificial agent – a widely used strategy to increase hydrogen production and also generate high-value by-products for the chemical industry. “When mixed with water, which oxidation is slow, this alcohol is preferentially oxidized”, says Professor Gonçalves. “Even though, the H2 is produced from the reduction of the water molecule and not as a by-product of methanol oxidation”, he adds.

By increasing the absorption of light and decreasing the loss of photogenerated charges, the enhanced material presented an excellent result in the production of hydrogen by photolysis: an increase of its photocatalytic activity of about 30 times compared with the pure semiconductor.

Brazilian scientific cooperation

This scientific work was led by Professor Renato Vitalino Gonçalves, who coordinates the Nanomaterials and Advanced Ceramics Group (NaCA) and the Artificial Photosynthesis and Nanomaterials Laboratory (LAPNano) at IFSC-USP. The synthesis of materials and the study of their structural, optical and electronic properties, as well as their photocatalytic performance for the production of green hydrogen were developed at IFSC-USP, within the doctoral research of Higor Andrade Centurion, supervised by Professor Gonçalves.

The identification and characterization of the nickel nanoparticles in the material was carried out in collaboration with a team from UFABC and LNNano-CNPEM, formed by Professor Flávio Leandro de Souza, postdoctoral student Ingrid Rodriguez-Gutierrez and researcher Jefferson Bettini. In collaboration with Professor Liane M. Rossi (IQ-USP), nickel was quantified using the flame atomic absorption spectroscopy technique.

In addition, with the collaboration of Professor Heberton Wender (UFMS) it was possible to carry out photoluminescence measurements that corroborated the suppression of recombination of charges photogenerated by the formation of the p – n junction.

Finally, computer simulations that made it possible to understand the behavior of the materials were carried out with Professor Matheus M. Ferrer, from UFPel, and Master’s student Lucas Gabriel Rabelo, from IFSC-USP, who also received guidance from Professor Gonçalves.

The work was funded mainly by the São Paulo research foundation (FAPESP) and, through the RCGI, by FAPESP/Shell. It also had financial support from the research foundation of Rio Grande do Sul (FAPERGS).

Paper reference: Constructing Particulate p−n Heterojunction Mo:SrTiO3/NiO@Ni(OH)2 for Enhanced H2 Evolution under Simulated Solar Light. Higor A. Centurion, Lucas G. Rabelo, Ingrid Rodriguez-Gutierrez, Mateus M. Ferrer, Jefferson Bettini, Heberton Wender, Liane M. Rossi, Flavio L. Souza, and Renato V. Gonçalves. ACS Appl. Energy Mater. 2022, 5, 12727−12738. https://doi.org/10.1021/acsaem.2c02337.

Corresponding author contact: rgoncalves@ifsc.usp.br.

Brazilian Materials Research Society (B-MRS) declares its total rejection of the serious aggression against democracy and the rule of law in our country, which took place yesterday in Brasília, with the invasion by terrorists of the headquarters of the three powers of the Republic.

B-MRS stands in solidarity with the Brazilian executive,, judiciary and legislative bodies in defense of the Federal Constitution, its values and principles.

It is essential to verify the facts and punish those responsible for terrorist acts, without amnesty, and with ‘Democracy forever’!

B-MRS Executive Board