TiO2 nanorods doped with g-C3N4 – Polyethylene composite coating for self-cleaning applications

Visible-light-absorbing graphitic carbon nitride–TiO2 nanorod nanomaterials (g-C3N4@TiO2NR) were successfully immobilized using a one-step UVA-induced photocatalytic procedure on commercially obtained flexible low-density polyethylene (LDPE) films. Self-cleaning properties were evaluated in solid–liquid and solid–gas phases using malachite green as a model molecule under UV-A and visible light irradiation. For comparison purpose, LDPE films containing P25 TiO2 nanoparticles was prepared using the same synthetic strategy (P25/LDPE). Among the fabricated films, the g-C3N4@TiO2NR/LDPE films exhibited the highest photocatalytic activity both in solid–liquid and solid–gas phases after 120 min of visible light irradiation (λ > 455 nm) removing efficiently malachite green stains probably due to the attack of photoinduced reactive oxygen species (ROS) such as singlet oxygen (1O2), hydroxyl radical (•OH) and superoxide anion radical (O2−•). Furthermore, the g-C3N4@TiO2NR/LDPE films retained their visible-light-photoinduced photocatalytic properties after four reuse cycles. The g-C3N4@TiO2NR/LDPE films also exhibited significant visible-light-photoinduced hydrophilicity. The high visible-light-photoinduced photocatalytic capacity of g-C3N4@TiO2NR/LDPE films was found to be related to the textural and electronic properties, superior visible-light absorption, and surface roughness of the films.Fil: Osorio Vargas, Paula Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentina. Universidad del Bio Bio; ChileFil: Pais Ospina, Daniel Humberto. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Tecnológica de Pereira; ColombiaFil: Marín Silva, Diego Alejandro. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Pinotti, Adriana Noemi. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería; ArgentinaFil: Damonte, Laura Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Canneva, Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. YPF - Tecnología; ArgentinaFil: Donadelli, Jorge Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. YPF - Tecnología; ArgentinaFil: Pereira da Costa, Luiz. Universidad Federal del Amazonas.; BrasilFil: Pizzio, Luis Rene. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Torres, Cecilia C.. Universidad Andrés Bello; ChileFil: Campos, Cristian H.. Universidad de Concepción; ChileFil: Rengifo Herrera, Julian Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentin

Organic Matter Characterization of Shale Rock by X-ray Photoelectron Spectroscopy: Adventitious Carbon Contamination and Radiation Damage

A detailed characterization of the organic matter in sediments gives a key parameter for the correct evaluation ofthe petroleum generation potential of a source rock and its modeling in an oil system. To understand the features of the organic matter stored in source rocks, a wide variety of routine techniques are used. Those techniques are mostly destructive, timeconsuming,and are not necessarily suitable for all the shale rocks. Thus, new technologies are being explored. XPS is a solid state,nondestructive, and direct method. It can be used to directly probe the speciation of organic carbon in sedimentary materials byC1s spectra measurements. In this work, we demonstrated that a heterogeneous layer of adventitious carbon (AC) is always present on the rock. This layer significantly altered the features of the organic compound fingerprint, which is measured by XPS of C1s. To acquire a reliable organic matter composition of a rock from XPS spectra it is necessary to remove the AC layer by sputtering it with Ar+. Further, the sputtering damage of the organic matter appears after an hour of radiation, and rocks become contaminated again during storage in the UHV chamber. The radiation damage by X-ray is also relevant in the XPS measurementof a rock. This damage is associated with an increment of AC contamination on the rock surface. To minimize this side effect,C1s spectra have to be measured immediately after the sputtering conditioning step. Thus, we developed a method for XPS measurements taking into account the AC contamination and radiation damage. We consider that the proposed method for outcrop shales can be applied to a wide range of rock sampling types, such as cuttings, damaged crowns, and so forth.Fil: Canneva, Antonela. YPF - Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Giordana, Iván Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. YPF - Tecnología; ArgentinaFil: Erra, Georgina. YPF - Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Calvo, Alejandra. YPF - Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

XPS direct analysis on shale rocks: Correlation with kerogen type and maturity

A method to study kerogen type and maturity of organic matter in source rocks using XPS was developed. Samples from three Argentinian shale rocks containing different kerogen types were analyzed by XPS directly, without kerogen isolation. Analysis focused on characterizing the chemical structure of kerogen, in particular of carbon species. Two new parameters were proposed: (%Cox/OCxps) that measures the oxidized organic carbon content, and ArP related to aromaticity ratio. A relationship was found between (%Cox/OCxps) and kerogen origin, allowing changes in kerogen type (from Type II to Type III) to be recognized. The aromaticity was estimated from Csp2 XPS peak and was compared to traditional maturity parameters such as vitrinite reflectance or pyrolysis Rock-Eval Tmax. A correlation between the methods was observed, suggesting the direct XPS analysis of shale rock as an estimation of kerogen maturity. Both maturity and kerogen type can be determined in the same measurement, performed directly on the sample, without organic matter isolation.Fil: Donadelli, Jorge Andrés. YPF - Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Canneva, Antonela. YPF - Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Erra, Georgina. YPF - Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Calvo, Alejandra. YPF - Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Synthesis of core-brush fluorescent silica nanoparticles with tunable hydrophilicity by ATRP method

Polymer coating on fluorescent silica nanoparticles enables to tailor made nanocomposite with unique tunable properties. Combining the emission of a fluorescent probe and the surface chemistry of a polymer shell a wide range of applications can be cover. The changing in the conformation of polymer chains enables to modify the hydrophilicity of the functionalized particles. For this, zwitterionic polymers are optimal since the electrostatic interaction between charged groups determines the conformational regime of the chains and the colloidal stability of the particle. In this work, we propose a functionalization of Amino Fluorescent Silica Nanoparticles (Amino-NPF) with a zwitterionic polymer by ATRP method. Poly [2- (Methacryloyloxy) ethyl] dimethyl- (3-sulfopropyl) ammonium hydroxide (PDMAPS) was successfully grafted onto the Amino-NPF surface. In particular, we followed three routes with different amount of catalyst. Route 1 corresponds to non-Cu (II) in solution, while pathways 2 and 3 consist of an increment in the metal concentration, 10% and 60% relative to Cu (I), respectively. A very short reaction time, only 15 min, was employed to diminish or avoid radical-radical termination. The stability and dispersability of the obtained core-brush nanoparticles in different solvents was evaluated. We demonstrate that the Cu (II) to Cu (I) concentration ratio defines the conformation of the polymer chains and in turn the hydrophilic character of the particles.Fil: Vera, Maria Laura. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy. - Universidad Nacional de Jujuy. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy. - Gobierno de la Provincia de Jujuy. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy; ArgentinaFil: Giussi, Juan Martín. YPF - Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Canneva, Antonela. YPF - Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Azzaroni, Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Calvo, A.. YPF - Tecnología; Argentin

Diferentes vías de preparación de mallas superhidrofóbicas sililadas para la separación petróleo-agua

En la industria del petróleo las membranas superhidrofóbicas-oleofílicas tienen un gran interés ya que permiten la separación de las fases hidrocarburo-agua. El objetivo del trabajo es encontrar un método de preparación que pueda ser sistematizado para su escalado de manera sencilla y robusta. En este trabajo se emplearon distintas metodologías de elaboración. Finalmente, las membranas fueron caracterizadas empleando diversas técnicas, tanto estructurales como de su performance como membranas de separación.Fil: Canneva, Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. YPF - Tecnología; ArgentinaFil: García Saggion, Nicolás Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. YPF - Tecnología; ArgentinaFil: Negri, Ricardo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: D'accorso, Norma Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaXXII Congreso Argentino de Fisicoquímica y Química InorgánicaLa PlataArgentinaUniversidad Nacional de la Plata. Facultad de IngenieríaAsociación Argentina de Investigación Fisicoquímic

Conformational Properties of Ethyl- and 2,2,2-Trifluoroethyl Thionitrites, (CX3CH2SNO, X = H and F)

Canneva A, Della Vedova CO, Mitzel NW, Erben MF. Conformational Properties of Ethyl- and 2,2,2-Trifluoroethyl Thionitrites, (CX3CH2SNO, X = H and F). The Journal of Physical Chemistry A. 2015;119(9):1524-1533.The simple 2,2,2-trifluoroethyl thionitrite molecule, CF3CH2SNO, has been prepared in good yield for the first time using CF3CH2SH and NOCl in slight excess. The vapor pressure of the red-brown compound CF3CH2SNO follows, in the temperature range between 226 and 268 K, the equation log p = 12.0-3881/T (p/bar, T/K), and its extrapolated boiling point reaches 51 degrees C. Its structural and conformational properties have been compared with the ethyl thionitrite analogue, CH3CH2SNO. The FTIR spectra of the vapor of both thionitrites show the presence of bands with well-defined contours, allowing for a detailed conformational analysis and vibrational assignment on the basis of a normal coordinate analysis. The conformational space of both thionitrite derivatives has also been studied by using the DFT and MP2(full) level of theory with extended basis sets [6-311+G(2df) and cc-pVTZ]. The overall evaluation of the experimental and theoretical results suggests the existence of a mixture of two conformers at room temperature. The relative abundance of the most stable syn form (N=O double bond syn with respect to the C-S single bond) has been estimated to be ca. 79 and 75% for CF3CH2SNO and CH3CH2SNO, respectively

From superhydrophilic to superhydrophobic polymer-nanoparticles coated meshes for water-oil separation systems with resistance to hard water

A one-step procedure is presented for developing novel superhydrophobic oil-water separation membranes, based on composites of nanoparticles and polymers. The combination of hydrophilic particles with hydrophobic polymers allows obtaining superhydrophobic coatings on metal meshes, with chemical and physical stability. The methodology consists of coating SiO2 hydrophilic nanoparticles with two hydrophobic polymers (polydimethylsiloxane and polyvinylidene fluoride, PDMS and PVDF, respectively) on metal meshes. The nanoparticles generate roughness in the nanoscale, while the combination of PVDF and PDMS provides hydrophobicity, chemical resistance, and reinforce of mechanical properties. Membranes were characterized by XPS, SEM, TEM, FTIR, TGA, water-contact-angles (WCA) measurements, and elongation tests. The membranes present oil flux in the order of 102 Lm−2s−1, with stable performance during several months for water/oil separation tests when using saline (Na+, Cl−) and hard water (Ca+2, Mg+2) solutions. The synergetic mixture of three components, PDMS-PVDF-SiO2, provides superhydrophobic behaviour while coatings formed by any combination of only two components do not show the targeted properties.Fil: Sosa, Mariana Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Canneva, Antonela. YPF - Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Kaplan, Andrea Edith. Universidad de Buenos Aires. Facultad de Odontología. Departamento de Materiales Dentales. Cátedra de Materiales Dentales; ArgentinaFil: D´accorso Norma Beatriz. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Negri, Ricardo Martin. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Inorgánica, Analítica y Química Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin

Manufacture, characterization and proton irradiation effects of 12C and 13C thick targets

Abstract: Alternative sources of neutron production other than nuclear fission reactions are important priorities in medical and nuclear applications due to costs, safety and ease of operation. In this work, 12C and 13C thick targets for neutron production through 12C(d,n) 13N and 13C(d,n) 14N , respectively, have been manufactured and characterized by different techniques. In order to evaluate the irradiation effects on these materials, the targets were irradiated with 150 keV proton beam. A complete characterization of these samples was performed using scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, Auger electron spectroscopy, X-ray photoemission spectroscopy and Raman spectroscopy. The results of these studies allowed us to establish that even though the irradiated samples present microstructural and chemical structure changes on its surface, the 12C and 13C thick targets were stable and would maintain their performance after proton irradiation at a fluence of 2.0×1018ions/cm2 and 3.7×1018ions/cm2, respectively. Graphical abstract: [Figure not available: see fulltext.]Fil: Bertolo, Alma Agostina. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Instituto Sabato; ArgentinaFil: Canneva, Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. YPF - Tecnología; ArgentinaFil: Donadelli, Jorge Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. YPF - Tecnología; ArgentinaFil: Gaviola, Pedro A.. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Instituto Sabato; ArgentinaFil: Kreiner, Andres Juan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: del Grosso, Mariela Fernanda. Comisión Nacional de Energía Atómica; Argentina. Universidad Tecnológica Nacional. Facultad Regional General Pacheco; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Fluorescent silica nanoparticles with chemically reactive surface: Controlling spatial distribution in one-step synthesis

The encapsulation of fluorescent dyes inside silica nanoparticles is advantageous to improve their quality as probes. Inside the particle, the fluorophore is protected from the external conditions and its main emission parameters remains unchanged even in the presence of quenchers. On the other hand, the amine-functionalized nanoparticle surface enables a wide range of applications, as amino groups could be easily linked with different biomolecules for targeting purposes. This kind of nanoparticle is regularly synthesized by methods that employ templates, additional nanoparticle formation or multiple pathway process. However, a one-step synthesis will be an efficient approach in this sort of bifunctional hybrid nanoparticles. A co-condensation sol-gel synthesis of hybrid fluorescent silica nanoparticle where developed. The chemical and morphological characterization of the particles where investigated by DRIFTS, XPS, SEM and SAXS. The nanoparticle fluorescent properties were also assessed by excitation-emission matrices and time resolved experiments. We have developed a one-pot synthesis method that enables the simultaneous incorporation of functionalities, the fluorescent molecule and the amino group, by controlling co-condensation process. An exhaustive characterization allows the definition of the spatial distribution of the fluorescent probe, fluorescein isothiocyanate, inside the particle and reactive amino groups on the surface of the nanoparticle with diameter about 100 nm.Fil: Vera, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Canneva, Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. YPF - Tecnología; ArgentinaFil: Huck Iriart, Cristián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Requejo, Felix Gregorio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Gonzalez, Monica Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Dell'arciprete, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Calvo, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. YPF - Tecnología; Argentin

The Structure and Conformation of (CH3)(3)CSNO

Canneva A, Erben MF, Romano RM, et al. The Structure and Conformation of (CH3)(3)CSNO. Chemistry - A European Journal. 2015;21(29):10436-10442.The gas-phase molecular structure of (CH3)(3)CSNO was investigated by using electron diffraction, allowing the first experimental geometrical parameters for an S-nitrosothiol species to be elucidated. Depending on the orientation of the SNO group, two conformers (anti and syn) are identified in the vapor of (CH3)(3)CSNO at room temperature, the syn conformer being less abundant. The conformational landscape is further scrutinized by using vibrational spectroscopy techniques, including gas-phase and matrix-isolation IR spectroscopy, resulting in a contribution of ca. 80:20 for the anti:syn abundance ratio, in good agreement with the computed value at the MP2(full)/cc-pVTZ level of approximation. The UV/Vis and resonance Raman spectra also show the occurrence of the conformational equilibrium in the liquid phase, with a moderate post-resonance Raman signature associated with the 350nm electronic absorption