Reactive molecular dynamics simulations of hydration shells surrounding spherical TiO 2 nanoparticles: Implications for proton-transfer reactions

In many potential applications, nanoparticles are typically in an aqueous medium. This has strong influence on the stability, optical properties and reactivity, in particular for their functionalization. Therefore, the understanding of the chemistry at the interface between the solvent and the nanoparticle is of utmost importance. In this work, we present a comparative ReaxFF reactive molecular dynamics investigation on spherical TiO2 nanoparticles (NSs) of realistic size, with diameters from 2.2 to 4.4 nm, immersed in a large drop of bulk water. After force field validation for its use for a curved anatase TiO2 surface/water interface, we performed several simulations of the TiO2 nanoparticles of increasing size in a water drop. We found that water can be adsorbed jointly in a molecular and dissociative way on the surface. A Langmuir isotherm indicating an adsorption/desorption mechanism of water on the NS is observed. Regarding the dissociative adsorption, atomistic details reveal two different mechanisms, depending on the water concentration around the NS. At low coverage, the first mechanism involves direct dissociation of a single water molecule, whereas, at higher water coverage, the second mechanism is a proton transfer reaction involving two water molecules, also known as Grotthuss-like mechanism. Thermal annealing simulations show that several water molecules remain on the surface in agreement with the experimental reports. The capacity of adsorption is higher for the 2.2 and 3.0 nm NSs than for the 4.4 nm NS. Finally, a comparative investigation with flat surfaces indicates that NSs present a higher water adsorption capacity (undissociated and dissociated) than flat surfaces, which can be rationalized considering that NSs present many more low-coordinated Ti atoms available for water adsorption. This journal is.Fil: Soria, Federico Ariel. Universita Di Milano Bicocca; Italia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Di Valentin, Cristiana. Università Di Milano Bicocca; Itali

Binding group of oligonucleotides on TiO2 surfaces: Phosphate anions or nucleobases?

Although the immobilization of oligonucleotides (nucleic acid) on mineral surfaces is at the basis of different biotechnological applications, an atomistic understanding of the interaction of the nucleic acid components with the titanium dioxide surfaces has not yet been achieved. Here, the adsorption of the phosphate anion, of the four DNA bases (adenine, guanine, thymine, and cytosine) and of some entire nucleotides and dinucleotides on the TiO2 anatase (1 0 1) surface is studied through dispersion-corrected hybrid density functional theory (DFT) calculations. Several adsorption configurations are identified for the separated entities (phosphate anion or base) and then considered when studying the adsorption of the entire nucleotides. The analysis shows that both the phosphate anion and each base may anchor the nucleotides to the surface in a collaborative and synergistic adsorption mode. The tendency is that the nucleotides containing the guanine base present the strongest adsorption while those made up with the thymine base have the lowest adsorption energies. Nucleotides based on adenine and cytosine have a similar intermediate behavior. Finally, we investigated the adsorption of competing water molecules to understand whether in the presence of the aqueous solvent, the nucleotides would remain bonded to the surface or desorb.Fil: Soria, Federico Ariel. Università degli Studi di Milano; Italia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Di Valentin, Cristiana. Università degli Studi di Milano; Itali

On the mechanism of silicon activation by halogen atoms

Despite the widespread use of chlorinated silicon as the starting point for further functionalization reactions, the high reactivity of this surface toward a simple polar molecule such as ammonia still remains unclear. We therefore undertook a comprehensive investigation of the factors that govern the reactivity of halogenated silicon surfaces. The reaction of NH3 was investigated comparatively on the Cl-Si(100)-2 × 1, Br-Si(100)-2 × 1, H-Si(100)-2 × 1, and Si(100)-2 × 1 surfaces using density functional theory. The halogenated surfaces show considerable activation with respect to the hydrogenated surface. The reaction on the halogenated surfaces proceeds via the formation of a stable datively bonded complex in which a silicon atom is pentacoordinated. The activation of the halogenated Si(100)-2 × 1 surfaces toward ammonia arises from the large redistribution of charge in the transition state that precedes the breakage of the Si-X bond and the formation of the Si-NH2 bond. This transition state has an ionic nature of the form Si-NH3 +X-. Steric effects also play an important role in surface reactivity, making brominated surfaces less reactive than chlorinated surfaces. The overall activation-energy barriers on the Cl-Si(100)-2 × 1 and Br-Si(100)-2 × 1 surfaces are 12.3 and 19.9 kcal/mol, respectively, whereas on the hydrogenated Si(100)-2 × 1 surface the energy barrier is 38.3 kcal/mol. The reaction of ammonia on the chlorinated surface is even more activated than on the bare Si(100)-2 × 1 surface, for which the activation barrier is 21.3 kcal/mol. Coadsorption effects in partially aminated surfaces and in the presence of reaction products increase activation-energy barriers and have a blocking effect for further reactions of NH3. © 2011 American Chemical Society.Fil: Soria, Federico Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Patrito, Eduardo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Paredes Olivera, Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

Chemical Stability toward O2 and H2O of Si(111) Grafted with —CH3, —CH2CH2CH3, —CHCHCH3, and —CCCH3

The chemical stability of compact monolayers on silicon toward oxidizing agents is a key issue for the use of such monolayers in devices such as solar cells or in the electronics industry. In this work, we investigated the reactivity toward H2O, O2, and OH species of monolayers terminated with a methyl group to unveil the mechanisms that prevent the oxidation of the underlying silicon. Density functional theory calculations were performed to investigate the reaction pathways for the two competing processes involved: diffusion through the monolayer and reaction with the terminal methyl group. Activation energy barriers for the diffusion of H2O and O2 are very sensitive to the monolayer structure, and they increase in the order —CH2—CH2—CH3 < —C≡C—CH3 < —CH═CH—CH3 with energy barriers of 0.0 kcal/mol (0.0 kcal/mol), 35.0 kcal/mol (42.5 kcal/mol), and 57.0 kcal/mol (64.1 kcal/mol), respectively, for H2O (O2). This agrees with ordering of stabilities reported experimentally for these monolayers. The oxidation of the terminal methyl group by O2 is less affected by steric constraints. The formation of the —CH2OOH species has an energy barrier of 56.5 kcal/mol on the rigid —CH3 monolayer, whereas this barrier decreases to 40.7 kcal/mol on the —C≡C—CH3 monolayer. In the case of the methyl monolayer, the abstraction of a H atom of the —CH3 group has smaller energy barriers with singlet O2 and OH reactants, with values of 38.4 and 3.5 kcal/mol, respectively. The high energy barriers of all of the processes investigated indicate that compact monolayers hinder the oxidation of the underlying substrate. The passivating capability of the monolayers correlates with the steric constraints for H2O and O2 diffusion.Fil: Soria, Federico Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Paredes Olivera, Patricia. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Patrito, Eduardo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

Thermal Stability of Organic Monolayers Grafted to Si(111): Insights from ReaxFF Reactive Molecular Dynamics Simulations

We used the ReaxFF reactive molecular dynamics simulations to investigate the chemical mechanisms and kinetics of thermal decomposition processes of silicon surfaces grafted with different organic molecules via Si-C bonds at atomistic level. In this work, we considered the Si(111) surface grafted with n-alkyl (ethyl, propyl, pentyl, and decyl) layers in 50% coverage and, Si-CH3, Si-CCCH3 and Si-CHCHCH3 layers in full coverage. Si radicals primarily formed by the homolytic cleavage of Si-C bonds play a key role in the dehydrogenation processes that lead to the decomposition of the monolayers. Contrary to commonly proposed mechanisms that only involve a single Si atom center, we found that the main decomposition pathways require two Si lattice atoms to proceed. The ability of surface silyl radicals to dehydrogenate the organic molecules depends on the flexibility of the carbon backbones of the organic molecules as well as on the C-H bond strength. The dehydrogenation of n-alkyl chains mainly involves the H atoms of the β-carbon (leading to 1-alkene desorption). However, as the surface coverage decreases, the flexibility of the alkyl chains allows for the dehydrogenation of any methylene group and even the terminal methyl group of the long decyl layer. On the contrary, the rigid carbon backbone of the Si-CCCH3 and Si-CHCHCH3 moieties hinders the dehydrogenation of the terminal methyl group, which confers these layers a higher thermal stability. For all layers, the surface ends up mostly hydrogenated as Si-C bonds break and new Si-H bonds are formed during the dehydrogenation reactions.Fil: Soria, Federico Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Zhang, Weiwei. State University of Pennsylvania; Estados UnidosFil: van Duin, Adri. State University of Pennsylvania; Estados UnidosFil: Patrito, Eduardo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

Absorption mechanism of dopamine/DOPAC-modified TiO2 nanoparticles by time-dependent density functional theory calculations

Donor-modified TiO2 nanoparticles are interesting hybrid systems shifting the absorption edge of this semiconductor from the ultra-violet to the visible or infrared light spectrum, which is a benefit for several applications ranging from photochemistry, photocatalysis, photovoltaics, or photodynamic therapy. Here, we investigate the absorption properties of two catechol-like molecules, that is, dopamine and DOPAC ligands, when anchored to a spherical anatase TiO2 nanoparticle of realistic size (2.2 nm), by means of time-dependent density functional theory calculations. By the differential absorbance spectra with the bare nanoparticle, we show how it is possible to determine the injection mechanism. Since new low-energy absorption peaks are observed, we infer a direct charge transfer injection, which, unexpectedly, does not involve the lowest energy conduction band states. We also find that the more perpendicular the molecular benzene ring is to the surface, the more intense is the absorption, which suggests aiming at high molecular packing in the synthesis. Through a comparative investigation with a flat TiO2 surface model, we unravel both the curvature and coverage effects.Fil: Ronchi, Costanza. Università Di Milano Bicocca; Italia. Universitat Jena; AlemaniaFil: Soria, Federico Ariel. Università Di Milano Bicocca; Italia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Ferraro, Lorenzo. Università Di Milano Bicocca; ItaliaFil: Botti, Silvana. Friedrich Schiller University Jena; AlemaniaFil: Di Valentin, Cristiana. Università Di Milano Bicocca; Itali

Influence of subsurface oxidation on the structure, stability, and reactivity of grafted Si(111) surfaces

We investigated the influence of intermolecular interactions and subsurface oxidation on the structure, surface bonding, and reactivity of compact monolayers of small organic and inorganic molecules bound to the Si(111) surface via Si-C, Si-N, and Si-O bonds. We considered the following modified surfaces: Si-CH3, Si-CCH, Si-CN, Si-CH2CH3, Si-OCH 3, Si-OH, Si-NH2, Si-NHOH, and Si-ONH2. The highest hydrogen bond strength (7.5 kcal/mol) was observed for the (1 × 1) Si-NHOH monolayer. The (1 × 1) Si-CH2CH3 monolayer had the highest repulsion at the DFT level, 9.1 kcal/mol. However, inclusion of dispersion interactions yielded a repulsion of only 1.8 kcal/mol. Subsurface oxidation was investigated for -H, -CH3, and -CH2CH 3 terminated surfaces with surface coverages of 100 and 50%. The oxidation of the third Si-Si backbond is considerably more exothermic than me oxidation of the first and second backbonds. For monolayers with a surface coverage of 50%, the oxidation of alkylated silicon atoms is more stable than the oxidation of hydrogenated silicon atoms. The oxidation of alkylated silicon atoms stabilizes the organic monolayer for two reasons: a decrease of repulsive interactions between adjacent alkyl chains (due to the increase in intermolecular separations) and a strengmening of the Si-C surface bond. The reactivity of the grafted surfaces was investigated in the low coverage limit for the surface hydroxylation reaction with water. The highest activation barriers are obtained for the -CH3 (40.3 kcal/mol) and -CH 2CH3 (40.4 kcal/mol) terminated surfaces. The presence of conjugation in the organic molecule lowers the activation barrier. On the -CCH terminated surface, the activation energy decreases to 29.2 kcal/mol. The nucleophilic attack of silicon by water is facilitated on the -Cl, -OCH 3, and -NH2 terminated surfaces due to the increased positive charge of the silicon atom. The -NH2 and -Cl grafted surfaces are the most reactive with activation energies of 7.9 and 13.4 kcal/mol.Fil: Juarez, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Soria, Federico Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Patrito, Eduardo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Paredes Olivera, Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

The role of the organic layer functionalization in the formation of silicon/organic layer/metal junctions with coinage metals

The design of silicon/alkyl layer/metal junctions for the formation of optimal top metal contacts requires knowledge of the mechanistic and energetic aspects of the interactions of metal atoms with the modified surface. This involves (a) the interaction of the metal with the terminal groups of the organic layer, (b) the diffusion of metal atoms through the organic layer and (c) the reactions of metal atoms with the silicon surface atoms. The diffusion through the monolayer and the metal catalyzed breakage of Si-C bonds must be avoided to obtain high quality junctions. In this work, we performed a comprehensive density functional theory investigation to identify the reaction pathways of all these processes. In the absence of a reactive terminal group, gold atoms may penetrate through a compact alkyl monolayer on Si(111) with no energy barrier. However, the presence of thiol terminal groups introduces a high energy barrier which blocks the diffusion of metals into the monolayer. The diffusion barriers increase in the order Ag < Au < Cu and correlate with the stability of metal-thiolate complexes whereas the barriers for the formation of metal silicides increase in the order Cu < Au < Ag in correlation with the increasing metallic radii. The reactivity of gold clusters with functionalized Si(111) surfaces was also investigated. Metal silicide formation can only be avoided by a compact monolayer terminated by a reactive functional group. The mechanistic and energetic picture obtained in this work contributes to understanding of the factors that influence the quality of top metal contacts during the formation of silicon/organic layer/metal junctions. © 2011 the Owner Societies.Fil: Juarez, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Soria, Federico Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Patrito, Eduardo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Paredes Olivera, Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

Reactive Force Field-Based Molecular Dynamics Simulations on the Thermal Stability of Trimesic Acid on Graphene: Implications for the Design of Supramolecular Networks

In this work, we used the ReaxFF force field to investigate the dynamics of different network structures of trimesic acid (TMA) molecules on graphene as a function of temperature. We considered the so-called honeycomb, filled honeycomb, flower, zigzag, and close-packed TMA motifs. The thermal stability was investigated using molecular dynamics simulations with the constant number of molecules, volume, and temperature and force-biased Monte Carlo calculations up to 650 K. Our simulations provide detailed atomistic insights into the intermolecular and molecule-substrate interactions responsible for the self-assembly or the breakage of the TMA networks at different temperatures. The dynamics of hydrogen bonding were followed by counting the number of hydrogen bonds as well as by analyzing OH radial distribution functions. According to the melting temperatures obtained, the honeycomb structure has a higher stability than the high-coverage zigzag and close-packed structures. Guest TMA molecules within the pores of the honeycomb motif further increase its thermal stability, thus showing the beneficial effect of host-guest interactions. The twisting and rotation of carboxylic groups with increasing temperature are responsible for the breakage of hydrogen bonds, which ultimately leads to the melting of the networks. Partial TMA desorption observed at the onset of network disordering was attributed to the intermolecular vibrational energy transfer between the molecules. For the high-coverage close-packed network and for an island of TMA molecules with a close-packed structure, we observed a phase transition to the honeycomb structure as a consequence of the stronger dimeric   −COOH bonding of the latter. The energetics of the formation of the different networks from TMA molecules in the gas phase was also investigated. Intermolecular interactions and TMA-graphene interactions have similar magnitudes. The stability of the different networks cannot be fully understood only based on energetic considerations, and in the case of the dense close-packed structure, MD simulations show how it is rapidly destabilized.Fil: Jacquelin, Daniela Karina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica; ArgentinaFil: Soria, Federico Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Teórica y Computacional; ArgentinaFil: Paredes Olivera, Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Teórica y Computacional; ArgentinaFil: Patrito, Eduardo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica; Argentin

Effect of nickel loading on hydrogen adsorption capacity of different mesoporous supports

Pure siliceous and aluminosilicate mesoporous molecular sieves of MCM-41 type have been used as support for nickel incorporation (2.5 wt%) by wet impregnation method. The hydrogen adsorption capacities at 77 K of these materials have been studied. Various techniques such as X-ray diffraction, N2 adsorption–desorption, X-ray photoelectron spectroscopy, Temperature-Programmed Reduction, UV–Vis diffuse reflectance spectroscopy and adsorption of pyridine coupled to infrared spectroscopy were employed to characterize the materials. In addition, Density Functional Theory calculations were used in order to interpret the results of hydrogen adsorption. The results obtained show that isolated metallic species are capable to promote hydrogen favorable sites. Isolated mononuclear Ni2+ species on the surface strengthen the interaction with the H2, enhancing the hydrogen adsorption capacity.Fil: Carraro, Paola María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; ArgentinaFil: Soria, Federico Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Vaschetto, Eliana Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; ArgentinaFil: Sapag, Manuel Karim. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Oliva, Marcos Iván. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Eimer, Griselda Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; Argentin