Postsynthetic Metalated MOFs as Atomically Dispersed Catalysts for Hydroformylation Reactions

A manganese-based metal-organic framework with dipyrazole ligands has been metalated with atomically dispersed Rh and Co species and used as a catalyst for the hydroformylation of styrene. The Rh-based materials exhibited excellent conversion at 80 °C with complete chemoselectivity, high selectivity for the branched aldehyde, high recyclability, and negligible metal leaching

Self-Assembly of Oriented Antibody-Decorated Metal–Organic Framework Nanocrystals for Active-Targeting Applications

Antibody (Ab)-targeted nanoparticles are becoming increasingly important for precision medicine. By controlling the Ab orientation, targeting properties can be enhanced; however, to afford such an ordered configuration, cumbersome chemical functionalization protocols are usually required. This aspect limits the progress of Abs-nanoparticles toward nanomedicine translation. Herein, a novel one-step synthesis of oriented monoclonal Ab-decorated metal–organic framework (MOF) nanocrystals is presented. The crystallization of a zinc-based MOF, Zn2(mIM)2(CO3), from a solution of Zn2+ and 2-methylimida-zole (mIM), is triggered by the fragment crystallizable (Fc) region of the Ab. This selective growth yields biocomposites with oriented Abs on the MOF nanocrystals (MOF*Ab): the Fc regions are partially inserted within the MOF surface and the antibody-binding regions protrude from the MOF surface toward the target. This ordered configuration imparts antibody–antigen rec-ognition properties to the biocomposite and shows preserved target binding when compared to the parental antibodies. Next, the biosensing performance of the system is tested by loading MOF*Ab with luminescent quantum dots (QD). The targeting efficiency of the QD-containing MOF*Ab is again, fully preserved. The present work represents a simple self-assembly approach for the fabrication of antibody-decorated MOF nanocrystals with broad potential for sensing, diagnostic imaging, and targeted drug delivery

Predicting needlestick and sharps injuries in nursing students: Development of the SNNIP scale

© 2020 The Authors. Nursing Open published by John Wiley & Sons Ltd. Aim: To develop an instrument to investigate knowledge and predictive factors of needlestick and sharps injuries (NSIs) in nursing students during clinical placements. Design: Instrument development and cross-sectional study for psychometric testing. Methods: A self-administered instrument including demographic data, injury epidemiology and predictive factors of NSIs was developed between October 2018–January 2019. Content validity was assessed by a panel of experts. The instrument's factor structure and discriminant validity were explored using principal components analysis. The STROBE guidelines were followed. Results: Evidence of content validity was found (S-CVI 0.75; I-CVI 0.50–1.00). A three-factor structure was shown by exploratory factor analysis. Of the 238 participants, 39% had been injured at least once, of which 67.3% in the second year. Higher perceptions of “personal exposure” (4.06, SD 3.78) were reported by third-year students. Higher scores for “perceived benefits” of preventive behaviours (13.6, SD 1.46) were reported by second-year students

Studio per la produzione e la caratterizzazione di foglietti arrotolati di grafite (carbon nanoscrolls)

The report on research activity of this doctoral thesis is divided into two sections. In the first section the study, production and functionalization of some newly discovered carbon structures called carbon nanoscrolls (CNS) are reported. These rolled structures arises from the curling of graphene sheets to produce tubular cylinders similar to the already known carbon nanotubes. Currently, these objects are studied mainly from a theoretical point of view but are considered good candidates for hydrogen storage, nanodevice production and reinforcement in composite materials. The production of CNS is carried out through an initial stage of reaction with metallic potassium, to give a graphite intercalation compound of minimum formula KC8, characterized by alternating graphene plans and potassium atoms, pale bronze in colour and highly reactive. A direct reaction with ethanol, under inert atmosphere, produces hydrogen and heat that producethe expansion of graphene sheets. The rolling of grapheme sheets is mediated by high power ultrasounds. The application of ultrasounds overcomes the energy barrier required for the bending of the sheets so that the edges can overlap and adhere by Van der Waals forces giving CNS. It has been devised a general procedure for CNS synthesis starting from a natural Madagascar-type graphite, purified by heat treatment and commercially available in flakes. The many experiments that we carried out (intercalation, exfoliation, ultrasonication) gave some rolled sheets in the samples but in a unexpectedly low yield. We then tried to optimize the CNS synthesis by implementing a preliminary expansion of graphite. Using a mixture of concentrated H2SO4/HNO3 as intercalating agents, followed by an expansion stadium by a thermal or treatment with microwaves. In both cases, the expansion of the graphemes was very good. We also applied a mechanical demolition procedure using a high-power ball-miller. This study was implemented on the basis of SEM observations, that showed how the large slats of graphite hampered wrapping. Actually the effect was beyond expectations, excessive crushing of graphite produced too small leaflets and even the formation of amorphous carbon, thereby invalidate this step. A new and efficient CNS synthetic procedure was pursued, using ozone and fuming HNO3 as intercalating agents, followed by exfoliation with ethanol and ultrasonication. This treatment produces a considerable improvement in the production of CNS. Some funzionalization reactions were also carried out on prepared CNS through the 1,3-dipolar cycloaddition reaction of azomethine ylides and the sidewall diazotation in a similar way used for carbon nanotubes. The second part of the project has involved the production of composite materials based on graphite oxide and polithiophenes to produce a material that synergistically combine the mechanical properties of graphite with an organic semiconducting polymer, with a possible use as component in electronic devices. The graphite oxide has been obtained with permanganate oxidation in strong mineral acids; it is easily dispersable in water and can restore the starting graphite in form of carbon nanoplatelets after reduction with hydrazine. The polymer has been produced in aqueous environment using thienyl monomers such as the 3.4-etilenedioxythiophene (EDOT) and the 3-hexylthiophene (3HT), pure or blended, in the presence of graphite oxide, ammonium persulphate (APS) as polymerizing agent and a surfactant to prevent precipitaion. After evaporation of the solvent, a composite material was obtained, in the form of thin and shiny black films, with little roughness, and relatively transparent to light in water. The conductiong, composite material was used for some tests, in a transistor (FET) configuration, at the Zernike Institute for Advanced Materials of the Universityt of Groningen. It has been shown that the composite is a good candidate to prepare organic-based diodes

The Chemistry of Ni-Sb Carbonyl Clusters - Synthesis and Characterization of the [Ni19Sb4(CO)26]4-Tetraanion and the Viologen Salts of [Ni13Sb2(CO)24]n-Carbonyl Clusters

Within the reinvestigation of Ni–Sb carbonyl cluster chemistry, we report here the synthesis and characterization of the new [Ni19Sb4(CO)26]4– cluster and the synthesis, structure, magnetic characterization and electrical resistivity of the viologen salts of the previously known [Ni13Sb2(CO)24]n– (n = 2, 3) anionic species. The crystal structures of [NEt4]4 [Ni19Sb4(CO)26], [EtV]8[Ni13Sb2(CO)24]3·4DMF·2C6H14 and [EtV]3[Ni13Sb2(CO)24]·1.5THF (EtV = 1,1 -diethyl-4,4 -bipyridilium cation, DMF = N,N-dimethylformamide, THF = tetrahydrofuran) are described. Notably, the unit cell of [EtV]8[Ni13Sb2(CO)24]3·4DMF·2C6H14 involves a mixture of two [Ni13Sb2(CO)24]3– trianions and one [Ni13Sb2(CO)24]2– dianion, as it also contains eight [EtV]+· radical monocations, which are assembled in infinite stacks. In contrast, the unit cell of the [EtV]3[Ni13Sb2(CO)24]·1.5THF salt contains four [Ni13Sb2(CO)24]3– trianions along with twelve [EtV]+· radicalmonocations, four of which are arranged into two pairs of isolated dimers, whereas the other two sets of four form two infinite stacks that extend over the whole crystal. The charges of the miscellaneous ions have been assigned on the basis of electroneutrality and spectroscopic evidence. More specifically, the infrared spectra of [EtV]8[Ni13Sb2(CO)24]3· 4DMF·2C6H14, both in the solid state and in solution, clearly indicate the presence of a 2:1 mixture of [Ni13Sb2(CO)24]3– and [Ni13Sb2(CO)24]2– anions. Resistivity measurements performed on pellets of powdered samples indicate that the [EtV]8[Ni13Sb2(CO)24]3·4DMF·2C6H14 salt substantially behaves as an insulator. A study of the magnetic behaviour of [EtV]8[Ni13Sb2(CO)24]3·4DMF·2C6H14 evidences pairing among the electrons of the EtV+· molecules, in agreement with DFT calculations, and the odd-electron clusters behave as paramagnetic centres of spin S = 1

Fe₃O₄@HKUST-1 and Pd/Fe₃O₄@HKUST-1 as magnetically recyclable catalysts prepared via conversion from a Cu-based ceramic

Nanocomposites obtained by integrating iron oxide magnetic nanoparticles (Fe3O4) into a metal-organic framework (HKUST-1 or Cu-3(BTC)(2), BTC = 1,3,5-benzenetricarboxylate) are synthesized through conversion from a composite of a Cu-based ceramic material and Fe3O4. In situ small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) measurements reveal that the presence of Fe3O4 leads to the fast conversion and synthesis of HKUST-1 with small particle sizes. The prepared MOF composite (Fe3O4@HKUST-1) is found to catalyze the one-pot sequential deacetalization-Knoevenagel condensation reaction as a magnetically collectable and recyclable catalyst. In addition, Pd nanoparticles are also incorporated into the material (Pd/Fe3O4@HKUST-1) by addition of a Pd colloidal solution during the conversion of the precursor composite to HKUST-1. The resulting Pd/Fe3O4@HKUST-1 can be utilized for hydrogenation of 1-octene in the liquid phase

Fe 3

Nanocomposites obtained by integrating iron oxide magnetic nanoparticles (Fe3O4) into a metal-organic framework (HKUST-1 or Cu-3(BTC)(2), BTC = 1,3,5-benzenetricarboxylate) are synthesized through conversion from a composite of a Cu-based ceramic material and Fe3O4. In situ small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) measurements reveal that the presence of Fe3O4 leads to the fast conversion and synthesis of HKUST-1 with small particle sizes. The prepared MOF composite (Fe3O4@HKUST-1) is found to catalyze the one-pot sequential deacetalization-Knoevenagel condensation reaction as a magnetically collectable and recyclable catalyst. In addition, Pd nanoparticles are also incorporated into the material (Pd/Fe3O4@HKUST-1) by addition of a Pd colloidal solution during the conversion of the precursor composite to HKUST-1. The resulting Pd/Fe3O4@HKUST-1 can be utilized for hydrogenation of 1-octene in the liquid phase

How Reproducible Are Surface Areas Calculated from the BET Equation?

Porosity and surface area analysis play a prominent role in modern materials science, where their determination spans the fields of natural sciences, engineering, geology and medical research. At the heart of this sits the Brunauer-Emmett-Teller (BET) theory,[1] which has been a remarkably successful contribution to the field of materials science. The BET method was developed in the 1930s for open surfaces but is now the most widely used metric for the estimation of surface areas of micro- and mesoporous materials.[2] Since the BET method was first developed, there has been an explosion in the field of nanoporous materials with the discovery of synthetic zeolites,[3] nanostructured silicas,[4–6] metal-organic frameworks (MOFs),[7] and others. Despite its widespread use, the manual calculation of BET surface areas causes a significant spread in reported areas, resulting in reproducibility problems in both academia and industry. To prove this, we have brought together 60 labs with strong track records on the study of nanoporous materials. We provided eighteen already measured raw adsorption isotherms and asked these researchers to calculate the corresponding BET areas. This round-robin exercise resulted in a wide range of values for each isotherm. We demonstrate here that the reproducibility of BET area determination from identical isotherms is a largely ignored issue, raising critical concerns over the reliability of reported BET areas in micro- and mesoporous materials in the literature. To solve this major issue, we have developed a new computational approach to accurately and systematically determine the BET area of nanoporous materials. Our software, called BET Surface Identification (BETSI), expands on the well-known Rouquerol criteria and makes, for the first time, an unambiguous BET area assignment possible