Macromolecules

We present a method for patterning substrates with a regular mesh of stable radical groups. Resulting from advanced block copolymer synthesis and annealing techniques, stable radical groups on a polymer backbone phase separate from the second block and arrange in ordered block copolymer morphologies. These meshes align in large regular patterns upon sample preparation on macroscopically structured substrates. Patterned stable radical groups may find application in selective catalysis, energy storage, data storage, or optical gratings. In addition, gas permeable membranes with reactive sites or charge storage zones with regular spacings in redox batteries may be feasible by our approach

Stability of the zwitterionic liquid butyl-methyl-imidazol-2-ylidene borane

Modification of the C2 position of the standard 1-butyl-3-methyl imidazolium cation by a borohydride group leads to a zwitterionic liquid (ZIL). The resulting imidazol-2-ylidene borane ZIL is liquid at room temperature. Dynamic viscosity as well as thermal and electrochemical stability are investigated. Thermal decomposition follows a similar pathway as in comparable imidazolium ionic liquids. The surprisingly low viscosity and good reductive stability make it a promising candidate for electrochemical applications

Анализ систем оценки информационно коммуникационных компетенций

The article considers the methods of development of information-analytical system of formation of information-communicative competence of students through the portal of "Electronic University of information technology"

Halogen free 1,2,3- and 1,2,4-triazolide based ionic liquids : synthesis and properties

Triazoles have been successfully used as building blocks to create "fully organic" ILs featuring on both sides organic ions, i.e., 1,2,3- or 1,2,4-triazolide anions and 1,2,4-triazolium or imidazolium cations. Glass transition temperatures, densities and viscosities of these ILs were determined. Their electrochemical and thermal stability, and also conductivity, are higher than those for known ILs

Graph-Based Approach to the Edit Distance Cryptanalysis of Irregularly Clocked Linear Feedback Shift Registers

This paper proposes a speed-up of a known-plaintext attack on some stream ciphers based on Linear Feedback Shift Registers (LFSRs). The algorithm consists of two basic steps: first, to guess the initial seed value of one of the LFSRs, and then to use the resulting binary sequence in order to deduce useful information about the cipher parameters. In particular, the proposed divide-and-conquer attack is based on a combination of graph-based techniques with edit distance concepts. While the original edit distance attack requires the exhaustive search over the set of all possible initial states of the involved LFSR, this work presents a new heuristic optimization that avoids the evaluation of an important number of initial states through the identification of the most promising branches of the search graph. The strongest aspects of the proposal are the facts that the obtained results from the attack are absolutely deterministic, and that many inconsistent initial states of the target LFSRs are recognized and avoided during search.This work was supported by the Spanish Ministry of Science and Innovation and European FEDER Fund under Project TIN2008-02236/TSI as well as by CDTI (Spain)and the companies INDRA, Unin Fenosa, Tecnobit, Visual Tool, Brainstorm, SAC and Technosafe under Project Cenit-HESPERIA.Peer reviewe

Polymerization in carbone : a novel method for the synthesis of more sustainable electrodes and their application as cathodes for lithium–organic energy storage materials based on vanillin

Sustainable energy storage materials are needed to implement necessary transitions to a more sustainable society. Therefore, we present novel vanillin (and thus ultimately possibly lignin)-derived electrode materials for lithium-ion-based energy storage systems. In the present approach, vanillin is first modified in two sustainable steps to afford bisvanillonitrile (BVN). The precursor materials for the electrodes are made from BVN and carbon black and are subsequently treated in the atmosphere of triflic acid in order to polymerize BVN. Used as a cathode material in a lithium-ion-based energy storage device, the resulting material shows capacities up to 90 mAh g–1 (respective to the whole electrode mass). This extraordinary performance can be attributed to a combination of non-Faradaic and Faradaic charge storage involving quinone units, which are abundantly found in the polymer backbone. In contrast to conventional organic electrode materials, excellent contact to carbon as a conductive additive is established by performing the polymerization in a mixture with carbon (in carbone), allowing the omission of additional unsustainable binder materials. Due to the sustainable synthesis and good performance, such sustainable electrodes may be applied in future energy storage devices

Sustainable Battery Materials from Biomass

Sustainable sources of energy have been identified as a possible way out of today's oil-dependency and are being rapidly developed. In contrast, storage of energy to a large extent still relies on heavy metals in batteries. Especially when built from biomass-derived organics, organic batteries are promising alternatives for truly sustainable energy storage. First described in 2008, research on biomass-derived electrodes has been taken up by a multitude of researchers worldwide. Nowadays, in principle electrodes in batteries could be composed of all kinds of carbonized and non-carbonized biomass: On the one hand, all kinds of (waste) biomass may be carbonized and used in anodes of lithium or sodium ion batteries, cathodes in metal-sulfur or metal-oxygen batteries, or as conductive additive. On the other hand, a plethora of biomolecules like quinones, flavins, or carboxylates contain redox active groups that can be used as redox active component in electrodes with very little chemical modification. Biomass-based binders can replace toxic haloginated commercial binders enabling a truly sustainable future of energy storage devices. Besides the electrodes, also electrolytes and separators may be synthesized from biomass. Recent research progress in this rapidly emerging field is summarized with focus on potentially fully biowaste-derived batteries

More sustainable energy storage: lignin based electrodes with glyoxal crosslinking

Lignin is a promising material to be used in sustainable energy storage devices. It may act as active component due to hydroquinone motives or as binder in electrodes. While usually it is blended or modified with unsustainable chemicals, we investigate crosslinking with glyoxal as a new route to more benign electrodes. For combining advantages of high charge (lignin as active material) and electrode stability (lignin as binder), we chose a two-step process in which we first form lignin-carbon composites and subsequently crosslink lignin on the carbon. We discuss crosslinking of the material as well as influences on charge storage. Final electrodes benefit from combined faradaic and non-faradaic charge storage and reach a capacity of 80 mAh/g at a discharge rate of 0.2 A/g