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Autor

  • Elert, Anna Maria (3)
  • Bonse, Jörn (1)
  • Braun, Ulrike (1)
  • Brzeska, J. (1)
  • Dörfel, Ilona (1)
  • Elert, Anna M. (1)
  • Fischer, Daniel (1)
  • Griepentrog, Michael (1)
  • Hertwig, Andreas (1)
  • Jönkkäri, I (1)
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Erscheinungsjahr

  • 2019 (1)
  • 2018 (2)
  • 2017 (1)

Schlagworte

  • Antibacterial (1)
  • Biological techniques (1)
  • Environmental Science (1)
  • FTIR (1)
  • Femtosecond laser (1)
  • Friction (1)
  • IR (1)
  • Microplastics (1)
  • Oxidation (1)
  • PUR (1)
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Organisationseinheit der BAM

  • 6 Materialschutz und Oberflächentechnik (4)
  • 6.6 Nano-Tribologie und Nanostrukturierung von Oberflächen (4)
  • 5 Werkstofftechnik (2)
  • 5.1 Materialographie, Fraktographie und Alterung technischer Werkstoffe (1)
  • 5.3 Mechanik der Polymerwerkstoffe (1)
  • 6.3 Makro-Tribologie und Verschleißschutz (1)
  • 6.4 Technologien mit Nanowerkstoffen (1)
  • 6.7 Oberflächenmodifizierung und -messtechnik (1)

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Branched Polyurethanes Based on Synthetic Polyhydroxybutyrate with Tunable Structure and Properties (2018)
Brzeska, J. ; Elert, Anna Maria ; Morawska, M. ; Sikorska, W. ; Kowalczuk, M. ; Rutkowska, M.
Branched, aliphatic polyurethanes (PURs) were synthesized and compared to linear analogues. The influence of polycaprolactonetriol and synthetic poly([R,S]-3-hydroxybutyrate) (R,S-PHB) in soft segments on structure, thermal and sorptive properties of PURs was determined. Using FTIR and Raman spectroscopies it was found that increasing the R,S-PHB amount in the structure of branched PURs reduced a tendency of urethane groups to hydrogen bonding. Melting enthalpies (on DSC thermograms) of both soft and hard segments of linear PURs were higher than branched PURs, suggesting that linear PURs were more crystalline. Oil sorption by samples of linear and branched PURs, containing only polycaprolactone chains in soft segments, was higher than in the case of samples with R,S-PHB in their structure. Branched PUR without R,S-PHB absorbed the highest amount of oil. Introducing R,S-PHB into the PUR structure increased water sorption. Thus, by operating the number of branching and the amount of poly([R,S]-3-hydroxybutyrate) in soft segments thermal and sorptive properties of aliphatic PURs could be controlled.
Assuring quality in microplastic monitoring: About the value of clean-air devices as essentials for verified data (2017)
Wesch, Ch. ; Elert, Anna Maria ; Wörner, M. ; Braun, Ulrike ; Klein, R. ; Paulus, M.
Avoiding aerial microfibre contamination of environmental samples is essential for reliable analyses when it comes to the detection of ubiquitous microplastics. Almost all laboratories have contamination problems which are largely unavoidable without investments in clean-air devices. Therefore, our study supplies an approach to assess background microfibre contamination of samples in the laboratory under particle-free air conditions. We tested aerial contamination of samples indoor, in a mobile laboratory, within a laboratory fume hood and on a clean bench with particles filtration during the examining process of a fish. The used clean bench reduced aerial microfibre contamination in our laboratory by 96.5%. This highlights the value of suitable clean-air devices for valid microplastic pollution data. Our results indicate, that pollution levels by microfibres have been overestimated and actual pollution levels may be many times lower. Accordingly, such clean-air devices are recommended for microplastic laboratory applications in future research work to significantly lower error rate
Antibacterial polymer fibres by rosin compounding and melt-spinning (2019)
Elert, Anna Maria ; Kanerva, M ; Puolakka, A ; Takala, T.M. ; Mylläri, V ; Jönkkäri, I ; Sarlin, E ; Seitsonen, J ; Ruokolainen, J ; Saris, P ; Vuorinen, J
The antibacterial features of natural pine/spruce rosin are well established, yet the functionality in various thermoplastics has not been surveyed. This work focuses on the processing of industrial grade purified rosin mixed with polyethylene (PE), polypropylene (PP), polylactic acid (PLA), polyamide (PA) and corn starch based biopolymer (CS). Homopolymer masterbatches were extrusion-compounded and melt-spun to form fibres for a wide range of products, such as filters, reinforcements, clothing and medical textiles. Due to the versatile chemical structure of rosin, it was observed compatible with all the selected polymers. In general, the rosin-blended systems were shear-thinning in a molten condition. The doped fibres spun of PE and PP indicated adequate melt-spinning capability and proper mechanical properties in terms of ultimate strength and Young's modulus. The antibacterial response was found dependent on the selected polymer. Especially PE with a 10 wt% rosin content showed significant antibacterial effects against Escherichia coli DH5α and Staphylococcus aureus ATCC 12598 when analysed in the Ringer's solution for 24 h.
Tribological performance of titanium samples oxidized by fs-laser radiation, thermal heating, or electrochemical anodization (2018)
Kirner, Sabrina V. ; Slachciak, Nadine ; Elert, Anna M. ; Griepentrog, Michael ; Fischer, Daniel ; Hertwig, Andreas ; Sahre, Mario ; Dörfel, Ilona ; Sturm, Heinz ; Pentzien, Simone ; Koter, Robert ; Spaltmann, Dirk ; Krüger, Jörg ; Bonse, Jörn
Commercial grade-1 titanium samples (Ti, 99.6%) were treated using three alternative methods, (i) femtosecond laser processing, (ii) thermal heat treatment, and (iii) electrochemical anodization, respectively, resulting in the formation of differently conditioned superficial titanium oxide layers. The laser processing (i) was carried out by a Ti:sapphire laser (pulse duration 30 fs, central wavelength 790 nm, pulse repetition rate 1 kHz) in a regime of generating laser-induced periodic surface structures (LIPSS). The experimental conditions (laser fluence, spatial spot overlap) were optimized in a sample-scanning setup for the processing of several square-millimeters large surface areas covered homogeneously by these nanostructures. The differently oxidized titanium surfaces were characterized by optical microscopy, micro Raman spectroscopy, variable angle spectroscopic ellipsometry, and instrumented indentation testing. The tribological performance was characterized in the regime of mixed friction by reciprocating sliding tests against a sphere of hardened steel in fully formulated engine oil as lubricant. The specific tribological performance of the differently treated surfaces is discussed with respect to possible physical and chemical mechanisms.
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