Lists of projects

Synthesis, Structure Elucidation and Modification of Zeolites and Porous Silica Materials.

According to the International Association of Zeolites ( zeolites are crystalline aluminosilicates with precisely defined microporous structures. The pores and cages have molecular dimensions which make it possible to discriminate between molecules of different sizes. Therefore , zeolites belongs to the type of materials known as molecule sieves. The porous system can be one-dimensional with parallel pores and no interconnections, or two/three dimensional with interconnected channels and/or cages. Zeolites are classified according to their pore sizes. The access to the micropores is definied by the numbers of oxygens atoms in the ring forming the aperture. Three types of zeolites are distinguished: the small pores, medium pores and large pores zeolites. In general the porous of the solids are classified according to the size: porous sizes in the range of 2nm and below are called micropores those in the range of 2 nm and 50 nm are denoted mesopores, and those above 50 nm are macropores. The distribution of sizes, shapes and volumes of the void spaces in porous materials directly relates to their ability to perform the desired function in a particular application. The need to create uniformity within the pore size, shape and volume has steadily increased over recent years because it can lead to superior applications properties.These microporous structures are attractive materials for many applications, including adsorption, catalysis and ion exchange and the range of reactions over which a zeolite can apply shape selective pressure is a function of the zeolites pore size and structure. Zeolites with pore sizes between ten and twenty angstroms would impact fine chemicals, pharmecuticals, and life sciences. Our group focus on the syntheses of large porous zeolites using new organic templates as structure directing agents (SDAs) and their complete characterization using High Resolution Electron Microscopy (HREM), Powder X-ray and Neutron Diffraction.

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Syntheses of Enantioselective Solids Catalysts and Chiral Zeolites for Fine Chemical Production.

Zeolites science started on 1756 when Cronstedt discovered and characterized the first zeolite, stilbite, as a hydrate aluminosilicate with alkaline and alkaline earth cations[29] and the full technological and industrial potential of zeolites was realized in 1932 when McBain selectively adsorbed molecules in zeolites and subsequently coined the term "Molecular Sieves". A careful and critical analysis of the zeolite and sol-gel chemistry science during these 256 years will show that zeolite science is not completely understood in some of its fundamental aspects and there are still several fundamental questions unanswered and challenges in this field. The synthesis of a chiral zeolite and solid with a chiral framework is an intensive area of research in our group.

Enantioselective, solid catalysts are worth targets of research and developments efforts from both the intellectual and commercial point of view. The investigations of these materials is warranted by the economic impact that some of these materials will have in the modern chemical industries, especially in the field of heterogeneous asymmetric synthesis, green chemistry, environmental sciences, petrochemical, fine chemical and pharmaceutical companies. Presently, in the field of industrial catalysis, homogeneous metal complexes with chiral ligands are still the most versatile enantioselective catalysts, however heterogeneous catalysts would be more preferable, due to several inherent practical advantages connected to separation, handling, stability, recovery and re-use. Chiral zeolites would be ideal materials for these tasks and the syntheses of such remarkable materials would be a landmark in the catalysis area. Through a combination of several techniques such as computer modeling, organic syntheses of chiral templates and inorganic sol gel chemistry, researchers in our groups are intensively working in order to achieve this goal.

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Chemeocatalytic Conversions of the Biomass Glycerol

Biodiesel is a clean-burning fuel currently being produced from grease, vegetable oils, or animal fats. Its chemical structure is that of fatty acid alkyl esters. Biodiesel is produced by the transeterification of oils with short-chain alcohols or by the transesterification o fatty acids. The transesterification reactions consists of transforming triglycerides into fatty alkyl ester, in the presence of an alcohol, such as methanol or ethanol, and a catalyst, such as an alkali or acid, with glycerol as a byproduct.

The chemical reaction is described and normally performed at 60-80oC. The glycerol and the biodiesel are normally separated by settling after the catalyst neutralization. The crude biodiesel and glycerol obtained are then purified. Glycerol is a valuable byproduct of the biodiesel production , with a current refined value around $ 1.10/kg. As biodiesel production increases, the cost of glycerol is projected to decrease significantly and in fact the price of glycerol has already dropped by almost half over the last few years and some experts have estimated that the cost of refined glycerol could drop to as low as 0.77/kg and the cost of the unrefined glycerol could decrease to 0.44/kg. Our group is focused on the development of new heterogeneous catalysts for the chemical transformation of glycerol into high-value fine chemicals through the process of dehydration, oxidation, hydrogenolysis, amination, etherofication. This research is being conducted with close collaboration with the Chemical Engineering Department of Federal University of Uberlandia-UFU.
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Development of New Heterogeneous Catalysts for Biorefinery and Petrochemical Refineries.

Biofuels produce significantly less greenhouse gas emission than fossil fuels and can even be greenhouse neutral if efficient methods for biofuels production are developed. In general regional issues greatly affect biomass cost, but biomass costs from cheapest to the most expensive are typically lignocellulose < starches < vegetable oils < terpenes < algaes. Lignocellulose is the cheapest and most abundant form of biomass, and on an energy basis is significantly cheaper than crude oil. In contrast to the petroleum derived feedstocks, biomass-derived compounds contains large amount of oxygen and their conversion into liquid fuels requires oxygen removal. Carbohydrates , which composes approximately 75 wt% of cellulosic biomass , have a C-to O ratio of 1:1. Water soluble biomass-derived oxygenates (including carbohydrates, polysaccharides, furfural and lignin-derived compounds) can be produced from cellulosic biomass by acid hydrolysis, pyrolysis, or liquefaction. Bio-oils, produced by fast pyrolysis or liquefaction from biomass are a mixture of more than 300 highly oxygenated compounds and bio-oils are thermally unstable and must be upgrade if they are to be used as fuels.

Fuels are low value commodity produced on a very large scale, and therefore development of economical processes for fuels production requires a large investment in both money and time. Most biomass conversion processes are started with the goal of rapidly developing commercial technologies, however most of the reactions involved in these processes are not well and fully understood, and it is likely that more scientific understanding is necessary in order to improve these processes. However it is perfectly clear that it will be vital that new and more efficient catalysts must be discovered for these reactions and it is likely that heterogeneous catalysis , which has been the backbone of the chemical and petroleum industry ,will play a key role in the upcoming transition to the carbohydrate economy. Following this approach one option for biofuel production is to use biomass-derived feedstocks in a petroleum refinery. Petroleum refineries are already built, and using this existing infrastructure for biofuel production would require little capital cost investment and in this case the Fluid Catalytic Cracking (FCC) process could be used. Most of the traditional FCC Catalysts have been explored for the catalytic cracking of biomass, however the results are not very encouraging and new FCC catalysts are need. Our group has focused in the syntheses of new catalysts based on mixed tetrahedral-octahedral microporous materials which will offer a new class of catalytically actives sites that are different from conventional zeolites based on (Niobium, Stannous, Molybdenum, Yttrium, Zirconium, and Vanadium) silicates. At the moment this project is being conducted in our group, however in the nearby future it will be also a project in collaboration with Federal University of Uberlandia-UFU, University of Toronto and University of Western Ontario with financial support from FAPESP.

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Mesoporous Inorganic-Organic Hybrid Materials for asymmetric catalysis.

Mesoporous organic-inorganic hybrid materials is a new class of materials characterized by a large specific surface areas and pores sizes ranging between 12 and 15nm. These materials can be obtained through the coupling of inorganic and organic components by templates synthesis. In our group we have focused our efforts in the syntheses and characterization of new mesoporous inorganic-organic hybrid materials for the purporse of assymetric catalysis.

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Functional Nanostructure for Biomedical Application.

Several devastating diseases such as cancer can be successful treated if they are detected in their early stage. Therefore an important area of research in disease detection lies in the use of magnetic resonance imaging (MRI), x-ray computed tomography, ultrasound and nuclear imaging. Nanotechnology and nanoscience can play a relevant role in the discovery of new functional materials that can be used as contrast agents for MRI and other clinical imaging modalities. Most of nanostructures are simple, single-purpose imaging agents based on spherical constructs, such as liposomes, micelles, nanoemulsions, macromolecules, dendrimers and solid nanoparticle structures. At the moment our group is focused in developing new contrast agent based on nanozeolitic structures doped with gadolinium and manganese.

Functional Nanostructure for Biomedical Application
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Enzyme-Magnetic Nanoparticle Conjugates for heterogeneous catalysis and environmental bioremediation.

Our group is taking advantage of the nanotechnology and traditional material sciences in order to prepare materials with new functionalities and enhancing their different areas of applications. We are developing new magnetic and non-magnetic nanoparticles which are used as solid support for enzymes immobilization. These inorganic solid- enzyme conjugates can be used as biocatalysts for the production of biodiesel. The positive results of this research will economically impact in the production of biodiesel, since the use of pure enzymes as catalysts is very expensive and it also carries all the typical disadvantages of the homogenous catalysts, specially the separation of the products and the recovery of the catalysts. The new inorganic solid-enzymes complexes will overcome these difficulties. These inorganic solid- enzymes complexes also have potential for bioremediation of contamination in complex geological environments.

Our group is targeting xenobiotic molecules can be attached in its active form to the nanoparticles and if the conjugates can then be transported while remaining stable through aquifer matrixes to reach places where contaminants are located and then detoxify them. The overall objective of our work in this area is to develop dispersed colloidal magnetic nanoparticles (MNPs) composed of transition metals that can be are conjugated to active enzymes (MNP-Es) and to then study the stability and activity of these conjugates for catabolic enzymes that are important for the biodegradation process. The specific objectives are to to produce transitional metals magnetic nanoparticles, afterwards the nanoparticles will be activated with enzymes via chemical cross-linking, and their activity and stability will be evaluated both after formation and during storage. This work holds great potential to impact the field of environmental biotechnology by offering a new technology for treatment of groundwater contamination that is recalcitrant to degradation in deep, confined aquifers where other treatment technologies have been ineffective.

Aquífero Grarani
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Nanomaterials and Metal-Organic Framework (MOFs) for Hydrogen Storage fuel cells.

Hydrogen is an renewable and clean energy. It is an convenient, safe, versatile fuel source that can be easily converted to a desired form of energy without releasing harmful emissions. Although, hydrogen is the ideal fuel for the future, hydrogen fuel cells have some practical issues associated with the cost benefit and infrastructure development for safety and economics. Hydrogen has a high energy density by weight, but it has a low energy density by volume as compared to hydrocarbon based fuel cells, therefore the hydrogen storage is one of the bottlenecks for the hydrogen fuels cells development since the high pressure compressed gas tanks are large and heavy. In addition the compression of hydrogen to high pressure requires energy as well, defeating some of the cost benefits with the fuels cells. Hydrogen fuel cells technologies will not be adopted unless the hydrogen storage tanks can be improved to decrease size and weight. Our group is researching the development of nanostructured materials and MOFs materials which present high volumetric and gravimetric hydrogen capacities in order to be used as solid state hydrogen storage used to supply hydrogen to fuel cells in a clean, inexpensive, safe and efficient manner.

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Solar Energy: Hybrid Inorganic Nanomaterials to enhance solar cell efficieny.

Greenhouse gas problems and its catastrophic consequence to the planet together with the fast economic growth of rapidly expanding national economies such as those of the BRIC nations (Brazil, Russia, India and China) have made energy security a national concern for many governments. To accommodate this combination of serious environmental problems and explosive growth scientists around the world are looking for a source of energy that is almost limitless and yet does add to the greenhouse emissions and the sun seems to be the solution. According to many experts more energy strikes the earth from the sunlight in one hour than all the energy consumed in the planet in a year. However currently solar power technology has little chance to compete with fossils fuels or large electric grids because the solar cells are not efficient enough and too expensive to manufacture for large-scale electricity generation. However the potential advancements in the field of nanotechnology may open the door to the production of cheaper and slightly more efficient solar cells. Our group is conducting experiments on the syntheses of highly ordered oxides nanotubes and hybrid nanomaterials to improve solar cell efficiency. We are also focusing on the syntheses of mesoporous and zeolite thin-films. These inorganic thin-films are intended to be used with dye-sensitized solar cell devices.

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Synthesis of polymeric non-viral vectors for treatment of Neoplasia Through Chemioembolization.

Chemoembolization is a procedure in which the blood supply to the tumor is blocked surgically or mechanically and anticancer drugs are administered directly into the tumor. This permits a higher concentration of drug to be in contact with the tumor for a longer period of time. In chemoembolization, anti-cancer drugs are injected directly into the blood vessel feeding a cancerous tumor. In addition, synthetic material called an embolic agent is placed inside the blood vessels that supply blood to the tumor, in effect trapping the chemotherapy in the tumor. A variety of materials may be used in the embolization process. Most embolization materials only cause temporary blockage of blood flow to the tumor cells, though in some cases materials will be used that can cause permanent blockage. Our group is working in the syntheses and characterization of polimeric and inorganic materials that might be good candidates for embolic agents in the form of microspheres. We have close collaboration with both Hospitals and private biomedical companies located in the Northwest of Sao Paulo State. The materials prepared in our laboratory are tested in vitro and in vivo in close collaboration with our scientists partners at hospitals and private companies. Most of the graduate students involved with this research theme are hired by the private companies of the biomedical sector.

Synthesis of Inorganic and Polimeric Microspheres for treatment of Neoplasia Through Chemioembolization
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Standing and Speaking up for Scientific Research and Chemical Education.

Science must be taught within the context of social responsibility and ethical behavior and scientists should reach out to the community. The modern scientists must be prepared to work in a national and international environment. The new generation of young scientists will meet very difficult challenges in the future. Problems with diseases, pollution , security and energy, education, food, water, urban sprawl, global warming , nuclear waste, nuclear power and proliferation of weapon of mass destruction will require a new army of well prepared scientists and engineers. These question present a very important and fundamental question for the science educator: How can we prepare the next generation to cope with these challenges? It is my opinion that modern science is highly interdisciplinary. Scientists are citizens who are rooted in a national, continental and worldwide context and not privileged citizens isolated in their laboratories and offices.

Therefore it will be my goal not only to engage the undergraduate and the graduate students in scientific research, but also try to make them to understand science in its broader aspects in the social, ethical and theoretical realm. I strongly believe that as a science educator I should strive to encourage analytical thinking in students and to promote scientific literacy. The students should be helped to understand the role of science in the community. It is important to me to allow the students to think in an unconventional way and encourage them to come up with original ideas, because I strongly believe that imagination, intuition and observation are the most important tools for doing science. This is the main philosophical approach that I have taken as a science educator.

Scientist should reach out to the community, therefore it is important to me to build bridges between the community and the academics institutions. I believe that the non-academic community and the public are genuinely interested in understanding science, but that they are deterred from doing so because there is no one to present science to people in a simple and friendly way. There are few scientists who take on this task. A large gap exists between the general public and the scientific community on such issues as research on deadly pathogens, stem cells, nuclear energy, clean and renewable energy, pollution and human cloning, to cite a few examples. I find this a cause of concern.

It is my opinion that scientists and science educators must do everything in their power to reach out the general public and present to society a view of the world which is clear and ethically grounded, in a way that the general public can understand it, debate it and finally to accept it. We at the LACET are opened to this dialogue and understanding. One current project in our research group is monthly seminars opened to the teenagers and science teachers of the public high schools of the S.J. Rio Preto. In these seminars we make all the necessary efforts to present science in a different context of languages and communication tools aiming to motivate the students to consider a possible career as scientist. Those students who feel strongly motivated and interested in chemical and physical sciences are supervised by the PhD and Masters students of our group.

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