One-pot synthesis of silica monoliths with hierarchically porous structure

Poly(furfuryl alcohol) (PFA) and block copolymer Pluronic F127 were used as pore templates to create mechanically robust silica monoliths with a hierarchical and interconnected macro?mesoporous network in an easy, reproducible bimodal scale templating process. Control over the morphology was obtained by varying the reactant ratios. Phase separation on the submicrometer scale occurred when furfuryl alcohol was cationically polymerized and therefore became immiscible with the solvent and the silica precursor. Upon a subsequent sol?gel reaction, a silica-F127 matrix formed around the PFA spheres, leading to macropore structures with mesoporous walls. Surface areas of the final structures ranged from 500 to 989 m2/g and a maximum pore volume of 4.5 mL/g was achieved. Under mildly acidic conditions, micelle-templated mesopores resulted. Interconnected macropores could be obtained by increasing the pH or the block copolymer concentration. The formation mechanism and the relationship between PFA, Pluronic F127 and acidity are discussed in detail.Fil: Drisko, Glenna L.. University of Melbourne; AustraliaFil: Zelcer, Andrés. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Caruso, Rachel A.. University of Melbourne; AustraliaFil: Soler Illia, Galo Juan de Avila Arturo. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentin

One-pot synthesis of hierarchically structured ceramic monoliths with adjustable porosity

Hierarchically porous oxides are used in a variety of applications within the energy sector (e.g., fuel cells, batteries), biology (e.g., scaffolds, biocatalysis), separations, and catalysis. This article describes a reproducible one-step method for the preparation of metal oxides with controllable hierarchical pore architectures. The preparation is demonstrated for a wide range of materials, specifically silica, titania, zirconia, aluminum titanium oxide, titanium zirconium oxide, and yttrium zirconium oxide monoliths. The samples were prepared by exploiting the polymerization and phase separation of furfuryl alcohol to produce a colloidal dispersion of poly(furfuryl alcohol) particles. The gelation in the sol-gel process occurred after the in situ formation of the template. The removal of the polymer template led to the formation of macropores, whereas inclusion of an amphiphilic block copolymer (Pluronic F127) assisted mesopore formation, either by templating or by stabilizing the inorganic building blocks. The macropore and mesopore morphology could be altered by varying the synthesis conditions. This control over the pore structure was demonstrated in the silica, titania, and titanium zirconium oxide materials.Fil: Drisko, Glenna L.. University of Melbourne; AustraliaFil: Zelcer, Andrés. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Luca, Vittorio. Comisión Nacional de Energía Atómica; ArgentinaFil: Caruso, Rachel A.. University of Melbourne; AustraliaFil: Soler Illia, Galo Juan de Avila Arturo. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Synthesis and photocatalytic activity of titania monoliths prepared with controlled macro- and mesopore structure

Herein, we report a one-pot synthesis of crack-free titania monoliths with hierarchical macro-mesoporosity and crystalline anatase walls. Bimodal macroporosity is created through the polymer-induced phase separation of poly(furfuryl alcohol). The cationic polymerization of furfuryl alcohol is performed in situ and subsequently the polymer becomes immiscible with the aqueous phase, which includes titanic acid. Addition of template, Pluronic F127, increases the mesopore volume and diameter of the resulting titania, as the poly(ethylene glycol) block interacts with the titania precursor, leading to assisted assembly of the metal oxide framework. The hydrophobic poly(propylene glycol) micelle core could itself be swollen with monomeric and oligomeric furfuryl alcohol, allowing for mesopores as large as 18 nm. Variations in synthesis parameters affect porosity; for instance furfuryl alcohol content changes the size and texture of the macropores, water content changes the grain size of the titania and Pluronic F127 content changes the size and volume of the mesopore. Morphological manipulation improves the photocatalytic degradation of methylene blue. Light can penetrate several millimeters into the porous monolith, giving these materials possible application in commercial devices.Fil: Drisko, Glenna L.. University of Melbourne; AustraliaFil: Zelcer, Andrés. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Wang, Xingdong. Commonwealth Scientific And Industrial Research Organization; AustraliaFil: Caruso, Rachel A.. School Of Chemistry; Australia. Commonwealth Scientific And Industrial Research Organization; AustraliaFil: Soler Illia, Galo Juan de Avila Arturo. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Assessment of the LeadCare® Plus for Use on Scandinavian Brown Bears (Ursus arctos)

publishedVersio

Use of social networks as a CSR communication tool

The aim of this paper is to analyse the use of online social networks as a tool for Corporate Social Responsibility (CSR) communication and management. To this end, an analysis was performed of the messages posted by the 20 Spanish companies with the highest market capitalisation and the responses that they received on two of the most popular online social networks, Facebook and Twitter. The results of the analysis of these data show that the tendency has been to use social networks for the one-way communication of aspects of CSR related with the organisation. Therefore, it is necessary to change the way companies communicate their CSR issues by shifting to a two-way communication approach, as has been the case in other kinds of enterprise relations with their stakeholders.The authors received no direct funding for this research

Highly Fluorinated Peptide Probes with Enhanced In Vivo Stability for 19^{19}F‐MRI

A labeling strategy for in vivo $^{19}$F-MRI (magnetic resonance imaging) based on highly fluorinated, short hydrophilic peptide probes, is developed. As dual-purpose probes, they are functionalized further by a fluorophore and an alkyne moiety for bioconjugation. High fluorination is achieved by three perfluoro-tert-butyl groups, introduced into asparagine analogues by chemically stable amide bond linkages. d-amino acids and β-alanine in the sequences endow the peptide probes with low cytotoxicity and high serum stability. This design also yielded unstructured peptides, rendering all 27 $^{19}$F substitutions chemically equivalent, giving rise to a single $^{19}$F-NMR resonance with <10 Hz linewidth. The resulting performance in $^{19}$F-MRI is demonstrated for six different peptide probes. Using fluorescence microscopy, these probes are found to exhibit high stability and long circulation times in living zebrafish embryos. Furthermore, the probes can be conjugated to bovine serum albumin with only amoderate increase in $^{19}$F-NMR linewidth to ≈30 Hz. Overall, these peptide probes are hence suitable for in vivo $^{19}$F-MRI applications

Copolymer-induced stabilizing effect of highly swollen hexagonal mesophases

We show quantitatively that tiny amounts of copolymer that decorate a oil/water interfaces can greatly enhance the stability of swollen surfactant hexagonal phases, comprising oil tubes regularly arranged in a water matrix. Such soft composite materials, whose both radius of the tubes and water channel between the tubes can be controlled independently over large ranges, offer a potential interest for the synthesis of mesoporous materials

Sociopolitical consequences of COVID-19 in the Americas, Europe, and Asia: A multilevel, multicountry investigation of risk perceptions and support for antidemocratic practices

Although different social crises may eventually favor undemocratic and authoritarian forms of governance, at some point, such antidemocratic practices require the support of a significant part of the population to be implemented. The present research investigates how and whether the COVID-19 pandemic might have favoured greater support for antidemocratic governmental practices, on the premise of regaining control and security. Using data from 17 countries (N = 4364) and national-level indicators (i.e., real number of contagions and deaths, and sociopolitical indicators), we test how the risk of contagion and death from COVID-19, along with personal orientations (i.e., social dominance orientation [SDO], right-wing authoritarianism [RWA], and perceived anomie) motivate authoritarian and antidemocratic practices. Results from multilevel models indicate that risk perception and perceptions of political instability predict a wish for stronger leadership, agreement with martial law, and support for a controlling government especially when SDO and RWA are high, while more egalitarian and less conservative people agree less with these authoritarian measures in spite of the levels of risk perception. We discuss the implications for these findings for future research on similar but also dissimilar external events (natural disasters, war, or terror incidents) and the consequences for societies with higher authoritarian tendencies.Fil: Pizarro, José J.. Universidad Católica del Norte; Chile. Universidad del País Vasco; EspañaFil: Cakal, Huseyin. Keele University; Reino UnidoFil: Méndez, Lander. Universidad del País Vasco; EspañaFil: Zumeta, Larraitz N.. Universidad del País Vasco; EspañaFil: Gracia-Leiva, Marcela. Universidad del País Vasco; EspañaFil: Basabe, Nekane. Universidad del País Vasco; EspañaFil: Navarro-Carrillo, Ginés. Universidad de Jaén; EspañaFil: Cazan, Ana Maria. Transilvania University of Brasov; RumaniaFil: Keshavarzi, Saeed. Independent Researcher; IránFil: López López, Wilson. Pontificia Universidad Javeriana; ColombiaFil: Yahiiaiev, Illia. Taras Shevchenko National University of Kyiv; UcraniaFil: Alzugaray Ponce, Carolina. Universidad Santo Tomas; ChileFil: Villagrán, Loreto. Universidad de Concepción; ChileFil: Moyano Díaz, Emilio. Universidad de Talca; ChileFil: Petrović, Nebojša. University of Belgrade; SerbiaFil: Mathias, Anderson. Universidad Autonoma de Coahuila; MéxicoFil: Techio, Elza M.. Universidade Federal da Bahia; BrasilFil: Wlodarczyk, Anna. Universidad Católica del Norte; ChileFil: Alfaro-Beracoechea, Laura. Universidad de Guadalajara; MéxicoFil: Ibarra, Manuel L.. Universidad Nacional Autónoma de México; MéxicoFil: Michael, Andreas. University of Cyprus; ChipreFil: Mhaskar, Sumeet. O.p. Jindal Global University; IndiaFil: Martínez Zelaya, Gonzalo. Universidad Viña del Mar; ChileFil: Bilbao, Marian. Universidad Alberto Hurtado; ChileFil: Delfino, Gisela Isabel. Universidad Pontificia Comillas; España. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Carvalho, Catarina L.. Universidad de Porto; PortugalFil: Pinto, Isabel R.. Universidad de Porto; PortugalFil: Mohsin, Falak Zehra. Karachi School Of Business And Leadership; PakistánFil: Espinosa, Agustín. Pontificia Universidad Católica de Perú; PerúFil: Cueto, Rosa María. Pontificia Universidad Católica de Perú; PerúFil: Cavalli, Stefano. Scuola Universitaria Professionale Della Svizzera Italiana; ItaliaFil: da Costa, Silvia. Universidad de Zaragoza; EspañaFil: Amutio, Alberto. Universidad Andrés Bello; Chile. Universidad del País Vasco; EspañaFil: Alonso Arbiol, Itziar. Universidad del País Vasco; EspañaFil: Páez, Darío. Universidad Andrés Bello; Chil

Enhanced Dispersion of TiO2 Nanoparticles in a TiO2/PEDOT:PSS Hybrid Nanocomposite via Plasma-Liquid Interactions

A facile method to synthesize a TiO2/PEDOT:PSS hybrid nanocomposite material in aqueous solution through direct current (DC) plasma processing at atmospheric pressure and room temperature has been demonstrated. The dispersion of the TiO2 nanoparticles is enhanced and TiO2/polymer hybrid nanoparticles with a distinct core shell structure have been obtained. Increased electrical conductivity was observed for the plasma treated TiO2/PEDOT:PSS nanocomposite. The improvement in nanocomposite properties is due to the enhanced dispersion and stability in liquid polymer of microplasma treated TiO2 nanoparticles. Both plasma induced surface charge and nanoparticle surface termination with specific plasma chemical species are proposed to provide an enhanced barrier to nanoparticle agglomeration and promote nanoparticle-polymer binding