LE PRODUZIONI BIOLOGICHE: UN SETTORE EMERGENTE

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Indium-Based Silica Materials: Sustainable Syntheses Combined with a Challenging Insertion in SiO₂ Mesoporous Structures

Les procédures durables optimisées dans des conditions acides et basiques sont répondent à certains des défis environnementaux actuels de la communauté scientifique. Dans cet article, les syntheses de deux familles de nanomatériaux à base d'indium et de silice sont rapportées. Les deux procédures ont été optimisées pour améliorer la durabilité des méthodes de synthèse et promouvoir leur préparation à température ambiante tout en évitant le traitement hydrothermal dans des conditions statiques à 100 °C. Une synthèse rapide à température ambiante de nanosphères poreuses a été conçue ainsi qu'une procédure "sans acide" pour des matériaux de type SBA-15. De plus, la substitution isomorphique du silicium par l'indium a été réalisée. Tous les matériaux ont été caractérisés en profondeur pour sonder leurs propriétés structurales, texturales et morphologiques (par exemple, la microscopie électronique à transmission, la physisorption de N2, la RMN du solide de 29Si en MAS). La grande surface spécifique et la mésoporosité ont toujours été préservées même sous les conditions de réaction douces employées. La structure en nid d'abeille et la morphologie sphérique des matériaux de type SBA-15 et des nanosphères ont également été observées. L'insertion de l'indium a été confirmée par des investigations de spectroscopie photoélectronique des rayons X (XPS).Optimized sustainable procedures in both acidic and basic conditions are considered to meet some of the current environmental challenges of the scientific community. In this paper, the successful syntheses of two classes of indium-based silica nanomaterials are reported. Both procedures were conceived to enhance the sustainability of the synthesis methods and promote their preparations at room temperature while avoiding the hydrothermal treatment under static conditions at 100 °C. A fast, room-temperature synthesis of porous nanospheres was conceived together with an “acid-free” procedure for SBA-15-like materials. Moreover, the isomorphic substitution of silicon with indium was achieved. All the materials were deeply characterized to probe their structural, textural and morphological properties (e.g., transmission electron microscopy, N2 physisorption, ssMAS NMR of 29Si). The high specific surface area and the mesoporosity were always preserved even under the mild reaction conditions employed. The honeycomb structure and the spherical morphology of SBA-15-like materials and nanospheres, respectively, were also observed. The insertion of indium was confirmed via X-ray photoelectron spectroscopy (XPS) investigations

Indium-Based Silica Materials: Sustainable Syntheses Combined with a Challenging Insertion in SiO₂ Mesoporous Structures

Les procédures durables optimisées dans des conditions acides et basiques sont répondent à certains des défis environnementaux actuels de la communauté scientifique. Dans cet article, les syntheses de deux familles de nanomatériaux à base d'indium et de silice sont rapportées. Les deux procédures ont été optimisées pour améliorer la durabilité des méthodes de synthèse et promouvoir leur préparation à température ambiante tout en évitant le traitement hydrothermal dans des conditions statiques à 100 °C. Une synthèse rapide à température ambiante de nanosphères poreuses a été conçue ainsi qu'une procédure "sans acide" pour des matériaux de type SBA-15. De plus, la substitution isomorphique du silicium par l'indium a été réalisée. Tous les matériaux ont été caractérisés en profondeur pour sonder leurs propriétés structurales, texturales et morphologiques (par exemple, la microscopie électronique à transmission, la physisorption de N2, la RMN du solide de 29Si en MAS). La grande surface spécifique et la mésoporosité ont toujours été préservées même sous les conditions de réaction douces employées. La structure en nid d'abeille et la morphologie sphérique des matériaux de type SBA-15 et des nanosphères ont également été observées. L'insertion de l'indium a été confirmée par des investigations de spectroscopie photoélectronique des rayons X (XPS).Optimized sustainable procedures in both acidic and basic conditions are considered to meet some of the current environmental challenges of the scientific community. In this paper, the successful syntheses of two classes of indium-based silica nanomaterials are reported. Both procedures were conceived to enhance the sustainability of the synthesis methods and promote their preparations at room temperature while avoiding the hydrothermal treatment under static conditions at 100 °C. A fast, room-temperature synthesis of porous nanospheres was conceived together with an “acid-free” procedure for SBA-15-like materials. Moreover, the isomorphic substitution of silicon with indium was achieved. All the materials were deeply characterized to probe their structural, textural and morphological properties (e.g., transmission electron microscopy, N2 physisorption, ssMAS NMR of 29Si). The high specific surface area and the mesoporosity were always preserved even under the mild reaction conditions employed. The honeycomb structure and the spherical morphology of SBA-15-like materials and nanospheres, respectively, were also observed. The insertion of indium was confirmed via X-ray photoelectron spectroscopy (XPS) investigations

Water Conservation Behavior and Environmental Concerns

Water conservation represents important pro-environmental behavior for a sustainable environment. This paper investigates the link between water conservation behavior and general environmental concerns using a large dataset from the Multipurpose Household Survey conducted annually by the Italian Central Statistics Office. Univariate probit models show that pollution and resource exhaustion are positively related to individual water conservation behavior while alteration of environmental heritage exhibits a negative relationship with water saving behavior. These findings are robust to the inclusion of environment knowledge and social capital variables. Robustness analysis also indicates that television and radio, participation in environmental initiatives, money for environmental protection and churchgoing are significant determinants of water conservation behavior

Composición que comprende un compuesto fotoactivo y un coiniciador y su uso como fotoiniciador

Solicitud de patente (concesión en curso).-- Referencia OEPM: P200502910.-- Fecha de presentación: 24/11/2005.-- Solicitante: Exotech, S.L. (Alboraia, Valencia).La presente invención se refiere a una composición química caracterizada porque comprende al menos: i) un primer componente que es al menos un compuesto fotoactivo seleccionado entre una sal de pirilio, una sal de tiopirilio, una sal de selenopirilio, una sal de teluropirilio, y una sal de las anteriores sustituida, y ii) un segundo componente que es al menos un coiniciador seleccionado entre uno o varios de los siguientes: a) aminas, b) sales de iodonio, c) sales de fosfonio, d) sales de sulfonio, e) sales de amonio cuaternario, f) poliéteres cíclicos, g) poliaminas cíclicas y, h) combinaciones de los mismos, y a su uso como fotoiniciadores.Peer reviewe

Hybrid catalysts for CO ₂ conversion into cyclic carbonates

The conversion of carbon dioxide into valuable chemicals such as cyclic carbonates is an appealing topic for the scientific community due to the possibility of valorizing waste into an inexpensive, available, nontoxic, and renewable carbon feedstock. In this regard, last-generation heterogeneous catalysts are of great interest owing to their high catalytic activity, robustness, and easy recovery and recycling. In the present review, recent advances on CO2 cycloaddition to epoxide mediated by hybrid catalysts through organometallic or organo-catalytic species supported onto silica-, nanocarbon-, and metal–organic framework (MOF)-based heterogeneous materials, are highlighted and discussed

R&D Spillovers Effects on strategic behaviour of Large International Firms

This study contributes to existing literature on firms’ innovative activity examining the relationship between the R&D rivalry and spillovers at the firm level. In particular, we present an empirical analysis in United States, Japan and Europe based upon a new dataset composed of 879 worldwide R&D-intensive firms. In order to identify the technological proximity, we use the Jaffe industry weight matrix, based on the construction of technological vectors for each firm, where its patents are distributed across technology classes, in such a way that we compute knowledge spillovers. Opportune econometric techniques, which deal with both firm’s unobserved heterogeneity and weak exogeneity of the explanatory variables, are implemented. In order to test the robustness of our results, we introduce also the combined spatial-autoregressive model with autoregressive disturbances and additional endogenous variables. The empirical results are differentiated across countries, and suggest that the spatial effects are statistically significan

R&D Spillovers Effects on strategic behaviour of Large International Firms

This study contributes to existing literature on firms’ innovative activity examining the relationship between the R&D rivalry and spillovers at the firm level. In particular, we present an empirical analysis in United States, Japan and Europe based upon a new dataset composed of 879 worldwide R&D-intensive firms. In order to identify the technological proximity, we use the Jaffe industry weight matrix, based on the construction of technological vectors for each firm, where its patents are distributed across technology classes, in such a way that we compute knowledge spillovers. Opportune econometric techniques, which deal with both firm’s unobserved heterogeneity and weak exogeneity of the explanatory variables, are implemented. In order to test the robustness of our results, we introduce also the combined spatial-autoregressive model with autoregressive disturbances and additional endogenous variables. The empirical results are differentiated across countries, and suggest that the spatial effects are statistically significan

A study on the stability of carbon nanoforms–polyimidazolium network hybrids in the conversion of co2 into cyclic carbonates:Increase in catalytic activity after reuse

Three different carbon nanoforms (CNFs), single-walled and multi-walled carbon nanotubes (SWCNTs, MWCNTs) and carbon nanohorns (CNHs), have been used as supports for the direct polymerization of variable amounts of a bis-vinylimidazolium salt. Transmission electron microscopy confirmed that all CNFs act as templates on the growth of the polymeric network, which perfectly covers the nanocarbons forming a cylindrical (SWCNTs, MWCNTs) or spherical (CNHs) coating. The stability of these hybrid materials was investigated in the conversion of CO(2) into cyclic carbonate under high temperature and CO(2) pressure. Compared with the homopolymerized monomer, nanotube-based materials display an improved catalytic activity. Beside the low catalytic loading (0.05–0.09 mol%) and the absence of Lewis acid co-catalysts, all the materials showed high TON values (up to 1154 for epichlorohydrin with SW-1:2). Interestingly, despite the loss of part of the polymeric coating for crumbling or peeling, the activity increases upon recycling of the materials, and this behaviour was ascribed to their change in morphology, which led to materials with higher surface areas and with more accessible catalytic sites. Transmission electron microscopy analysis, along with different experiments, have been carried out in order to elucidate these findings