Investigation of metal clusters dispersed in styrene-co-(ethyl methacrylate) copolymers by means of high resolution transmission electron microscopy

Styrene/ethyl methacrylate (SEMA) colloids were obtained by cocondensation at 77 K of the monomers with several metals such as Au, Pd, In and Sn. The colloids were polymerized with 2,2′-azoisobutyronitrile and dibenzoyl peroxide as radical initiators at 60°C for 3.5 h. A viscosity average molecular weight (10⁴ < M _v < 10⁵) was obtained depending upon the metal used. The particle size of these clusters dispersed in the copolymers ranges from 20 to 31 Å. The metal clusters are incorporated in the copolymers.     

A Study of the Swelling Properties of Polymer Nanocomposites through Electrical and Optical Characterization

In the present study, polymer nanocomposite layers for sensing applications are characterized by means of an optical method based on white light interferometry. The study focuses on poly (hydroxy ethyl methacrylate) (PHEMA) and on nanocomposite Carbon black (CB)/PHEMA layers commonly used in chemical sensor technology for volatile organic compounds (VOCs) detection. The interferometric spectra of these two different materials, recorded during analyte exposure, are analyzed in terms of film expansion. Comparison between PHEMA and PHEMA/CB layer shows that the nanocomposite undergoes a more pronounced swelling process. In order to achieve a better comprehension of the sensing mechanism and to improve the sensor performances, the variations of the electrical signal of a nanocomposite-based chemiresistor in presence of VOCs are examined and compared to the optical behaviour.     

Metal‐Ligand Cooperative Synthesis of Benzonitrile by Electrochemical Reduction and Photolytic Splitting of Dinitrogen

Thermal nitrogen fixation relies on strong reductants to overcome the extraordinarily large N?N bond energy. Photochemical strategies that drive N₂ fixation are scarcely developed. Here, the synthesis of a dinuclear N₂‐bridged complex is presented upon reduction of a rhenium(III) pincer platform. Photochemical splitting into terminal nitride complexes is triggered by visible light. Clean nitrogen transfer with benzoyl chloride to free benzamide and benzonitrile is enabled by cooperative 2 H⁺/2 e^? transfer of the pincer ligand. A three‐step cycle is demonstrated for N₂ to nitrile fixation that relies on electrochemical reduction, photochemical N₂‐splitting and thermal nitrogen transfer.     

Microchip gel electrophoretic analysis of perchloric acid‐soluble serum proteins in systemic inflammatory disorders

Perchloric acid (PCA) precipitation is a well‐known method for the separation of heavily glycosylated proteins and for reducing the masking effect of major serum proteins. The aim of this study is to characterize PCA‐soluble serum proteins in healthy individuals and in patients with systemic inflammatory diseases, such as Crohn's disease and sepsis. A PCA precipitation protocol was prepared and adapted to the analytical methods. After PCA treatment of the serum, the soluble proteins in the supernatant were analyzed by SDS‐PAGE and by microchip gel electrophoresis (MGE). Characteristic changes of the electrophoretic patterns of the PCA‐soluble fractions were observed. Four characteristic bands (at ～11, ～65, ～85, and ～120 kDa) with varying intensity were detected by MGE. The proportion of the ～65, ～85, and ～120 kDa bands were significantly higher in systemic inflammatory conditions than in healthy individuals (p < 0.001), and characteristic patterns were observed in patients with acute inflammation. The marked differences in the acid‐soluble protein patterns, which were observed in patients with ongoing systemic inflammation, might be a good indicator of inflammation. The MGE analysis is a fast screening and quantification method for the detection of characteristic changes among acid‐soluble serum proteins.     

Relationship between (micro)structure and functional (photocatalytic and adsorption) properties of anatase–mordenite nanocomposite

Research on Chemical Intermediates - Anatase–mordenite nanocomposite was synthesized in&nbsp;situ and characterized by X-ray diffraction analysis, Brunauer–Emmett–Teller...     

One‐Electron Reduction of Acenaphthene‐1,2‐Diimine Nickel(II) Complexes

New nickel‐based complexes of 1,2‐bis[(2,6‐diisopropylphenyl)imino]acenaphthene (dpp‐bian) with BF₄^? counterion or halide co‐ligands were synthesized in THF and MeCN. The nickel(I) complexes were obtained by using two approaches: 1) electrochemical reduction of the corresponding nickel(II) precursors; and 2) a chemical comproportionation reaction. The structural features and redox properties of these complexes were investigated by using single‐crystal X‐ray diffraction (XRD), cyclic voltammetry (CV), and electron paramagnetic resonance (EPR) and UV/Vis spectroscopy. The influence of temperature and solvent on the structure of the nickel(I) complexes was studied in detail, and an uncommon reversible solvent‐induced monomer/dimer transformation was observed. In the case of the fluoride complex, the unpaired electron was found to be localized on the dpp‐bian ligand, whereas all of the other nickel complexes contained neutral dpp‐bian moieties.     

The RgI<Subscript>2</Subscript> (ion-pair states) van der Waals complexes

This paper is an overview of our recent experimental investigations of the RgI₂ van der Waals complexes, Rg = He, Ar, Kr, performed by means of laser induced fluorescence spectroscopy, optical-optical double resonance and supersonic molecular beam techniques. Spectroscopic parameters of these complexes in the E0 _g ⁺ ion-pair state, such as binding energies and several spectroscopic constants, have been determined. Most likely, the potential energy surfaces of the all RgI₂(E) complexes under study present T-shaped minima. Vibrational and electronic predissociations of the RgI₂(E) complexes were analyzed. Relative contributions of the different electronic predissociation channels and vibrational distributions of the decay products were determined. Possible mechanisms of the complexes decay are suggested and discussed.     

Screen-printing of microfibrillated cellulose for an improved moisture management,strength and abrasion resistant properties of flame-resistant fabrics

Cellulose - Low moisture absorbency of hydrophobically coated flame-resistant (FR) fabrics do not correlate well with the thermophysiological comfort. In this frame, we were the first to study the...