U.S. undergraduate students may select from amongst the following projects offered by the University of Perugia (Perugia, Italy) for the 2015 summer ACS IREU:
|Project Code||Project Title||Project Mentor|
|PER.1||Synthesis and Applications of Metallic and Hybrid Nanoarchitectures
||Prof. Loredana Latterini|
|PER.2||Designing metal fragments for catalytic water oxidation||Dr. Alceo Macchioni|
|PER.3||Ab-initio study of charge displacement in water’s intermolecular interactions||Prof. Francesco Tarantelli|
|PER.4||Environmentally-friendly methodologies for the preparation of organic semiconductors towards the fully green production of solar electricity||Prof. Luigi Vaccaro|
|PER.5||The development of Chemical Artificial Intelligence||Prof. Pier Luigi Gentili|
*Please note, only four projects will be selected for Perugia.
Metal nanoparticles exhibit a number of unique optical properties due to the excitation of collective oscillations of the electron density or plasmon resonances. Various nanoparticle assemblies are of particular interest because they have the potential to exhibit a range of novel phenomena due to the coherent interaction of their plasmon resonances. These phenomena are very promising for applications in a new generation of photonic and antenna devices. The project involves the development of new methods for the preparation of uniform metal (Ag, Au, Ni) and hybrid nanoparticles, assembling them in various 1D, 2D, and 3D architectures, and their comprehensive characterization using optical, electron, and scanning probe microscopy (SPM), as well as different spectroscopic techniques. Hybrid structures will be synthesized using sol-gel methods, by coating metal nanoparticles with different metal oxides, semiconductors (SiO2, TiO2, ZnO), and polymeric layers to produce novel nanocomposite materials with tailored optical and electronic properties. The nanoparticles will be assembled on chemically modified and patterned surfaces. The results of these studies will provide fundamental information about near- and far-field interactions between metal nanoparticles under visible irradiation. This information will be used to design new materials with designed optical, chemical properties to be used as antenna media in photovoltaic or sensing applications or as catalysts in selective oxidation or reduction reactions.
The summer research program consists of many small projects comprising different methods and techniques, which can be easily accomplished in a few weeks. IREU students involved in this project will have the opportunity to choose from relatively simple projects related to synthesis and characterization of nanoparticles to more sophisticated procedure to investigate and analyze the photoinduced reactions of the nanomaterials. The program provides various levels of complexity that will satisfy abilities and needs of different students.
Water oxidation to molecular oxygen is an essential process for implementing an artificial photosynthetic apparatus aimed at the splitting of H2O into H2 and O2, whose realization would contribute to solve the worldwide energetic problem in a green and sustainable way. Water oxidation is intrinsically a difficult process consisting in the abstraction of four electrons from two water molecules. In addition of having a disadvantageous thermodynamics, the process shows overpotentials that makes it difficult also from the kinetic point of view. Hence, an efficient catalytic system becomes necessary, capable of interfacing the monoelectronic charge separation process with the multielectron oxidative and reductive processes.
At the present, only a few metal complexes capable to oxidize water are known but their performances are still much lower than those of the catalytic system acting in the natural photosynthesis process. Furthermore, the reaction mechanism of the oxidation process for most of them is almost completely unknown.
We aims at (1) designing and synthesizing new organometallic compounds for the catalytic splitting of water and testing them in catalysis, (2) investigating the reaction mechanism of water oxidation by means of classical spectrophotometric techniques (UV-VIS) and advanced NMR techniques and (3) anchoring the catalysts with the best performances on regular polymeric structures, as for instance dendrimers, or on solid surfaces.
Summer projects for undergraduates will involve synthesis, characterization and test of new iridium organometallic catalysts for water oxidation. In the course of their research projects, students will learn synthetic procedures, NMR techniques for the intra- and inter-molecular characterization, catalytic tests based on UV-VIS spectroscopy.
While the interaction energy surfaces of water with a large number of other chemical systems have been extensively and accurately studied, very little still is known about the very nature of these non-covalent interactions beyond standard van-der-Waals models. As a result, while water is the most ubiquitous and arguably the most important chemical species for the sustainment of life on earth, there are still severe limits to our understanding of hydrogen-bonding, of solvation, and of other important interactions of water in atmospheric and interstellar chemistry.
We propose to use our recently introduced theoretical analysis of the electron charge displacement taking place upon formation of a chemical interaction to obtain useful and detailed information on the nature of intermolecular forces. A wide choice of molecular complexes, typically of small to medium size will be studied. In particular, we focus on the role played by charge-transfer components and attempt to explain the marked directionality which appears to be so peculiar of water’s interactions. The electron density studied in these investigations is obtained by the most accurate quantum-chemical methods available today.
As previous experience has shown, due to the small size of the molecules studied and the high degree of modularity of the project, some of these investigations are ideally suited to be carried out by an IREU student in few weeks. The subject matter is of basic, general appeal, and oriented towards the illustration of fundamental aspects of chemical bonding. The visiting student will be gradually exposed to the underlying theoretical models and rapidly enabled to carry out calculations in autonomy, using the most popular ab-initio programs.
Despite the latest impressive results, further significant enhancement in organic photovoltaic performance is necessary in order to meet the requirements for large-scale commercialization as a renewable energy source.
Besides, the high environmental cost associated with the currently available methodologies for the synthesis of organic semiconductors, represents a serious limitation for the future application of these compounds as green alternatives to silicon-based devices.
In this context, Green chemistry principles should be applied for the definition of more environmentally efficient synthetic methodologies able to turn the Organic PV approach fully green.
According to our expertise, organic semiconductors will be prepared by minimizing the use of toxic organic solvents and by defining innovative synthetic procedures using green alternative reaction media such as water or solvent-free conditions (SolFC). In addition, new solid catalytic systems will be designed and prepared in order to minimize the catalyst’s dispersion.
The fully green synthetic approach include also the minimization of costly labor and the possibility of producing the desired materials in large scale quantity at the minimal environmental cost. In fact, it is planned the definition of automated protocols by realizing cyclic continuous-flow reactors operating under solvent-free conditions. This approach is very promising to keep the best efficiency of the catalyst making very simple and reproducible its recovery and reuse.
Undergraduates students can participate this research by choosing small projects concerning the catalyst preparation, the reaction condition optimization or the scale-up process for the set-up of a continuous-flow reactor and the definition of automated protocols.
Up to three students can profitably fit into ongoing research being supervised by post-doc fellows who will help to finalize their piece of work into a scientific publication on a specialized journal (as it happened in the previous year).
Researchers working in the field of Artificial Intelligence and human-level intelligent agents are driven by the ambitious projects of understanding the foundations and running mechanisms of the human mind, and trying to reproduce them artificially. These projects have been receiving a renewed spur by the research initiative named “The Decade of the Mind” since 2007. A deep understanding of how the mind perceives, thinks, and acts, and its imitation will have a revolutionary impact in science, medicine, economic growth, security, and well-being. Our intelligence grounds on the working mechanism of the human nervous system. The human nervous system is a “computational machine” based on a complex “wetware” of neuronal cells collecting, relaying, processing and storing information under the shape of electrochemical signals. It is worthwhile trying to imitate human intelligence by using chemical systems. In our group, we propose the use of chromogenic and fluorogenic compounds as surrogates of sensors, and the use of bistable chemical reactions as surrogates of neurons and neural dynamics.
The purpose of the work will be the development of an artificial chemical retina to detect the UV frequencies. The working principles of the human retina will be imitated. The student will learn in detail how humans distinguish colours and how it is possible to mimic human vision to distinguish the frequencies of the ultraviolet region of the electromagnetic spectrum. Within ten weeks, the student will perform photochemical experiments in both liquid solutions and polymeric films and will be able to prepare a first prototype of artificial retina. Moreover, the student will learn how to process spectroscopic and time-resolved data.