Zur Untersuchung der Gerbstoffe, bezw. des Leders

Ohne Zusammenfassung     

Eisen und Stab

Ohne Zusammenfassung     

Auf das Vorkommen von Arsen und Vanadin im käuflichen Aetznatron

Analytical and Bioanalytical Chemistry -     

Silicate-Phenolic Networks: Coordination-Mediated Deposition of Bioinspired Tannic Acid Coatings

Surface modification with polyphenolic molecules has been pursued in biomedical materials owing to their antioxidant, anti-inflammatory, and antimicrobial characteristics. Recently, the use of silicic acid (Si_aq) as a mediator for efficient surface deposition of tannic acid (TA) was reported, but the postulated Si-TA polymeric networks were not characterized. Herein, we present unambiguous evidence for silicate-TA networks that involve Si−O−C motifs by using solid-state NMR spectroscopy, further supported by XPS and ToF-SIMS. By using QCM-D we demonstrate the advantages of Si_aq, compared to using transition-metal ions, to improve the coating efficiency under mildly acidic conditions. The presented homogenous coating buildup and validated applicability in inorganic buffers broadens the use of TA for surface modifications in technological and biomedical applications.     

Tensor of internal stresses in polycrystalline grains with complex bending

Processes that occur upon the straining of a polycrystal are studied. Components of the internal stress tensor were determined. Changes in the bending and torsion stresses in the crystal lattice of a strained polycrystal are analyzed. A correlation between changes in the internal stress tensor components and the fraction of material with complex bending is established.     

Synthesis and Investigation of New Tetrathiafulvalenes Able to Form Intermolecular Hydrogen Bonds of the Nucleic Acids Base Pairs Type

Abstract

The synthetic methods are worked out for preparing of 2,4-dioxopyrimido- and 2,4-aminooxopyrimidotetrathiafulvalenes. Redoxproperties and formation of charge transfer complexes and cation-radical salts are investigated. X-ray crystal structure confirm formation of dimers by means of hydrogen bonds.     

Processability improvement of polyolefins through radiation-induced branching

Radiation-induced long-chain branching for the purpose of improving melt strength and hence the processability of polypropylene (PP) and polyethylene (PE) is reviewed. Long-chain branching without significant gel content can be created by low dose irradiation of PP or PE under different atmospheres, with or without multifunctional branching promoters. The creation of long-chain branching generally leads to improvement of melt strength, which in turn may be translated into processability improvement for specific applications in which melt strength plays an important role. In this paper, the changes of the melt flow rate and the melt strength of the irradiated polymer and the relationship between long-chain branching and melt strength are reviewed. The effects of the atmosphere and the branching promoter on long-chain branching vs. degradation are discussed. The benefits of improved melt strength on the processability, e.g., sag resistance and strain hardening, are illustrated. The implications on practical polymer processing applications such as foams and films are also discussed.