Incorporating different vegetable oils into an aqueous dispersion of hybrid organic nanoparticles

Quantum dots (QDs) are routinely employed for bioimaging applications and detection of pathogens and toxins. Their use as surrogates to study the fate and transport of non-fluorescent nanoparticles is limited due to high cost, detection of limit issues, and lack of sufficient data related to health effects. Systematic studies on the impact of QDs on environment and health may facilitate its safe use for environmental applications. This review summarizes the studies conducted with QDs with a focus on environmental applications and provides toxicity data important to human health.     

Incorporation of Pure Fullerene into Organoclays: Towards C60‐Pillared Clay Structures

In this work, we demonstrate the successful incorporation of pure fullerene from solution into two‐dimensional layered aluminosilicate minerals. Pure fullerenes are insoluble in water and neutral in terms of charge, hence they cannot be introduced into the clay galleries by ion exchange or intercalation from water solution. To overcome this bottleneck, we organically modified the clay with quaternary amines by using well‐established reactions in clay science in order to expand the interlayer space and render the galleries organophilic. During the reaction with the fullerene solution, the organic solvent could enter into the clay galleries, thus transferring along the fullerene molecules. Furthermore, we demonstrate that the surfactant molecules, can be selectively removed by either simple ion‐exchange reaction (e.g., interaction with Al(NO₃)₃ solution to replace the surfactant molecules with Al³⁺ ions) or thermal treatment (heating at 350 °C) to obtain novel fullerene‐pillared clay structures exhibiting enhanced surface area. The synthesized hybrid materials were characterized in detail by a combination of experimental techniques including powder X‐ray diffraction, transmission electron microscopy, X‐ray photoemission, and UV/Vis spectroscopy as well as thermal analysis and nitrogen adsorption–desorption measurements. The reported fullerene‐pillared clay structures constitute a new hybrid system with very promising potential for the use in areas such as gas storage and/or gas separation due to their high surface area.     

Hydrophobic waterborne coating for cellulose containing hybrid organic nanoparticle pigments with vegetable oils

Vegetable oils were combined with recent nanotechnology as a sustainable method for tuning the hydrophobicity of cellulose and paper surfaces. Different soy-, sunflower-, corn-, castor-, rapeseed- and hydrogenated oils were incorporated into an aqueous dispersion of hybrid styrene maleimide nanoparticles. Here, we investigate the formation of novel coatings from these dispersions and their performance on paper and paperboard, compared with model aluminum substrates. The coated papers are evaluated by static and dynamic contact angles, microscopy, atomic force microscopy, infrared and Raman spectroscopy. The nanoparticle pigments form a porous coating after drying, while the water repellence and hydrophobicity of paperboard and paper improved with contact angles of 90–99° after drying and 98–112° after ageing. The coatings with poly(unsaturated) oils have best hydrophobicity for dispersions with an optimum viscosity of 115–150 cp required for good coverage of the paper. While homogeneous coverage of the cellulose fibers is a primary requirement, thin coatings often provide higher contact angles on paper due to roughness of the underlaying fibrous surface. After ageing, the coatings are chemically stable without oil leakage and constant imide content, while an increase in contact angles is attributed to variations in coating morphology through local re-arrangements over the paper substrate.     

Spatial Separation of Covalent,Ionic, and Metallic Interactions in Mg11Rh18B8 and Mg3Rh5B3

The crystal structures of Mg₁₁Rh₁₈B₈ and Mg₃Rh₅B₃ have been investigated by using single‐crystal X‐ray diffraction. Mg₁₁Rh₁₈B₈: space group P4/mbm; a=17.9949(7), c=2.9271(1) Å; Z=2. Mg₃Rh₅B₃: space group Pmma; a=8.450(2), b=2.8644(6), c=11.602(2) Å; Z=2. Both crystal structures are characterized by trigonal prismatic coordination of the boron atoms by rhodium atoms. The [BRh₆] trigonal prisms form arrangements with different connectivity patterns. Analysis of the chemical bonding by means of the electron‐localizability/electron‐density approach reveals covalent B? Rh interactions in these arrangements and the formation of B? Rh polyanions. The magnesium atoms that are located inside the polyanions interact ionically with their environment, whereas, in the structure parts, which are mainly formed by Mg and Rh atoms, multicenter (metallic) interactions are observed. Diamagnetic behavior and metallic electron transport of the Mg₁₁Rh₁₈B₈ and Mg₃Rh₅B₃ phases are in agreement with the bonding picture and the band structure.     

Rational Design of Ag/TiO2 Nanosystems by a Combined RF‐Sputtering/Sol‐Gel Approach

The present work is devoted to the preparation of Ag/TiO₂ nanosystems by an original synthetic strategy, based on the radio‐frequency (RF) sputtering of silver particles on titania‐based xerogels prepared by the sol–gel (SG) route. This approach takes advantage of the synergy between the microporous xerogel structure and the infiltration power characterizing RF‐sputtering, whose combination enables the obtainment of a tailored dispersion of Ag‐containing particles into the titania matrix. In addition, the system′s chemico‐physical features can be tuned further through proper ex situ thermal treatments in air at 400 and 600 °C. The synthesized composites are extensively characterized by the joint use of complementary techniques, that is, X‐ray photoelectron and X‐ray excited Auger electron spectroscopies (XPS, XE‐AES), secondary ion mass spectrometry (SIMS), glancing incidence X‐ray diffraction (GIXRD), field emission scanning electron microscopy (FE–SEM), transmission electron microscopy (TEM), electron diffraction (ED), high‐angle annular dark field scanning TEM (HAADF–STEM), energy‐filtered TEM (EF–TEM) and optical absorption spectroscopy. Finally, the photocatalytic performances of selected samples in the decomposition of the azo‐dye Plasmocorinth B are preliminarily investigated. The obtained results highlight the possibility of tailoring the system characteristics over a broad range, directly influencing their eventual functional properties.     

Selective organic functionalization of graphene bulk or graphene edges

Graphene sheets have been functionalized with a PAMAM dendron, finding that graphene can be efficiently functionalized all over the surface, or only at the edges, depending on the reactions used in the functionalization process.     

Point defect clusters and dislocations in FIB irradiated nanocrystalline aluminum films: an electron tomography and aberration-corrected high-resolution ADF-STEM study

Focused ion beam (FIB) induced damage in nanocrystalline Al thin films has been characterized using advanced transmission electron microscopy techniques. Electron tomography was used to analyze the three-dimensional distribution of point defect clusters induced by FIB milling, as well as their interaction with preexisting dislocations generated by internal stresses in the Al films. The atomic structure of interstitial Frank loops induced by irradiation, as well as the core structure of Frank dislocations, has been resolved with aberration-corrected high-resolution annular dark-field scanning TEM. The combination of both techniques constitutes a powerful tool for the study of the intrinsic structural properties of point defect clusters as well as the interaction of these defects with preexisting or deformation dislocations in irradiated bulk or nanostructured materials.     

F-Doped Co3O4 photocatalysts for sustainable H2 generation from water/ethanol

p-Type Co(3)O(4) nanostructured films are synthesized by a plasma-assisted process and tested in the photocatalytic production of H(2) from water/ethanol solutions under both near-UV and solar irradiation. It is demonstrated that the introduction of fluorine into p-type Co(3)O(4) results in a remarkable performance improvement with respect to the corresponding undoped oxide, highlighting F-doped Co(3)O(4) films as highly promising systems for hydrogen generation. Notably, the obtained yields were among the best ever reported for similar semiconductor-based photocatalytic processes.