Filters

2022 - 20233

More filters

20233
Reset filters

Settings

Start date: 2022 × Has files: Yes × Version: publishedVersion × Publisher: Weinheim : Wiley-VCH × WGL Institute: INP ×

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Self-Activation of Inorganic-Organic Hybrids Derived through Continuous Synthesis of Polyoxomolybdate and para-Phenylenediamine Enables Very High Lithium-Ion Storage Capacity
    (Weinheim : Wiley-VCH, 2023) Mohamed, Mana Abdirahman; Arnold, Stefanie; Janka, Oliver; Quade, Antje; Presser, Volker; Kickelbick, Guido
    Inorganic-organic hybrid materials with redox-active components were prepared by an aqueous precipitation reaction of ammonium heptamolybdate (AHM) with para-phenylenediamine (PPD). A scalable and low-energy continuous wet chemical synthesis process, known as the microjet process, was used to prepare particles with large surface area in the submicrometer range with high purity and reproducibility on a large scale. Two different crystalline hybrid products were formed depending on the ratio of molybdate to organic ligand and pH. A ratio of para-phenylenediamine to ammonium heptamolybdate from 1 : 1 to 5 : 1 resulted in the compound [C6H10N2]2[Mo8O26] ⋅ 6 H2O, while higher PPD ratios from 9 : 1 to 30 : 1 yielded a composition of [C6H9N2]4[NH4]2[Mo7O24] ⋅ 3 H2O. The electrochemical behavior of the two products was tested in a battery cell environment. Only the second of the two hybrid materials showed an exceptionally high capacity of 1084 mAh g−1 at 100 mA g−1 after 150 cycles. The maximum capacity was reached after an induction phase, which can be explained by a combination of a conversion reaction with lithium to Li2MoO4 and an additional in situ polymerization of PPD. The final hybrid material is a promising material for lithium-ion battery (LIB) applications.
  • Thumbnail Image
    Item
    Oral SARS-CoV-2 reduction by local treatment: A plasma technology application?
    (Weinheim : Wiley-VCH, 2022) von Woedtke, Thomas; Gabriel, Gülsah; Schaible, Ulrich E.; Bekeschus, Sander
    The SARS-CoV-2 pandemic reemphasized the importance of and need for efficient hygiene and disinfection measures. The coronavirus' efficient spread capitalizes on its airborne transmission routes via virus aerosol release from human oral and nasopharyngeal cavities. Besides the upper respiratory tract, efficient viral replication has been described in the epithelium of these two body cavities. To this end, the idea emerged to employ plasma technology to locally reduce mucosal viral loads as an additional measure to reduce patient infectivity. We here outline conceptual ideas of such treatment concepts within what is known in the antiviral actions of plasma treatment so far.
  • Thumbnail Image
    Item
    Plasma Spraying of Kaolinite for Preparing Reactive Alumino-Silicate Glass Coatings
    (Weinheim : Wiley-VCH, 2022) Warr, Laurence N.; Wolff, Thorben; Testrich, Holger; Grathoff, Georg; Kruth, Angela; Foest, Rüdiger
    Thermally treated kaolinite is used to develop a range of alumino-silicate-based precursor materials but its behavior during plasma spraying has not been well-researched. In this study, two types of kaolinite samples were investigated in the form of low defect (KGa-1b) and high defect (KGa-2) varieties. The extreme temperatures of the plasma stream (up to 20 000 K) induced flash melting to produce a highly porous alumino-silicate glass without any crystallization of new Al−Si oxide minerals. The glass is comprised largely of intact or deformed spheres (average diameters 1.14–1.44 μm), which indicates rapid quenching and solidification before impact. The subspherical structures contain up to 40 % closed pore space caused by the rapid escape of water during melting. The low-density, porous alumino-silicate glass coatings with predicted specific surface areas (>0.95 m2/g) and hardnesses >1.8 GPa represent a potentially reactive but physically stable substrate ideal for further chemical functionalization.