Ultrahigh ionic exclusion through carbon nanomembranes

The collective “single‐file” motion of water molecules through natural and artificial nanoconduits inspires the development of high‐performance membranes for water separation. However, a material that contains a large number of pores combining rapid water flow with superior ion rejection is still highly desirable. Here, a 1.2 nm thick carbon nanomembrane (CNM) made from cross‐linking of terphenylthiol (TPT) self‐assembled monolayers is reported to possess these properties. Utilizing their extremely high pore density of 1 sub‐nm channel nm−2, TPT CNMs let water molecules rapidly pass, while the translocation of ions, including protons, is efficiently hindered. Their membrane resistance reaches ≈104 Ω cm2 in 1 m Cl− solutions, comparable to lipid bilayers of a cell membrane. Consequently, a single CNM channel yields an ≈108 higher resistance than pores in lipid membrane channels and carbon nanotubes. The ultrahigh ionic exclusion by CNMs is likely dominated by a steric hindrance mechanism, coupled with electrostatic repulsion and entrance effects. The operation of TPT CNM membrane composites in forward osmosis is also demonstrated. These observations highlight the potential of utilizing CNMs for water purification and opens up a simple avenue to creating 2D membranes through molecular self‐assembly for highly selective and fast separations

Lehrerstudie ProLEG: Professionalisierung von Lehrkräften für einen reflektierten Umgang mit Ethnizität und Geschlecht in der Grundschule. Kurz-Dokumentation ausgewählter Daten und Ergebnisse. Lehrerausbildung und Schule in der Diskussion.

Hüpping B, Büker P, Winheller S, Müller M, Rendtorff B. Lehrerstudie ProLEG: Professionalisierung von Lehrkräften für einen reflektierten Umgang mit Ethnizität und Geschlecht in der Grundschule. Kurz-Dokumentation ausgewählter Daten und Ergebnisse. Lehrerausbildung und Schule in der Diskussion. Vol 20. Paderborn: PLAZ-Forum; 2013

LaCo1–x_{1– x}Fex_xO3_3 Nanoparticles in Cyclohexene Oxidation

The identification of structure–activity relationships is challenging for complex oxides like lanthanum-based perovskite nanoparticles. The purpose of this study is to examine the structure of LaCo$_{1– x}$Fe$_x$O$_3$ nanoparticles and develop a detailed structural model to identify subtle changes of the structure after catalysis. Therefore, small nanoparticles with a significant fraction of surface atoms and varying iron content (x = 0, 0.5, 1) are synthesized in the gas phase by chemical vapor synthesis and tested in cyclohexene oxidation in the liquid phase. The crystal structure is examined by X-ray and selected area electron diffraction. Additionally, the local structure of the cations is probed by X-ray absorption spectroscopy at the Co, Fe, La K, and La L$_3$-edges. For a quantitative analysis of the local structure before and after catalysis, an atomistic model is refined by the available extended X-ray absorption fine structure spectra using Reverse Monte Carlo methods. The produced nanoparticles are small with a coherent diffraction domain size between 5 and 10 nm, highly crystalline, and consist mainly of the perovskite phase with a secondary spinel phase. In cyclohexene oxidation, the cobalt-containing samples exhibit significant catalytic activities. The active samples show structural changes after catalysis accompanied by reconstruction of the local structure surrounding the cations in the perovskite phase, which resembles edge-sharing cobalt octahedra

Anpassung des neuen Begutachtungsverfahrens an die Begutachtung von Kindern.

Meintrup V, Eckhardt S, Büker C, Gansweid B, Wingenfeld K. Anpassung des neuen Begutachtungsverfahrens an die Begutachtung von Kindern. In: Gaertner T, Gansweid B, Gerber H, Schwegler F, Heine U, eds. Die Pflegeversicherung – Handbuch zur Begutachtung, Qualitätsprüfung, Beratung und Fortbildung. 3.rd ed. Berlin/Boston: Walter de Gruyter; 2014: 289-294