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The aim of this study was to research the influence of carbonate species on the thermal decomposition of lanthanum oxide compounds. To obtain adequate carbonate fractions, pure lanthanum hydroxide and oxide, respectively, were stored in a humid carbon dioxide atmosphere. In the process, lanthanum oxide converts within 24 h to lanthanum hydroxide because of its high affinity to water. Furthermore lanthanum hydroxide has the tendency to form carbonates, due to their basic character. By means of the results of TG-FTIR and TEM, a simplified model could be derived; the thermal decomposition of carbonated lanthanum hydroxide consists of two interfering reactions: The first reaction is the thermal decomposition of lanthanum hydroxide, and the second reaction is the thermal decomposition of lanthanum hydroxide carbonate.

Background: Refractory Ceramic fibres (RCF) are man-made mineral fibres used in high performance thermal insulation applications and mostly to line furnaces, kilns and other industrial heaters. Analogous to asbestos fibres, RCF are respirable, show a pleural drift and can persist in human lung tissue for more than 20 years after exposure. Pleural changes such as localised or diffuse pleural thickening as well as pleural calcification were reported. Case presentation: A 45 years old man worked in high performance thermal insulation applications using refractory ceramic fibres (RCF) for almost 20 years. During a biennial occupational medical prophylaxis to ensure early diagnosis of disorders caused by inhalation of aluminium silicate fibres with X-ray including high-resolution computed tomography (HRCT) showed bilateral pleural thickening and a pleural calcification next to a rounded atelectasis. Asbestos exposure could be excluded. In pulmonary function test a restrictive lung pattern could be revealed. In work samples scanning electron microscopy (SEM) including energy dispersive X-ray analysis (EDX) classified aluminium silicate fibres. X-ray powder diffraction and transmission electron microscopy (TEM) showed crystalline as well as amorphous fibres. Conclusions: A comprehensive lung function analysis and in case of restrictive lung disorders additional CT scans are needed in RCF exposed workers in accordance to the guidelines for medical occupational examinations comparable to asbestos exposed workers.

We report a novel method for the direct synthesis of mono- and bis-arylated alkynes utilizing catalytically activated CaC2 as the alkyne component. This fluoride-activated cross coupling reaction provides advantages over existing methods regarding operational simplicity, use of readily available starting materials, and low cost.

Containing two environmentally friendly elements, tin monosulfide (SnS) is considered to be a possible candidate for sustainable thermoelectrics in the medium temperature range. Nanostructured SnS was synthesized via mechanical alloying and a solvothermal method. Two different ways for compacting of the nanopowders were applied, cold pressing and hot pressing, yielding similar results. A maximum ZT value of 0.075 at 773 K was obtained, independently from the preparation procedures. In order to improve the thermoelectric properties, mechanically alloyed SnS was doped with copper, silver, palladium, and platinum. Using silver as dopant, the efficiency could be doubled, while a tin substitution with the other elements did barely affect the thermoelectric transport. A comparison to single crystalline SnS reveals a reduced thermal conductivity through nanostructuring. The structure of the products was examined via X-ray diffraction (XRD) and transmission electron microscopy (TEM) showing a nanoscopic character with slightly varying lattice constants. In the case of larger sized impurity atoms secondary phases occur, indicating the solubility limits were reached and only partial incorporation of the added dopant amount into the matrix took place

In this study, two different synthetic methods in aqueous solution are presented to tune the optical properties of CdTe and CdSe semiconductor nanoparticles. Additionally, the influence of different temperatures, pressures, precursor ratios, surface ligands, bases, and core components in the synthesis was investigated with regard to the particle sizes and optical properties. As a result, a red shift of the emission and absorption maxima with increasing reaction temperature (100 to 220°C), pressure (1 to 25 bar), and different ratios of core components of alloyed semiconductor nanoparticles could be observed without a change of the particle size. An increase in particle size from 2.5 to 5 nm was only achieved by variation of the mercaptocarboxylic acid ligands in combination with the reaction time and used base. To get a first hint on the cytotoxic effects and cell uptake of the synthesized quantum dots, in vitro tests mesenchymal stem cells (MSCs) were carried out.

Nanostructured iron oxide is coated on commercial SnO2 nanoparticles via a simple solution route. The method involves the thermal decomposition of an iron carbonyl complex (Fe(CO)5) in the presence of SnO2 and a surfactant in an organic solvent. The resulting FeOx/SnO2 nanocomposite showed an enhanced performance as an anode material for lithium ion batteries. In a conventional electrolyte containing 5 wt % fluoroethylene carbonate (FEC), a composite FeOx/SnO2 (∼1:3 mol ratio) exhibited a stable capacity ∼480 mAh/g (at a rate of 400 mA/g) for up to 150 cycles compared with

We have synthesized undoped, Co-doped (up to 5%), and Se-doped (up to 4%) FeS2 materials by mechanical alloying in a planetary ball mill and investigated their thermoelectric properties from room temperature (RT) to 600 K. With decreasing particle size, the undoped FeS2 samples showed higher electrical conductivity, from 0.02 S cm−1 for particles with 70 nm grain size up to 3.1 S cm−1 for the sample with grain size of 16 nm. The Seebeck coefficient of the undoped samples showed a decrease with further grinding, from 128 μV K−1 at RT for the sample with 70-nm grains down to 101 μV K−1 for the sample with grain size of 16 nm. The thermal conductivity of the 16-nm undoped sample lay within the range from 1.3 W m−1 K−1 at RT to a minimal value of 1.2 W m−1 K−1 at 600 K. All doped samples showed improved thermoelectric behavior at 600 K compared with the undoped sample with 16 nm particle size. Cobalt doping modified the p-type semiconducting behavior to n-type and increased the thermal conductivity (2.1 W m−1 K−1) but improved the electrical conductivity (41 S cm−1) and Seebeck coefficient (-129 μV K−1). Isovalent selenium doping led to a slightly higher thermal conductivity (1.7 W m−1 K−1) as well as to an improved electrical conductivity (26 S cm−1) and Seebeck coefficient (110 μV K−1). The ZT value of FeS2 was increased by a factor of five by Co doping and by a factor of three by Se doping.