Sorry, this entry is only available in Brazilian Portuguese.
A little bit of the brief and intense story of the startup Nanogreen (Joinville, SC) and the vision of its entrepreneurs.
Nanogreen is a startup committed to participating in the emerging Brazilian market of nanoparticle production. These particles, measuring less than 100 nanometers in at least one of their dimensions, have unique properties due to their size, and are capable of conferring interesting properties to the materials to which they are incorporated. In addition to being the subject of intense research, nanoparticles are already used to manufacture a wide range of products, from socks to milk containers, in addition to paints and sensors – a market whose size is still difficult to determine but which moves billions of dollars around the world.
At Nanogreen, the main competitive advantage in a national context is the nanoparticle manufacturing method, based on the laser ablation technique. Briefly, it consists of using samples of the material that will compose the nanoparticles (e.g. titanium or gold) as targets of the laser. The samples are submerged in liquid and the laser light beam is placed over them. The radiation removes material from the surface of the target, and finally, the ablated material forms the nanoparticles in the liquid medium.
Innovative in the Brazilian industrial context, this method, which is based on technologies in the public domain (not protected by patents) stands out for its low environmental impact, without the use of toxic substances. In addition, the method can generate nanoparticles from the most diverse materials, including metals, polymers, ceramics and even organic materials (Nanogreen is testing tree barks, for example). Finally, through changes in the process parameters and the production medium (distilled water, alcohol, solvent etc.), it is possible to alter the size and distribution of the nanoparticles, the state of agglomeration, the composition of the final product, and also functionalize the surface of the particles according to the customer’s needs.
Nanogreen currently works with customized development of nanoparticles for the client’s desired application. “We perform a joint development, in order to find the best solution, working in the form of consulting and development. Subsequently, we sell the made-to-order products developed,” says Moisés Teixeira. For the future, the entrepreneurs of Nanogreen plan to have a portfolio of products developed, ready to be manufactured on demand. “This will allow us to focus only on supply, or to maintain both fronts. All of this will depend on how the market and technology behaves, but these are scenes of the next chapters,” he adds. Generating patents from the development work is also a possibility contemplated by the entrepreneurs of Nanogreen.
The startup staff currently consists of three members who gather together academic training and research and development experience in laser and nanoparticle production techniques. For everyone, Nanogreen was the first experience of creating a company. The partner Edson Costa Santos holds a degree from the Brazilian Federal University of Santa Catarina (UFSC) and master’s degree and doctorate from Osaka University, Japan, both in Mechanical Engineering. At Nanogreen, he works in business development and strategic contacts. In addition to being CEO of Nanogreen, Costa Santos is currently senior manager of innovation at Carl Zeiss AG in Germany. The second active partner, Moisés Felipe Teixeira, who holds a degree, a master’s degree and a doctorate degree in Materials Science and Engineering from UFSC, is responsible for the administration of the company. The team also includes the grant holder Lucas Bóries Fachin, chemical engineer from UFSC, who works with product development and research of new materials.
In terms of infrastructure, Nanogreen needs a series of manufacturing and characterization equipment that the startup is not able to acquire. However, these entrepreneurs have overcome this difficulty through partnerships and agreements with research institutions and universities, as well as payment outsourcing of machine hours and analysis. According to the entrepreneurs, the idea is to acquire, as soon as possible, equipment for the manufacture of nanoparticles by means of public funding, external investors or bank loans.
Emergence of the startup
The idea of working with laser ablation came around ten years ago, from the experience of the partner Edson Costa Santos with laser technologies, during his doctorate in Japan. However, the first products were developed in Brazil about three years ago on an experimental basis within SENAI Institute of Innovation, where Costa Santos was director. By having direct contact with that technology, the entrepreneurs saw the business potential. “Since the SENAI Institute’s focus is not on the type of sale and business we are doing today, the creation of the company was the best way to bring this technology to the Brazilian market,” says Costa Santos.
A milestone in the brief history of Nanogreen was the incubation approval at the Technological Innovation Park of Joinville and Region (Inovaparq), in 2016. At that time, the partners incubated “only” an idea, which arose when they saw the lack of suppliers of nanoparticles of some materials, together with the low level of customization that traditional suppliers offered. The entrepreneurs of Nanogreen wanted to bring to Brazil a different way of manufacturing and supplying nanoparticulated products. “We combined the desire to be enterpreneurs this with innovative technology,” recalls Moisés. “With the approval of the incubator, we saw that more people believed in us and that from this point onwards we had a mission that was already greater than ourselves,” he adds.
Initially, the entrepreneurs disbursed their own resources to finance the incubator’s monthly fee, the first materials for production, the accounting and all that was needed. However, soon after the first year the company was set up, in 2018, two Nanogreen projects were approved. In an innovation support program (Innovation Synapse), Nanogreen received R$ 100.000 to invest in the company, develop a project and hire a fellow (Lucas Bóries Fachin). In another program (the Call for Innovation for Industry), Nanogreen received R$ 500.000 to develop a project. “It was here we had the first signs that there were more people believing in our idea,” says Fachin.
Also in 2018, Nanogreen was contemplated by the program InovAtiva Brazil, dedicated to “accelerate” startups. “We were recognized by a team of mentors as one of the featured companies within the program that year,” recalls Lucas. “This award was the peak of the company thus far and achieving this recognition has indicated we are on the right path and that there are many people who perceive in our idea a technological potential able to change the world,” he adds.
According to the entrepreneurs, many discussions, turning points and changes of plans have taken place over the short and intense journey of Nanogreen. 2019 was the year of the first commercial operation of the startup: a research and development agreement with a large textile company to optimize some products. “Additionally, we have some grant projects with partner companies already being developed, but the first invoice will be issued for now,” says Costa Santos.
See our interview with the entrepreneurs.
B-MRS Newsletter: What were the most important factors that enabled the creation and development of the startup?
Nanogreen: Due to the highly scientific and specialized nature of Nanogreen, undisputedly the greatest factor in making the company feasible was the partners’ technical knowledge. Due to the fact we work with new and advanced technology, manufacture and application knowledge is what allowed the incubation and approval in the cited programs. In addition to the need for in-depth knowledge about the laser, characterization techniques such as scanning electron microscopy, chemical characterization, concentration measurement techniques and cohesion strength are very important for good quality product development. In addition, the approvals gave way to opportunities to participate in events and mentoring of Synapse of Innovation and InovAtiva Brazil, for example, which help in legal issues, accounting and business matters, which are usually the most complicated for those of us with technical backgrounds.
B-MRS Newsletter: What were the main difficulties faced by the startup thus far?
Nanogreen: The main difficulty at the beginning was the initial investment, where there was a lack of resources for investments in the company and for hiring people. In a highly scientific and research-and-development-intensive business such as nanotechnology, the initial cost is considerable in terms of high first returns, however such an investment is not available without investors or customers seeing the technology validated in business practice, but for such validation we need the first development, which falls into a rather complicated cycle. Therefore, the existence of development notices and subsidy for new technologies is very important. When talking about IT companies and software, investments are lower and returns are faster, which explains the ease of investment and the amount of companies we see in these areas. Industrial and material development is a little behind this.
B-MRS Newsletter: What do you believe is the startup’s main contribution to society?
Nanogreen: To introduce a manufacturer of nanoparticles into the national market, increasing domestic competition and reducing the need for imports. This would reduce time and import fees, lowering costs for some products that need this technology and which can make applications viable. Other than that, we work with green-based technology, which does not use solvents or toxic products in the production of nanoparticles. This ensures that our product is considerably purer than that produced by chemical routes, but also avoids the need for treatment of effluents, risk of river and groundwater spills and so on. Thus, we are helping to further prevent the degradation of the environment.
B-MRS Newsletter: What is your goal/dream for the startup?
Nanogreen: The goal is to be the largest and most innovative manufacturer of non-toxic nanoparticulated products in Brazil, within a short period of time, and in the future to expand that reputation to Latin America. We are also planning the internationalization of Nanogreen, and there are now several Brazilian programs to support such initiatives!
B-MRS Newsletter: Leave a message for people who are thinking about the possibility of creating a startup.
Moisés Teixeira: My message to anyone reading this story and dreaming about beginning a startup is that you are the size of your dream. So dream big, dream big. If you have a good idea and are willing to undertake this and have time to dedicate yourself, dive right in. No one will put your idea into practice, except for you, so trust yourself, strive, work hard and make it happen. Innumerous obstacles will appear along the way, but when you believe, anything is possible. Finally, no one is better suited to handle your business than you, so carpe diem, roll up your sleeves and get on with it. What I can say is that once you enter this world, there is no turning back, undertaking this mission is a passion and is addictive.
Professor Elson Longo (CDMF-UFSCar), founding member and former president of B-MRS, is the corresponding author of an article that appears in the Top 100 2018 ranking of the journal Scientific Reports in the area of Materials Science. The ranking highlights the most read articles in 2018, among those published that year in the journal of the Nature group. The paper was published on January 30, 2018 and received 1,042 views throughout the year.
Entitled Towards the scale-up of the formation of nanoparticles on alpha-Ag2WO4 with bactericidal properties by femtosecond laser irradiation, the article is signed by eleven authors, six of them from Brazilian institutions, including the researcher Camila Cristina de Foggi (UNESP), who is also a B-MRS member.
The work proposes a new process to produce bactericidal nanocomposites based on silver nanoparticles and semiconductor materials. The method increases 32 times the bactericidal action of the nanocomposite and, at the same time, generates a new class of spherical nanoparticles.
Fernando Galembeck’s interest in research began in adolescence, when he realized the economic value of scientific knowledge while working in his father’s company in the pharmaceutical segment. Today, at age 75, Fernando Galembeck can look back at his own scientific trajectory and tell many stories about the generation and application of knowledge.
A founding member of B-MRS, Galembeck was chosen this year to deliver the Memorial Lecture “Joaquim da Costa Ribeiro” – a distinction awarded annually by B-MRS to the trajectory of a distinguished researcher in the Materials area. The honor is also a tribute to Joaquim da Costa Ribeiro, pioneer of experimental research in Materials in Brazil. The lecture, titled “Materials for a better future,” will take place at the opening of the XVII B-MRS Meeting on September 16 of this year, and will address issues such as needs, shortages and promises in the Materials area.
Galembeck graduated in Chemistry in 1964 from the University of São Paulo (USP). After getting his degree, he remained at USP working as an instructor (1965-1980) while doing his Ph.D. in Chemistry (1965-1970), in which he developed research on dissociation of a metal-metal bond. After his Ph.D., he completed post-doctoral internships in the United States, at the universities of Colorado, in the city of Denver (1972-1973) and California, in the city of Davis (1974), working in the field of Physical-Chemistry of biological systems. In 1976, back at USP, he had the opportunity to create a laboratory of colloids and surfaces at the Institute of Chemistry, in an agreement that involved the Institute, Unilever, the Brazilian Academy of Sciences and the Royal Society. From that moment on, Galembeck became more and more involved with the development of new materials, especially polymeric materials, and their manufacturing processes.
In 1980, he joined the State University of Campinas (Unicamp), after which he became a full professor in 1988, where he remained until his retirement in 2011. Since then, he has been a contributing professor at the institution. At Unicamp, he held management positions, notably vice-rector of the university, as well as director of the Institute of Chemistry and coordinator of its post-graduate program. In July 2011, he took over the newly created Brazilian National Nanotechnology Laboratory (LNNano), at the National Center for Energy and Materials Research (CNPEM), remaining in this post until 2015.
Throughout his career, he has held direction or coordination positions at the Brazilian Academy of Sciences (ABC), the Ministry of Science, Technology and Innovation (MCT), the National Council for Scientific and Technological Development (CNPq), Sao Paulo Research Foundation (FAPESP), Brazilian Chemical Society, (SBQ), Brazilian Society for the Advancement of Science (SBPC) and the Brazilian Society of Microscopy and Microanalysis (SBMM), among other entities.
Prof. Galembeck is the author of roughly 279 scientific papers published in peer-reviewed journals, with over 3,700 citations, 35 patents and more than 20 books and book chapters. He has supervised nearly 80 master’s and doctoral degrees.
Fernando Galembeck received numerous awards and distinctions, among them the Anísio Teixeira Award, from CAPES, in 2011; the Telesio-Galilei Gold Metal 2011, from the Telesio-Galilei Academy of Science (TGAS), the Almirante Álvaro Alberto Award for Science and Technology 2006, from CNPq and the Conrado Wessel Foundation; the José Pelúcio Ferreira Trophy, from Finep, in 2006; the Grand Cross of the National Order of Scientific Merit, in 2000, and the National Commendation of Scientific Merit, in 1995, both from the Presidency of the Republic of Brazil. He also received a series of acknowledgments from companies and associations, such as CPFL, Petrobrás, Union Carbide do Brasil, the Brazilian Association of Paint Manufacturers, the Brazilian Chemical Industry Association, the Union of Chemical Industry for Industrial Purposes of the State of Rio de Janeiro, Brazilian Polymer Association, Brazilian Chemical Society (which created the Fernando Galembeck Technological Innovation Award), the Union of Engineers in the State of São Paulo and the Electrostatic Society of America.
This scientist has been a fellow of TWAS (The World Academy of Sciences) since 2010 and from the Royal Society of Chemistry since 2014.
In this interview, you will be able to know a little more about this Brazilian researcher and his work.
SBPMat Newsletter: – Tell us what led you to become a scientist and work on issues in the field of Materials.
Fernando Galembeck: – My interest in research work started during my adolescence, when I comprehended the importance of new knowledge, of discovery. I found this when I was working, after school, at my father’s pharmaceutical laboratory, as I could see how the newest, latest products, were important. I also saw how costly it was, for the lab, to depend on imported raw materials, which were not produced in Brazil, and that in the country there was no competence to manufacture them. Then I realized the value of new knowledge, as well as the importance and the economic and strategic significance of such breakthroughs.
This feeling was increased when I took my major in Chemistry. I enrolled into the Chemistry course because one of my school teachers had suggested that I should seek a career related to research. He must have seen some inclination, some tendency of mine. So I attended the Chemistry course provided by the Philosophy School, in an environment where the research activity was very vivid. Because of that, I decided to conduct my Doctoral studies at USP. At that time, there were no regular graduate studies in Brazil yet. The advisor with whom I defended my dissertation, Professor Pawel Krumholz, was a great researcher, who also had built a very important career working on a company. He was the industrial director of Orquima, a major company by that time. That boosted my interest in research.
I worked with Chemistry for some years and my interest in materials came from a curious occurring. I was almost graduating, in my last vacations during the undergraduate studies. I was at an apartment, resting after lunch. I remember looking at the walls of this apartment and noticing that, with all I had learned in the Chemistry course, I did not have much to say about the things I could see: the paint, the coverings etc. That was Chemistry, but also Materials, and there was not much interest in Materials in the Chemistry course. Actually, Materials became very important in Chemistry mainly because of plastic and rubber, which, at the time, did not have the importance they have today. I’m talking about 1964, when petrochemicals were practically non-existent, in Brazil.
Well, then I started to work with Physical Chemistry, to later work a little in a field that is more oriented to Biochemistry, that is Biological Physical Chemistry and, in 1976, I received a task from the USP Department, which was to build a colloids and surfaces laboratory. One of our first projects was to modify plastic surfaces, in that case, Teflon. Then I realized that a major part of the colloids and surfaces Chemistry existed due to Materials, because the subject lends itself to create and develop new materials. From that moment on, I was getting increasingly involved with Materials, mainly polymers, a little less with ceramics, and even less with metals.
SBPMat Newsletter: – What are, in your own opinion, your main contributions to the field of Materials? Consider, in your answer, all aspects of your professional activity, including cases of knowledge transfer to the industry.
Fernando Galembeck: – I will tell the story in order, more or less. I think that the first important result in the field of Materials was exactly a technique intended to modify the surface of Teflon, that material in which it is very difficult to stick something. There is even that expression, “Teflon politicians”, the ones for which does not matter what you throw at them, they do not stick to anything. But, in certain situations, we want the Teflon to have adhesion. So, by a somewhat complicated path, I managed to see that I already knew how to modify Teflon, but I had never realized that is was important. I knew the phenomenon; I had observed it during my PhD defense. I knew that there was a change happening in Teflon. But it was during a visit to a Unilever laboratory in 1976, when I was talking to a researcher, that I saw that there were people striving to modify the surface of Teflon and achieve adhesion. Then, bringing the problem and the solution together, as soon as I returned to Brazil, I tried to see if I what I had previously observed was really useful, and it worked. That led to the first paper I wrote by myself and my first patent application, at a time when almost nobody talked about patents in Brazil, especially in the university environment. I was very enthusiastic about this: I was approached by companies that were interested in applying what I had done; one the modification in Teflon itself, the other in a different polymer. So I felt great, because I had made a discovery, I had a patent, and there were companies which, at least, would like to know what it was to see if there was a way to use it. One more thing: soon after the paper I wrote was published, I was invited to attend a conference in the United States, which addressed exactly the issue of modifying surfaces. Polymers, plastic and rubber surfaces, a subject with which I was involved for pretty much the rest of my life, up until now.
I will mention a second fact that did not have the same effects, so far. I discovered a method that enables the characterization and separation of very small particles. That was a very interesting paper. It was released, also produced a patent, but had no practical consequences. Recently, there have been some issues related to nanoparticles, which is a very important subject in Materials now, offering a chance to apply what I did over 30 years ago. The name of the technique is osmosedimentation.
Next there was some work that I did by collaborating in projects with Pirelli Cabos. With all this story of surfaces and polymers, I think I had become more or less known and was approached by Pirelli, which contracted me as a consultant and commissioned projects I had at Unicamp. An outcome of these projects, that I think is the most important, was the development of an insulator for very high voltages. This work was not only mine, but rather of a very large team, in which I took part. There were several people from Pirelli, and several from Unicamp. The result of this project was that the Brazilian Pirelli managed to be hired to provide high voltage cables for the Eurotunnel, back in the ‘80s. I think this was a very important case, as it led to a product and brought substantial economic results. I would like to stress that this was done in Brazil, by a Brazilian team. They were not a Brazilian company, but the team was based here.
Then I worked on several studies with nanoparticles, at a time when we did not even call them nanoparticles; we called them fine particles or simply small colloidal particles. The first work I published on nanoparticles was in 1978. There were other things I did next, which ultimately turned into a work on aluminum phosphate, which gave rise to several theses carried out in the laboratory and publications, and was also licensed by a company of the Bunge group, which basically exploits phosphates. The subject started in my laboratory, stayed in the laboratory for several years, then a company from the Bunge group here in Brazil became interested, started to participate, we collaborated. This became a rather large development project. Bunge later found the project unfeasible in Brazil and today it is the United States. I think it’s a pity that it is there, but there were other issues involved, including disagreements with Unicamp, which owns the patents. Recently, the company of the group that worked with these phosphates was Amorphic Solutions, which offered the product on the Internet, for various applications. From what I understand, they are currently emphasizing its use as an anticorrosive material for steel protection. I have recent information that Bunge has negotiated the rights to these products with a large chemical company, but I do not know the details.
About the same time, in another project on nanoparticles, clay/natural rubber nanocomposites were developed. This was licensed by a Brazilian company called Orbys, which released a product called Imbrik, that showed to be good for rubber rolls for paper manufacturing.
Another case with a product. I had done a project with Oxiteno, which manufactures raw materials for latex, the surfactants. They wanted to get an ideia of how much you can change the latex changing the surfactant. I conducted a project with them that I consider one of the most interesting among those in which I have been involved. In the end, we realized that, by changing the surfactant a bit, we changed the latex a lot. These are used in paints, adhesives, resins. So we realized we had a great versatility. This work was published and promoted. It did not result in a patent because it was a comprehension project. So, another company, Indústrias Químicas Taubaté (IQT) approached me to produce cationic latex, but using a new path. Cationic latex in general is made of quaternary ammonium salts, which have some environmental restrictions. The company wanted an alternative that did not have those restrictions. By the end of the project, we produced cationic latex without environmental restrictions, and the IQT put the product on the market.
My participation in a Navy project of developing carbon fibers was a great challenge that gave me big satisfaction. My group participated by synthesizing copolymers of acrylonitrile, up to the scale of ten liters. The results were transferred to a company that produced pilot scale production at the old Rhodia-Ster and Radicci plant in São José dos Campos. The selected copolymer was spun and then pyrolyzed, at the Technological Center of Marinha, in São Paulo. It resulted in a high performance carbon fiber, which was used in the manufacture of a centrifuge, used in Aramar. The challenge was to find the copolymer that showed good performance in the later stages of fiber production, which was achieved.
There was another case that was also very interesting, even though it was canceled. Here in Brazil, there was a large manufacturer of polyethylene terephthalate, PET, which is used for many things, including bottles. They knew about the work I had done with nanocomposites, the one with Orbys I mentioned before, so they approached me wanting to produce PET nanocomposites. We had to find out how to escape from what was already patented abroad and discovered a whole new path. The company was called Rhodia-Ster, and today it is part of another Italian company, called Mossi e Ghisolfi. The company was enthusiastic and ended up patenting it in Brazil, and then later abroad. At a certain point, they decided that they would conduct the work internally, and so they did for some years. One day, my contact within the company called me to tell this: “look, we were working with two technologies; the one held by Unicamp and another one, in another country. Both are working, but the company has reached a point where it has chosen to complete the development of only one”. When coming to the final stage in developing materials, the projects costs are too high. One have to use large amounts of materials, run many tests with customers. So, the company decided to take one project further, and, unfortunately, it was not the one in which I had worked. At the end, it was a little frustrating, but I think that it was interesting, because, during this whole time, the company invested a lot in the path we had started here. Not only that, each project brings resources for the laboratory, jobs at the university and the company etc. So, these projects result in many benefits, even when they are not concluded.
Now, fast forwarding, I will arrive at a more recent result of my work at CNPEM, where I was until 2015. A goal of CNPEM is the use of renewable source materials to make advanced materials. It has a whole philosophy behind it, related to the depletion of natural resources, to sustainability… The goal was to do new things with materials derived from biomass, and the main interest is in cellulose. It is the most abundant polymer in the world, but it is a very difficult polymer to work with. You cannot process pulp as you process polyethylene, for example. One of the goals is to plasticize cellulose; that is, to work the cellulose as closely as possible to the one we use to work with synthetic polymers. An initial result within this idea was the creation of cellulose adhesives in which the only polymer is cellulose itself. Then, by then no longer at CNPEM, we obtained graphite exfoliation, which generated a family of paints, pastes and conductive adhesives, which are the object of a PIPE project recently approved by Fapesp.
This is the latest case. In the middle of the way, many other projects were conducted with companies, for issues of their interest. Coating something, gluing another, modifying a polymer to achieve a certain result. But these were answers to demands from companies, instead of researches started at the laboratory.
SBPMat Newsletter: – Leave a message for our readers who are starting their careers as scientists.
Fernando Galembeck: – First of all, in any chosen career, there must be a dose of passion. It does not matter if you are going to work in the Stock Market, Healthcare or whatever you may do; above all, your taste must decide. If a person chooses a career because it will give them money or status… I think it is a bad choice. If you do things with pleasure, with interest, the money, prestige and status will come from other paths. The goal is to do what makes you happy, what makes you feel good when you do it, what makes you feel accomplished. It is true not only for the scientific career, but also to any other career. In science, it is crucial.
Another point is that you must be prepared to work hard. There is no easy way. I know some young people who are constantly seeking the great idea that will bring them success with relatively little work. Well, I’d better not count on it. It may even happen, but waiting for it is almost the same as wait to win the Lottery and get rich.
I’m over 75, therefore I have met many people and seen many things happen. Something that strikes me is how young people who seemed very promising end up not working very well. Frankly, I think it is bad for youngsters to achieve success too early, because I have the impression they get used to this idea that things will always work out fine. And the problem is that there isn’t anything, anyone, any company that will always work. There will always be the moment of failure, the moment of frustration. If the person is prepared for that, when the times come, he or she will overcome it, while others are crushed – they cannot move one. That is why we must be careful not to be deceived by our success and think that, because it worked once, it will always work. You must be prepared to fight.
When I was in college, thinking about doing research seemed a very strange thing to do, crazy talk. People did not know very well what it was, or why would someone choose to do it. Some people said that research was something like priesthood. I have always worked with research, associated with teaching, consulting and, without having ever sought to become rich, I managed to have an economic status that I deem very comfortable. But I insist, my goal was to enable the development, to produce material, not the money I would receive. Money came, as it does. So, I suggest you to focus on your work, on the results and the contribution that said work may give to other people, to the environment, to the community, to the country, to knowledge. The rest comes as a bonus.
In short, my message is: work seriously, earnestly and passionately.
Finally, I would like to point out that I think the research work, the development work, really helps you to grow as a person. It will depart you from ideas that are not very fruitful and guide you towards attitudes that are really important and helpful. A student asked Galileo once: “Master, what is the method?”, and Galileo’s answer was: “The method is the doubt”. I think it is very important in the research activity, which, for Materials in particular, is especially interesting because the final product is something you can hold in your hands. In the research activity you have to always wonder, “I’m thinking like this, but is this right?”, or “This guy wrote this, but what are his bases to write it?”. This attitude is very different from the dogmatic one, which is common in the realms of politics and religion, and very different from the attitude of someone who has to deceive, as the lawyer who works for a corrupt or drug dealer. The researchers have to commit themselves to the truth. Of course there are also people who call themselves researchers and spread disinformation. Some years ago, people were talking about something called “Bush science”, an expression referring to President Bush. This Bush science was the arguments fabricated by people who gained money as scientists, but who produced arguments to sustain Bush’s policies. In other words, the problem exists in science as well, but then we get back to what I said earlier. You cannot become a scientist because of money, or to achieve prestige, or to be invited to have dinner with the president; you must enter this field because of your interest in the subject itself.
[Paper: High-yield synthesis of bundles of double- and triple-walled carbono nanotubes on aluminum flakes. Thiago H.R. da Cunha, Sergio de Oliveira, Icaro L. Martins, Viviany Geraldo, Douglas Miquita, Sergio L.M. Ramos, Rodrigo G. Lacerda, Luiz O. Ladeira, Andre S. Ferlauto. Carbon 133(2018) 53-61.]
Aluminum flakes to produce carbon nanotubes
A team of scientists from institutions in Minas Gerais made a promising contribution to the production of carbon nanotubes. These hollow cylinders, whose carbon walls are only 1 atom thick, are already part of some products (batteries, automotive materials, water filters), but their industrial production is still incipient and needs solutions to lower costs and to increase efficiency, among other challenges.
The Brazilian researchers introduced a novelty in a stage of one of the most consolidated techniques for the mass production of nanotubes, chemical vapor deposition (CVD). As a result, the team was able to produce double- and triple-walled nanotube bundles (somewhat similar to two or three hollow cylinders, one inside the other). Thin, long and of high purity, the nanotubes had diameters of 3 to 8 nanometers, lengths up to 50 thousand times the diameter (from 150 to 300 micrometers) and 90% of carbon in their composition.
“The main contribution of this work is the presentation of a scalable and cost effective process for the synthesis of carbon nanotube bundles with large surface area (625 m2/g) and aspect ratio (50000:1),” says Thiago Henrique Rodrigues da Cunha, researcher of the Nanomaterials Technology Center (CTNano) of the Brazilian Federal University of Minas Gerais (UFGM) and corresponding author of this paper, which was recently published in the journal Carbon (impact factor 2017 = 7,082).
The method, in addition to generating good quality nanotubes, allows producing relatively large quantities of this material using relatively low amounts of raw materials. “Even using small systems, it is possible to obtain carbon nanotubes at a kilogram/day scale,” says the researcher. As the nanotubes obtained showed a very large ratio between surface area and mass (more than 625 square meters weighing only one gram), the production of nanotubes by this method could reach a few million square meters per day.
With the nanotubes obtained and a type of alcohol, the scientific team prepared a paste which was distributed over filter paper, forming a film that was separated from the paper when the paste dried. The black film was 40 micrometers thick and was flexible and foldable. Macroscopic aggregates of carbon nanotubes like this are commonly called buckypapers.
“The buckypaper produced from these nanotubes exhibited great surface area and good electrical conductivity, which makes them particularly interesting in the manufacture of electrodes for batteries and supercapacitors,” says Thiago da Cunha, who adds that the CTNano team is already working to use the buckypapers in these energy storage devices. A patent on the process was deposited at the end of 2017. “Our intention is to introduce this technology to potential partners in order to convert it into a high value-added product,” reveals Cunha.
The secret of the process
The CVD nanotube production processes take place inside a tube furnace into which gas containing carbon and catalytic nanoparticles are inserted. Subjected to high temperatures, the gas decomposes, and the carbon atoms deposit on top and around the nanoparticles, forming tubes (the nanotubes). The nanoparticles can be prepared in the same furnace used for nanotube growth.
The secret of the method developed by the Minas Gerais team lies precisely in the preparation of the catalytic nanoparticles. In broad lines, it is a matter of preparing a powder containing iron (Fe) and cobalt (Co) on aluminum flakes (material that had never before been mentioned in the scientific literature as a support for the growth of nanoparticles). The mixture is then subjected to temperatures of 350 to 650 °C for 4 hours, in an atmosphere similar to the air we breathe. This process, known as calcination, produces nanoparticles of iron and/or cobalt oxides. Then, the catalyst nanoparticles, still on the aluminum flakes, are introduced into the CVD furnace, whose internal temperature is brought to 730 °C. The ethylene gas (C2H4) is then introduced, which supplies the carbon so that the nanotubes grow perpendicular to the aluminum flakes.
Scientists observed an interesting advantage of using this new medium. During the calcination, a thin layer of aluminum oxide is formed on the surface of the aluminum that encapsulates the nanoparticles and prevents them from agglomerating or spreading. In addition, in the next step of the process, the aluminum oxide acts as a matrix of the nanotubes, driving their growth in the form of aligned bundles.
To test whether the calcination temperature of the nanoparticles would influence their performance as catalysts, the CTNano team carried out some experiments. The conclusion was that calcination at temperatures of 500-550 °C produces more mixed oxide nanoparticles (containing both iron and cobalt, of the CoFe2O4 formula) and produces better results in the production of nanotubes, both quantitatively (yield) and qualitative (diameter of the nanotubes).
“Unlike other methods described in the literature, which generally display low yield and are dependent on relatively expensive techniques (evaporation, sputtering) for the preparation of the catalyst, we describe in this paper a simple method to produce a catalyst in powder form, which can be used for continuous production of few-walled nanotubes using the chemical vapor deposition technique (CVD),” summarizes Thiago da Cunha.
The work was funded by the Brazilian agencies Fapemig (Minas Gerais State Research Foundation) and CNPq, as well as Petrobras. The work was carried out at CTNano, except for the microscopy images, conducted at the UFMG Microscopy Center.
CTNano emerged in 2010 based on the motivation to develop products, processes and services using carbon nanotubes and graphene, in order to meet industrial demands in line with the training of qualified human resources. The research realized in CTNano has already originated 26 patents and contributed to the development of more than 200 researchers in the area. According to Thiago da Cunha, CTNano will inaugurate, in 2018, its own headquarters with an area of approximately 3,000 m², located in the Technology Park of Belo Horizonte (BH-TEC).
[Paper: Conversion of “Waste Plastic” into Photocatalytic Nanofoams for Environmental Remediation. Geovania C. de Assis, Euzébio Skovroinski, Valderi D. Leite, Marcelo O. Rodrigues, André Galembeck, Mary C.F. Alves, Julian Eastoe, and Rodrigo J. de Oliveira. ACS Appl. Mater. Interfaces, 2018, 10 (9), pp 8077–8085. DOI: 10.1021/acsami.7b19834].
Polystyrene, from pollutant to environmental remediator
A team composed of seven researchers from Brazil and one from the United Kingdom used polystyrene waste, which is a potential environmental polluter, to produce a material that works as an environmental remediator by degrading toxic compounds in water bodies and waterways. Therefore, the research makes a contribution to two disturbing environmental problems: on the one hand, the presence of large amounts of plastic waste on the planet; on the other hand, pollution or contamination with toxic substances in aquatic ecosystems.
The research was reported in a paper recently published in the journal Applied Materials & Interfaces (impact factor = 7,504).
We know that polystyrene is used to make disposable cups and cutlery, yogurt pots, combs, hangers, organizer boxes and many other utilities, in addition to being the main component of the well-known isopor®. “We present an alternative to reuse one of society’s most demanded plastics,” says Professor Rodrigo José de Oliveira, from Paraíba State University (UEPB), corresponding author of the paper.
The material developed by the scientific team consists of a porous polymer matrix impregnated with nanoparticles of tin dioxide (SnO2). In this composite material, while the nanoparticles are largely responsible for degrading the toxic compounds (dyes) by a photocatalytic process, the polymer matrix, which is produced from polystyrene waste, creates an environment favorable to photocatalytic activity and supports the nanoparticles, allowing them to be easily removed from the waters, and reused in new processes of environmental remediation.
The authors of the article called the new composite material “nanofoam”. Although they have a few centimeters in diameter and pores of a few micrometers, the foams have received the prefix “nano” because their photocatalytic properties are due to the presence of nanometric-sized tin dioxide (spherical nanoparticles of about 20 nm). “Nanomaterials are those that present new properties due to a distinct physics that appears in this size scale,” recalls Oliveira.
To obtain composite foams, the team used low cost equipment and procedures based on well-known physicochemical properties. The preparation process is described in broad lines as follows. First, small pieces of polystyrene waste are dissolved in cyclohexane solvent, and the tin dioxide nanoparticles, which here were manufactured by the team, are added to the solution. This part of the process is carried out above the so-called “theta temperature (θ)” of the cyclohexane and polystyrene solution, which is about 36 °C, because below this temperature the solution undergoes a phase separation. Second, the preparation is carried out for 10 minutes at a temperature of 10 °C. As a consequence of this temperature decrease, some phenomena take place. The solution separates into two phases, one rich in polystyrene and the other rich in cyclohexane, and the solvent freezes. At the end of the cooling process, the phases are distributed in such a way that they form a polystyrene structure with holes filled with frozen cyclohexane. In order to remove the solvent from the foams, a lyophilization process is applied, whereby the cyclohexane undergoes sublimation. As a final result, a porous solid is obtained that the authors of the article called nanofoam.
“We have shown that a dense polystyrene waste can be readily converted into a porous polymer matrix, which is desirable for making new materials, that is, a noble end to pollution that has mobilized governments from industrialized countries,” says Professor Oliveira.
Finally, the scientific team evaluated the efficiency of the new material as an environmental remediator by testing the ability of nanofoams to degrade a magenta-like dye called rhodamine B. This compound, which is used as a marker in health, research, agriculture areas, is toxic to the reproductive and neurological system, and in some studies it has been pointed out as a carcinogenic agent.
The nanofoams of Professor Oliveira and his collaborators managed to degrade 98.2% of rhodamine B – a result superior to those obtained with photocatalytic nanoparticles outside the polystyrene matrix. In addition, the nanofoams demonstrated very good performance when reused: they degraded more than 96% of rhodamine B in the first four cycles. “It is desirable to use a matrix because it facilitates the final recovery of the photocatalyst, since the foam is easily removed from the medium using steel tweezers, in addition to an increase in the surface area due to higher oxide dispersion in the matrix,” says Oliveira.
History of the work
Rodrigo de Oliveira was involved in his doctorate when, in 2011, he had the idea of obtaining new catalytic materials, taking advantage of the characteristic of some solutions in which their phases are separated by the effect of temperature (known as “thermally induced phase separation,” TIPS). Oliveira was in an internship abroad (the so-called “doctoral sandwich”) in the group of Professor Julian Eastoe at the University of Bristol. In this group, Oliveira had found the double possibility of working with surfactants, the subject of his doctoral research, and also improving his command of the English language. “In Bristol, Julian presented me with a paper he had published decades ago on the use of TIPS to study microemulsions and the formation of calcium carbonate foams,” Oliveira recalls. By the end of the internship, the Ph.D. work had developed a surfactant foam decorated with gold nanoparticles. In England, in addition to this work in Bristol, Oliveira made contact with a renowned group at Cardiff University dedicated to catalysis research, led by Professor Graham Hutchings. “The possibility of obtaining new catalytic materials using TIPS was cogitated,” recalls Oliveira.
In 2012, Oliveira obtained a doctor’s degree in Chemistry from the Federal University of Pernambuco (UFPE). Shortly after, after qualifying in the selection process of UEPB, he became a professor of that institution. The young researcher then saw the opportunity to realize the idea he had envisaged in England. In order to carry it out, he had to venture into a new research line, different from what he had pursued during his undergraduate, master’s and doctoral works, but he was already experienced with this. In fact, during his undergraduate, master’s and doctorate courses in Chemistry, all of them at UFPE under the guidance of Professor André Galembeck, he had addressed three very different research topics. “André has always been open to proposals and ideas, including those that differed from the group’s research history,” declares Oliveira.
There was no lack of courage, but Oliveira had just arrived at UEPB and had no infrastructure available, nor the financial resources to build it. “From 2012 to now, our struggle has been to establish a research group in physical chemistry of materials, and one of the focused lines is the use of TIPS to make materials from plastic waste,” he says. In the case of nanofoams, the researcher was able to develop the work within Geovânia Cordeiro de Assis’s master’s thesis, defended in 2016 and supervised by Oliveira together with professor Mary Cristina Ferreira Alves (co-supervisor). For the preparation of the nanofoams, the team used simple and inexpensive equipment (“a $ 20 refrigeration plate purchased from China’s import website and a vacuum pump”). For the characterizations, which necessarily require more expensive equipment, Oliveira had the collaboration of colleagues from UFPE, University of Brasilia and University of Bristol.
Other materials with environmental applications will be generated in the city of Campina Grande, in the laboratory of Professor Oliveira, using various types of plastics, including those with a more complex composition such as styrofoam®, which is composed of expanded polystyrene and other chemical components. In addition to developing materials to contribute to the remediation of ecosystems, the group is using them for more fundamental studies, which could generate nanomaterials with sophisticated structures.
“Unfortunately, we are constantly faced with the lack of characterization equipment, and nowadays neither the collaborators with the best of intentions have the resources to help us as before,” Oliveira laments. “I realize there are quality human resources in our institution; however, more investments in infrastructure are fundamental to maintain the quality of the work, training of human resources and internalization of state of art science,” he adds.
How many scientific vocations were aroused, and how many domestic accidents were caused, by experimental chemistry games for children (which until some time ago did not follow all the toy safety standards)? The Argentine scientist Galo Juan de Ávila Arturo Soler Illia belongs to this group. He remembers that his interest in science lit up (literally) with a small fire caused by a chemistry lab set in his parents’ home – two lawyers, members of the Radical Civic Union, that was also the party of Galo Soler Illia’s grandfather, President Arturo Umberto Illia, who ruled Argentina from 1963 to 1966, until undergoing a coup.
Today, Galo Soler Illia can be considered one of the best known researchers in the Brazil´s neighboring country, both in the scientific community (he is among the 30 Argentine scientists best positioned in Google Scholar for the citations to his works, and has also received the top national science awards) and among the lay public (in the field of Nanotechnology, he is a very active and didactic presenter in all the media, and is usually an information source for Argentine journalists).
Galo Soler Illia was born in Buenos Aires on May 31, 1970. He completed his primary studies in a private constructivist school, Bayard College. In 1983, he enrolled in the National School of Buenos Aires, a public institution dependent on the University of Buenos Aires (UBA), which among other things was characterized by a high study demand, a wealth of extracurricular activities and better-quality infrastructure than other public schools. In 1988, he graduated from the college with a specialization in Sciences. Both in primary and secondary education he had the opportunity to carry out activities in science labs.
In 1989, Soler Illia began to study in a Chemistry Sciences course at UBA. During the undergraduate course, he began teaching in the Department of Physical, Analytical and Inorganic Chemistry of UBA and doing research in a group of Materials Chemistry and also in a laboratory set up in the house of a friend. In 1993, he obtained a bachelor’s degree in Chemistry, with a grade point average of 9.13 / 10.
From 1994 to 1998, Soler Illia completed his doctorate in Chemistry, also at UBA, under the guidance of Professor Miguel Angel Blesa. Through research on nanoparticles of mixed metal hydroxides, he generated knowledge about the complex mechanism of particle formation, which would be very useful in his research as a postdoc and as a professional researcher, focused on the synthesis of materials with high control of their characteristics. Concomitantly to the doctorate, he continued to teach, as an assistant, at UBA.
In 1999, he moved to France, together with his wife Astrid Grotewold, also a chemist, and remained there until 2002. Soler Illia did postdoctoral studies at the Université Pierre et Marie Curie (Paris), under the supervision of Dr. Clément Sanchez, with a 2-year scholarship from CONICET, the main Argentine entity in support of science and technology. In the post-doc, Soler Illia developed methods to produce highly controlled porosity materials. This period resulted in Soler Illia’s most cited articles so far, with more than 1,800 citations in one of the papers, according to Google Scholar. At the end of his stay in France, Soler Illia also worked on applications of mesoporous thin films for the research and development center of the company Saint Gobain.
Galo Soler Illia returned to Argentina in early 2003, at a time when the country was ending great political instability, which caused the Presidency of the Republic to appoint 5 different people in just 11 days. In addition, the country was still under the effects of the severe economic crisis that had reached its peak in 2001. However, Soler Illia was quickly able to enter the research career at CONICET, working at the National Atomic Energy Commission (CNEA) and without wasting time, founded the Chemistry Group of Nanomaterials, which to date operates in the design and development of nanostructured materials. In 2004, the scientist became a professor of UBA in the department where he studied for his bachelor’s degree and doctorate.
In early 2015, Illia became director of the Institute of Nanosystems (INS) of the National University of San Martín, located in the metropolitan area of Buenos Aires. The INS is defined as a space for nanoscience and nanotechnology research, development and creation, whose ultimate goal is to solve priority problems of industry and society in general. At the institute, Soler Illia has a multidisciplinary scientific team of 4 researchers (4 more in 2017), 6 graduate and post-doc students and 1 laboratory technician, and also a management team of 6 professionals.
Currently, in addition to being director of INS, Galo Soler Illia is principal researcher of CONICET and associate professor at UBA. He is a member of advisory boards at the Argentinean Nanotechnology Foundation (FAN) and at the Brazilian National Synchrotron Light Laboratory, and also a member of the editorial board of the Journal of Sol-Gel Science and Technology (Springer). Moreover, Soler Illia has a scientific dissemination column on Nanotechnology in a television broadcast program called “Scientists Made in Argentina”, which airs once a week on the Argentine public channel. Finally, Soler Illia has just been appointed (November of this year) as member of the Argentine Presidential Council 2030, composed of intellectuals from various fields to advise the president of Argentina, Mauricio Macri.
Soler Illia, whose h-index is 44, has produced over 120 papers published in international scientific journals, with about 11,000 citations, according to Google Scholar. He has supervised 7 completed PhD theses and is the author of 2 dissemination books on nanotechnology. He is also the author of 4 patent applications.
His work was recognized with a series of awards for science, technology, innovation and scientific popularization, among them the main Argentinean awards, like Houssay Award (2006 and 2009), from the Secretary and later Ministry of Science and Technology; the KONEX Award (2013) from the eponymous foundation and the Innovar Award (2011 and 2016) from the Ministry of Science, Technology and Productive Innovation. He also received distinctions from the National Academy of Exact Sciences, FAN, Argentinean Association of Physicochemical Research, CONICET, BGH and Dupont companies, among others. In May of this year, Galo Soler Illia was appointed titular scholar of the Argentinean National Academy of Exact Sciences, Physics and Natural Sciences, a select group of only 36 scientists.
Here’s an interview with the Argentine scientist.
SBPMat newsletter: Tell us why you became a scientist and work in the field of materials.
Galo Soler Illia: I always liked Chemistry. This started when I received a chemistry game, I was five years old, and while experimenting with it I burned my parent`s dinner table. Later, during my high school studies I was a bit of a nerd, writing software code for physics classes at my school. Writing code aroused my curiosity to know how things worked and how problems could be solved. I learned a lot. Near the end of secondary education, I decided to study Chemistry because I believed it was a very versatile and wonderful course that had great possibilities in many fields. At that time, I was really interested in Biotechnology, which was a new area. At the time I started my undergraduate studies at the University of Buenos Aires (UBA), the area of Materials Chemistry had began to emerge. Still a student, I began teaching as an assistant in the Department of Inorganic, Analytical Chemistry and Physical Chemistry of the Faculty of Exact and Natural Sciences, inspired by the example of young and enthusiastic teachers who were returning from abroad and who propagated an atmosphere of work and demand. Together with my best friends, we set up a laboratory on the terrace of one of my friend’s home. There we grew crystals and planned molecule synthesis. Since we spent all day at university and had some spare time, I found a place to work, without a salary or scholarship, in a Materials Chemistry group that had just begun. Everything was very fast, and before I noticed it I had finished my undergraduate studies and began my doctorate, manufacturing microparticles for catalysts. It was a beautiful time of my life, a time from which I still retain my innate curiosity, my willingness to explore and build materials and a wonderful group of friends, who have become outstanding colleagues now spread out throughout the world.
SBPMat newsletter: In your opinion, what are your main contributions to the Materials area, considering all aspects of your scientific activity?
Galo Soler Illia: I have always been interested in building materials, in the chemist’s task to join atom with atom, to manufacture new architectures. I focused on understanding the physicochemical phenomena that take place during the production of a material. When you know and understand these processes, you go from simply “preparing” a material to being able to design it and synthesize it, however complex it may be. And we can take advantage of the properties of the chemical elements to obtain the properties we desire. I’ll give three examples. In my thesis, I studied the precipitation and aggregation of nanoparticles of mixed metal hydroxides, precursors of catalysts. We discovered a very interesting world and were able to contribute to understanding the complexity behind a dynamic particle formation mechanism: the effects of particle shape and structure, the importance of metals coordination in the formation of a mixed phase, the evolution of surface charge and its effect on the stability of a colloid and much more, which helped me in the future as a solid basis for my research. I was fortunate to be able to work with Miguel Blesa, Alberto Regazzoni and Roberto Candal, three excellent Masters who guided me, stimulated and corrected me.
In my second phase, I worked in Paris in the laboratory of Clément Sanchez. I used what I had learned in order to develop methods to produce highly controlled porosity materials, known as organized mesoporous materials. Again, I became interested in the materials formation mechanisms, which are complex because they require controlling the growth of small inorganic species and their self-assembling with micelles. It is a small physical-chemical symphony, which one must learn to play. We had to use, develop and combine many characterization techniques to understand the phenomena taking place and how they controlled the formation and organization of pore systems, the stability and crystallinity of materials, which among others are important variables in the final performance of these solids.
In my third phase, back in Argentina, I set up a research group at the National Atomic Energy Commission in Buenos Aires, and devoted myself to building more complex architectures based on everything I had learned. My best contributions in this regard refer to the use of forces and interactions at the nanoscale to manufacture many different nanocomposites with designed and surprising optical and catalytic properties. All this required new laboratories, training human resources and the transfer of basic science to technologies. Particularly, over the last years we have worked with companies and aspire to generate nanotechnology in Argentina, extending the knowledge of our laboratory to society.
SBPMat newsletter: Briefly tell us about your interaction with Brazil. Do you come here often for collaborations, events, use of labs, seminars? Have you worked with Brazilian groups or in Brazilian laboratories?
Galo Soler Illia: I returned to Argentina in 2003 and I knew right away about what was being developed in Brazil. Since that time, I began developing projects at the National Laboratory of Synchrotron Light (LNLS), which is a beacon for all those who work in Materials in Latin America. The interaction with the synchrotron staff was very important for us to be able to characterize our materials, and we are amazed to see how the installations have improved over the years. A few months ago I had the opportunity to visit the Sirius building, which is simply stunning and which will be a world reference. I also had the opportunity to visit several universities, teaching courses and collaborating in the education of undergraduate and postgraduate students. Furthermore, we created the School of Materials Synthesis in Buenos Aires, which will have its eighth edition in 2017. This school was designed to generate a community of Latin American scientists qualified with skills in the rational synthesis of materials. We started with many Brazilian students, thanks to the support of the Argentinean-Brazilian Nanotechnology Society, which unfortunately has stopped working. It is truly beautiful to see how students from both countries work together in the laboratories and discuss and present their work in “portunhol” [hybrid mixture of Spanish-Portuguese]. From this school, and with the help of several colleagues, collaborative networks are emerging that will undoubtedly provide us with the technological base for larger joint ventures. I travel to Brazil several times a year and always admire the strength of the country to boost local technological development. I hope that after these difficult times, we may continue growing together.
SBPMat newsletter: We always ask the guest being interviewed in this section to leave a message for the readers who are beginning their scientific careers. What would you say to these junior scientists?
Galo Soler Illia: Looking back, I have three recommendations to young scientists. One is to never lose your imagination and your ability to ask questions; the second is to work hard to find the answers, and the third is to make use of the surprises. Sometimes, we train to develop a path and a strategy and we focus on the rigor to demonstrate and formalize what we find. However, it is crucial to know that this path is full of interesting nooks and turns, and sometimes an aspect we hadn’t taken into account opens up a new and unexplored landscape. Newton said that we, scientists, are sometimes like children on the beach, we find a shell that is prettier than the others and we are happy, but there lies before us the vast ocean of truth. My advice is to continually seek our shells, enjoy them and let us come within reach of understanding the wonders of our universe. And always keep in mind that developing science in our continent is a beautiful challenge that will add richness to our countries and well-being to our brothers.
[Paper: Hybrid tantalum oxide nanoparticles from the hydrolysis of imidazolium tantalate ionic liquids: efficient catalysts for hydrogen generation from ethanol/water solutions. Virgínia S. Souza, Jackson D. Scholten, Daniel E. Weibel, Dario Eberhardt, Daniel L. Baptista, Sérgio R. Teixeira and Jairton Dupont. J. Mater. Chem. A, 2016, 4, 7469-7475. DOI: 10.1039/C6TA02114J.]
Super efficient nanoparticles to catalyze production of hydrogen, an alternative fuel.
While some automobiles which use hydrogen fuel are entering the market, scientists from around the world are still trying to find cleaner, more sustainable, safer and cost-effective ways to generate and store hydrogen. In fact, even though it is the most abundant element in the universe and found in the water and in numerous other compounds, hydrogen cannot actually be found in its pure form on our planet. It must therefore be obtained from other chemical compounds.
One of the best methods to produce hydrogen, from ecological and economical points of view, is water splitting. This technique consists of separating water molecules into its two primary elements, generating hydrogen (H2) and oxygen (O2) gases. This separation can be achieved through the use of the abundant solar energy, at room temperature. However, in practice, for sunlight to split one water molecule, it requires nanoparticles made of semiconducting materials to act as catalysts, or more specifically, as photocatalysts.
In a study fully carried out in Brazil, a team of scientists developed a new simple and efficient method to produce tantalum oxide nanoparticles (Ta2O5) with outstanding performance catalysts for hydrogen generation. The research was reported in a paper recently published in the Journal of Materials Chemistry A (impact factor: 8.262).
This study was funded by the Brazilian research agencies CAPES and CNPq, as the doctoral research of Virgínia Serra Souza at the Chemistry Institute of the Federal University of Rio Grande do Sul (IQ-UFRGS), under the guidance of Professor Jairton Dupont.
“The idea for this research came when we were looking for an alternative and efficient route for the synthesis of Ta2O5 nanoparticles, and after some experiments we decided to test the possibility of using ionic liquids as stabilizing sources and agents of the nanomaterials”, says Professor Jackson Damiani Scholten, who is one of the corresponding authors of the paper and member of the research group of IQ-UFRGS. This group has extensive experience in the study and development of ionic liquids (salts which are in liquid state at room temperature). Due to their physicochemical properties, ionic liquids can be used in the preparation of nanoparticles as stabilizers to keep the particles in the nanometric range.
Souza, Scholten and Dupont prepared two types of ionic liquids containing tantalum and create the conditions for the hydrolysis reaction (breaking the chemical bonds of a compound by the addition of water). The elements resulting from the hydrolysis, from the water and the ionic liquid, recombine to form tantalum oxide nanoparticles.
The team realized it had produced tantalum oxide nanoparticles ranging between 1.5 and 22 nm, the smaller ones had been generated from one of the ionic liquids and the larger ones from the other. With the assistance of Professor Daniel E. Weibel, also from IQ-UFRGS, they studied the surface composition of the nanoparticles. These scientists proposed that the nanoparticles obtained were hybrid: remains of ionic liquid were observed around the tantalum oxide.
To see how the nanoparticles behaved as catalysts in the separation of water molecules to generate hydrogen, the team conducted photocatalytic tests at the facilities of the Institute of Physics – UFRGS, provided by Professor Sérgio R. Teixeira. The tests were carried out in a solution that besides water contained ethanol – a compound that helps to increase the hydrogen production rate.
“We were delighted that the Ta2O5 nanoparticles showed one of the best results ever published for the production of H2 from a water/ethanol solution”, recalls Professor Scholten. In the article, this exceptional result was attributed to the presence of ionic liquid in the nanoparticles. “We believe that the residual ionic liquid enhances the formation of a hydrophilic regions on the surface of Ta2O5, favoring the approximation of polar molecules (water and ethanol)”, explains Scholten. To be certain about this, the scientists removed the ionic liquid from the nanoparticles by heat treatment and confirmed their very low photocatalytic activity.
In another stage of the research, Dario Eberhardt, then professor at the University of Caxias do Sul (UCS), collaborated with the team in the deposition of roughly 1 nm platinum nanoparticles on the surface of the hybrid tantalum oxide nanoparticles by the sputtering technique, carried out at IF-UFRGS. Professor Daniel L. Baptista, of IF-UFRGS, helped to characterize the material. In the tests, the performance of the tantalum oxide nanoparticles with photocatalytic ionic liquid was even better with the addition of platinum.
This work, carried out in southern Brazil, presented a new method to produce super-efficient catalysts for hydrogen production, a promising alternative fuel from water and ethanol, two renewable and abundant resources.
[Paper: Charge transfer effects on the chemical reactivity of PdxCu1−x nanoalloys. M. V. Castegnaro, A. Gorgeski, B. Balke, M. C. M. Alves and J. Morais. Nanoscale, 2016,8, 641-647. DOI: 10.1039/C5NR06685A]
Taming the reactivity of nanoalloys
When, in 2009, the Electron Spectroscopy Laboratory (LEe-) group of the Federal University of Rio Grande do Sul (UFRGS) decided to start developing in-house metal nanoparticles required for their studies, they came across some issues. Many synthesis methods reported in the literature did not provide the expected results when made in the Brazilian laboratory.
Strongly motivated by curiosity, as usual, says professor Jonder Morais, LEe- researcher, the group members were able, after much dedication, to develop new routes of synthesis that, in addition to being reproducible, are environment-friendly, efficient and cost-effective. “The first articles were published in international journals in 2013, initially with palladium (Pd), platinum (Pt) and silver (Ag) nanoparticles applied to the catalytic decomposition of nitric oxide. Subsequently, we published some works focused in “in situ” studies aimed at determining the mechanisms of formation and growth of monometallic nanoparticles. We have recently started reporting the results obtained with more complex systems, such as palladium and copper (Pd-Cu) nanoalloys,” states Professor Morais.
The latter group includes the results recently reported in an article published in the journal Nanoscale, whose main authors are Professor Jonder Morais and Marcus Vinicius Castegnaro, a physics doctoral student at UFRGS, advised by Morais. The research covered the entire process from the production of nanomaterials to the survey of their applications. “It was important to have dedicated students, willing to face the challenge of preparing accurately their own samples, and correlating the electronic and structural properties to understand the final properties in terms of chemical reactivity,” says Morais.
In the article published in Nanoscale, nanoparticles composed of palladium and copper alloys were produced by applying a simple method developed by the LEe- team. This process is carried out under mild conditions to the environment and health (aqueous, ambient temperature and pressure, and use of cheap and innocuous substances, such as ascorbic acid and sodium citrate). Several samples were synthesized by this route, containing three different amounts of palladium and copper atoms.
The synthesized nanoparticles have undergone a series of analyses conducted at UFRGS, in Porto Alegre (Rio Grande do Sul State), they traveled to Campinas (São Paulo State) for another series of analyses on equipment of the National Center for Research in Energy and Materials (CNPEM) and crossed the ocean to Johannes Gutenberg University, in Germany, for some additional measures. From characterization, the authors concluded that the nanoparticles were approximately 4 nm in size and were highly crystalline, among other characteristics. In addition, through experiments conducted by the XANES in situ technique, the team of scientists exposed the nanoparticles to carbon monoxide (CO) at 450 ° C and surveyed the reactivity of the nanoalloys, i.e., their ability to react chemically.
After studying the results of the characterization, the authors of the article were able to conclude that the alloy composition affects the ability of nanoalloys to reduce (gain electrons) and to oxidize (lose electrons). In fact, the greater the amount of palladium, the easier the reduction, and the harder the oxidation.
“The published results, obtained by the association of several experimental techniques are relevant to an understanding of the origin of high catalytic reactivity of palladium and copper (Pd-Cu) nanoalloys, as well as to elucidating similar behavior of other bimetallic systems”, highlights Jonder Morais. “Mostly, these results can be used in the “design “of new nanomaterials more efficient for various applications, such as in the petrochemical industry, in fuel cells or in the control of greenhouse gas emissions,” he concludes.
The doctoral thesis that won the Capes Award for Doctoral Theses in the field of materials research was also winner of a Grand Capes Award. The thesis was defended in 2014 by Edroaldo Lummertz da Rocha to obtain the doctoral degree in Materials Science and Engineering from the Federal University of Santa Catarina (UFSC). The award was delivered in a ceremony, in December 10th at Capes central office, in Brasília.
The Grand Award selects the best thesis of each of the three major evaluation areas of Capes, which is the government agency linked to the Brazilian Ministry of Education in charge of promoting high standards for post-graduate courses in Brazil. To run for the Grand Award, the authors of winners theses in the Capes Award must present a video lesson of 20 to 30 minutes, destined to high school students, approaching the thesis theme in a proper way to the target audience.
In his video, Edroaldo presents the contributions of his doctorate research to the development of nanostructures that, introduced in the human body, would have therapeutically effects against cancer and, at the same time, would generate less collateral effect than the methods currently used (surgery, chemotherapy and radiotherapy). To present these contributions, the video explains concepts such as cancer and bionanotecnology. The video also presents the development of CellNet software, in which Edroaldo participated during his doctorate, which helps in the investigation of transformation of cells from a type to another (for example, stem-cell in other cells or skin cells in heart cells). See here the video lesson prepared by Edroaldo and also the videos of the other candidates to the Grand Award.