Designing Covalent Organic Frameworks with a Tailored Ionic Interface for Ion Transport across One-Dimensional Channels

A strategy based on covalent organic frameworks for ultrafast ion transport involves designing an ionic interface to mediate ion motion. Electrolyte chains were integrated onto the walls of one-dimensional channels to construct ionic frameworks via pore surface engineering, so that the ionic interface can be systematically tuned at the desired composition and density. This strategy enables a quantitative correlation between interface and ion transport and unveils a full picture of managing ionic interface to achieve high-rate ion transport. Moreover, the effect of interfaces was scaled on ion transport; ion mobility is increased in an exponential mode with the ionic interface. This strategy not only sets a benchmark system but also offers a general guidance for designing ionic interface that is key to systems for energy conversion and storage.     

Bestimmung spezifischer Oberfl?chen aus der Aktivit?t einer IR-Absorptionsbande

Zusammenfassung Durch Symmetrieerniedrigung der Carbonationen an der Oberfläche von Calcitpräparaten wird die infrarotverbotene symmetrische Valenzschwingung aktiviert.Aus der Intensität dieser Infrarotabsorption kann auf die Oberflächenentwicklung geschlossen werden. Am Beispiel von Cadmiumcarbonat wird durch Vergleich dieser Messungen mit röntgenographischen Methoden der Teilchengrößenbestimmung und BET-Messungen der spezifischen Oberflächen gezeigt, daß die Methode geeignet ist, schnelle Oberflächenbestimmungen durchzuführen.Wir. danken der Deutschen Forschungsgemeinschaft und dem-Verband der Chemischen Industrie für die Förderung dieser Arbeit.     

The Hydrophobic Gap at High Hydrostatic Pressures

We have gained new insight into the so‐called hydrophobic gap, a molecularly thin region of decreased electron density at the interface between water and a solid hydrophobic surface, by X‐ray reflectivity experiments and molecular dynamics simulations at different hydrostatic pressures. Pressure variations show that the hydrophobic gap persists up to a pressure of 5 kbar. The electron depletion in the interfacial region strongly decreases with an increase in pressure, indicating that the interfacial region is compressed more strongly than bulk water. The decrease is most significant up to 2 kbar; beyond that, the pressure response of the depletion is less pronounced.     

Fluorogel Elastomers with Tunable Transparency,Elasticity, Shape‐Memory,and Antifouling Properties

Omniphobic fluorogel elastomers were prepared by photocuring perfluorinated acrylates and a perfluoropolyether crosslinker. By tuning either the chemical composition or the temperature that control the crystallinity of the resulting polymer chains, a broad range of optical and mechanical properties of the fluorogel can be achieved. After infusing with fluorinated lubricants, the fluorogels showed excellent resistance to wetting by various liquids and anti‐biofouling behavior, while maintaining cytocompatiblity.