Filters

2020 - 20233

More filters

2021 - 20243
Reset filters

Settings

search.filters.applied.f.access: openAccess × Author: Herbeck-Engel, Petra ×

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    When Ultimate Adhesive Mechanism Meets Ultimate Anti‐Fouling Surfaces - Polydopamine Versus SLIPS: Which One Prevails?
    (Weinheim : Wiley-VCH, 2020) Prieto-López, Lizbeth Ofelia; Herbeck-Engel, Petra; Yang, Li; Wu, Qian; Li, Juntang; Cui, Jiaxi
    What happens when the extremely adhesive and versatile chemistry of polydopamine (PDA) is in contact with the extremely slippery surfaces known as slippery liquid‐infused porous substrates (SLIPS)? Inspired by the pitcher plant, SLIPS possess excellent repellence against a variety of complex liquids and have been proposed as promising antifouling surfaces because of their successful performance even in marine environments. In the counterpart, inspired by the adhesive proteins enabling the strong adhesion of mussels to multiple substrates, PDA has been extensively studied for its ability to adhere on nearly every type of substrate. The interaction between various SLIPS systems and the highly fouling medium from the oxidative polymerization of dopamine is explored here. A PDA coating is observed on all the SLIPS evaluated, modifying their hydrophobicity in most cases. In‐depth study of silicone‐based SLIPS shows that hydrophobicity of PDA coated SLIPS partially recovers with time due to percolation of the lubricant through the coating. “Strongly” bound PDA species are attributed to the formation of dopamine‐polydimethylsiloxane species on the crosslinked matrix, rendering a coating that withstands repeated washing steps in various solvents including water, hexane, and toluene. The results not only satisfy scientific curiosity but also imply a strategy to modify/bond SLIPS.
  • Thumbnail Image
    Item
    Raman and NMR spectroscopic and theoretical investigations of the cubic laves-phases REAl2 (RE = Sc, Y, La, Yb, Lu)
    (London : Soc., 2023) Gießelmann, Elias C. J.; Engel, Stefan; Kostusiak, Weronika; Zhang, Yuemei; Herbeck-Engel, Petra; Kickelbick, Guido; Janka, Oliver
    The cubic Laves-phase aluminides REAl2 with RE = Sc, Y, La, Yb and Lu were prepared from the elements by arc-melting or using refractory metal ampoules and induction heating. They all crystallize in the cubic crystal system with space group Fd3̄m and adopt the MgCu2 type structure. The title compounds were characterized by powder X-ray diffraction and spectroscopically investigated using Raman and 27Al and in the case of ScAl2 by 45Sc solid-state MAS NMR. In both, the Raman and NMR spectra, the aluminides exhibit only one signal due to the crystal structure. DFT calculations were used to calculate Bader charges illustrating the charge transfer in these compounds along with NMR parameters and densities of states. Finally, the bonding situation was assessed by means of ELF calculations rendering these compounds aluminides with positively charged REδ+ cations embedded in an [Al2]δ− polyanion.
  • Thumbnail Image
    Item
    Safe-by-Design part II: A strategy for balancing safety and functionality in the different stages of the innovation process
    (Amsterdam : Elsevier, 2021) Tavernaro, Isabella; Dekkers, Susan; Soeteman-Hernández, Lya G.; Herbeck-Engel, Petra; Noorlander, Cornelle; Kraegeloh, Annette
    Manufactured nanomaterials have the potential to impact an exceedingly wide number of industries and markets ranging from energy storage, electronic and optical devices, light-weight construction to innovative medical approaches for diagnostics and therapy. In order to foster the development of safer nanomaterial-containing products, two main aspects are of major interest: their functional performance as well as their safety towards human health and the environment. In this paper a first proposal for a strategy is presented to link the functionality of nanomaterials with safety aspects. This strategy first combines information on the functionality and safety early during the innovation process and onwards, and then identifies Safe-by-Design (SbD) actions that allow for optimisation of both aspects throughout the innovation process. The strategy encompasses suggestions for the type of information needed to balance functionality and safety to support decision making in the innovation process. The applicability of the strategy is illustrated using a literature-based case study on carbon nanotube-based transparent conductive films. This is a first attempt to identify information that can be used for balancing functionality and safety in a structured way during innovation processes.