Ion dynamics in Li-bearing antiperovskites

Li and H Dynamics in Poorly Conducting Li₂OHCl Directly Probed by Nuclear Spin Relaxation - few more information from NMR to complete the picture on ion dynamics in antiperovskites. See Jonas's work just published in J. Phys. Chem. C

  Curious about Macromolecular Chemistry in Austria?

Then have a look to the current special issue of Monatshefte für Chemie - Chemical Monthly edited by Gregor Trimmel and Christian Slugovc. The issue contains a series of articles representative for the Macromolecular Chemistry conducted in Austria.
The issue includes four works on polymer photochemistry on hydrogels, sequence-dependent orthogonality in vat photo-polymerization, multiphoton grafting onto polymers and easily degradable photopolymers. What is more are works on nanophase separated acrylamides and underwater glues or chemical vapor deposition with carbohydrate-derivatives and electro-active polymers. Further two works on porous polymers report carbon-foam metal foil composites and high-flux water filters made by foaming of oxidized nano-cellulose. Finally, a review article on poly(ether)-synthesis via oxa-Michael polymerization is disclosed.
 

  Review on oxa-Michael polymerization available

Researchers of the CD-Laboratory for Organocatalysis in Polymerization published a review article on making poly(ether)s by oxa-Michael reactions of alcohols and electron deficient olefins. This route provides access to poly(ether)s featuring an additional functional group, e.g. an ester- or an amide-group, in the polymer backbone and rivals similar polymers prepared from less sustainable amines or thiols. The article summarizes the current state of the art and discusses challenges as well as future perspectives of the oxa-Michael polymerization.

  Making porous current collectors for batteries

Researchers from the National Institute of Chemistry Ljubljana, Varta Innovation GmbH and Porous Materials@Work for Sustainability disclosed a way of preparing conducting macroporous carbon coatings on conductive substrates. The work published in Monatshefte für Chemie is focusing on the preparation of poly(dicyclopentadiene) derived porous conductive coatings on metal foils and their scope and limitation when used as binder free current collector in lithium-sulfur cells.

  Stray Capactiances in Battery Research

Electrolytes and impedance spectroscopy; take care, in general, of stray capacitances affecting the impedance response. Ilie Hanzu et al. show how coin cells might work as airtight containers to study battery electrolytes. See his paper published with the team of Solid State Ionics.

  Site-specific Li hopping processes visulaized by 2D EXSY NMR

⁶Li NMR rules: beta-Li₃VF₆ provides a range of important Li⁺ geometric environments in one and the same crystal structure to elucidate qualitatively a ranking of the energetic exchange preferences; great collaboration with Martin Lerch's group from TU Berlin. Paper appeared in Mat. Res. Bull.

  Dual-curing of electron-deficient olefins and alcohols

In the CD-laboratory for Organocatalysis in Polymerization a method to anionically copolymerize electron deficient olefins and alcohols has been developed. Now the results are published in Polymer Chemistry and are available for everybody as an open access communication.
In particular, the authors demonstrate the preparation of cross-linked polymers from off-stoichiometric oxa-Michael formulations proceeding via a self-limiting base catalyzed reaction. In the first place the difunctional Michael acceptors such as diacrylates react with substoichiometric amount of diols. Later, preferably at higher temperatures, the remaining vinyl groups are then anionically polymerized. For both steps of the dual curing process, the same catalyst is used. The method allows for a convenient tuning of the properties of the resulting polymer networks by simply varying the amount of the diol in the formulation.

  Making and breaking oxa-Michael derived bonds in polymers

Researchers from the CD-laboratory for Organocatalysis in Polymerization and the National Institute of Chemistry in Ljubljana disclosed a fundamental work on using the reversibility of the oxa-Michael reaction in macromolecules in the journal Polymer Chemistry.
In model studies with oxa-Michael adducts derived from vinylsulfones, acrylonitrile or acrylates it could be shown that the Brønsted-base catalyzed retro oxa-Michael reaction allows for fast alcohol exchange at temperatures above 100 °C. The reversibility can be utilized to build covalent adaptable networks as demonstrated by reprocessing oxa-Michael derived polymer networks at temperatures above 140 °C. Furthermore, oxa-Michael polymers can be depolymerized into small fragments in additional presence of alcohols. These findings show opportunities on how to face the challenges regarding the circular economy of plastics.

  Porphyrinic MOFs for oxygen sensing: Mirror, mirror on the wall, who's the most sensitive of them all?

A group of researchers from the Porous Materials@Work for Sustainability consortium uncovered the structure sensitivity relationship in porphyrinic zirconium-organic frameworks when used for optical oxygen sensing. The paper in ACS Applied Nano Materials establishes an oxygen sensitivity trend increasing in the order PCN-222 < PCN-223 < PCN-224. High sensitivity is above all caused by a maximized porphyrin−porphyrin separation in these nanostructured materials, which results in an increase of the fluorescence decay time, which, in turn, increases the probability of the quenching event. Defects in the nanostructure are another factor explaining variations in sensitivity within the same MOF type prepared with varying reaction conditions. Properly grown PCN-224 crystals show the highest sensitivity ever reported for a porphyrin based oxygen sensing material.

  Na-ion batteries: Fast interfacial ion dynamics in LTO

Just accepted in J. Physics: Energy: We probed rather fast Li and Na exchange in the solid solutions of sodiated Li₄Na_xTi₅O₁₂ (LTO). LTO is one of the most important anode materials guaranteeing extremely stable cycling conditions.

While Na(23) NMR helped throwing light on self-diffusion properties and activation barriers, with Li(7) NMR we were able to directly visualize the fast Li ions dynamics in the interfacial regions of the nanostructured sample. Download the paper from IOP.